CN111432555A - Double-sided PCB and one-time double-sided plastic packaging method thereof - Google Patents

Abstract

The invention provides a double-sided PCB and a primary double-sided plastic package method thereof, wherein the double-sided PCB comprises a substrate, a first surface to be plastic packaged and a second surface to be plastic packaged, which are positioned at two sides of the substrate, the first surface to be plastic packaged and the second surface to be plastic packaged both comprise a functional area and a non-functional area surrounding the functional area, electronic components are preset in the functional area, a plurality of mold flow holes penetrating through the substrate are formed in the overlapping positions of the non-functional area of the first surface to be plastic packaged and the non-functional area of the second surface to be plastic packaged of the PCB on the substrate, the mold flow flows from the first surface to be plastic packaged to the second surface to be plastic packaged through the plurality of mold flow holes formed in the non-functional area of the substrate, after molding, the plastic package glue left in the mold flow holes can tightly connect the plastic package glue of the first surface and the plastic package glue of the second surface together, the phenomenon of separation between the plastic packaging glue on the two sides and the substrate is prevented, so that the quality of the product after plastic packaging is improved.

Description

Double-sided PCB and one-time double-sided plastic packaging method thereof

Technical Field

The invention relates to the technical field of electronic module plastic package, in particular to a double-sided PCB and a one-time double-sided plastic package method thereof.

Background

At present, electronic products in the communication field are increasingly integrated and miniaturized, and since a system-in-package (SIP) module can miniaturize a microelectronic system, the SIP module is widely applied to the electronic products, and the market of the double-sided SIP module is increasingly large.

In a double-sided SIP module, a plastic package adhesive and a substrate interface at a corner of a mold are often delaminated during a single double-sided plastic package process. When the molded PCB was cut into individual PCB units, separation of the interface of the molding layer and the substrate was observed. Delamination is often observed after high temperature processing such as laser cutting and sputtering processes. Therefore, the invention provides a PCB and a one-time double-sided plastic packaging method thereof, which aim to solve the problem of separation or layering of a plastic packaging layer of the double-sided PCB and a substrate interface.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a double-sided PCB and a one-time double-sided plastic package method thereof.

The technical scheme provided by the invention is as follows:

the utility model provides a two-sided PCB board, includes the base plate, is located the first face of treating the plastic envelope of base plate both sides and treats the second face of plastic envelope, treat that the first face of plastic envelope and the second face of treating the plastic envelope all contain functional area and encircle functional area's non-functional area has preset electronic components in the functional area the PCB board is treated the first face non-functional area of plastic envelope and is treated the position department that the second face non-functional area of plastic envelope overlaps on the base plate and seted up a plurality of runs through the orifice of mould of base plate.

In the technical scheme, a plurality of mold flow holes penetrating through the substrate are formed in the position, overlapped on the substrate, of a first surface non-functional area to be subjected to plastic packaging and a second surface non-functional area to be subjected to plastic packaging of the double-sided PCB. Because the functional areas on both sides of the substrate are provided with electronic elements, and the mold flow holes are through holes penetrating through the substrate, in order to avoid destroying the electronic elements in the functional area on any side of the substrate and the effectiveness of the electrical connection of the substrate, the opening positions of the mold flow holes should not be located in the functional area on any side of the substrate, but should be arranged on the substrate at the positions where the two sides of the substrate belong to the non-functional area, namely, the position where the non-functional area on the first side to be subjected to plastic packaging and the non-functional area on the second side to be subjected to plastic packaging of the PCB are overlapped on the substrate.

The mold flow holes are formed in the positions, overlapped on the substrate, of the two non-functional areas of the substrate, the mold flow can penetrate through the mold flow holes in the substrate during plastic package and flows from the first surface of the substrate to the second surface of the substrate, so that the first surface and the second surface of the substrate are wrapped in the plastic package glue, after the plastic package is formed, the plastic package layers of the first surface and the second surface of the substrate are fixedly connected through the plastic package glue solidified in the mold flow holes, and even after high-temperature process processing such as a cutting or sputtering process and the like, the plastic package layer of the first surface and the plastic package layer of the second surface of the PCB after the plastic package cannot be separated from the substrate. In the plastic package process, gas in a single cavity of the lower die can overflow to the upper die through the die flow holes, so that the pressure in the upper die cavity and the lower die cavity is balanced, and the problem of deformation of the substrate caused by overlarge pressure in the lower die cavity is solved.

