Chip bottom heat dissipation structure
The chip bottom heat dissipation structure using PCB metal blocks and thermal pads addresses heat dissipation challenges while preserving RF performance and structural integrity, enhancing stability and reliability.
Patent Information
- Application Number
- CN202421902594.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-07
- Publication Date
- 2025-07-15
- Estimated Expiration
- 2034-08-07
AI Technical Summary
In the prior art, the front heat dissipation of the chip will affect the RF performance, and the bottom PCB drilling heat dissipation alone cannot meet the heat dissipation requirements. At the same time, placing a radiator on the front will lead to the problem of mismatch of RF parameters.
A heat sink, a PCB board and a thermal pad are arranged at the bottom of the chip, and connected to the metal block through a PCB opening, heat conduction is carried out using the thermal pad and the metal block, and copper contact is designed on the inner wall of the opening to form a ground to ensure electromagnetic compatibility.
It improves the heat dissipation efficiency and stability of the chip, maintains the chip to operate within the appropriate temperature range, while keeping the RF performance unaffected, and enhancing electromagnetic compatibility.
Smart Images
Figure CN223108882U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a heat dissipation structure, in particular to a heat dissipation structure at the bottom of a chip. Background Art
[0002] In electronic circuit design, many chips have heat dissipation requirements. However, when using front-side heat dissipation, it will affect the performance of the chip, such as affecting the wireless radio frequency reception sensitivity of the chip; or due to structural limitations on the front side, it is impossible to place a radiator. But simply using the PCB punching at the bottom of the chip for the radiator cannot meet the heat dissipation requirements.
[0003] Since the wafer body inside the chip leads out signals to the pins of the chip by bonding wires (or copper wires), if a heat conduction pad (containing a metal component) or a radiator is added to the front of the chip, it will change the parasitic capacitance around the bonding wire (or copper wire), resulting in a situation where the radio frequency parameters do not match, thereby affecting the radio frequency performance, especially the index of reception sensitivity; and this kind of mismatch is usually difficult to compensate in the external circuit, and the differences between different boards are also relatively large. Summary of the Utility Model
[0004] The technical problem to be solved by the utility model is to provide a heat dissipation structure at the bottom of a chip to solve the problems in the background art.
[0005] The heat dissipation structure at the bottom of the chip of the utility model is realized through the following technical solutions, including a heat sink, a PCB board and a chip; the heat sink is arranged above the PCB board, and the chip is installed at the bottom of the PCB board;
[0006] A PCB opening is provided at the position corresponding to the chip on the PCB board, and the heat dissipation structure on the heat sink passes through the opening and is connected to the chip.
[0007] As a preferred technical solution, the heat dissipation structure includes a heat conduction pad and a metal block;
[0008] The metal block is embedded in the PCB opening in the middle of the PCB through a pressing process, the heat conduction pad is arranged above the metal block and is in contact with the heat sink.
[0009] As a preferred technical solution, a heat dissipation pad is provided at the bottom of the chip, and the heat dissipation of the chip body package is carried out through the heat dissipation pad.
[0010] As a preferred technical solution, the heat sink is a common aluminum profile radiator or other types of radiators.
[0011] As a preferred technical solution, the heat conduction pad (5) is a silicone heat conduction pad or heat conduction silicone grease.
[0012] As a preferred technical solution, the shape of the PCB opening is selected according to the shape of the heat dissipation pad at the bottom of the chip.
[0013] As a preferred technical solution, copper is designed on the inner wall of the PCB opening (4), and when the metal block (6) is pressed, the metal block (6) contacts the copper on the inner wall.
[0014] As a preferred technical solution, half-openings are designed at the position of the inner wall of the PCB opening to ensure that the copper on the inner wall is not easily detached.
[0015] As a preferred technical solution, the metal block is a copper block or other metals that meet the requirements of SMT soldering. After the metal block is pressed, the side of the metal block close to the chip is flush with the PCB board to meet the flatness requirements of SMT soldering.
