A chip packaging structure and a packaging method

Abstract

The application discloses a packaging structure of a chip, which comprises a chip carrier lead frame, a plurality of piers are arranged on the base island of the chip carrier lead frame, a folded edge part is arranged on the periphery of the base island of the chip carrier lead frame, a bonding material layer is filled in the plastic packaging area of the chip carrier lead frame, the bonding material layer completely wraps the piers and bonds and fixes the chip body, a chip positioning part is arranged on the folded edge part, and the chip positioning part is used for physical packaging of the chip body on the chip carrier lead frame.

Description

Technical Field

[0001] This invention relates to the field of chip packaging technology, and more specifically to a chip packaging structure and packaging method. Background Technology

[0002] Modern technology has led to the development of system terminal products that are lightweight, small in size, multifunctional, fast in communication, fast in charging, low in power consumption, and long in standby time. In particular, there are already portable terminal system products, such as communication smartphones, tablet computers, laptops, consumer electronics, and wearable electronics.

[0003] Semiconductor chip packaging technology is particularly crucial in electronic devices. It is responsible for achieving lightweight, thin, short, and small package dimensions. In addition to the above, it also meets the requirements of high power, multiple functions, anti-interference, high density, and high durability and reliability. Therefore, recent packaging technologies have developed technologies such as Through-Silicon Via (TSV), TSV Stacking, Rerouting Lines (RDL), Fan Out (FO) or Fan In (FI), Metal Bump, Metal Bump Stacking, and Under Bump Metallization to connect metal bumpers or subsequent process technologies.

[0004] Whether it is a traditional packaging technology or an advanced packaging technology and structure, there are micro-cracks in the chip body and the bonding material, which lead to defects that frequently occur in semiconductor packaging structures. Summary of the Invention

[0005] The purpose of this invention is to provide a chip packaging structure and packaging method. By setting several piers on the base island of the chip carrier lead frame, and setting the bottom surface of the pier's umbrella disk as a concave structure and the top surface of the pier's umbrella disk as a slot structure, the adhesion between the adhesive material and the chip carrier lead frame and the piers is increased when the chip body is fixed by the adhesive material, thereby improving the connection and tightness between the chip body and the piers.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] A chip packaging structure, comprising:

[0008] A chip carrier lead frame has several bridge piers on its base island and a folded edge on the periphery of the base island. The encapsulated area of ​​the chip carrier lead frame is filled with an adhesive material to form an adhesive material layer. The adhesive material layer completely wraps the bridge piers and bonds and fixes the chip body.

[0009] A chip positioning part is disposed on the folded edge part, and the chip positioning part is used for the physical packaging of the chip body on the chip carrier lead frame.

[0010] As a further aspect of the present invention: a plurality of limiting keyways are provided on the folded edge portion, and each limiting keyway is matched with one of the chip positioning portions.

[0011] As a further aspect of the present invention: the chip positioning part includes a guide rod, the guide rod is disposed through a limiting keyway, a positioning anchor is disposed at the bottom end of the guide rod, and a chip positioning block is disposed at the bottom end of the guide rod.

[0012] As a further aspect of the present invention: the positioning anchor at the bottom of the guide rod is located within the area covered by the adhesive material.

[0013] As a further aspect of the present invention: the chip positioning block includes a primary positioning substrate and a secondary positioning substrate, wherein the secondary positioning substrate is slidably connected to the primary positioning substrate.

[0014] As a further embodiment of the present invention: a T-shaped groove is formed on the top surface of the primary positioning substrate in the horizontal direction, and a T-shaped block is formed on the bottom surface of the secondary positioning substrate in the horizontal direction. The secondary positioning substrate is slidably connected to the T-shaped groove on the top surface of the primary positioning substrate through the bottom T-shaped block.

[0015] As a further aspect of the present invention: the bridge pier is a T-shaped structure and includes an umbrella-shaped plate, the bottom surface of which is concave to embed and fix the adhesive material.