Preferably, the mold flow holes include first mold flow holes, and the first mold flow holes are arranged at intervals at the overlapping position on the substrate and close to the edge of the substrate along the first surface non-functional area to be subjected to plastic packaging and the second surface non-functional area to be subjected to plastic packaging.

Because of the separation of plastic envelope layer and base plate often all is from the edge of base plate, in this technical scheme, through set up first mould flow hole on the base plate, and first mould flow hole closes on the base plate edge to make behind the plastic envelope, the first face plastic envelope layer and the second face plastic envelope layer of base plate edge can link together through the plastic envelope glue in the first mould flow hole, thereby solve the PCB board after the plastic envelope and take place the problem of separation between plastic envelope layer and the base plate from base plate edge.

Preferably, the substrate forms a pattern including a plurality of vertexes, and the first orifice is disposed at least adjacent to all of the vertexes.

In the technical scheme, the plurality of first mold flow holes are formed in the plurality of vertexes of the substrate, so that the plastic-packaged PCB cannot be layered with the substrate from the plastic packaging layer of the first surface and the second surface from the corners.

Preferably, the mold flow hole further comprises a second mold flow hole, and the second mold flow hole is uniformly opened at the overlapping position of the first surface non-functional area to be subjected to plastic packaging and the second surface non-functional area to be subjected to plastic packaging on the substrate and is far away from the edge of the substrate.

In this technical scheme, through treat that the first face non-functional area of plastic envelope and the second face non-functional area of waiting the plastic envelope overlap position department evenly sets up second orifice of mould on the base plate to the edge of base plate is kept away from to second orifice of mould, makes during the plastic envelope, and the gas in the lower mould die cavity can escape to the upper mould die cavity through second orifice of mould, makes the pressure in upper and lower mould die cavity reach balanced, thereby solves the deformation problem that the base plate leads to because of the unbalanced pressure that the face receives from top and bottom. Meanwhile, after the plastic sealing glue in the second die flow hole is solidified, the first surface plastic sealing layer and the second surface plastic sealing layer of the PCB can be tightly connected with the substrate, so that the plastic sealing effect is better.

Preferably, the PCB further includes a non-plastic-sealed region located on the second surface of the substrate, and the mold flow hole is opened in a region outside the non-plastic-sealed region.

In the technical scheme, the PCB further comprises a non-plastic-sealed area located on the second surface of the substrate, and the non-plastic-sealed area is used for exposing a part of the substrate of the PCB after plastic sealing and is used for installing functional elements such as an antenna, so that the non-plastic-sealed area also belongs to a functional area and cannot be provided with a mold flow hole.

Preferably, the aperture of the mold flow hole is suitable for the plastic sealant fluid to pass through.

In the technical scheme, the mold flow holes are formed to enable the plastic package adhesive fluid to penetrate through the substrate, so that the hole diameter of each mold flow hole is not too small, and the plastic package adhesive fluid can pass through the mold flow holes during plastic package.

A one-time double-sided plastic package method based on a double-sided PCB comprises the following steps:

s10, providing a double-sided PCB, wherein the PCB comprises a substrate, a first surface to be plastically packaged and a second surface to be plastically packaged, which are positioned on two sides of the substrate, and a plurality of mold flow holes penetrating through the substrate are formed in the position, overlapped on the substrate, of a non-functional area of the first surface to be plastically packaged and a non-functional area of the second surface to be plastically packaged of the PCB;

s20, placing the PCB on a lower die, closing an upper die, and tightly pressing the PCB by the outer edges of the upper die and the lower die so that a first surface to be subjected to plastic packaging and a second surface to be subjected to plastic packaging of the PCB are respectively positioned in an upper die cavity and a lower die cavity of a die;

s30, vacuumizing an upper die cavity and a lower die cavity of the die to remove air in the die;

s40, injecting plastic package glue into the glue injection port of the upper die, so that the plastic package glue flows into the lower die cavity through the die flow hole of the PCB and coats the area to be plastic packaged of the PCB;

and S50, demolding to obtain the PCB after plastic packaging.

