Integrated packaging structure capable of reducing warping of transparent plastic package body

Abstract

The utility model discloses an integrated packaging structure capable of reducing warping of a transparent plastic package body, comprising a substrate which comprises a block mounting area and a product mounting area; a plurality of block structures, wherein the block structures are mounted on the block mounting areas; a plurality of chips, wherein the chips are mounted on the product mounting area on the substrate; and the plastic packaging layer is arranged on the substrate and wraps the chip and the filling grid structure. According to the packaging structure, the block structure is arranged on the substrate, and the chip is partitioned, so that the warping degree of a plastic packaging body of a product after compression molding and cooling is reduced, the realization of automatic operation of a machine table is more convenient, and the cost of an injection molding mold and the cost of changing the machine and cleaning the mold are reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of photosensitive chip packaging, in particular to an integrated packaging structure for reducing the warping of a transparent plastic packaging body. Background Art

[0002] During the chip encapsulation process, transparent EMC (ElectroMagnetic Compatibility) is encapsulated on the surface of IC (integrated circuit) to protect the chip and circuit from external dust, moisture, ions, radiation, mechanical shock, etc. It can also ensure the normal input of optical signals and convert optical signals into electrical signals. Due to the excessively high CTE of transparent EMC, the internal stress generated by the mismatch between the CTE of the chip after compression molding, the interconnection material (solder ball) and the substrate causes excessive warpage of the product encapsulation body. See Figure 1 In order to improve the problem of excessive warping of products after plastic packaging, it is usually achieved by reducing the volume of plastic packaging, dividing the packaging into blocks or increasing the tensile stress of the PCB, so as to reduce the warping and realize automated operation.

[0003] In the prior art, the chip encapsulation process includes transfer molding and compression molding. In transfer molding, the warping of the chip product plastic encapsulation body can be reduced by block injection molding and unit injection molding, but the cost of injection molding molds and equipment EMC plastic encapsulation material transfer components is too high. The warping phenomenon of the product cannot be overcome in the compression molding process. Utility Model Content

[0004] The technical problem to be solved by the utility model is to provide an integrated packaging structure for reducing the warping of a transparent plastic package body, thereby solving the warping phenomenon of the plastic package body of a product in a compression molding process.

[0005] In order to solve the above technical problems, the technical solutions provided by the utility model are as follows:

[0006] An integrated packaging structure for reducing warping of a transparent plastic package, comprising:

[0007] A substrate, the substrate comprising a block mounting area and a product mounting area;

[0008] A plurality of blocking structures, wherein the blocking structures are mounted on the blocking mounting area;

[0009] A plurality of chips, wherein the chips are mounted on the product mounting area;

[0010] A plastic encapsulation layer is disposed on the substrate and covers the chip and the blocking structure.

[0011] Furthermore, the width of the blocking structure located at the feed end and the discharge end is greater than the width of the blocking structure located in the middle of the product mounting area.

[0012] Furthermore, the number of the blocking structures located in the middle of the product mounting area is three.

[0013] Furthermore, the blocking structure is mounted using low-fluidity glue.

[0014] Furthermore, the material of the blocking structure includes silicon, copper or phosphor copper.

[0015] Furthermore, the thickness of the blocking structure is less than or equal to the thickness of the plastic packaging colloid.

[0016] Furthermore, the chip and the substrate are connected by wire bonding.

[0017] Compared with the prior art, the integrated packaging structure for reducing the warping of the transparent plastic package provided by the utility model has the following beneficial effects:

[0018] The packaging structure divides the transparent plastic package into sections by arranging a blocking structure made of a material with a small thermal expansion coefficient on the substrate, thereby reducing stress and reducing the degree of warping of the plastic package after the product is compression molded and cooled, making it easier to realize automatic operation of the machine and reducing the cost of injection molding molds and machine modification and mold cleaning. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of warping of a transparent plastic package in the prior art;

[0020] Figure 2 A schematic diagram of the layout of a PCB substrate provided in an embodiment of the utility model;

[0021] Figure 3 A schematic diagram of gluing the blocking mounting area of ​​a PCB substrate provided by an embodiment of the utility model;

[0022] Figure 4 A side view of a blocking structure mounted on a substrate provided by an embodiment of the utility model;

[0023] Figure 5 This is a front view schematic diagram of an embodiment of the utility model after mounting a blocking structure on a substrate;

[0024] Figure 6 It is a schematic diagram of the embodiment of the utility model after the chip is mounted in the product mounting area on the substrate;

[0025] Figure 7 This is a schematic diagram of an embodiment of the utility model using a transparent EMC plastic packaging material to plasticize a colloid. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0027] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "front", "back", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0028] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, an integral connection, or a detachable connection; it can be the internal connection of two components; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0029] See also Figure 2-Figure 7 This embodiment provides an integrated packaging structure for reducing warping of a transparent plastic package, including:

[0030] The substrate includes a blocking mounting area and a product mounting area. When copper or silicon wafer materials are used to establish the blocking mounting area, the flatness requirements of the feed and discharge ends after the product is plastic-sealed are taken into consideration, so wider blocking structures are added to the left and right ends of the substrate to ensure that the feed and discharge are flat in the material box without jamming. Adding three blocking structures in the middle can ensure that the product will not bend in a "U" shape after plastic sealing. As a whole, the width of the blocking structure at the feed end and the discharge end is greater than the width of the blocking structure located in the middle of the product mounting area. In this embodiment, at the discharge end and the feed end, the width of the blocking structure is set to three times the width of the chip unit, and the width of the blocking structure is set to the width of a single chip unit. For details, see Figure 2 .