[0016] The umbrella disk has adsorption slots on its surface, and an adsorption cavity is formed between the adsorption slots and the chip body.

[0017] As a further aspect of the present invention: a plurality of heat dissipation grooves are provided on the bottom surface inside the chip carrier lead frame, and the heat dissipation grooves are in the shape of a trumpet.

[0018] As a further aspect of the present invention, the adhesive material is epoxy resin or solder.

[0019] As a further aspect of the present invention: a chip packaging method, which uses the packaging mechanism described above, comprising the following specific steps:

[0020] Step 1: Multiple bridge piers are formed on the base island surface of the chip carrier lead frame using 3D printing technology. Then, the surfaces of the multiple bridge piers are flattened using a flattening mold to ensure that the overall height of the bridge piers is consistent. Finally, an etching process is used to create a concave-convex or hollowed-out effect on the surface of the bridge piers.

[0021] Step 2: Inject adhesive material into the base island of the chip carrier lead frame and within the encapsulation area of ​​multiple piers to form an adhesive material layer, ensuring that the adhesive material layer completely covers the surface of the piers and the base island where the chip carrier lead frame is located.

[0022] Step 3: Place the chip body horizontally on the adhesive material containing the bridge piers, and adjust the chip positioning parts on both sides of the chip carrier lead frame to make the primary positioning substrate of the chip positioning part abut against the side of the chip body, and overlap the secondary positioning substrate of the chip positioning part at the edge of the chip body.

[0023] Step 4: Evaporate the moisture in the adhesive material using a fixed high-temperature oven or a temperature-programmable oven, so that the adhesive material is completely fixed between the base island of the chip carrier lead frame and the chip body.

[0024] Step 5: The metal wires are bonded to the chip body and the internal pins using a wire bonding device. Then, the chip body is encapsulated on the chip carrier lead frame by sequentially performing plastic encapsulation, baking, laser printing, lead cutting, electroplating of the metal surface, and forming of the external pins.

[0025] The beneficial effects of this invention are:

[0026] (1) The present invention sets several bridge piers on the base island of the chip carrier lead frame, and sets the bottom surface of the umbrella plate of the bridge pier as a concave structure and the top surface of the umbrella plate of the bridge pier as a hollow groove structure, thereby increasing the adhesion between the adhesive material and the chip carrier lead frame and the bridge pier when the chip body is fixed by the adhesive material, and improving the connection tightness between the chip body and the bridge pier.

[0027] (2) The present invention provides chip positioning parts on both sides of the chip carrier lead frame. According to the size of the chip body, the position of the guide rod in the limiting keyway is adjusted so that the first positioning substrate abuts against the side of the chip body. Then, by adjusting the position of the secondary positioning substrate on the primary positioning substrate, the bottom surface of the secondary positioning substrate overlaps the edge of the chip body, thereby achieving the limiting and pressing of the chip body. It has strong applicability and enables the chip packaging mechanism to package chips of different sizes and specifications. At the same time, it also further improves the packaging tightness of the chip body and the chip carrier lead frame. Attached Figure Description

[0028] The invention will now be further described with reference to the accompanying drawings.

[0029] Figure 1This is the main view of the present invention;

[0030] Figure 2 yes Figure 1 Enlarged view of point A in the middle;

[0031] Figure 3 This is a schematic diagram of the chip positioning block of the present invention;

[0032] Figure 4 This is a schematic diagram of the structure of the adsorption groove of the present invention;

[0033] Figure 5 This is a schematic diagram of the heat dissipation groove of the present invention;

[0034] Figure 6 This is a schematic diagram of the structure of the bridge pier of the present invention.

