WO2013079705A1

WO2013079705A1 - Apparatus and method

Info

Publication number: WO2013079705A1
Application number: PCT/EP2012/074169
Authority: WO
Inventors: Edwin Wolterink; Henri VAN EGMOND; Erik VERHOEVEN
Original assignee: Anteryon International BV
Current assignee: Anteryon International BV
Priority date: 2011-11-30
Filing date: 2012-11-30
Publication date: 2013-06-06
Anticipated expiration: 2014-05-30
Also published as: TW201339630A

Abstract

There is disclosed a pick and place assembly machine for assembling a first part and a second part to form a module, the machine operable to: align a first part with a second part in relative position with respect to each other in accordance with an assembled module configuration; space apart the first and second parts at a distance from each other in accordance with the assembled module configuration; and provide a bond medium disposed between the first and second parts for bonding the first and second parts in the assembled configuration. Further disclosed is a method for assembling a first part and a second part to form a module, the method comprising: aligning a first part with a second part in relative position with respect to each other in accordance with an assembled module configuration; spacing apart the first and second parts at a distance from each other in accordance with the assembled module configuration; and providing a bond medium disposed between the first and second parts for bonding the first and second parts in the assembled configuration.

Description

Apparatus and method.

The present invention relates to apparatus for and a method of operating a pick and place machine for assembling modules. In particular, but not exclusively, the apparatus and method relate to assembling multi-part modules such as for forming a lens module comprising a lens assembly and one or more spacer substrates.

Compact camera modules have become a standard component in mobile devices such as mobile phones. A Camera Module consists of PCB board, an Imaging Sensor Module and a Lens Module. The Lens Module consists of a lens assembly and a housing shielding it from unwanted light and environmental influences. The housing may also be shared with the housing of the complete Camera module. The outer contours of a compact camera module are in many cases designed as drop-in component into mobile devices.

The mass volume requirements together with the increasing drive for reducing costs triggered the development of wafer level based methods for producing and packaging the camera modules and related image sensor and optics.

The aim of packaging is to integrate the several optical, mechanical, environmental and electronic functions of a Compact Camera Module and a Lens Module. The functional elements consist of a CMOS or CCD image capturing device, the imaging lenses together with optical functions such as IR filters, AR coats and light blocking structures such as baffles etc. In most cases, micro lenses and color filters are positioned on the image sensor surface.

A variety of methods have been disclosed to manufacture lens assemblies. The traditional process consists of assembling single lens elements into a lens holder.

The lens elements are usually formed by injection moulding or glass pressing. Integrated Lens Stacks relating to lens assemblies based on wafer level manufacturing have been disclosed in WO2004027880. In this process, lens elements, spacers and other optical functions are manufactured at the wafer level. After singulation (i.e. separation of the wafer into individual modules) integrated lens modules are obtained.

Regarding the Image Sensor Module, two fundamentally different assembly concepts coexist i.e. Chip-on-Board (COB) and Chip Scale Packaging (CSP). The latter integrates a sensor cover plate before assembling the optics. The image sensor substrate comprises the image sensing area including the pixel map. The bottom spacer may either be part of the lens stack or is part of the surrounding housing.

US2005077458 discloses a CSP packaging which is typical for wafer level manufacturing of Image Sensor Modules. US20100052192 discloses a method for manufacturing an encapsulated Compact Camera Module obtained by wafer level packaging of the Image Sensor Module and Integrated Lens Stack elements.

Wafer level manufacturing of opto-electronic components in general assumes a wafer to wafer assembly of the optics wafer with the image sensor wafer. The aim is to reduce costs through maximizing the simultaneous processing of components followed by a singulation, usually dicing, step. This assumption is based on the very high yields using state-of-art manufacturing front end processes for electronic components on silicon wafers. These processes benefit from a decades track record of process development using silicon as a substrate. However, the processes for manufacturing optical components on wafer level are based on different materials (glass, polymer) and processes (injection moulding, UV, thermal replication, glass pressing). In addition, refractive optical structures require extreme, i.e. high, shape accuracies with comparably high aspect ratios. So, in many cases, the yield involving manufacturing of optics on wafer level is lower than may be obtainable for electronic components. As a result an Image Sensor Module wafer with good yield may be assembled on an optical wafer with a lower yield. Reject optics may therefore be combined with good image sensors, resulting in reject Compact Camera Module despite the presence of good electronic components.

Another disadvantage or feature of a wafer to wafer approach is the possible or inherent footprint mismatch between the optics and the image sensor. The footprint of the active area of the image sensor, matching the imaging area of the optics is typically 40 % of the total footprint of the Image Sensor Module. In a wafer- to-wafer assembly, the pitch of the lens modules has to be matched with the pitch of the Image Sensor Modules. As a result, the pitch of optical elements on a lens wafer cannot be optimized to closest packaging. This results in increasing manufacturing costs for the optics and resulting Compact Camera Module.

Another problem or feature involves the control of the Back Focal length (BFL) of the imaging optics. The control of the BFL within microns is a main contributor to the yield in manufacturing Compact Camera Module. The BFL is to a large extent determined through the wafer level control on of the thickness and shape tolerances in all optical and spacer layers of the Integrated Lens Stack.

In addition, when assembling a lens module upon the Image Sensor Module, the distance between the bottom optical surface of the lens module and the image plane has to be very accurately controlled. This can be performed through active alignment assembly methods l.e: The image is projected on an image sensor and the quality of the resulting focal postion is measured. According to the result, the lens module is vertically displaced to a position where a optimal image quality is obtained. The whole procedure of measuring and adjusting is time consuming and requires expensive assembly with in line focus length measurement..

An alternative approach is to provide tight tolerance spacers bottom structures allowing passive mount. This spacer is in most cases part of the Lens Module as disclosed in WO2004027880. The spacer can be manufactured on either wafer level or on single level, the latter being disclosed in US6406583. According to this concept expensive processes and materials are necessary to manufacture and integrate this tight tolerance bottom spacer. The related processes to manufacture the spacers involve materials such as glass and ceramics that are hard to process. In addition these materials are brittle, which limits their application to thicknesses above 250 microns.

An alternative way to provide the bottom spacer function is to integrate it in the housing as disclosed in US20110050988. The housing is then a separate, pre-manufactured part that is assembled with the lens stack and the Image Sensor Module. According to this concept, the tolerance problems involve the whole housing element and related assembly issues. Additional complications such as misalignment and tilt of the Integrated Lens Stack within the inner contours of the housing may occur.

US8013289 discloses a method where single lens elements are mounted on a carrier frame substrate. US7813043 requires dedicated tools for aligning single lens elements in the trough hole of the carrier substrate. It also requires a 'saddle structure' as support to enable dicing.

A new generation of Compact Camera Module involves compound eye cameras. The image is obtained from at least two lens apertures assigned to one imaging detecting system. The sensor system may be either at least two separate sensors or a single sensor sharing at least two lens apertures.

In addition to the above mentioned problems for a single aperture Compact Camera Module, cross talk between adjacent lens apertures within one array must be prevented through incorporating light blocking structures as disclosed in US20100127157. Another method to provide a light blocking structure is by providing a cavity of the sensor cover substrate and filling the cavity with an opaque material. This involves an additional step in the manufacturing.

Aspects and embodiments of the invention were devised with the foregoing in mind.