Further, the PCB board further includes a non-plastic package region located on the second surface of the substrate, the mold flow hole is opened in a region outside the non-plastic package region, and step S10 further includes:

and arranging a metal cover in the non-plastic packaging area, wherein the height of the metal cover is not higher than the height of the plastic packaging layer on the second surface of the substrate.

In the technical scheme, the PCB further comprises a non-plastic packaging area located on the second surface of the substrate, and the metal cover is arranged in the non-plastic packaging area, so that the non-plastic packaging area cannot be subjected to plastic packaging in a plastic packaging process. However, the height of the plastic packaging layer of the metal cover arranged in the non-plastic packaging area is not higher than that of the second surface of the substrate, otherwise, the thickness of the PCB board after plastic packaging is increased, and the product after plastic packaging cannot meet the requirements of customers.

Compared with the prior art, the double-sided PCB and the one-time double-sided plastic package method thereof provided by the invention have the following beneficial effects:

1. according to the invention, the non-functional areas of the first surface and the second surface of the double-sided PCB to be subjected to plastic package are provided with the plurality of first mold flow holes at the overlapping position of the substrate and close to the edge of the substrate, so that the plastic package mold flow flows from the first surface to be subjected to plastic package to the second surface to be subjected to plastic package through the first mold flow holes, and after the plastic package part is formed, the plastic package glue remained in the first mold flow holes can tightly connect the substrate, the plastic package layer of the first surface and the plastic package layer of the second surface together to lock the substrate and the plastic package layers on the two surfaces of the substrate, so that the phenomenon that the plastic package layers on the two surfaces are separated from the substrate in the subsequent high-temperature processing processes of cutting, sputtering or the like is prevented, and the yield of products after plastic package is improved.

2. According to the invention, the plurality of second mold flow holes are formed in the non-functional areas of the first surface and the second surface of the substrate to be subjected to plastic package at the overlapping position of the substrate and far away from the edge of the substrate, so that on one hand, during plastic package, plastic package mold flow can be ensured to smoothly flow into the second surface from the first surface of the substrate, the effect of balancing mold flow on two surfaces of the substrate is achieved, and the pressure in the upper mold cavity and the lower mold cavity is balanced to the greatest extent. On the other hand, the plastic package layer of the first surface and the plastic package layer of the second surface after plastic package can be tightly connected together so as to lock the substrate and the plastic package layers on the two surfaces of the substrate.

3. The double-sided PCB plastic package is molded in one step, secondary packaging is not needed, the influence caused by the secondary packaging process is eliminated, meanwhile, the plastic package time is shortened, and the plastic package efficiency is improved.

Drawings

The above features, technical features, advantages and implementation manners of a PCB board and a primary double-sided plastic package method thereof will be further described in the following detailed description of preferred embodiments in a clearly understandable manner with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of the structure of a PCB board of the present invention;

FIG. 2 is another schematic view of the PCB of the present invention;

FIG. 3 is a schematic view of another structure of the PCB of the present invention;

FIG. 4 is a schematic diagram of a PCB structure after plastic encapsulation according to the present invention;

FIG. 5 is another schematic structural diagram of the PCB after the plastic package of the present invention;

fig. 6 is a schematic diagram of a PCB structure including a non-molding region according to the present invention.

The reference numbers illustrate: the molding compound comprises a substrate 100, an electronic component 101, a mold flow hole 102, a first surface functional area 111, a first surface non-functional area 112, a second surface functional area 121, a second surface non-functional area 122, a second surface non-molding area 123, a first mold flow hole 1021, a second mold flow hole 1022, a first mold cavity 201, a second mold cavity 202 and a molding compound 400.

Detailed Description

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following description will be made with reference to the accompanying drawings. It is obvious that the drawings in the following description are only some examples of the invention, and that for a person skilled in the art, other drawings and embodiments can be derived from them without inventive effort.