[0035] In the picture:

[0036] 1. Chip carrier lead frame; 101. Folded edge; 102. Limiting keyway; 103. Heat dissipation groove; 104. Rectangular cavity;

[0037] 2. Chip positioning section; 201. Primary positioning substrate; 202. Secondary positioning substrate; 203. T-slot; 204. T-block; 205. Guide rod; 206. Positioning anchor;

[0038] 3. Bridge pier; 301. Adsorption slot; 302. Support column; 303. Umbrella plate;

[0039] 4. Adhesive layer;

[0040] 5. Chip body. Detailed Implementation

[0041] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] Example 1

[0043] Please see Figure 1 As shown, the present invention is a chip packaging structure, including a chip carrier lead frame 1. A bridge pier 3 is fixedly disposed above the base island of the chip carrier lead frame 1 and in the area covered by the molding compound. An adhesive material is filled in the molding compound area of ​​the chip carrier lead frame 1 to form an adhesive material layer 4. The adhesive material layer 4 completely covers the bridge pier 3, and the chip body 5 is horizontally fixed on the chip carrier lead frame 1 containing the bridge pier 3 by the adhesive material.

[0044] For details, please refer to Figure 4 The chip carrier lead frame 1 has folded edges 101 around its base island surface. The folded edges 101 around the base island surface of the chip carrier lead frame 1 form a seal against the adhesive material on the base island surface of the chip carrier lead frame 1, preventing the adhesive material from overflowing and causing contamination to other non-adhesive material areas.

[0045] See Figure 2 Chip positioning parts 2 are provided on the folded edges 101 on both sides of the base island surface of the chip carrier lead frame 1. The chip body 5 set on the base island of the chip carrier lead frame 1 is further fixed by the chip positioning parts 2.

[0046] Specifically, a number of limiting keyways 102 are provided on the folded edges 101 on both sides of the chip carrier lead frame 1, and each limiting keyway 102 matches a chip positioning part 2;

[0047] The chip positioning part 2 includes a guide rod 205, which passes through the limiting keyway 102. The bottom end of the guide rod 205 is located in the area covered by the adhesive material, and a positioning anchor 206 is provided at the bottom end of the guide rod 205. The positioning anchor 206 has a disc-shaped structure, and the diameter of the positioning anchor 206 is larger than the width of the limiting keyway 102. The positioning anchor 206 prevents the guide rod 205 from being pulled out through the folded edge part 101.

[0048] See Figures 2-3 The top end of the guide rod 205 is connected to the bottom surface of the primary positioning substrate 201. The top surface of the primary positioning substrate 201 is provided with a T-slot 203 in the horizontal direction. The bottom surface of the secondary positioning substrate 202 is provided with a T-block 204 in the horizontal direction. The T-block 204 is adapted to the T-slot 203. The secondary positioning substrate 202 is slidably connected to the T-slot 203 on the top surface of the primary positioning substrate 201 through the bottom T-block 204, so as to realize the adjustment of the position of the secondary positioning substrate 202 on the primary positioning substrate 201. By adjusting the lateral position of the guide rod 205 in the limiting keyway 102, the position of the primary positioning substrate 201 in the horizontal direction can be adjusted.

[0049] When in use, the chip positioning unit 2 adjusts the position of the guide rod 205 in the limiting keyway 102 according to the size of the chip body 5, so that the first positioning substrate 201 abuts against the side of the chip body 5. Then, by adjusting the position of the secondary positioning substrate 202 on the primary positioning substrate 201, the bottom surface of the secondary positioning substrate 202 overlaps the edge of the chip body 5, thereby limiting and pressing the chip body 5.

[0050] The moisture in the adhesive material is then evaporated by a fixed high-temperature oven or a temperature-programmable oven, so that the adhesive material forms a fixation on the guide rod 205 and the positioning anchor 206, thereby completing the position definition of the entire chip positioning part 2 on the chip carrier lead frame 1.

[0051] For details, please refer to Figure 6 The pier 3 is a T-shaped structure and includes a support column 302 and an umbrella plate 303. The umbrella plate 303 is located at the top of the support column 302, and the bottom of the support column 302 is located on the base island of the chip carrier lead frame 1.

[0052] Among them, the bottom surface of the umbrella disk 303 is a concave structure, which enables the umbrella disk 303 to embed and reinforce the adhesive material.

