US20080020511A1

US20080020511A1 - Structure of image sensor module and a method for manufacturing of wafer level package

Info

Publication number: US20080020511A1
Application number: US11/790,717
Authority: US
Inventors: Wen-Kun Yang; Wen Pin Yang
Original assignee: Advanced Chip Engineering Technology Inc
Current assignee: Advanced Chip Engineering Technology Inc
Priority date: 2006-07-19
Filing date: 2007-04-27
Publication date: 2008-01-24
Also published as: SG139625A1; CN101110438A; JP2008042899A; KR20080008255A; US7498646B2; DE102007031966A1; US20080017941A1; TW200807702A

Abstract

The present invention discloses an image sensor module and forming method of wafer level package. The image sensor module comprises a metal alloy base, a wafer level package, a lens holder, and flexible printed circuits (F.P.C.). The wafer level package having a plurality of image sensor dice and a plurality of solder balls is attached to the metal alloy base. A plurality of lens are placed in the lens holder, and the lens holder is located on the image sensor dice. The lens holder is placed in the flexible printed circuits (F.P.C.), and the flexible printed circuits (F.P.C.) has a plurality of solder joints coupled to the solder balls for conveniently transmitting signal of the image sensor dice. Moreover, the image sensor dice may be packaged with passive components or other dice with a side by side structure or a stacking structure.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This is a divisional application of the application of Ser. No. 11/488,653, filed on Jul. 19, 2006, now pending, of which the entire disclosure is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention
This invention relates to an image sensor module, and more particularly to an image sensor module and a structure and method for manufacturing of wafer level package that can lower the cost, raise the yield and reliability.
2. Description of the Prior Art
The semiconductor technologies are developing very fast, and especially semiconductor dice have a tendency toward miniaturization. However, the requirements for the functions of the semiconductor dice have an opposite tendency to variety. Namely, the semiconductor dice must have more I/O pads into a smaller area, so the density of the pins is raised quickly. It causes the packaging for the semiconductor dice to become more difficult and decrease the yield.
The main purpose of the package structure is to protect the dice from outside damages. Furthermore, the heat generated by the dice must be diffused efficiently through the package structure to ensure the operation the dice.
The earlier lead frame package technology is already not suitable for the advanced semiconductor dice due to the density of the pins thereof is too high. Hence, a new package technology of BGA (Ball Grid Array) has been developed to satisfy the packaging requirement for the advanced semiconductor dice. The BGA package has an advantage of that the spherical pins has a shorter pitch than that of the lead frame package and the pins is hard to damage and deform. In addition, the shorter signal transmitting distance benefits to raise the operating frequency to conform to the requirement of faster efficiency. Most of the package technologies divide dice on a wafer into respective dice and then to package and test the die respectively. Another package technology, called “Wafer Level Package (WLP)”, can package the dice on a wafer before dividing the dice into respective dice. The WLP technology has some advantages, such as a shorter producing cycle time, lower cost, and no need to under-fill or molding.
The dice are, such as image sensor dice. Now, the image sensor module is formed by using a method of COB or LCC. The one drawback of the method of the COB is lower yield rate during packaging process due to particle contamination on sensing area. Besides, the drawbacks of the method of the LCC are higher packaging cost due to materials and lower yield rate during packaging process due to particle contamination on sensing area. Moreover, SHELL CASE company also develops wafer level package technique, the image sensor dice packaged by the SHELL CASE is higher cost due to requiring two glass plate and complicate process. And, the transparency is bad due to epoxy wearing out, and the potential reliability may be reduced.
Therefore, the present invention has been made in view of the above problems in the prior arts, and it is an objective of the present invention to provide a new image sensor module.