An aspect, or possibly object, of the present invention is to provide a method for manufacturing lens modules allowing the use of a single or limited set of spacer substrates. Another aspect, or possibly object, of the present invention is to provide a method for manufacturing lens modules in which height tolerances and production platform flexibility are improved towards design and resulting reduced costs.

Another aspect, or possibly object, of the present invention is to provide a method for manufacturing camera modules wherein the aforementioned problems of the prior art are minimized.

Viewed from another aspect an embodiment of the present invention relates to a method of forming a lens module, comprising a lens assembly and one or more spacer substrates, the method comprising: a) Providing a spacer substrate comprising at least one aperture, having dimensions of at least the cross section of the optical path of a lens module,

b) Providing a lens assembly,

c) Applying an adhesive on the circumference of said apertures on said spacer substrate for forming a contact interface between said spacer and said lens assembly,

d) Aligning the lens assembly on the spacer substrate at said contact interface,

e) Pressing the lens assembly in the adhesive present at said contact interface,

f) Curing the adhesive,

g) Overmolding the obtained array of lens assemblies on the spacer substrate with a resin, h) Singulating the overmoulded array of lens assemblies present on said spacer substrate into singulated lens modules.

According to an embodiment of the present invention there is provided a method for improving height tolerances and production platform flexibility towards design and resulting reduced costs. The present method optimizes yield through exclusively combining Known Good Dies with Known Good Lenses. In addition the present method allows using a single or limited set of spacer substrates. The same spacer substrate design can be used for Integrated Lens Stacks with different outer dimensions. The present method enables the combination of Integrated Lens Stack, i.e. lens assemblies, with different footprints within one frame.

The present inventors found that the exact focal length of the lens modules thus manufactured is adjusted by step e) of the application of the adhesive. According to the present method it is thus possible to apply a specific height of adhesive for each single lens module present on the spacer substrate. The spacer substrate as such is a substrate in which several apertures are present, and each aperture functions as a spacer element for each individual lens assembly. A spacer substrate may also be a semiconductor substrate or a semiconductor substrate with integrated spacer structures. The spacer structures can be provides by adhesion, an additive process or as an integrated part of the semiconductor substrate. The optical properties of each lens assembly are known, so the height, or the amount, of adhesive to be applied on the substrate, i.e. around the circumference of each individual aperture, is known. Therefore, according to the present method, it is possible to manufacture individual lens modules which meet the required optical properties, especially with regards to the focal length.

According to a specific embodiment step e) comprises pressing the lens assembly according to a reference level preset by an assembly machine. This enables the manufacturing of individual lens modules present on the same and corresponding spacer substrate. The reference level is determined, inter alia, by the optical properties of the individual lens assemblies. In such a case, the pressing level can be different for each lens assembly.

In an embodiment the adhesive according to step c) is applied in a thickness range of 5- 100 urn, especially in the range of 10-80, more especially in the range 20-60 and yet more especially in the range 30-40 urn.

According to an embodiment the singulated lens module obtained from step h) is aligned on an image sensor for obtaining a camera module, wherein an additional step of overmoulding can be carried out.

An embodiment of a lens assembly has been disclosed in International application WO 2004/027880. Such a lens assembly may comprise a micro spacer plate, a cover plate and a lens substrate provided with a lens. The micro spacer plate is provided with a hole for passing image forming light rays from the lens element, i.e. object side, to the image side., An infra-red reflection coating can be provided between the lens substrate and the cover plate, and an anti- reflex coating can be provided over the lens substrate and the lens element. An adhesive layer is present between the cover plate and the micro spacer plate and another adhesive layer can be present between the lens substrate and the cover plate. Preferably, the adhesive layers are rim-shaped, the adhesive material being present outside an area coinciding with the projection of the circumference of the lens element on the surfaces of the micro-spacer plate and the cover plate. To prevent ghost it may be advantageous to provide an anti-reflection layer on the side wall of the micro-spacer plate, thereby by preventing unwanted reflections of light. Such an anti- reflection layer can be provided for instance by coating the side wall of the micro- spacer plate with a low reflecting material, for instance with black resist. The coating may be applied by means of spraying. A lens assembly may comprise several lens substrates, lens elements, anti- reflex layers, and spacer plates. The lenses present on the lens substrates are preferably manufactured by a replication process. The replication process for making polymer lenses is known per se from U.S. Pat. Nos. 4,756,972 and 4,890,905, which disclose the possibility of manufacturing a high-quality optical component by means of a replication process.

Such a replication process is considered to be a quick and inexpensive manner of manufacturing optical components in large numbers. In the replication process, a mould having a precisely defined surface, for example an aspherical surface, is used, and a small amount of a radiation curable resin, for example a UV curable resin, is applied to the mould surface. Subsequently, the resin is spread over the mould surface, so that the cavities in the mould are filled with the resin, after which the whole is irradiated so as to cure the resin and the thus cured product is removed from the mould. The cured product is a negative of the mould surface. An advantage of the replication process is that lenses having a complex refractive surface, such as an aspherical surface, can be manufactured in a simple manner without having to subject the lens body to intricate grinding and polishing processes.

The replica layer used in the present optical system is may be, or even preferably, composed of a UV curable polymer, selected from the group of polycarbonates, polystyrenes, poly(meth)acrylates, polyurethanes, polyamids, polyimids, polyethers, polyepoxides and polyesters. Suitable replication technologies are disclosed in U.S. patents Nos. 6,773,638 and 4,890,905, which may be considered to be fully incorporated herein.

From International application WO 03/069740 in the name of the present inventor there is also known a replication process by which an optical element is formed.

In an embodiment of the present invention the outermost lens element of said lens assembly comprises a conical flange that is sloped at an angle for anchoring the overmoulding resin with said lens assemblies. Such a sloped outermost lens element provides additional grip for the material used for the overmoulding step. The overmoulding step forms an outer layer around the lens assembly and functions not only as "packaging material" but as a moisture and dust barrier as well. And by overmoulding the obtained assembly is less susceptible for mechanical forces and impact from the environment.

According to an embodiment of the present invention there is provided a method for improving height tolerances and production platform flexibility towards design and resulting reduced cost, which method comprises the following steps

A method for manufacturing lens stacks, or lens assemblies, comprises a step of assembling Known Good Lens stacks using assembly machines (step E1 ) upon a spacer substrate functioning as a carrier or frame. The spacer substrate can be of any stable material, but preferably a material that is frequently used in mounting electronic components such as composite material (FR4) and metals. These materials are cheap and readily available even on very thin thicknesses far below 250 microns. During this assembly, the lens stack is positioned against an absolute reference plane, compensating variations in the layer thickness of the adhesive.

The overmoulding step is performed using foil moulding equipment, wherein a liquid or liquefied compound material is injected in a cavity with tightly controlled height gap between the top and bottom surface of the mold. By using such a process few and possibly no additional tolerances are introduced resulting from misalignment of assembled housings. The moulding material is opaque and may contain metal particles for EMI shielding. The moulding material may either only surround the side walls of the lens stacks. Top light shielding layer around the aperture of the lens can be present as an opaque top layer on the lens stack. The top layer can also be provided by the overmoulding process using a mould shielding the aperture of the lens. Another possibility is to separately provide a top cap on either the lens module or the camera module.