[0053] Furthermore, an adsorption groove 301 is formed on the surface of the umbrella disk 303, and an adsorption cavity is formed between the adsorption groove 301 and the chip body 5. This increases the adsorption adhesion of the umbrella disk 303 surface to the chip body 5 through the adsorption groove 301, thereby further improving the fixing strength of the chip body 5 on the chip carrier lead frame 1.

[0054] In one specific embodiment, see Figure 5 Several heat dissipation grooves 103 are provided on the bottom surface inside the chip carrier lead frame 1. The heat dissipation grooves 103 have a funnel-shaped structure with a small opening at the top and a large opening at the bottom. This makes it difficult for the adhesive material to flow into the heat dissipation grooves 103 during the curing process of the chip carrier lead frame 1. At the same time, the large diameter at the bottom of the heat dissipation grooves 103 facilitates heat dissipation.

[0055] Furthermore, a rectangular cavity 104 is formed on the outer bottom surface of the chip carrier lead frame 1. The rectangular cavity 104 forms a heat dissipation function for the chip carrier lead frame 1, thereby improving the performance of the chip body 5 on the chip carrier lead frame 1.

[0056] Among them, heat conduction grooves can be opened around the bottom surface of the chip carrier lead frame 1 to facilitate the heat of the chip carrier lead frame 1 to be discharged through the bottom surface.

[0057] It should be noted that the bonding material includes epoxy resin or soft solder. Epoxy resin includes conductive epoxy resin and non-conductive epoxy resin. Soft solder includes solder paste, lead paste, or any substance that is both conductive and has bonding ability.

[0058] Example 2

[0059] A chip packaging method, used to package the aforementioned chip, includes the following steps:

[0060] S1: Multiple bridge piers 3 are formed on the base island surface of the chip carrier lead frame 1 using 3D printing technology. Then, the surface of the multiple bridge piers 3 is flattened using a flattening mold to make the overall height of the bridge piers 3 consistent. The surface of the bridge piers 3 is formed by etching process to create a concave-convex or hollowed-out effect.

[0061] S2: Inject adhesive material into the base island of the chip carrier lead frame 1 and within the encapsulation area of ​​multiple bridge piers 3 to form an adhesive material layer 4, and make the adhesive material layer 4 completely cover the bridge piers 3 and the base island surface where the chip carrier lead frame 1 is located.

[0062] S3: Place the chip body 5 horizontally on the adhesive material containing the bridge pier 3, and adjust the chip positioning parts 2 on both sides of the chip carrier lead frame 1 so that the primary positioning substrate 201 of the chip positioning part 2 abuts against the side of the chip body 5, and the secondary positioning substrate 202 of the chip positioning part 2 overlaps at the edge of the chip body 5.

[0063] S4: The moisture in the adhesive material is evaporated by a fixed high-temperature oven or a temperature-programmable oven, so that the adhesive material is completely fixed between the base island of the chip carrier lead frame 1 and the chip body 5.

[0064] S5: The bonding of the metal wires on the chip body 5 and the inner pins is completed by the metal wire bonding equipment, and the chip body 5 is packaged on the chip carrier lead frame 1 by plastic encapsulation, baking, laser printing, lead cutting, electroplating of metal surface and forming of outer pins in sequence.

[0065] By adapting the pier 3, the adhesive material adheres more firmly to the chip carrier lead frame 1. By setting the folded edge 101 on the chip carrier lead frame 1, the area of ​​the adhesive material layer 4 is fully filled with adhesive material, avoiding pollution caused by diffusion in the non-adhesive material area, and strengthening the adhesion of the pier 3 to the adhesive material.

[0066] When the voids that need to be close to zero are encased within the binding material layer, the gas in the binding material can be extracted out of the binding material by creating a negative pressure under vacuum during the high-temperature evaporation of water.

[0067] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the claims of this invention should still fall within the patent coverage of this invention.