SUMMARY OF THE INVENTION

Therefore, the present invention has been made in view of the above problems in the prior arts, and it is an objective of the present invention to provide an image sensor module and a structure and method for manufacturing of wafer level package.
Another objective of the present invention is to provide an image sensor module to conveniently make a final testing of the wafer level package.
Still objective of the present invention is to lower the cost of the package structure.
Still another objective of the present invention is to raise the yield of the package structure.
Still another objective of the present invention is to offer the thinner body of the image sensor package and module.
Another objective of the present invention is to provide package structure with a high yield and reliability, and it can apply for semiconductor industry and LCD industry.
As aforementioned, the present invention provides an image sensor module and a method for manufacturing of wafer level package. The image sensor module comprises a metal alloy base, a wafer level package, a lens holder and flexible printed circuits (F.P.C.)/board. The material of the metal alloy base comprises Fe—Ni alloy, Fe—Ni—Co alloy, Cu—Fe alloy, Cu—Cr alloy, Cu—Ni—Si alloy, Cu—Sn alloy or Fe—Ni alloy laminated fiber glass materials. The wafer level package having a plurality of image sensor dice and a plurality of solder balls or bumps is attached to the isolating base. A plurality of lens are placed in the lens holder, and the lens holder is located on the image sensor dice. The lens holder is placed in the flexible printed circuits (F.P.C.), and the flexible printed circuits (F.P.C.) has a plurality of solder joints coupled to the solder balls for conveniently transmitting signal of the image sensor dice. Moreover, the image sensor dice may be packaged with passive components or other dice with a side by side structure or a stacking structure.
The present invention also provides a wafer level package structure. The package structure comprises a metal alloy base, a first die and a second die, a first dielectric layer, a second dielectric layer, a contact conductive layer, an isolation layer and solder balls. The first die and second die are adhered to the metal alloy base. The first dielectric layer is formed on the metal alloy base and filled in a space except the first die and second die on the metal alloy base. The second dielectric layer is formed on the second die. The contact conductive layer is formed on a first metal pad of the first die and a second metal pad of the second die to cover the first metal pad and second metal pad, and the contact conductive layer is electrically coupled to the first metal pad and second metal pad, respectively. The isolation layer is formed on the contact conductive layer, and the isolation layer has openings formed on the contact conductive layer. The solder balls or bumps are welded on the openings and electrically coupled with the contact conductive layer, respectively. The first die is selected from a DSP die, an active die, a passive die, a support die, a CPU die or a processor die, and the second die is a CMOS image sensor die. The image sensor die is packaged with the DSP die, active die, passive die, support die, CPU die or processor die with a side by side structure.
The present invention also provides a wafer level package structure. The package structure comprises a metal alloy base, a first die and a second die, a first dielectric layer, a second dielectric layer, a first and second contact conductive layer, an isolation layer and solder balls. The first die is adhered to the metal alloy base. The first dielectric layer is formed on the metal alloy base and filled in a space except the first die on the metal alloy base. The first contact conductive layer is formed on a first metal pad of the first die to cover the first metal pad, and the first contact conductive layer is electrically coupled to the first metal pad, respectively. The second die is adhered to the first die. The second dielectric layer is formed on the first dielectric layer and filled in a space except the second die, and the second dielectric layer has via hole formed on the first contact conductive layer. The third dielectric layer is formed on the second die. The second contact conductive layer is formed on a second metal pad of the second die and filled in said via hole to cover the second metal pad, and the second contact conductive layer is electrically coupled to the second metal pad and the first contact conductive layer. The isolation layer is formed on the second contact conductive layer, and the isolation layer has openings formed on the second contact conductive layer. The solder balls are welded on the openings and electrically coupled with the second contact conductive layer, respectively. The first die is selected from a DSP die, an active die, a passive die, a support die, a CPU die or a processor die, and the second die is a CMOS image sensor die. The image sensor die is packaged with the DSP die, active die, passive die, support die, CPU die or processor die with a stacking structure.
The present invention also provides a process of wafer level package. First, a first photo resist pattern is formed on metal pads of a plurality of dice on a wafer to cover the metal pads. A silicon-dioxide layer is formed on the first photo resist pattern and the plurality of dice. Then, the silicon-dioxide layer is cured. The first photo resist pattern is removed. The plurality of dice on the wafer is sawed to form individual dice. Next, the good dice are selected and attached to a metal alloy base. The metal alloy base is cured. A material layer is formed on the metal alloy base to fill in a space among the plurality of dice on the metal alloy base. The material layer is cured. A second dielectric layer is formed on the material layer and the metal pads. After that, a partial region of the second dielectric layer on the metal pads is etched to form first openings on the metal pads. The second dielectric layer is cured. A contact conductive layer is formed on the first openings to electrically couple with the metal pads, respectively. A second photo resist layer is formed on the contact conductive layer. Then, a partial region of the second photo resist layer is removed to form a second photo resist pattern and expose the contact conductive layer to form second openings. The conductive lines are formed on the second photo resist pattern and the second openings and coupled with the contact conductive layer, respectively. The remaining second photo resist layer is removed. Following that, an isolation layer is formed on the conductive lines and the second dielectric layer. A partial region of the isolation layer on the conductive lines is removed to form third openings. The isolation layer is cured. Finally, the solder balls are welded on the third openings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of an image sensor module according to the present invention;