The step of singulation (usually dicing) and sorting results in Known Good lens modules. The materials in the dicing lane allow a fast throughput with considerable lower risk in chipping and cracks, compared to existing processes dicing to brittle materials such as glass. The smooth edged packaging also ensures sufficient robustness against reliability failures such as delamination and pop corning. The spacer substrate functioning as assembly carrier has now become an integral part of the resulting lens module.

The next phase involves the manufacturing of Camera Modules, where the Known Good lens Modules are assembled on Known Good Image Sensor Modules, packaged and singulated.

In a first step image sensor modules are assembled on a moulding substrate. In a subsequent step the lens modules are assembled using similar assembly technology as described above. In a next step a similar foil moulding process is performed, followed by a singulation step.

The moulding substrate may be any rigid material to fix the attached image sensor modules, or assemblies of lens module with image sensor modules. The material can be for temporary use or may be the printed circuit board where upon a ball grid array or wire bond are attached

In the case of a temporary use, the moulding substrate can be rigid or a foil (e.g. dice tape or release foil) The moulding substrate may be detached at any step starting from the step of foil moulding. The moulding substrate may also function as a protective cover over the ball grid array prior to final assembly on a PCB board. Dicing may be partially performed, i.e. only through moulding material and partially in the moulding substrate. PCB materials may be rigid FR4 or flexible.

The thus obtained camera module has a housing consisting of moulding material resulting from the lens module process, spacer substrate material and moulding material.

Additional light blocking walls between the lens aperture can be provided. The foil moulding technology allows creating a large variety of shapes of walls. By using such a method it is possible to create a lens module and a camera module with tightly controlled Back Focal length within a robust packaging. The related production platform according to this invention accommodates a large variety of lens modules, single / multiaperture camera modules using materials, substrates, moulding processes and assembly machines with a proven track record in the electronic component manufacturing industry.

More in detail, in the present method the height tolerance z of the lens module is now predominantly determined by the capability of assembly only, instead of the sum of tolerances of the process for manufacturing the spacer substrate + (plus) the capability of the machine assembling lens housing + (plus) the tolerance of the prefabricated lens housings according to the prior art.

In a similar way, the height tolerance of the present camera module is now determined by the capability of the assembly machines. The claimed method enables the combination of Integrated Lens Stack, i.e. lens assemblies, with different footprints within one frame. The claimed method avoids tolerances resulting from misalignment of assembled lens in the housing.

The overmoulding process in step upon a moulding substrate provides a camera module where the moulding material is filling all space between the ball grid array except the contact surface of the ball grid array, which is protected by the moulding substrate.

The moulding substrate provides several functions as array based carrier and/or protective cover. The claimed method enables the light shielding and cross talk barriers of compound eye cameras in one step.

One or more embodiments of the present invention benefit from proven machine technology based concepts in positioning and assembly of electronic components in general.

The claimed method allows or may allow using very thin, non brittle, spacer substrates that can or may be manufactured at low costs. Yield losses resulting from chipping on spacer substrate are or may be reduced. The overall production costs decrease and the production line is or may be more flexible towards variations in designs and allows or may allow fast ramp up to volume after design in.

In the case of multi-aperture camera, the present method allows or may allow combining easily different types of lens modules of different sizes, different MxN array configurations on either a shared or separate image sensor modules.

BRIEF DESCRIPION OF THE DRAWINGS

Figure 1 illustrates a typical lens stack as provided by a replication method.

Figure 2 schematically shows an embodiment of a lens module according to the method of the present invention

Figure 3 schematically shows an embodiment of a single aperture camera module according to the method of the invention

Figure 4 shows a multi- aperture camera module according to the method of the invention.

Figure 5 shows an embodiment of the present method for manufacturing a lens module. Figure 6 shows an embodiment of the present method for manufacturing a single aperture camera module.

Figure 7 shows an embodiment of the present method for manufacturing a multi aperture camera module.

Figure 8 shows an embodiment of the present method for manufacturing a lens module. Figure 9 shows an embodiment of the present invention for packaging a lens module.

The image sensors mentioned in the present application included all known CSP, COB, Flip Chip packaging technologies and related interconnection technologies for CCD and front end and back end CMOS technologies. The packaging solutions according to embodiments of the invention are also applicable for light emitting and projecting devices where image sensor is replaced by light emitting element such as LED, VCSEL, laser diode. As the material for sensor cover plate any transparent optical material can be used. The cavity can be made by dicing, etching, powder blasting.

In the figures disclosed in this application the following features can be mentioned .Instead of lens stack lens assemblies provided by alternative technologies, single and wafer level, can be processed. These technologies include: injection moulding, glass moulding and any hybrid technology based on assembling optical elements manufactured by UV thermal replication and one or more of these technologies. Any lens shape, substrate thickness, dimension, buffer layer typically 0- 100 micron, lens sags typically <300 micron (< 1000 micron) can be used. Optical components may be refractive, diffractive, holographic, or focusable based nematic liquid crystal, piezoelectric or voice coil or mechanical principles. An array camera has

N x M apertures, with N≥1 and M>N.

Multi aperture camera's consist of assemblies of single lens stacks in an array or include a stack of layers having multiple lens elements. Footprints of each sub camera may differ in size and shape (e.g. hexagonal). Lens contours may vary in diameter, shape and may be intersecting. Spacer substrate material comprises any stable and polymeric, composite, glass, ceramic, metals material but preferably. Dimensions thickness 20-1000 micron. Hole profile: different pitch, hole shapes and dimensions, even within the same substrate. Singulation: dicing, cutting, laser cutting..lens modules may also be diced in groups resulting in an arrayed lens module. Lens placement: lens stacks with different designs, footprint may be combined.

Overmoulding: moulding materials: ,

Light shielding on the object side can be provided using several methods:

Simultaneously with overmoulding step, though providing an opaque top layer in the lens stack, trough providing a separate shielding cap. Assembled lens module can be any combination of lens modules. Singulating: dicing, cutting, laser cutting...camera modules may also be diced in groups resulting in an arrayed lens module.

Suitable wafer level optics technologies are disclosed in WO2004027880A2 which may be considered to be fully incorporated herein. Suitable replication technologies are disclosed in U.S. patents Nos. 6,773,638 and 4,890,905, which may be considered to be fully incorporated herein.

Spacers mentioned in the Figures are made of a rigid material, for example glass, silicon or a composite material such as FR4. In an embodiment the spacer plate is so configured that it will not interfere with the light path through the two separate lens elements. The spacer plate comprises an opening which is positioned coaxially with a main optical axis of the lens element in question, whilst in a special embodiment the side of said opening is provided with an anti- reflective coating.

Suitable technologies regarding a multi- aperture camera through assembling discrete optical elements, lens housing and optical blocking structures are disclosed in US2010/0127157, and US2010/0039713. These documents are incorporated here by reference. The optical elements can be manufactured through injection moulding or glass moulding of a thermoplast or pressing a glass preshape in a single cavity or plural cavity mould. Suitable technologies for manufacturing present cover plate and present lens holder for wafer level optics camera are disclosed in US2010/0052192, US2009/0321861 and US2010/01 17176. These documents are incorporated here by reference.

