Transfer injection molding IC packaging structure and preparation mold thereof

Abstract

The invention relates to the field of transfer injection molding IC packaging structures, and discloses a transfer injection molding IC packaging structure which comprises a substrate, a plurality of chips are arranged at the top end of the substrate in an array mode, a plastic packaging area is arranged between every two adjacent chips, a confluence area is formed in the middle of the substrate, a second runner is arranged above the confluence area in parallel, and the confluence area is communicated with the plastic packaging area. A plurality of first flow channels are fixedly arranged at the bottom end of the second flow channel, the lower portion of each first flow channel directly faces the confluence area, a plurality of third flow channels are fixedly arranged at the top end of the second flow channel, one side of each third flow channel communicates with a fourth flow channel, and each fourth flow channel communicates with a fifth flow channel on one side; according to the structure, the injection molding path is shortened, the flowing resistance of a plastic package material is reduced, meanwhile, gas exhaust is facilitated, and the phenomena of filling encapsulation and cavities caused by injection molding on one side in the existing transfer injection molding IC packaging process are effectively improved.

Description

Technical Field

[0001] The present invention relates to the field of transfer molding IC packaging structures, and specifically to a transfer molding IC packaging structure and its preparation mold. Background Art

[0002] The plastic encapsulant used in IC packaging is a thermosetting material. Its characteristic is that the greater the injection path value during the injection molding process, the greater the plastic encapsulation flow resistance at that place. In the traditional runner structure, the confluence area is located at the gate. The plastic encapsulant directly flows from the gate into the confluence area and then flows from the confluence area to the far end to complete the mold flow filling of the chips on the entire substrate. Using this transfer molding die structure for injection molding has the following disadvantages: The injection path is long. During the flow of the thermosetting plastic encapsulant, the flow resistance is large, and the gas inside the mold cavity is not easily discharged. The increase in flow resistance is not conducive to product filling, making it easy for the product to have defects such as poor encapsulation, and the product becomes a defective product. Summary of the Invention

[0003] The purpose of the present invention is to provide a transfer molding IC packaging structure and its preparation mold to solve the problems raised in the above background art.

[0004] To achieve the above purpose, the present invention provides the following technical solution: A transfer molding IC packaging structure and its preparation mold, including a substrate. A plurality of chips are arranged in an array on the top of the substrate, and the plastic encapsulation area is between adjacent chips. A confluence area is opened at the middle position of the substrate, and a second runner is arranged in parallel above the confluence area. The confluence area is communicated with the plastic encapsulation area, and a plurality of first runners are fixedly arranged at the bottom end of the second runner. Each first runner is directly opposite the confluence area below, and a plurality of third runners are fixedly arranged at the top end of the second runner. Each third runner is respectively communicated with a fourth runner on one side, and each fourth runner is communicated with a fifth runner on one side. A plurality of transfer injection slots are fixedly arranged at the bottom end of each fifth runner.

[0005] Preferably: Both the confluence area and the second runner are rectangular ring structures.

[0006] Preferably: Each fourth runner is an L-shaped structure, and two adjacent fourth runners are arranged in parallel along the vertical direction.

[0007] Preferably: A plurality of the third runners are evenly distributed on the surface of the second runner.

[0008] Preferably: Each first runner is vertically distributed with respect to the second runner, and a plurality of first runners are evenly distributed at the bottom end of the second runner.

[0009] Preferably: A plurality of the transfer injection slots are equidistantly distributed at the bottom end of the fifth runner, and each transfer injection slot is connected to an external device for providing injection plastic.

[0010] A preparation mold for a transfer molding IC packaging structure according to any one of the above, wherein the upper mold and the lower mold of the mold include the above structure, and both the upper mold and the lower mold of the mold are made of metal.

[0011] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0012] The structure of the present invention shortens the injection path, reduces the flow resistance of the encapsulant, and at the same time is conducive to gas discharge, effectively improving the filling and encapsulation and void phenomena caused by one-side injection in the existing transfer molding IC packaging process; the injection path is shortened, so that the substrate can be designed as a larger-size and larger-scale substrate containing more chips, saving injection costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a schematic structural diagram of the present invention;

[0014] Figure 2 is a side view schematic diagram of the second runner of the present invention;

[0015] Figure 3 is a side view schematic diagram of the fifth runner of the present invention.