FIG. 2 is a schematic diagram of a package with a side by side structure according to the present invention;

FIG. 3 is a schematic diagram of a package with a stacking structure according to the present invention;

FIG. 4A to FIG. 4J are schematic diagrams of a method for manufacturing of wafer level package according to the present invention;

FIG. 5 is a schematic diagram of a final testing of multi-CSP according to the present invention;

FIG. 6 is a schematic diagram of an application for LCD industry according to one embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Some sample embodiments of the invention will now be described in greater detail. Nevertheless, it should be recognized that the present invention can be practiced in a wide range of other embodiments besides those explicitly described, and the scope of the present invention is expressly not limited expect as specified in the accompanying claims.
Then, the components of the different elements are not shown to scale. Some dimensions of the related components are exaggerated and meaningless portions are not drawn to provide a more clear description and comprehension of the present invention.
The die of the present invention may be packaged with passive components (ex. capacitors) or other dice with a side by side structure or a stacking structure. The IC package can be finished by semiconductor industry and LCD, PCB industry.
As aforementioned, the present invention provides an image sensor module, as shown in FIG. 1. The cross-section of the wafer level package structure of the present is indicated as 101. The image sensor module comprises a metal alloy base 100, a wafer level package 101, a lens holder 102, and flexible printed circuits (F.P.C.) 103. For example, the material of the metal alloy base 100 comprises Fe—Ni alloy, Fe—Ni—Co alloy, Cu—Fe alloy, Cu—Cr alloy, Cu—Ni—Si alloy, Cu—Sn alloy or Fe—Ni alloy laminated fiber glass materials etc., wherein shape of the base may be a round or rectangular. For example, Fe—Ni alloy comprises ASTM F30 or Alloy 42 (42Ni58Fe), wherein composition of the Fe—Ni alloy comprises 42% Ni and 58% Fe. The main properties of the Alloy 42 comprises CET about 4.0˜4.7 (ppm/° C.), thermal conductivity about 12 (W/m-° C.), electrical resistivity about 70 (μΩ-cm) and Yield bend fatigue strength about 620 (MPa). In addition, the Fe—Ni—Co alloy comprises ASTM F15 or Kovar (29Ni17Co54Fe), wherein composition of the Fe—Ni—Co alloy comprises 29% Ni, 17% Co and 54% Fe. Similarly, the main properties of the Kovar comprises CET about 5.1˜8.7 (ppm/° C.), thermal conductivity about 40 (W/m-° C.) and electrical resistivity about 49 (μΩ-cm). In other words, the metal alloy of the present invention may be employed as a lead/lead frame alloys. Special alloys like ASTM F30 or Alloy 42 and ASTM F15 or Kovar have gained wide acceptance because of their thermal expansion coefficients, which closely match those of ceramics, and their high formability. Alloy 42 and Kovar are commonly used for lead and leadframe fabrication in ceramics chip carriers. As above-mentioned, the coefficients of thermal expansion of both these materials match well with those of silicon which are 2.3 ppm/° C., and that of ceramics substrate (3.4 to 7.4 ppm/° C.). Kovar and Alloy 42 also have high fatigue strength. Alloy 42 has a fatigue strength of 620 MPa compared with only 380-550 MPa for most cooper alloys. The lead material should be electrically conductive to serve as the electrical path for the signals. Moreover, the lead material should be resistant to corrosion, which increases the electrical resistance of the leads, causing electrical failure and can eventually result in mechanical fracture. The lead materials in the present invention may comprise Fe—Ni alloy, Fe—Ni—Co alloy, Cu—Fe alloy, Cu—Cr alloy, Cu—Ni—Si alloy, Cu—Sn alloy or Fe—Ni alloy laminated fiber glass materials etc.
The wafer level package 101 has a plurality of image sensor dice 104 and the dice 105, for example digital signal process (DSP) dice, with a side by side structure. Note that the dice 105 are optionally disposed. The image sensor dice 104 may be CMOS image sensor dice. The dice 105 are selected from a DSP die, an active die, a passive die, a support die, a CPU die or a processor die etc. The image sensor dice 104 and the dice 105 are packaged with a side by side structure. In the wafer level package 101, the image sensor dice 104 and the dice 105 are adhered to the metal alloy base 100 by an UV curing type and/or heat curing type adhesion material 106 with good thermal conductivity. The wafer level package 101 has a plurality of metal soldering balls 107 to be a signal transmitting mechanism. The metal soldering balls 107 may be solder balls or bumps 107.
A dielectric layer 108 is formed on the metal alloy base 100 and filled in a space except the image sensor dice 104 and the dice 105 on the metal alloy base 100. The material of the dielectric layer 108 may be silicon rubber based material.