Alternatively lens holder, cover plate can be provided through assembling injection molded, ceramic or metal housing. Sumitomo Bakelite: X83563-,X84179,G750L-B

Typical sizes for the present camera module height is about 4-10mm, for camera module foot print; 4x4mm to 20x20 mm. The dimension is not necessarily square, but in special embodiments also constructions of different sizes are possible, e.g. 4x10mm. According to an embodiment the image sensor package is within the range of 0.4 -0,8mm. Dimensions of lens diameters are within a range of 2-4 mm, glass substrates within a range of 0.200-1 mm. For the replicated lenses one may apply a sag height in a range of 20 μ - 250μ, or even in a range of 500 -1000 μ. Typical dimensions for a buffer layer are 30 μ - 100μ.

Figure 1 illustrates a typical lens stack 204, comprising lens elements 201 , a buffer layer 203, lens substrates 200. This stack 204 shows a combination of two lens substrates 200, but embodiments of the present invention are not restricted to the number of lens substrates, nor to the number of lens elements 201. In an embodiment the buffer layer 203 can be omitted. The lens stack 204 may have one or more anti-reflex layers, diaphragms (not shown).

Figure 2 schematically shows an embodiment of a lens module or lens stack fabricated according to the method of an embodiment of the present invention. The lens module 300 comprises a lens stack 204, present in a spacer substrate 301 , wherein a lens moulding resin 303 encapsulates the lens stack 204. Spacer substrate 301 may comprise two separate spacer substrate layers, each comprising apertures. The dimension of the aperture of the one spacer substrate is greater than the dimension of the aperture of the other spacer, wherein the lens stack 204 fits accurately in the aperture of the largest dimension. Such a construction can be completed by the provision of an adhesive in the narrow gap created by the lens stack 204 and the inner diameter of the aperture of the one spacer plate.

Figure 3 schematically shows an embodiment of a single aperture camera module 410 according to a method in accordance with an embodiment of the invention. On top of image sensor module 400 lens stack 204 is present. Image sensor 400 is provided with an overmoulding substrate 401 and lens module 204 is encapsulated with lens moulding resin 403.

Figure 4 shows a multi- aperture camera module according to a method in accordance with an embodiment of the invention. Figure 4 clearly shows the presence of two lens modules 204a, 204b on top of image sensor module 400. Image sensor module 400 may consist of several individual image sensor modules (not shown). The lens modules 204a, 204b are encapsulated by camera moulding resin 403. Image sensor module 400 is positioned on top of overmoulding substrate 401. Light shielding walls 405 may be present between lens modules 204, 204.

Figure 5 shows an embodiment of the present method for manufacturing a lens module. This figure 5 does not show the individual steps for manufacturing the lens modules but only refers to the singulation step A in which individual lens modules are obtained through, for example, a dicing line according to reference number 501. Step B of Figure 5 comprises the positioning of the individual lens modules 204 in a spacer substrate 301 provided with apertures for accurate positioning. The circumference of the apertures is provided with an adhesive (not shown) for adhering the lens modules 204a, 204b and 204c to the spacer substrate 301. In step C an overmoulding resin 303 is applied in the spaces between the lens modules 204 positioned on the spacer substrate 301. Step D shows an additional of step of singulation the individual lens modules.

Figure 6 shows an embodiment of the present method for manufacturing a single aperture camera module. Image sensor modules 400 are placed on top of overmoulding substrate 401 in step A. According to step B resin encapsulated single aperture camera modules 410 are positioned on top of the image sensor modules 400. In step C a resin is applied in the spaces between the resin encapsulated camera modules resulting in completely encapsulated camera modules. In step D singulating of the individual a single aperture camera module is carried out.

Figure 7 shows an embodiment of the present method for manufacturing a multi aperture camera module and comprises basically the same steps as discussed in Figure 6. Several image sensor modules 400 are provided on top of overmoulding substrate 401 in step A. According to step B resin encapsulated multi aperture camera modules 500 comprising lens modules 204, 204 are positioned on top of each of the image sensor modules. In step C a resin 403 is applied in the spaces between the resin encapsulated multi aperture camera modules resulting in completely encapsulated camera modules. In step D singulating of the individual multi aperture camera module is carried out.

Figure 8 shows an embodiment of the present method for manufacturing a lens module. In step A carrier or substrate 800 comprising apertures 801 is provided with adhesive for adhering lens module or die 802. In a specific embodiment the adhesive can be applied directly to the die 802 as well. Bonding of the dies 802 is shown in step B. The step of overmoulding the thus adhered dies 6802 to the carrier 800 is shown in step C. Singulating of the individual elements, through dicing, is shown in step D. Step E clearly shows the thus obtained products 804, in which the carrier 800 forms an integral part of the thus obtained lens module 804. The cross section of a stack of lenses is schematically shown in step F. The thus obtained lens module 804 is ready to be used in a method for manufacturing a camera module as discussed before.

Figure 9 shows an embodiment of the present invention for packaging a lens module.

Step A shows the positioning of a lens stack, comprising substrates 903, 901 , lens elements 902, 904, 905, 907, on a substrate or carrier 910 by an adhesive 91 1. Outermost lens element 902 shows a conical flange 906 that is sloped at an angle for anchoring the overmoulding resin 91 1 (see step B) with said lens assemblies. The height of the die is indicated with arrow 912. The singulation takes place according to step C. The presence of such a flange 906 can be omitted, in special embodiments.

Particular aspects in in accordance with embodiments of the invention are set forth below in the following numbered clauses.

1. A method of forming a lens module, comprising a lens assembly and one or more spacer substrates, the method comprising: i) Providing a spacer substrate comprising several apertures having dimensions of at least the cross section of the optical path of a lens module,

j) Providing a lens assembly.

k) Applying an adhesive on the circumference of said apertures on said spacer substrate for forming a contact interface between said spacer and said lens assembly.

I) Aligning the lens assembly on the spacer substrate at said contact interface

m) Pressing the lens assembly in the adhesive present at said contact interface

n) Curing the adhesive,

o) Overmolding the obtained array of lens assemblies on the spacer substrate with a resin, p) Singulating the overmoulded array of lens assemblies present on said spacer substrate into singulated lens modules.

2. A method according to clause 1 , wherein step e) comprises pressing the lens assembly according to a reference level preset by an assembly machine. 3. A method according to clause 1 , wherein step c) the adhesive is applied in a thickness range of 5-100 micron.

4. A method according to clause 1 further comprising aligning the lens module obtained from step h) to an image sensor fitting within a sensor cavity of said lens.

5. A method according to clause 1 , wherein said lens assembly comprises one or more lenses, separated by one or more spacers, wherein said one or more spacers are adhered to said one or more lenses by one or more adhesives.

6. A method according to clause 5, wherein the outermost lens element of said lens assembly comprises a conical flange that is sloped at an angle for anchoring the overmoulding resin with said lens assemblies.

7. A method of forming a camera module the method comprising: q) Providing an image sensor module on a PCB substrate,

r) Providing at least one lens module for each image sensor module

s) Applying an adhesive on the contact interface between the lens module and the image sensor module.

t) Aligning the lens module with a predefined position on image sensor module u) Pressing the lens assembly in the adhesive according to reference level preset by the assembly machine,

v) Curing the adhesive,

w) Overmolding the obtained array of lens assemblies on the spacer substrate.

x) Singulating into camera modules.