Claims

1. A chip packaging structure, characterized in that, include: A chip carrier lead frame (1) is provided with several bridge piers (3) on the base island of the chip carrier lead frame (1). A folded edge (101) is provided on the periphery of the base island of the chip carrier lead frame (1). An adhesive material is filled in the plastic encapsulation area of ​​the chip carrier lead frame (1) to form an adhesive material layer (4). The adhesive material layer (4) completely wraps the bridge piers (3) and bonds and fixes the chip body (5). Chip positioning part (2), the chip positioning part (2) is disposed on the folded edge part (101), the chip positioning part (2) is used for the physical packaging of the chip body (5) on the chip carrier lead frame (1); The folded edge (101) is provided with a plurality of limiting keyways (102), and each limiting keyway (102) matches one of the chip positioning parts (2); The chip positioning part (2) includes a guide rod (205), which passes through the limiting keyway (102). A positioning anchor (206) is provided at the bottom end of the guide rod (205), and a chip positioning block is provided at the bottom end of the guide rod (205). The positioning anchor (206) at the bottom of the guide rod (205) is located within the area covered by the adhesive material; The chip positioning block includes a primary positioning substrate (201) and a secondary positioning substrate (202), wherein the secondary positioning substrate (202) is slidably connected to the primary positioning substrate (201). The top surface of the primary positioning substrate (201) is provided with a T-shaped groove (203) in the horizontal direction, and the bottom surface of the secondary positioning substrate (202) is provided with a T-shaped block (204) in the horizontal direction. The secondary positioning substrate (202) is slidably connected to the T-shaped groove (203) on the top surface of the primary positioning substrate (201) through the bottom T-shaped block (204). The pier (3) is a T-shaped structure and includes an umbrella plate (303). The bottom surface of the umbrella plate (303) is concave, which embeds and fixes the adhesive material. The umbrella disk (303) has an adsorption groove (301) on its surface, and an adsorption cavity is formed between the adsorption groove (301) and the chip body (5).

2. The chip packaging structure according to claim 1, characterized in that, The chip carrier lead frame (1) has several heat dissipation grooves (103) on its inner bottom surface, and the heat dissipation grooves (103) have a horn-shaped structure.

3. The chip packaging structure according to claim 1, characterized in that, The adhesive is epoxy resin or solder.

4. A chip packaging method, characterized in that, The encapsulation method uses the encapsulation structure described in any one of claims 1-3, and the specific steps are as follows: Step 1: Multiple bridge piers (3) are formed on the base island surface of the chip carrier lead frame (1) using 3D printing technology. Then, the surfaces of the multiple bridge piers (3) are flattened using a flattening mold to ensure that the overall height of the bridge piers (3) is consistent. Finally, the surface of the bridge piers (3) is etched to create a concave-convex or hollowed-out effect. Step 2: Inject adhesive material into the base island of the chip carrier lead frame (1) and within the encapsulation area of ​​multiple piers (3) to form an adhesive material layer (4), and make the adhesive material layer (4) completely cover the surface of the piers (3) and the base island where the chip carrier lead frame (1) is located. Step 3: Place the chip body (5) horizontally on the adhesive material containing the bridge pier (3), and adjust the chip positioning parts (2) on both sides of the chip carrier lead frame (1) so that the primary positioning substrate (201) of the chip positioning part (2) abuts against the side of the chip body (5), and the secondary positioning substrate (202) of the chip positioning part (2) overlaps at the edge of the chip body (5). Step 4: Evaporate the moisture in the adhesive material by using a fixed high-temperature oven or a temperature-programmable oven, so that the adhesive material is completely fixed between the base island of the chip carrier lead frame (1) and the chip body (5). Step 5: The metal wires are bonded to the chip body (5) and the inner pins using a wire bonding device. Then, the chip body (5) is encapsulated on the chip carrier lead frame (1) by plastic encapsulation, baking, laser printing, lead cutting, electroplating of the metal surface, and forming of the outer pins.

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