For the sake of simplicity, the drawings only schematically show the parts relevant to the present invention, and they do not represent the actual structure as a product. In addition, in order to make the drawings concise and understandable, components having the same structure or function in some of the drawings are only schematically illustrated or only labeled. In this document, "one" means not only "only one" but also a case of "more than one".

According to an embodiment provided by the present invention, as shown in fig. 1-2, a double-sided PCB includes a substrate 100, a first surface to be plastic-encapsulated and a second surface to be plastic-encapsulated, the first surface to be plastic-encapsulated includes a functional region 111 of the first surface and a non-functional region 112 surrounding the first surface of the functional region, the second surface to be plastic-encapsulated includes a functional region 121 of the second surface and a non-functional region 122 surrounding the second surface of the functional region, an electronic component 101 is preset in the functional region 111 of the first surface to be plastic-encapsulated and the functional region 121 of the second surface to be plastic-encapsulated, and a plurality of mold flow holes 102 penetrating through the substrate 100 are opened at positions where the first surface non-functional region 112 to be plastic-encapsulated and the second surface non-functional region 122 to be plastic-encapsulated overlap on the substrate 100. In this embodiment, the mold flow hole 102 is formed in the overlapping portion of the first surface non-functional region 112 to be mold-sealed and the second surface non-functional region 122 to be mold-sealed of the substrate 100, so that the molding compound 400 smoothly flows from the first surface to be mold-sealed to the second surface during the mold-sealing.

Since the first mold flow hole 1021 formed in the substrate 100 is a through hole, in order not to destroy the electrical performance of the substrate 100 and the electronic component 101 preset in the first surface functional area 111 to be mold-sealed and the second surface functional area 121 to be mold-sealed, it is required to ensure that the first mold flow hole 1021 is located at an overlapping portion of the first surface non-functional area 112 to be mold-sealed and the second surface non-functional area 122 to be mold-sealed.

As shown in fig. 2, in another embodiment of the present invention, the mold flow holes 102 include first mold flow holes 1021, and the first mold flow holes 1021 are arranged at intervals along the overlapping position of the first non-functional area 112 to be molded and the second non-functional area 122 to be molded on the substrate 100 and near the edge of the substrate 100. During plastic packaging, the plastic packaging adhesive 400 flows from the first surface to the second surface through the first mold flow hole 1021, and finally the first mold flow hole 1021 is filled, so that the plastic packaging layers of the first surface and the second surface are connected into a whole through the plastic packaging adhesive 400 in the first mold flow hole 1021, and the separation phenomenon cannot occur between the substrate 100 and the plastic packaging layers of the first surface and the second surface. Even in the subsequent high-temperature processing processes such as cracking, shielding layer sputtering and the like, the plastic package layers of the first surface and the second surface are not separated from the substrate 100.

As shown in fig. 2, specifically, the pattern formed on the substrate 100 includes a plurality of vertices, and the first mold flow hole 1021 is disposed near all the vertices and is disposed at an overlapping portion of the first surface non-functional area 112 to be molded and the second surface non-functional area 122 to be molded. After the molding, the molding layer on the first side and the molding layer on the second side are easily separated from the substrate 100, and the molding layers are separated from the surface of the substrate 100 from the top of the substrate 100. In this embodiment, the first mold flow holes 1021 are arranged near all the vertices, so that the plastic package layers of the first surface and the second surface are connected into a whole through the plastic package adhesive 400 in the first mold flow holes 1021 after plastic package, which can solve the problem of separation of the plastic package layer from the substrate 100 from the vertices of the substrate 100, and prevent the plastic package layer from being separated from the substrate 100 to a greater extent. And the plastic package layer of the first surface and the second surface after plastic package and the substrate 100 form a whole, so that the plastic package layer and the edge of the substrate 100 can not be separated even in subsequent high-temperature processes such as laser, cutting, splitting, sputtering of a shielding layer and the like.

In this embodiment, in addition to providing the first orifice 1021 adjacent to all vertices, the first orifice 1021 may be added as appropriate. As shown in fig. 3, the substrate 100 is square, and in addition to the first orifice 1021 near the four vertices, the first orifice 1021 may be additionally provided at the edge position.