Embodiments of the present invention provide a method for manufacturing lens modules allowing the use of a single or limited set of spacer substrates. Another embodiment of the present invention provides a method for manufacturing lens modules in which height tolerances and production platform flexibility are improved towards design and resulting reduced costs. The related production platform according to an embodiment of this invention accommodates a large variety of lens modules, single / multiaperture camera modules using materials, substrates, moulding processes and assembly machines with a proven track record in the electronic component manufacturing industry.

The embodiments described in the foregoing illustrate a particular aspect in accordance with the present invention. Viewed from another perspective, embodiments in accordance with the present invention may provide an apparatus and method for placing components spaced apart from each other or from a substrate at a predetermined distance the thickness of a bonding medium such as a glue, epoxy or adhesive, in a bond direction being such as to establish the predetermined distance. The predetermined distance maybe a distance which is an operational parameter for the components when they are joined together or supported on the substrate.

In accordance with one aspect there is provided a pick and place assembly machine for assembling a first part and a second part to form a module, the machine operable to: align a first part with a second part in relative position with respect to each other in accordance with an assembled module configuration; space apart the first and second parts at a distance from each other in accordance with the assembled module configuration; and provide a bond medium disposed between the first and second parts for bonding the first and second parts in the assembled configuration.

In accordance with another aspect there is provided a method for assembling a first part and a second part to form a module, the method comprising: aligning a first part with a second part in relative position with respect to each other in accordance with an assembled module configuration; spacing apart the first and second parts at a distance from each other in accordance with the assembled module configuration; and providing a bond medium disposed between the first and second parts for bonding the first and second parts in the assembled configuration.

In accordance with a yet another aspect there is provided a module comprising a first part and a second part bonded together by a bond medium, wherein the spacing of the first part from the second part is an operational parameter of the module and the thickness of the bond medium in the bond direction is in accordance with the spacing desired for the operational parameter. Such a module may be fabricated by a pick and place machine as set out in the one aspect above and/or in accordance with a method as set out in the another aspect above.

A pick and place assembly machine and method in accordance with the one and further aspects provide for flexible automated fabrication of multipart modules where the spatial separation of respective parts are important. By first calculating the necessary separation for each component part, for example a lens would have its focal length measured before assembly, manufacturing tolerances may be taken into account. The amount of bond medium such as a glue, adhesive or epoxy, may be selected for each individual module based upon the manufacturing tolerances measured for each of the components making up the multicomponent module. This may lead to a greater yield since devices which fall outside acceptable limits may be compensated for by appropriate configuration of bond medium thickness. Thus, individual modules may be fabricated independently of each other in dependence upon manufacturing tolerances of their component parts being taken into consideration in evaluating the distance information which is then used by the pick and place assembly machine to determine the spacing apart of the respective parts.

One or more embodiments in accordance with this aspect will now be described, by way of example only, with reference to the further drawings appended to the description and listed here below:

Figures 10 (a) & (b) schematically illustrate the effect of manufacturing tolerances for an optical module;

Figure 1 1 schematically illustrates adjusting the height of a lens to bring the focal plane to a desired location on another component;

Figure 12 illustrates a first stage of mounting a lens in order to reduce the defocus distance; Figure 13 illustrates an arrangement in which a lens assembly is mounted to a light emitting device;

Figure 14 illustrates the arrangement of component elements and their assembly in a pick and place machine to form a lens assembly;

Figure 15 illustrates a lens assembly arrangement showing the various dimension used in calculating adhesive thickness;

Figure 16 is a depiction of a Dataconn EVO 2200 pick and place machine; and

Figure 17 is a depiction of a gripper mechanism over a substrate. Turning now to figure 10(a), a component having relative position as an important operational parameter is illustrated by way of a lens component 1002. Light passes through the lens 1002 and is focussed over its focal length 1006 to a target focal plane 1008. Typically, lens components are mounted on a spacer substrate of some kind incorporating a flange to space the lens away from the subject upon which the spacer and lens combination is eventually mounted. Consequently, distance 1006 is often termed the Flange Back Focal Length (FBFL).

Figure 10(b) illustrates a lens 1002' which due to manufacturing tolerances has a focal plane 1012 different from the desired or target focal plane 1008. Lens 1002' may be considered to be defocused by an amount 1010 due to the manufacturing tolerances compared to the target arrangement illustrated in figure 10(a). Consequently, it cannot be used in the same

arrangement as would be used for figure 10(a). If the defocus distance 1010 is greater than a few microns for imaging applications and greater than a few tens of microns for any the applications the FBFL variation due to defocus 10 10 should be compensated for.

A particular example for an LED configuration is illustrated in figure 11. A lens 1002' having manufacturing tolerances resulting in a defocus and variation in FBFL relative to design reference lens 1002 is combined with an LED 1012 mounted on a substrate 1016. The target focal plane is the top of the LED 1014. In the combined arrangement it is desirable for the defocus distance 1010 from the top of the LED 1014 to be or be close to zero so that the top of the LED 1014 is at or close to the focal plane of the lens 1002'. Thus the lens 1002' should be positioned above the LED 1012 so that the distance 1006 is to the top of the LED 1014.

Figure 12 illustrates a first stage in accordance with an embodiment of the present invention in which a lens 1002' having an FBFL variation due to manufacturing tolerances is mounted in order to reduce the defocus distance 1010 to or close to zero. As illustrated in figure 12, the lens 1002' is mounted on a spacer element 1018, i.e. a substrate material with a hole or aperture in it. A first amount of glue 1020 is placed between the spacer element 1018 and the lens 1002' in order to create a lens assembly 1022. The thickness of the glue 1020 is selected so as to reduce the defocus distance 1010. Preferably, the defocus distance may be reduced to its minimum acceptable value. However, if the lens assembly 1022 is to be mounted to something else then the thickness of the glue 1020 is not so important but merely must not be so thick so that the focal plane 1008 is not withdrawn upwards relative to the spacer element 1018 and amounts greater than a device with which the lens assembly 1022 is to interact when mounted to something else.

Figure 13 illustrates an arrangement in which the lens assembly 1022 figure 12 is mounted to a light emitting device, for example an LED 1028 itself mounted on a substrate 1024. In the arrangement illustrated in figure 13 the focal plane 1008 of the lens assembly 1022 should be at the active region, active optical region or focal plane of the LED 1030. Configuring the arrangement so that the focal plane 1008 falls on the active region, active optical region or focal plane of the LED 1030 may be achieved by ensuring that the thickness of glue 1026 corresponds to the distance the assembly illustrated in figure 12 needs to be raised to ensure that focal plane 1008 falls on the active region, active optical region or focal plane LED 1030. The thickness of glue 1026 needs to be maintained to an accuracy determined by the application to which the lens assembly 1022 is put. In the present example that accuracy is to a few tens of microns. However, should lens assembly 1022include a receiving device, for example an image sensor, it may be used in an imaging application and then the accuracy will be to a few microns. Although reference has been made to the active region, focal plane or active optical region of an LED, the target focal plane or target Z distance from a second component or part should be used for the determination of overall Z direction displacement.

A mechanism for arranging a component such as a lens or other position dependent component onto a substrate, whether the final substrate or an intermediate substrate spacer, is illustrated with reference to the respective diagrams in figure 14. Figure 14 describes pick and place equipment and the various steps in using that it and place equipment to mount a lens 1002 onto a spacer element 1018.