A contact conductive layer 109 is formed on metal pads 115 of the image sensor dice 104 and metal pads 116 of the dice 105 to cover the metal pads 115, 116. That is to say, the contact conductive layer 109 may be electrically coupled to the metal pads 115, 116, respectively. The material of the contact conductive layer 109 may be selected from Ni, Cu, Au and the combination thereof.
Moreover, a film layer 110 can be covered on the image sensor dice 104. The material of the film layer 110 is SiO₂, Al₂O₃or Fluoro-polymer film formed by spin coating to be a protection film. The thickness of the film layer 110 is controlled less preferably 0.2 μm (micro meter) so that it can't affect the function of the image sensor dice 104. The film layer 110 may comprise a filtering film 111 (optional layer), for example IR filtering layer, formed on the film layer 110 to be a filter.
An isolation layer 112 is formed on the contact conductive layer 109, and the isolation layer 112 has openings on the contact conductive layer 109. The isolation layer 112 should not cover the image sensor area of dice 104 for conveniently sensing the image. The material of the isolation layer 112 is selected from epoxy, resin, SINR, BCB, PI and the combination thereof.
The lens holder 102 is located on the image sensor dice 104, and lens 113, 114 are placed in the lens holder 102. The lens holder 102 is placed in the flexible printed circuits (F.P.C.) 103, and the flexible printed circuits (F.P.C.) 103 has a plurality of solder joints 117 coupling to the solder balls 107 for conveniently transmitting signal. Therefore, the combination of the lens holder 102 and the flexible printed circuits (F.P.C.) 103 of the present invention has a function of probe card, and it can be used to be a final testing of the Multi-CSP, as shown in FIG. 5.
As aforementioned, the present invention also provides a wafer level package structure, as shown in FIG. 2. The package structure comprises a metal alloy base 200, image sensor dice 201 and dice 202, a first dielectric layer 205, a second dielectric layer 207, contact conductive layer 206, isolation layer 209 and solder balls 208. In one embodiment, the material of the metal alloy base 200 comprises Fe—Ni alloy, Fe—Ni—Co alloy, Cu—Fe alloy, Cu—Cr alloy, Cu—Ni—Si alloy or Cu—Sn alloy etc., wherein shape of the base may be a round or rectangular. The image sensor dice 201 and the dice 202 are packaged with a side by side structure. The image sensor dice 201 and the dice 202 are adhered to the metal alloy base 200 by an UV curing type and/or heat curing type adhesion material 203 with good thermal conductivity. The first dielectric layer 205 is formed on the metal alloy base 200 and filled in a space except the image sensor dice 201 and the dice 202 on the metal alloy base 200. The material of the first dielectric layer 205 may be silicon rubber based material.
The second dielectric layer 207 is formed on the image sensor dice 201 to cover a sensing area of the image sensor dice 201. The material of the second dielectric layer 207 is SiO₂, Al₂O₃, Fluoro polymer film to be a protection film. Besides, a filtering film may be formed on the second dielectric layer 207, and the filtering film is, for example IR filtering layer, to be a filter. The second dielectric layer 207 can be formed by wafer level process before dicing saw the silicon wafer.
The contact conductive layer 206 is formed on metal pads 210 of the image sensor dice 201 and metal pads 204 of the dice 202 to cover the metal pads 210,204. Namely, the contact conductive layer 206 may be electrically coupled to the metal pads 210,204, respectively. The material of the contact conductive layer 206 may be selected from Ni, Cu, Au and the combination thereof. The metal pads 210,204 are, for example Al pads. The isolation layer 209 is formed on the contact conductive layer 206, and the isolation layer 209 has openings on the contact conductive layer 206. The material of the isolation layer 209 is selected from epoxy, resin, SINR (Siloxane polymer), BCB or PI. The metal soldering balls 208 are formed on the openings by welding method so that the metal soldering balls 208 are electrically coupled with the contact conductive layer 206, respectively. The metal soldering balls 208 may be solder balls or solder bumps 208.
The dice 202 may be selected from a DSP die, an active die, a passive die, a support die, a CPU die or a processor die, and the image sensor dice 201 are CMOS image sensor dice. The image sensor dice 201 are packaged with the dice 202 with a side by side structure.