[0016] In the figure: 1. Substrate; 2. Chip; 3. Encapsulation area; 4. Confluence area; 5. Second runner; 6. Third runner; 7. First runner; 8. Fourth runner; 9. Fifth runner; 10. Transfer groove. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0018] Embodiment 1

[0019] Please refer to Figures 1 - 3, A transfer molding IC package structure and its preparation mold in the figure include a substrate 1. A number of chips 2 are arranged in an array on the top of the substrate 1, and the plastic encapsulation area 3 is between adjacent chips 2. A bus bar area 4 is opened in the middle position of the substrate 1, and a second runner 5 is arranged in parallel above the bus bar area 4. The bus bar area 4 is communicated with the plastic encapsulation area 3, and a number of first runners 7 are fixedly arranged at the bottom of the second runner 5. Each first runner 7 faces the bus bar area 4 below, and a number of third runners 6 are fixedly arranged at the top of the second runner 5. Each third runner 6 is respectively communicated with a fourth runner 8 on one side, and each fourth runner 8 is respectively communicated with a fifth runner 9 on one side. A number of transfer injection slots 10 are fixedly arranged at the bottom of each fifth runner 9.

[0020] In this embodiment, both the bus bar area 4 and the second runner 5 are rectangular ring structures. Each fourth runner 8 is an L-shaped structure, and two adjacent fourth runners 8 are arranged in parallel in the vertical direction. A number of third runners 6 are evenly distributed on the surface of the second runner 5. Each first runner 7 is vertically distributed with the second runner 5, and a number of first runners 7 are evenly distributed at the bottom of the second runner 5. A number of transfer injection slots 10 are equidistantly distributed at the bottom of the fifth runner 9, and each transfer injection slot 10 is connected to a device providing injection molding material externally.

[0021] Further, the chips 2 are fixedly arranged on the substrate 1 in an array according to the layout requirements. The substrate 1 with the chips 2 mounted is placed in the upper and lower molds, and the molds are closed. A high pressure is applied to clamp the molds closed. When pressurizing, the injection head moves upward. Using the conventional plastic encapsulation method, the preheated encapsulation plastic material is pressed into the cavity filled via a plunger. The device providing injection molding material externally injects the high-temperature melted plastic encapsulation material into the entire runner through the transfer injection slots 10 along the fifth runner 9, flows to the third runner 6 through the fourth runner 8, enters the second runner 5 through the third runner 6, and flows to the bus bar area 4 through a number of first runners 7 at the bottom of the second runner 5. The plastic encapsulation material in the bus bar area 4 flows towards the four sides of the substrate 1 simultaneously to complete the filling of the plastic encapsulation area 3.

[0022] According to the preparation mold of a transfer molding IC package structure according to any one of the above, the upper mold and the lower mold of the mold include the above structure, and both the upper mold and the lower mold of the mold are made of metal.

[0023] It should be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprising", "including" or any other variant thereof are intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements not only includes those elements but also includes other elements not expressly listed, or elements inherent to such process, method, article or device.

[0024] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A transfer molding IC package structure, comprising a substrate (1), characterized in that: A plurality of chips (2) are arranged in an array at the top of the substrate (1), and a plastic encapsulation area (3) is provided between adjacent chips (2). A bus bar area (4) is formed in the middle of the substrate (1), and a second flow channel (5) is arranged in parallel above the bus bar area (4). The bus bar area (4) is communicated with the plastic encapsulation area (3), and a plurality of first flow channels (7) are fixedly arranged at the bottom end of the second flow channel (5). Each first flow channel (7) faces the bus bar area (4) below, and a plurality of third flow channels (6) are fixedly arranged at the top end of the second flow channel (5). Each third flow channel (6) is respectively communicated with a fourth flow channel (8) on one side, and each fourth flow channel (8) is communicated with a fifth flow channel (9) on one side. A plurality of transfer injection slots (10) are fixedly arranged at the bottom end of each fifth flow channel (9).

2. The transfer molding IC package structure according to claim 1, wherein: Both the bus bar area (4) and the second flow channel (5) are rectangular ring structures.

3. The transfer molding IC packaging structure according to claim 2, wherein: Each fourth flow channel (8) is an L-shaped structure, and two adjacent fourth flow channels (8) are arranged in parallel in the vertical direction.

4. The transfer molding IC package structure according to claim 3, wherein: A plurality of the third flow channels (6) are evenly distributed on the surface of the second flow channel (5).

5. The injection molded IC package structure according to claim 4, wherein: Each first flow channel (7) is vertically distributed with respect to the second flow channel (5), and a plurality of first flow channels (7) are evenly distributed at the bottom end of the second flow channel (5).

6. The injection-molded IC package structure according to claim 5, wherein: A plurality of the transfer injection slots (10) are equidistantly distributed at the bottom end of the fifth flow channel (9), and each transfer injection slot (10) is connected to a device for providing injection molding material externally.

7. The preparation mold for a transfer molding IC packaging structure according to any one of claims 1-6, characterized in that: The upper mold and the lower mold of the mold include the above structure, and both the upper mold and the lower mold of the mold are made of metal.

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