A detail of pick and place equipment is illustrated in figure 14(a) and shows a gripper 1030 spaced above a work surface for the machine such as a table 1032 providing a reference level or datum position. The direction perpendicular to the table 1032 is generally referred to as the "Z" direction 1034. In general overview as illustrated in figure 14(b), gripper 1030 picks lens element 1002 and places it on glue 1036 disposed on spacer element 1038.

The detailed process is illustrated in figure is 14 (c) to 14 (g). Initially, figure 14(c), spacer 1038 is picked and placed on table 1032. The pick and place equipment then applies an amount of glue 1036 to the spacer element 1038, figure 14(d). There are two basic approaches which may be applied following on from this stage. In the first approach the thickness of glue 1036 applied to the spacer 1038 is sufficient to place the focal plane of the lens at the target focal plane. The thickness of the glue may be determined from the following equations and with reference to figure 15. First of all a target distance in the said direction is determined (Z target) viz:

Z target = lens height (1039) + FBFL(1043)+ target focal distanced 040). (1 ) The target focal distance 1040 is the distance between the surface of the table 1032 and the focal plane of the lens 1002 determined by optical design.

The glue thickness is determined as follows:

Glue thickness = Z target - lens height (1039)-spacer thickness(1041 ) + cure

shrink/expand factor. (2)

This gives a desired glue thickness (DGT) for glue 1036.

In one embodiment, glue 1036 has a thickness corresponding to DGT. The pick and place equipment then positions the lens 1002 on the glue 1036, figure 14(e). In accordance with conventional pick and place equipment the gripper 1030 is connected to a force feedback sensor so that the equipment may determine the amount of force experienced by the gripper 1030 when placing the lens 1002 on the glue 1036. When the force exceeds a predetermined amount the pick and place equipment determines that sufficient contact has been made with the glue 1036 and releases the lens 1002. It is usually the case that the force necessary to determine sufficient contact has been made sufficiently low so as not to compress the glue 1036 by a significant amount.

The glue may then be cured, figure 14(f) and the lens assembly 1022 removed from the pick and place machine, figure 14(g).

In another embodiment, the Z target distance is achieved by modifying the thickness of glue 1036 whilst in situ.

The amount of glue 1037 placed on spacer element 1038 as illustrated in figure 14(d) is not an exact thickness DGT but slightly over the DGT amount to allow for an amount of compression. Thus, the amount of glue provided on the spacer element 1038 does not need to fall within such precise limits as for the previously described embodiment. In this embodiment the pick and place equipment is operated to push the lens 1002 down onto "over thickness" glue 1037 until the Z target distance calculated in accordance with equation (1 ) above is achieved.

As will be evident from the foregoing description, certain key parameters relating to the lens 1002 should be determined and provided to the pick and place equipment utilisation in evaluating equations (1 ) and (2). For the avoidance of doubt, these parameters are the lens height, the FBFL (also distance to the lens focal plane), spacer thickness and the target focal distance. These parameters are either known for the manufacturing process since devices are being manufactured to certain size and in the case of the FBFL (distance to focal plane) can be measured when the lens is still on its fabrication wafer, i.e. before singulation, or when it has been singulated and is placed on a tape ready for use in a pick and place machine. Thus as can be seen from the foregoing, Z- control results from using previously measured individual z- values (FBFL, thicknesses) for each part and reference plane in the machine framework.

Although the foregoing has been described with reference to a lens and lens assembly it will be evident to the person of ordinary skill in the art that the same principles and teaching may be applied to other components having spatial and precision dependent operational parameters.

For example, a more general equation may be expressed as follows:

Adhesive(bond) thickness target = Z target distance -Top Component(e.g Lens) height - Bottom part (e.g spacer substrate) height + curing shrink factor. (3)

Other configurations are envisaged. For example, using machine table 1032 as a reference level the equations for deriving the Z target and adhesive thickness are given as: Z target = lens height (1039)+ FBFL(1043) target focal distanced 040) + thickness of substrate 1024 (4)

And Glue thickness 1026 = Z target - lens height (1039)-spacer thickness(1038) + cure

shrink/expand factor -thickness of substrate 1024 (5)

Another example uses the top surface of substrate 1024 as a reference level. This surface effectively takes over the role of surface 1032 . The thickness of substrate 1024 does not have to be known. In this approach:

Z target = lens height (1039)+ FBFL(1043) target focal distanced 040) (6) And

Glue thickness = Z target - lens height (1039)-spacer thickness(1038) + cure shrink/expand factor. (7) Control and achievement of required qlue(bond) thickness

In one approach, a predetermined amount of adhesive is applied to a bond surface of at least one of the components (parts) to be bonded. The adhesive height after applying is higher than the target adhesive thickness.

The adhesive "excess" height should be in the region of at least the total tolerance budget and preferably twice the total tolerance budget of the parts to be assembled.

In one embodiment for a target of 50 microns thickness an initial 70 micron adhesive thickness is used. So compression is 20 microns.

The excess height should not to be too great because of possible overflow of the glue. These values are valid for a tolerance range of +/- 10 micron of the parts. (Tolerances of spacer substrates and "lenses + FBL" are typically +/- 5 micron).

The volume of adhesive is determined by the width of the surfaces to be adhered. A typical width is 100-200 micron, but may be up to 500 microns.

Based on the above design rules or guidance, the exact or appropriate amount of adhesive to be applied can be calculated.

The machine may be considered to determine the plane of the reference level 1032. The movement of the pick and place machine is used to control a distance separation between the components. The final distance between the components is set and determined by the thickness of the cured adhesive height.

The machine moves the components to be joined to a XY position using known means, such as a vision system.

Adhesive is applied on the bottom (a bonding surface) of the part to be placed. There are several options to provide the appropriate amount or dose exact volumes, such as the non- limiting examples of needle (currently used) , ink jet (no spacer balls) , screen print, dipping, tampon and stamp printing.

The machine brings the two parts (eg lens and spacer) towards the target Z point.

Using pure position control requires Direct Z- translation towards Z-target using linear motors. The motors can be adjusted at 0.1 micron level.

Force measurement is not necessary to set the target adhesive distance, although detecting contact with a glue surface through force response is an option. The purpose of the force response is to ensure that there is contact with the adhesive, but not too much further translation in the Z direction which could result in the adhesive being displaced and partially blocking the aperture in the spacer. The use of spacer balls with diameter coinciding with target adhesive thickness means that the machine may be moved to bring parts together till a force response signals the contact with the spacer ball.

One variation of the pure position control approach is for the machine to go slightly past the adhesive target and pull back towards the target position. Then pull forces may be measured.

Another variation is to dispose adhesive droplets on top and bottom component parts. By making contact, the droplets merge and are pulled out, causing possible waist in the junction of the adhesive droplets.

Since shrinking of adhesive during curing may occur any shrink values should be determined, and are generally known for adhesives, and are incorporated in the formula to determine the target adhesive thickness.

Collapse of adhesive through viscosity drop during curing should be avoided. One way to avoid such collapse is to conduct UV curing within the machine, for example whilst parts are held in place for a machine enabled for line UV curing. Offline post curing (thermal glues) may also be used.

Another approach is to form a stable adhesive. This requires a minimum viscosity at assembly temperature and is very dependent on adhesive width. The greater the aspect ratio of the adhesive, the greater the risk of collapse.