Moreover, the present invention also provides another wafer level package structure, as shown in FIG. 3. In one embodiment, the dice are packaged with a stacking structure. The package structure comprises a metal alloy base 300, image sensor dice 301 and dice 302, a first dielectric layer 303, a second dielectric layer 304, a third dielectric layer 311, contact conductive layer 305 a, 305 b, an isolation layer 306 and solder balls 307. For example, the material of the metal alloy base 300 comprises Fe—Ni alloy, Fe—Ni—Co alloy, Cu—Fe alloy, Cu—Cr alloy, Cu—Ni—Si alloy, Cu—Sn alloy or Fe—Ni alloy laminated fiber glass materials etc. As above-mentioned, shape of the base may be a round or rectangular. The image sensor dice 301 and the dice 302 are packaged with a stacking structure. The dice 302 are adhered to the metal alloy base 300 by an UV curing type and/or heat curing type adhesion material 310 a with good thermal conductivity. The first dielectric layer 303 is formed on the metal alloy base 300 and filled in a space except the dice 302 on the isolating base 300. The material of the first dielectric layer 303 may be silicon rubber based material.
The contact conductive layer 305 a is formed on metal pads 309 of the dice 302 to cover the metal pads 309 to electrically couple to the metal pads 309, respectively. The image sensor dice 301 are adhered to the dice 302 by an UV curing type and/or heat curing type adhesion material 310 b with good thermal conductivity. The second dielectric layer 304 is formed on the first dielectric layer 303 and filled in a space except the image sensor dice 301, and the second dielectric layer 304 has via hole 312 formed on the contact conductive layer 305 a. The material of the second dielectric layer 304 is silicon rubber, PI, SINR, BCB etc.
Besides, the third dielectric layer 311 is formed on the image sensor dice 301 to cover a sensing area of the image sensor dice 301. However, the third dielectric layer 311 should not affect function of the image sensor dice 301. The material of the third dielectric layer 311 is SiO₂, Al₂O₃, Fluoro polymer film to be a protection film. Specially, a filtering film may be formed on the third dielectric layer 311 on the image sensor dice 301, and the filtering film is, for example IR filtering layer, to be a filter. The third dielectric layer 311 can be formed by wafer level process before dicing saw the silicon wafer.
The contact conductive layer 305 b is formed on metal pads 308 of the image sensor dice 301 and filled in the via hole 312 to cover the metal pads 308. Namely, the contact conductive layer 305 b is electrically coupled to the metal pads 308 and the contact conductive layer 305 a. The material of the contact conductive layer 305 a, 305 b may be selected from Ni, Cu, Au and the combination thereof. The metal pads 308, 309 are, for example Al pads. The isolation layer 306 is formed on the contact conductive layer 305 b, and the isolation layer 306 has openings on the contact conductive layer 305 b. The material of the isolation layer 306 is selected from epoxy, resin, SINR, BCB, PI and the combination thereof.
The metal soldering balls 307 are formed on the openings by welding method so that the metal soldering balls 307 are electrically coupled with the contact conductive layer 305 b, respectively. The metal soldering balls 307 may be solder balls or solder bumps 307.
The dice 302 may be selected from a DSP die, an active die, a passive die, a support die, a CPU die or a processor die, and the image sensor dice 301 are CMOS image sensor dice. The image sensor dice 301 are packaged with the dice 202 with a stacking structure.
FIG. 4A to FIG. 4J are schematic diagrams of a method for manufacturing of wafer level package according to the present invention.
Moreover, the present invention provides a process of wafer level package. First, a first photo resist pattern 402 is formed on metal pads 401 of a plurality of dice 400 on a wafer to cover the metal pads 401, as shown in FIG. 4A. A first dielectric layer is formed on the first photo resist pattern 402 and the dice 400. Then, the first dielectric layer is cured. The first photo resist pattern 402 is removed to form a dielectric layer 403. The material of the dielectric layer 403 is SiO₂by spin coating method (SOG) to be a protection film. The plurality of dice 400 on the wafer is sawed along the sawing line 404 to form individual dice, as shown in FIG. 4B. Specially, a filtering film may be formed on the dielectric layer 403, and the filtering film is, for example IR filtering layer, to be a filter, as referring to above embodiment.
A step of back lapping the processed silicon wafer is used to get a thickness of the wafer around 50-300 μm after the step of removing first photo resist pattern 402. The processed silicon wafer with the aforementioned thickness is easily sawed to divide the dice 400 on the wafer into respective dice. The back lapping step may be omitted if the processed silicon wafer is not hard to saw without back lapping. The dice 400 comprise at least two types of dice.