[0016] As a preferred technical solution, the metal block is installed on the PCB board before SMT soldering. During SMT soldering, the stencil needs to be opened at the position of the metal block to apply solder paste, and then a good solder joint is made with the chip to reduce the thermal resistance.
[0017] The beneficial effects of the present utility model are as follows:
[0018] 1. By arranging a metal block and a heat conduction pad at the bottom of the PCB board, the present utility model enables heat to be more effectively transferred from the chip to the heat sink, thereby accelerating the diffusion of heat, improving the overall heat dissipation efficiency, and enabling the heat generated by the chip to be quickly conducted to the heat sink through the arrangement of the heat dissipation structure, which helps to maintain the chip operating within a suitable temperature range and improves the overall stability and reliability.
[0019] 2. The shape of the PCB opening of the present utility model can be selected according to the shape of the heat dissipation pad at the bottom of the chip, increasing the design flexibility; copper is designed on the inner wall of the PCB opening, and the metal block (6) contacts the copper on the inner wall to form a ground connection, which helps to improve the electromagnetic compatibility of the electronic device.
[0020] 3. By designing half-openings on the inner wall of the PCB opening, similar to postage stamp holes, the present utility model effectively prevents the copper on the inner wall from falling off during the pressing process; among them, the metal block is flush with the PCB board after being pressed, meeting the flatness requirements of SMT soldering and ensuring the welding quality. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for describing the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.
[0022] Figure 1 is a three-dimensional structural schematic diagram of the present utility model;
[0023] Figure 2 is an exploded structural schematic diagram of the present utility model;
[0024] Figure 3 is a front structural schematic diagram of the present utility model;
[0025] Figure 4 is a sectional structural schematic diagram of A_A of the present utility model;
[0026] Figure 5 is a heat dissipation structural schematic diagram of the present utility model;
[0027] Figure 6 is a PCB opening structural schematic diagram of the present utility model.
[0028] Description of reference numerals:
[0029] 1, heat sink; 2, PCB board; 3, chip; 4, PCB opening; 5, thermal pad; 6, metal block; 7, semi-opening. Detailed implementation manners
[0030] All features disclosed in this specification, or all steps in the disclosed methods or processes, except for mutually exclusive features and / or steps, can be combined in any manner.
[0031] As Figures 1-4 shown, a chip bottom heat dissipation structure of the present utility model includes a heat sink 1, a PCB board 2 and a chip 3; the heat sink 1 is disposed above the PCB board 2, and the chip 3 is mounted at the bottom of the PCB board 2;
[0032] A PCB opening 4 is provided at the position corresponding to the chip 3 on the PCB board 2, and the heat dissipation structure on the heat sink 1 passes through the opening and is connected to the chip 3.
[0033] As Figure 5 shown, the heat dissipation structure includes a thermal pad 5 and a metal block 6;
[0034] The metal block 6 is embedded in the PCB opening 4 in the middle of the PCB by a pressing process, and the thermal pad 5 is disposed above the metal block 6 and is in contact with the heat sink 1.
[0035] Wherein, a heat dissipation pad is provided at the bottom of the chip 3, and the heat dissipation of the chip 3 body package is carried out through the heat dissipation pad.
[0036] In order to meet the heat dissipation requirements, in this embodiment, the heat sink (1) is an aluminum profile radiator.
[0037] In addition, the heat-conducting pad (5) can be a silica gel heat-conducting pad or heat-conducting silicone grease.
[0038] Among them, the shape of the PCB opening 4 is selected according to the shape of the heat-dissipating pad at the bottom of the chip 3, such as square, circular or other shapes.
[0039] To meet the requirements of electrical connection (grounding requirements), copper is designed on the inner wall of the PCB opening (4). When the metal block (6) is pressed, the metal block (6) contacts the copper on the inner wall to form a ground connection.