Viscosity of adhesives should be engineered to conform to the above design

rules/guidance. This can be achieved with the right combination of resin, fillers and curing process.

Surface tension on adhering surfaces may also prematurely spread out the adhesive. Also this has to be engineered based on a combination of surface treatments matching the surface properties of the adhesives used.

The addition of grooves or specific features with sharp edges can be applied on the surfaces as flow stops. They prevent adhesive from spreading out.

Once the assembly of a module, such as a camera module has been completed, it is desirable if not essential to protect it from damage and stray light. This is achieved by overmoulding the module the special materials and carefully defined properties.

Overmoulding occurs in a very precisely confined mould cavity. Overmoulding yield is to a large extent determined by the distribution in heights of the components to be

overmoulded. Failure modes are bleeding, incomplete overmoulding or even cracks. The forces in the overmoulding machine are concentrated on the highest spot within an array of components to be overmoulded.

This requirement is not only important for single components but it is even more critical for array types components such as array camera's. In addition, the process for realizing the light blocking barrier between 2 subcamera's is very sensitive for variations in height control.

Additionally, the following should be considered.

1. The optimization of focal length, and the resulting change to the value of Z target could take into account the effect of different colour filters within a colour camera. There may be a relationship between the value of Z target and colour filters used within the camera. Different wavelengths will behave differently as they pass through the lens, so resulting in different focal lengths for different colours; this would enable the focal position to be optimized for each colour, so improving the performance of the camera.

2. The change in the value of Z target (figure 15) by lens relative to the assembly reference (figure 14) accounts for variations in the measured optical focal lengths of the lens and the calculated absolute height of the focal plane of the imager/LED. The absolute height of the imager/LED will vary dependent on the position of the imager/LED within the wafer. During the machine calibration process the assembly reference may be measured at, for example 6, positions across the wafer. From these 6 positions it is possible to calculate the assembly reference by individual imager/LED position and thus the absolute height of the focal plane of the imager/CCD above the assembly reference. The knowledge of the absolute height allows setting the correct value of Z target.

3. The use of closed loop control to set the value of Z target by lens involves the

measurement of the top plane or active optical region of each spacer for each target imager/LED assembly. This is important in an imaging array application such as a mega pixel applications (i.e. > 2 mega pixel), where there are multiple lenses per imager.

As used herein any reference to "one embodiment" or "an embodiment" means that a particular element, feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment.

As used herein, the terms "comprises," "comprising," "includes," "including," "has," "having" or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Further, unless expressly stated to the contrary, "or" refers to an inclusive or and not to an exclusive or. For example, a condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present).

In addition, use of the "a" or "an" are employed to describe elements and components of the invention. This is done merely for convenience and to give a general sense of the invention. This description should be read to include one or at least one and the singular also includes the plural unless it is obvious that it is meant otherwise.

In view of the foregoing description it will be evident to a person skilled in the art that various modifications may be made within the scope of the invention. For example, specific embodiments in accordance with the invention disclose positioning at a z distance using reference planes but the reference planes may not or need not be horizontal or substantially parallel with a bond plane of devices to be bonded. Positioning at a Z spacing in a vertical or transverse direction to a bond plane may include or be followed by additional movements such as inclination and/or rotation of one or more of the parts to be bonded by the placement machine. Furthermore, other devices including but not limited to a lens, sensor, capacitor, microphone, wave guides, interferometric devices, Fabry Perot filters, microfluidic devices; light sources , laser diode, LED, VCSEL, illumination module, projection module and camera module may also be fabricated using embodiments of the invention.

The scope of the present disclosure includes any novel feature or combination of features disclosed therein either explicitly or implicitly or any generalisation thereof irrespective of whether or not it relates to the claimed invention or mitigate against any or all of the problems addressed by the present invention. The applicant hereby gives notice that new claims may be formulated to such features during prosecution of this application or of any such further application derived therefrom. In particular, with reference to the appended claims, features from dependent claims may be combined with those of the independent claims and features from respective independent claims may be combined in any appropriate manner and not merely in specific combinations enumerated in the claims.

Claims

Claims:

1. A pick and place assembly machine for assembling a first part and a second part to form a module, the machine operable to:

align a first part with a second part in relative position with respect to each other in accordance with an assembled module configuration;

space apart the first and second parts at a distance from each other in accordance with the assembled module configuration; and

provide a bond medium disposed between the first and second parts for bonding the first and second parts in the assembled configuration.

2. A pick and place assembly machine according to claim 1 , wherein said first part is

disposed in the machine to provide a reference position for determining the distance in accordance with the assembled module configuration.

3. A pick and place assembly machine according to claim 1 , wherein the work surface of the pick and place assembly machine provides a reference position for determining the distance in accordance with the assembled module configuration.

4. A pick and place assembly machine according to any preceding claim, wherein the first part is a module component.

5. A pick and place assembly machine according to any preceding claim, wherein the first part comprises a substrate for supporting the second part.

6. A pick and place assembly machine according to claim 5, wherein the first part is a substrate for supporting plural second parts.

7. A pick and place assembly machine according to claim 5 or 6, wherein the first part comprises a substrate for mounting a semiconductor component.

8. A pick and place assembly machine according to any preceding claim, wherein the second part is a module component.

9. A pick and place assembly machine according to claim 8, wherein the second part forms with the first part at least a part of a module wherein the distance between the first and second part is an operational parameter of the module.

10. A pick and place assembly machine according any preceding claim, further operable to place a portion of the bond medium on one or other of the first and second parts prior to placing them in the assembled configuration.

1 1. A pick and place assembly machine according to claim 10, wherein the portion of bond medium has a thickness in a bond direction corresponding to the distance in accordance with the assembled configuration.

12. A pick and place assembly machine according any of claims 1 to 9, further operable to place a portion of the bond medium on both of the first and second parts prior to placing them in the assembled configuration.

13. A pick and place assembly machine according to claim 12, wherein respective portions of the bond medium are arranged to combine such that the combination of respective portions has a thickness in a bond direction corresponding to the distance in accordance with the assembled configuration.

14. A pick and place assembly machine according to any of claims 1 to 9, further operable to introduce the bond medium into the space between the first and second parts in the assembled configuration.

15. A pick and place assembly machine according to any preceding claim wherein the bond medium includes one or more spacer elements, for example spheres, the machine further operable to bring the first and second parts together against the bond medium until a resistive force from the one or more spacer elements is experienced.

16. A pick and place assembly machine according to claim 15, the machine further operable to sense the resistive force and responsive to the resistive force satisfying a threshold value stop bringing the first and second parts together.

17. A pick and place assembly machine according to any preceding claim, wherein the bond medium is a curable bond medium, for example UV curable and/or thermally curable.

18. A pick and place assembly machine according to any preceding claim, wherein the

module may include one or more of the following: lens, sensor, capacitor, microphone, wave guides, interferometric devices, Fabry Perot filters, microfluidic devices; light sources , laser diode, LED, VCSEL, illumination module, projection module and camera module.

19. A pick and place assembly machine according to any of claims 1 to 18, operable to form a lens module wherein the first part comprises a spacer substrate including an aperture and the second part comprises a lens assembly, the pick and place machine further operable to:

apply the bond medium to one or other or both of the spacer substrate and lens assembly;

align the lens assembly with the spacer substrate and aperture in accordance with an assembled configuration; and

place the lens assembly to the bond medium to form a space between the spacer and lens assembly wherein the space conforms to a focal length requirement for the lens module.