Next, the divided dice are tested to choose standard good dice 400 there from. The standard good dice 400 are picked and replaced onto a metal alloy base 405 with a wider distance between two adjacent dice and adhered to the metal alloy base 405 with an UV curing type and/or heat curing type adhesion material 406 with good thermal conductivity. The metal alloy base 405 is cured by UV light or thermal, as shown in FIG. 4C. The adhesion material 406 is coating on the metal alloy base 405, and the thickness of the adhesion material 406 is preferably 20-60 μm. Similarly, the material of the metal alloy base 405 comprises Fe—Ni alloy, Fe—Ni—Co alloy, Cu—Fe alloy, Cu—Cr alloy, Cu—Ni—Si alloy, Cu—Sn alloy or Fe—Ni alloy laminated fiber glass materials etc., and wherein shape of the base may be round or rectangular.
The dice 400 have I/O pads 401 on the upper surface. The adhesive material 406 of the present invention is preferably good thermal conductive material, so the problems (such as stress) resulted from the temperature difference between the dice 400 and the metal alloy base 405 can be avoided.
A material layer 407 is formed on the metal alloy base 405 to fill in the space among the die 400 and adjacent dice 400, and the surface of the material layer 407 and the surface of the die 400 are at same level, as shown in FIG. 4D. The material of the material layer 407 can be UV curing type or heating curing type material. Then, the material layer 407 is cured by UV or thermal. The material layer 407 may be formed by a screen printing method or a photolithography method. The material layer 407 functions as a buffer layer to reduce a stress due to temperature, etc. The material layer 407 can be an UV and/or heat curing material, such as silicon rubber, epoxy, resin, BCB, SINR, PI and so on.
A second dielectric layer 409 is coated on the material layer 407 and metal pads 401. The material of the second dielectric layer can be .SINR, BCB, PI, epoxy etc.
Then, the partial area of the second dielectric layer on the metal pads 401 is removed by using a photo mask to form first openings 408 on the metal pads 401, and then the dielectric layer 409 is cured by UV or heating, as shown in FIG. 4E. Next, the plasma etching (RIE) can be used optionally to clean the surface of the metal pads 401 to make sure no residual materials on the metal pads 401.
The contact conductive layer 410 is formed on the first openings 408 to electrically couple with the metal pads 401 respectively, as shown in FIG. 4F. The preferable material of the contact conductive layer 410 is Ti, Cu, or the combination thereof. The contact conductive layer 410 can be formed by a physical method, a chemical method, or the combination thereof, for example: CVD, PVD, sputter, and electroplating.
A second photo resist layer is formed on the contact conductive layer 410. And then, a partial region of the second photo resist layer is exposed and developed by using a photo mask to form a second photo resist pattern 411 and expose the contact conductive layer 410 to form second openings 412, as shown in FIG. 4G.
Then, conductive lines 413 by electroplating method are formed on the second openings 412 to couple with the contact conductive layer 413 respectively, as shown in FIG. 4H. The material of the conductive lines 413 are preferably Cu, Ni, Au, or the combination thereof. The conductive lines 413 are called re-distribution layer (RDL).
The remaining second photo resist layer 411 is removed. An isolation layer is formed on the conductive lines 413 and the dielectric layer 409. A partial region of the isolation layer is removed to form a isolation layer 414 and third openings 415 on the conductive lines 413, as shown in FIG. 4I. The isolation layer can be formed by a spin coating method or a screen printing method.
The present invention may optionally comprises a step of forming an epoxy layer (not shown) on back surface of the metal alloy base 405.
The isolation layer 414 is cured. The UBM (not shown) and Solder balls 416 are formed on the third openings 415, as shown in FIG. 4J. The solder balls 416 may be placed on the third openings 415 by a screen printing method and the solder balls 416 joined together with surfaces of the conductive lines 413 by IR reflow method.
Finally, the metal alloy base 405 is sawed along the sawing line 417 to separate individual IC package.
Therefore, the image sensor module and wafer level package of the present invention can lower the cost of the package structure and raise the yield of the package structure. Moreover, the package size of the present invention can be easily adjusted to test equipment, package equipment, etc.
Moreover, the present invention can be applied for packaging of semiconductor equipment and for IC packaging of LCD/PCB equipment. FIG. 6 is a schematic diagram of an application for LCD industry according to one embodiment of the present invention. The panel scale packages (PSP's) 601 are formed on a base 600.
Although specific embodiments have been illustrated and described, it will be obvious to those skilled in the art that various modifications may be made without departing from what is intended to be limited solely by the appended claims.