The plastic package spare after the plastic envelope is as shown in fig. 4 and fig. 5, and in this embodiment, through setting up first mould orifice 1021, not only make the base plate 100 after the plastic envelope, the plastic envelope layer of first face and the second facial plastic envelope layer can form a complete whole, and simultaneously, can also guarantee that the deformation can not appear at the in-process base plate 100 of plastic envelope, two-sided PCB board plastic envelope one shot forming, do not need secondary packaging, the secondary packaging process has been eliminated and has been brought the influence, the plastic envelope time has also been shortened simultaneously, the plastic envelope efficiency has been improved.

As shown in fig. 2, in another embodiment of the present invention, the mold flow hole 102 further includes a second mold flow hole 1022, the second mold flow hole 1022 is opened at a position where the first surface non-functional region 112 to be molded and the second surface non-functional region 122 to be molded overlap on the substrate 100, and is far away from an edge of the substrate 100, that is, the second mold flow hole 1022 is a through hole penetrating through the substrate 100 and is opened inside the substrate 100, so as to avoid the first surface functional region 111 and the second surface functional region 121 to be molded, and at the same time, the electrical performance of the substrate 100 cannot be damaged. The second mold flow hole 1022 is disposed so that a mold cavity where the first surface to be molded is located is communicated with a mold cavity where the second surface to be molded is located. During plastic packaging, the plastic packaging adhesive 400 can flow from the first mold cavity 201 where the first surface to be plastic packaged is located into the second mold cavity 202 where the second surface to be plastic packaged is located. If the apertures, number and arrangement of the second mold flow holes 1022 are properly set, the speed of the molding compound 400 flowing through the second mold flow holes 1022 can be increased, the pressures in the first mold cavity 201 and the second mold cavity 202 can be balanced to the maximum extent, so that the pressures applied to the two sides of the substrate 100 are consistent, thereby ensuring that the substrate 100 is not deformed, and reducing the stress risk of the substrate 100.

As shown in fig. 6, in actual production, the PCB further includes a non-molding region 123 located on the second surface of the substrate 100, and the first mold flow hole 1201 and the second mold flow hole 1022 should be opened in regions outside the non-molding region. Since no molding compound flows into the second non-molding region 123, the opening of the mold flow hole 102 does not produce any beneficial effect, but the opening of the mold flow hole 102 may damage the electronic component in the first functional region 111 of the substrate 100. In order to ensure that the non-molding region 123 of the substrate 100 is not molded, in a specific implementation, a metal cover may be disposed on the non-molding region 123 of the second surface of the substrate 100 in advance, and the metal cover can better shield the non-molding region during molding, so that the substrate 100 with the non-molding region can also be molded by one-step double-sided molding. In the plastic packaging process, the second surface non-plastic packaging region 123 of the substrate 100 is protected, which is not limited to the above technical solution, as long as the shielding object covering the second surface non-plastic packaging region 123 can be easily removed after plastic packaging.

A one-time double-sided plastic package method for a double-sided PCB comprises the following steps:

s10, providing a double-sided PCB, wherein the PCB comprises a substrate 100, a first surface to be plastically packaged and a second surface to be plastically packaged, which are positioned at two sides of the substrate 100, and a plurality of mold flow holes 102 penetrating through the substrate 100 are formed in the overlapping position of the non-functional area of the first surface to be plastically packaged and the non-functional area of the second surface to be plastically packaged of the PCB on the substrate 100; s20, placing the PCB on the lower die, closing the upper die, and pressing the PCB tightly by the outer edges of the upper die and the lower die so that the first surface to be subjected to plastic packaging and the second surface to be subjected to plastic packaging of the PCB are respectively positioned in the upper die cavity and the lower die cavity of the die;

s30, vacuumizing an upper die cavity and a lower die cavity of the die to remove air in the die;

s40, injecting the plastic package glue 400 into the glue injection port of the upper die, so that the plastic package glue 400 flows into the lower die cavity through the die flow hole 102 of the PCB to coat the area of the PCB to be subjected to plastic package;

and S50, demolding to obtain the PCB after plastic packaging.