20. A pick and place assembly machine according to any of claims 1 to 18, operable to form an array of lens modules and wherein the first part is a spacer substrate comprising plural apertures; the pick and place machine further operable to apply the bond medium to plural locations on the spacer substrate corresponding to the plural apertures, align plural lens assemblies to respective apertures and place plural lens assemblies to the bond medium to form a space between the spacer and respective lens assemblies corresponding to respective focal length requirements for respective lens modules thereby to form the array of lens modules.

21. A pick and place assembly machine according to claim 17 or 18, further operable to provide a bond medium curing environment.

22. A pick and place assembly machine according to any preceding claim, further operable to receive the distance information for the second part or respective second parts and space apart the first part from the second part or respective second parts in accordance with the distance information.

23. A pick and place assembly machine according to claim 22, further operable to receive different distance information for two or more respective second parts and space apart the two or more respective second parts differently in accordance with the different distance information.

24. A pick and place assembly machine according to any preceding claim, further operable to determine the distance by reference to force feedback information derived from a place actuator responsive to placing the second part to the first part or respective second parts to the first part when the bond medium is between the first and second parts.

25. A method for assembling a first part and a second part to form a module, the method comprising:

aligning a first part with a second part in relative position with respect to each other in accordance with an assembled module configuration;

spacing apart the first and second parts at a distance from each other in accordance with the assembled module configuration; and

providing a bond medium disposed between the first and second parts for bonding the first and second parts in the assembled configuration.

26. A method according to claim 25, wherein said first part provides a reference position for determining the distance in accordance with the assembled module configuration.

27. A method according to claim 25, wherein a machine work surface provides a reference position for determining the distance in accordance with the assembled module configuration.

28. A method according to any of claims 25 to 27, wherein the first part is a module

component.

29. A method according to any of claims 25 to 27, wherein the first part comprises a

substrate for supporting the second part.

30. A method according to claim 29, wherein the first part is a substrate for supporting plural second parts.

31. A method according to claim 29 or 30, wherein the first part comprises a substrate for mounting a semiconductor component.

32. A method according to any of claims 25 to 31 , wherein the second part is a module

component.

33. A method according to claim 32, wherein the second part forms with the first part at least a part of a module wherein the distance between the first and second part is an operational parameter of the module.

34. A method according any of claims 25 to 33, further comprising placing a portion of the bond medium on one or other of the first and second parts prior to placing them in the assembled configuration.

35. A method according to claim 34, wherein the portion of bond medium has a thickness in a bond direction corresponding to the distance in accordance with the assembled configuration.

36. A method according any of claims 25 to 34, further comprising placing a portion of the bond medium on both of the first and second parts prior to placing them in the assembled configuration.

37. A method according to claim 36, wherein respective portions of the bond medium are arranged to combine such that the combination of respective portions has a thickness in a bond direction corresponding to the distance in accordance with the assembled configuration.

38. A method according to any of claims 25 to 34, further comprising introducing the bond medium into the space between the first and second parts in the assembled

configuration.

39. A method according to any of claims 25 to 38 wherein the bond medium includes one or more spacer elements, for example spheres, the machine further operable to bring the first and second parts together against the bond medium until a resistive force from the one or more spheres is experienced.

40. A method machine according to claim 39, the machine further operable to sense the resistive force and responsive to the resistive force satisfying a threshold value stop bringing the first and second parts together.

41. A method machine according to any of claims 25 to 40, wherein the bond medium is a curable bond medium, for example UV curable and/or thermally curable.

42. A method according to any of claim 25 to 41 , wherein the module may include one or more of the following: lens, sensor, capacitor, microphone, wave guides, interferometric devices, Fabry Perot filters, microfluidic devices; light sources , laser diode, LED, VCSEL, illumination module, projection module and camera module.

43. A method according to any of claims 25 to 42, for forming a lens module wherein the first part comprises a spacer substrate including an aperture and the second part comprises a lens assembly, the method further comprising: applying the bond medium to one or other or both of the spacer substrate and lens assembly;

aligning the lens assembly with the spacer substrate and aperture in accordance with an assembled configuration; and

placing the lens assembly to the bond medium to form a space between the spacer and lens assembly wherein the space conforms to a focal length requirement for the lens module.

44. A method according to any of claims 25 to 42, for forming an array of lens modules and wherein the first part is a spacer substrate comprising plural apertures; the method further comprising applying the bond medium to plural locations on the spacer substrate corresponding to the plural apertures, aligning plural lens assemblies to respective apertures and placing plural lens assemblies to the bond medium to form a space between the spacer and respective lens assemblies corresponding to respective focal length requirements for respective lens modules thereby to form the array of lens modules.

45. A method according to any of claims 25 to 44, further comprising curing the bond

medium.

46. A method according to any of claims 25 to 45, further comprising receiving the distance information for the second part or respective second parts and spacing apart the first part from the second part or respective second parts in accordance with the distance information.

47. The method according to claim 46, further comprising receiving different distance

information for two or more respective second parts and spacing apart the two or more respective second parts differently in accordance with the different distance information.

48. A method according to any of claims 25 to 47, further comprising determining the

distance by reference to force feedback information derived from a place actuator responsive to placing the second part to the first part or respective second parts to the first part when the bond medium is between the first and second parts.

49. A method according to claim 43 or 44 or any of claims 45 to 48 dependent on claim 43 or 44, further comprising overmoulding the lens assembly or array of lens assembly with a resin.

50. A method according to claim 49, further comprising singulating the overmoulded array of lens assemblies into simulated lens modules.

51. A method according to claim 49, further comprising singulating the overmoulded array of lens assemblies into camera modules.

52. A module comprising a first part and a second part bonded together by a bond medium, wherein the spacing of the first part from the second part is an operational parameter of the module and the thickness of the bond medium in the bond direction is in accordance with the spacing desired for the operational parameter.

53. A module fabricated by a pick and place machine in accordance with any of claims 1 to 24 and/or in accordance with the method in accordance with any of claims 25 to 51.

54. A method of assembling a module comprising a reference substrate and least one

component to be mounted on the reference substrate, the steps including:

a. Defining an X-Y plane with respect to the reference substrate and least one component and which is substantially parallel to surfaces on the reference substrate and least one component which are to be joined together

b. Applying a pre-determined amount of adhesive to surfaces on one or both of the reference substrate or the component in an area in which they are to be bonded together;

c. Aligning the components in the X-Y plane;

d. Placing the component and reference substrate at a pre-determined spaced apart distance from each other on said X-Y plane such that the reference substrate and component are both in contact with the adhesive;

e. Curing the adhesive to bond the reference substrate and component together.

55. A module comprising a reference substrate and at least one other component bonded together by an adhesive, the reference substrate and component being held at a predetermined spaced apart distance from each other by the adhesive.

56. A pick and place assembly machine substantially as hereinbefore described respectively corresponding to respective embodiments and corresponding drawings.

57. A method substantially as hereinbefore described respectively corresponding to

respective embodiments and corresponding drawings.

58. A module substantially as hereinbefore described respectively corresponding to

respective embodiments and corresponding drawings.