Claims

1. A process of wafer level package, comprising the steps of:

forming a first photo resist pattern on metal pads of a plurality of dice on a wafer to cover said metal pads;

forming a first dielectric layer on said first photo resist pattern and said plurality of dice;

removing said first photo resist pattern;

sawing said plurality of dice on said wafer to form individual dice;

selecting good said dice and attaching said good dice to a metal alloy base, wherein material of said metal alloy base comprises Fe—Ni alloy, Fe—Ni—Co alloy, Cu—Fe alloy, Cu—Cr alloy, Cu—Ni—Si alloy, Cu—Sn alloy or Fe—Ni alloy laminated fiber glass materials;

forming a material layer on said base to fill in a space among said plurality of dice on said base;

forming a second dielectric layer on said material layer;

etching a partial region of said second dielectric layer to form first openings to expose metal pads on said dice;

forming a contact conductive layer on said first openings to electrically couple with said metal pads, respectively;

forming a second photo resist layer on said second dielectric layer and said contact conductive layer;

removing a partial region of said second photo resist layer to form a second photo resist pattern to expose said contact conductive layer to form second openings;

forming conductive lines on said second photo resist pattern and said second openings being coupled with said contact conductive layer, respectively;

removing remaining said second photo resist pattern;

forming an isolation layer on said conductive lines and said second dielectric layer;

removing a partial region of said isolation layer on said conductive lines to form third openings; and

welding solder balls on said third openings.