[0031] The blocking structure is mounted in the blocking mounting area, wherein the blocking structure is mounted by glue. The materials of the blocking structure include silicon wafers, copper, phosphor copper and other materials with a CTE thermal expansion coefficient lower than 20. The CTE values ​​of the main materials in the specific chip packaging structure are as follows:

[0032] Material CTE / (ppm / ℃) Application in flip chip silicon 2.5 Chip or silicon substrate FR-4 substrate 16 Organic substrate Alumina 6.9 Ceramic Substrate copper 13-18 Copper or brass solder 18-22 interconnection Polyimide 45 Flexible organic substrates Black Epoxy 55-75 Resin in underfill Transparent epoxy resin 70-170 Resin in underfill

[0033] The thickness of the barrier is less than or equal to the thickness of the plastic encapsulation colloid, because setting the same thickness as the plastic encapsulation colloid or exceeding the thickness of the plastic encapsulation colloid may result in the plastic encapsulation colloid not being fully filled during compression molding, generating bubbles and the risk of damaging the mold. In this embodiment, it is preferred to use a silicon sheet or a copper sheet to set the barrier area thickness to be 50 μm lower than the plastic encapsulation body.

[0034] A plurality of chips, wherein the chips are mounted on a product mounting area on a substrate and are interconnected by wire bonding to connect the chips and the substrate;

[0035] A plastic encapsulation layer, which is disposed on the substrate and covers the chip and the filling barrier structure;

[0036] Since a blocking structure made of a material with a small thermal expansion coefficient, such as a silicon wafer (CET is 2.5PPM / ℃) or a copper sheet (CET is 13-18PPM / ℃) is provided on the substrate, the product is partitioned, the product stress is reduced, and the warping degree of the product transparent plastic package is reduced.

[0037] Correspondingly, the manufacturing process of the integrated packaging structure for reducing the warping of the transparent plastic packaging body is as follows:

[0038] Step A: Make the substrate, which includes the block mounting area and the product mounting area. Figure 2 ;

[0039] Step B: Glue the blocking mounting area on the substrate. Use low-fluidity glue to prevent it from flowing to the product mounting area and hindering the subsequent product mounting. For details, see Figure 3 ;

[0040] Step C: Block mounting. The thickness of the block shall not exceed the thickness of the plastic sealant. For details, see Figure 4 and Figure 5 ;

[0041] Step D: Place the die on the substrate in the product mounting area. Figure 6 ;

[0042] Step E: Bonding wires between the chip and the substrate to connect the chip and the substrate;

[0043] Step F: The product is encapsulated by a transparent EMC encapsulation colloid. The encapsulation layer is disposed on the substrate and covers the chip and the filling grid structure. For details, see Figure 7 ;

[0044] This packaging structure solves the problem of excessive warpage caused by compression molding of transparent EMC plastic packaging materials during compression molding. By setting a blocking structure made of a material with a small thermal expansion coefficient on the substrate, the chip is partitioned, which reduces the warpage of the product after compression molding and cooling, makes it easier to realize automatic operation of the machine, and reduces the cost of injection molding molds and machine modification and mold cleaning.

[0045] In short, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An integrated packaging structure for reducing warping of a transparent plastic package, characterized in that: include, A substrate, the substrate comprising a block mounting area and a product mounting area; A plurality of blocking structures, wherein the blocking structures are mounted in the blocking mounting area, the width of the blocking structures at the feed end and the discharge end is greater than the width of the blocking structure located in the middle of the product mounting area, the material of the blocking structures includes silicon, copper or phosphor copper, and the thickness of the blocking structures is less than or equal to the thickness of the plastic encapsulation colloid; A plurality of chips, wherein the chips are mounted on the product mounting area; A plastic encapsulation layer is disposed on the substrate and covers the chip and the blocking structure.

2. The integrated packaging structure for reducing warping of a transparent plastic package according to claim 1, characterized in that: There are three blocking structures located in the middle of the product mounting area.

3. The integrated packaging structure for reducing warping of a transparent plastic package according to claim 1, characterized in that: The blocking structure is mounted by low-fluidity glue.

4. The integrated packaging structure for reducing warping of a transparent plastic package according to claim 1, characterized in that: The chip and the substrate are connected by wire bonding.

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