[0040] Such as Figure 6 As shown, the present utility model designs a semi-opening 7 at the position of the inner wall of the PCB opening 4, which is similar to a postage stamp hole. During pressing, it can ensure that the copper on the inner wall is not easily peeled off.
[0041] In addition, the metal block 6 is a copper block or other metals that meet the requirements of SMT soldering. After the metal block 6 is pressed, the side of the metal block 6 close to the chip 3 is flush with the PCB board 2 to meet the flatness requirements of SMT soldering.
[0042] In addition, the metal block 6 is installed on the PCB board 2 before SMT soldering. During SMT soldering, the stencil needs to be opened at the position of the metal block 6 and solder paste is applied, and then it is soldered well with the chip 3 to reduce the thermal resistance.
[0043] Due to the existence of the metal block in the present utility model, if the metal block is relatively large, the preheating time of SMT soldering may become longer. Therefore, it is necessary to appropriately adjust the furnace temperature curve to avoid the phenomenon of false soldering.
[0044] After assembly, the heat of the chip is transferred from the heat-dissipating pad at the bottom of the chip, through the metal block, the heat-conducting pad to the radiator, and finally the heat is dissipated into the air. Because the thermal resistance of the metal block can be made very low, the heat dissipation ability is greatly enhanced. Even without using the front radiator, the chip can meet the heat dissipation requirements.
[0045] The above is only the specific implementation manner of the present utility model, but the protection scope of the present utility model is not limited thereto. Any change or replacement that can be thought of without creative work should be covered within the protection scope of the present utility model. Therefore, the protection scope of the present utility model should be subject to the protection scope defined by the claims.
Claims
1. A heat dissipation structure at the bottom of a chip, characterized in that: It includes a heat sink (1), a PCB board (2), and a chip (3); the heat sink (1) is disposed above the PCB board (2), and the chip (3) is mounted on the bottom of the PCB board (2); a PCB opening (4) is provided at the position corresponding to the chip (3) on the PCB board (2), and the heat dissipation structure on the heat sink (1) passes through the opening and is connected to the chip (3).
2. The bottom heat dissipation structure of the chip (3) according to claim 1, wherein: The heat dissipation structure includes a heat conduction pad (5) and a metal block (6); the metal block (6) is embedded in the PCB opening (4) in the middle of the PCB by a pressing process, the heat conduction pad (5) is disposed above the metal block (6) and is in contact with the heat sink (1).
3. The bottom heat dissipation structure of the chip (3) according to claim 1, characterized in that: A heat dissipation pad is provided at the bottom of the chip (3), and heat dissipation of the chip (3) body package is performed via the heat dissipation pad.
4. The bottom heat dissipation structure of the chip (3) according to claim 1, characterized in that: The heat sink (1) is an aluminum profile heat sink.
5. The bottom heat dissipation structure of the chip (3) according to claim 2, characterized in that: The heat conduction pad (5) is a silicone heat conduction pad or heat conduction silicone grease.
6. The bottom heat dissipation structure of the chip (3) according to claim 1, characterized in that: The shape of the PCB opening (4) is selected according to the shape of the heat dissipation pad at the bottom of the chip (3).
7. The bottom heat dissipation structure of the chip (3) according to claim 2, characterized in that: The inner wall of the PCB opening (4) is designed with copper, and when the metal block (6) is pressed, the metal block (6) contacts the copper on the inner wall.
8. The bottom heat dissipation structure of the chip (3) according to claim 1, characterized in that: A semi-opening (7) is designed at the position of the inner wall of the PCB opening (4) to ensure that the copper on the inner wall is not easily detached.
9. The bottom heat dissipation structure of the chip (3) according to claim 2, characterized in that: The metal block (6) is a copper block or other metal that meets the requirements of SMT welding. After the metal block (6) is pressed, the side of the metal block (6) close to the chip (3) is flush with the PCB board (2) to meet the flatness requirements of SMT welding.