2. The process in claim 1, further comprising a step of sawing said base to isolate said plurality of dice after the step of said welding solder balls.

3. The process in claim 1, further comprising a step of back lapping said wafer to get a thickness of said wafer around 100-300 cm after the step of said removing first photo resist pattern.

4. The process in claim 1, further comprising a step of forming an epoxy layer on back surface of said base.

5. The process in claim 1, wherein said plurality of dice comprise at least two types of dice.

6. The process in claim 1, wherein material of said first dielectric layer is SiO2 by spin coating.

7. The process in claim 1, wherein material of said first dielectric layer is silicon rubber based material.

8. The process in claim 1, wherein material of said material layer is silicon rubber, epoxy, BCB, BT, polyimide (PI) or SINR(Siloxane polymer).

9. The process in claim 1, wherein material of said second dielectric layer is silicon rubber, epoxy, SINR(Siloxane polymer), BCB or polyimide (PI).

10. The process in claim 1, further comprising a step of forming a filtering film on said first dielectric layer, said filtering film is an IR filtering layer.

11. The process in claim 1, wherein material of said contact conductive layer is selected from Ti, Cu and the combination thereof.

12. The process in claim 1, wherein material of said isolation layer is selected from epoxy, resin and the combination thereof.

13. The process in claim 1, wherein material of said conductive lines is selected from Ni, Cu, Au and the combination thereof.

14. The process in claim 1, wherein said step of welding said solder balls comprises placing said solder balls on said third openings by a screen printing method and joining said solder balls together with surfaces of said conductive lines by an IR reflow method.

15. A process of wafer level package, comprising the steps of:

forming a first dielectric layer on a plurality of dice on a wafer by using a first photo resist pattern;

sawing said plurality of dice on said wafer to form individual dice;

forming a second dielectric layer on said material layer;

forming a second photo resist pattern to expose said contact conductive layer to form second openings;

removing remaining said second photo resist pattern;

welding solder balls on said third openings.

16. The process in claim 15, further comprising a step of sawing said base to isolate said plurality of dice after the step of said welding solder balls.

17. The process in claim 15, further comprising a step of back lapping said wafer to get a thickness of said wafer around 100-300 μm after the step of said removing said first photo resist pattern.

18. The process in claim 15, further comprising a step of forming an epoxy layer on back surface of said base.

19. The process in claim 15, wherein said plurality of dice comprise at least two types of dice.

20. The process in claim 15, wherein material of said first dielectric layer is SiO2 by spin coating.

21. The process in claim 15, wherein material of said first dielectric layer is silicon rubber based material.

22. The process in claim 15, wherein material of said material layer is silicon rubber, epoxy, resin, BCB, BT, polyimide (PI) or SINR(Siloxane polymer).

23. The process in claim 15, wherein material of said second dielectric layer is SINR(Siloxane polymer), BCB or polyimide (PI).

24. The process in claim 15, further comprising a step of forming a filtering film on said first dielectric layer, said filtering film is an IR filtering layer.

25. The process in claim 15, wherein material of said contact conductive layer is selected from Ti, Cu and the combination thereof.

26. The process in claim 15, wherein material of said isolation layer is selected from epoxy, resin and the combination thereof.

27. The process in claim 15, wherein material of said conductive lines is selected from Ni, Cu, Au and the combination thereof.

28. The process in claim 15, wherein said step of welding said solder balls comprises placing said solder balls on said third openings by a screen printing method and joining said solder balls together with surfaces of said conductive lines by an IR reflow method.