It should be noted that, if the PCB further includes a non-molding region 123 located on the second surface of the substrate 100, the first mold flow hole 1021 and the second mold flow hole 1022 should not be opened in the non-molding region 123 of the second surface, and a metal cap should be disposed in the non-molding region 123 of the second surface of the substrate 100 in advance. The height of the metal cap may be equal to or slightly lower than the height of the molding compound layer on the second surface of the substrate 100, but not higher than the height of the molding compound layer, otherwise the metal cap is placed in a molding compound mold, which may cause the mold to be unable to be closed. Meanwhile, the height of the metal cover exceeds the height of a preset plastic package layer of the second surface, so that the thickness of a plastic package product exceeds the requirement of a customer, and the reject ratio of the product is increased.

It should be noted that the above embodiments can be freely combined as necessary. The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims (8)

1. The utility model provides a two-sided PCB board, includes the base plate, is located the first face of treating the plastic envelope of base plate both sides and treats the second face of plastic envelope, its characterized in that: treat that the first face of plastic envelope and the second face of treating the plastic envelope all contain the functional area and encircle the non-functional area of functional area has preset electronic components in the functional area the PCB board is treated the first face non-functional area of plastic envelope and is treated the second face non-functional area of plastic envelope and is seted up a plurality of flowmeters holes that run through on the base plate in the position department of overlapping on the base plate.

2. A double-sided PCB board as in claim 1 wherein: the mold flow holes comprise first mold flow holes, and the first mold flow holes are arranged at intervals along the overlapped positions of the first surface non-functional area to be subjected to plastic packaging and the second surface non-functional area to be subjected to plastic packaging on the substrate and close to the edge of the substrate.

3. A double-sided PCB board as in claim 2 wherein: the pattern formed by the substrate comprises a plurality of vertexes, and the first orifice is at least arranged close to all the vertexes.

4. A double-sided PCB board as in claim 1 wherein: the mold flow hole further comprises a second mold flow hole, and the second mold flow hole is uniformly formed in the position where the first surface non-functional area to be subjected to plastic packaging and the second surface non-functional area to be subjected to plastic packaging are overlapped on the substrate and is far away from the edge of the substrate.

5. A double-sided PCB board as in claim 1 wherein: the PCB further comprises a non-plastic-sealed area located on the second surface of the substrate, and the mold flow holes are formed in an area outside the non-plastic-sealed area.

6. A double-sided PCB board as in claim 1 wherein: the aperture of the mold flow hole is suitable for plastic sealing glue fluid to pass through.

7. A one-time double-sided plastic package method based on a double-sided PCB is characterized in that:

the method comprises the following steps:

s10, providing a double-sided PCB, wherein the PCB comprises a substrate, a first surface to be plastically packaged and a second surface to be plastically packaged, which are positioned on two sides of the substrate, and a plurality of mold flow holes penetrating through the substrate are formed in the position, overlapped on the substrate, of a non-functional area of the first surface to be plastically packaged and a non-functional area of the second surface to be plastically packaged of the PCB;

s20, placing the PCB on a lower die, closing an upper die, and tightly pressing the PCB by the outer edges of the upper die and the lower die so that a first surface to be subjected to plastic packaging and a second surface to be subjected to plastic packaging of the PCB are respectively positioned in an upper die cavity and a lower die cavity of a die;

s30, vacuumizing an upper die cavity and a lower die cavity of the die to remove air in the die;

s40, injecting a plastic package colloid into the glue injection port of the upper die, so that the plastic package colloid flows into the lower die cavity through the die flow hole of the PCB and coats the area to be plastic packaged of the PCB;

and S50, demolding to obtain the PCB after plastic packaging.

8. The one-time double-sided plastic package method based on the double-sided PCB as recited in claim 7, wherein: the PCB board still includes the non-plastic envelope region that is located the base plate second face, the mould orifice is seted up the region outside the non-plastic envelope region, step S10 still includes:

and arranging a metal cover in the non-plastic packaging area, wherein the height of the metal cover is not higher than the height of the plastic packaging layer on the second surface of the substrate.

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