Integrated structure of PCB and pin heat dissipation substrate

Abstract

The invention discloses an integrated structure of a PCB (Printed Circuit Board) and a pin heat dissipation substrate. The integrated structure comprises a PCB body and the pin heat dissipation substrate, the back surface of the PCB body is welded with the pin heat dissipation substrate, the PCB body is provided with a heat conduction through hole penetrating through the PCB body, one end of the heat conduction through hole is in contact with the pin heat dissipation substrate, and the other end of the heat conduction through hole extends to the front surface of the PCB body. According to the integrated structure, the back surface of the PCB body is directly welded with the pin heat dissipation substrate, and the heat conduction through holes are arranged, so that heat generated by a heating element on the PCB is quickly conducted to the pin heat dissipation substrate through the heat conduction through holes, and the pin unit is in full contact with a heat dissipation medium, so that the heat is quickly dissipated.

Description

Technical Field

[0001] This invention relates to the field of embedded PCB heat dissipation technology, specifically to an integrated structure of a PCB and a pinfin heat dissipation substrate. Background Technology

[0002] With the rapid development of electronic technology, embedded PCBs are increasingly widely used in fields such as communications, industrial control, and automotive electronics. Their integration level is constantly increasing, and their power density is also rising significantly, leading to a sharp increase in the heat generated during PCB operation. If the heat cannot be dissipated in time, the operating temperature of electronic components on the PCB will rise, thereby affecting the stability, reliability, and lifespan of the components, and even causing failures such as burnout. Therefore, heat dissipation performance has become one of the key factors restricting the development of embedded PCBs.

[0003] Current embedded PCB heat dissipation solutions mostly employ external heat dissipation structures, where the heat sink is fixed to the PCB surface using fasteners or adhesives. This external layout has significant drawbacks: Firstly, the connection path between the heat dissipation structure and the PCB is relatively long, resulting in large stray inductance, which can easily generate electromagnetic interference, affecting the normal operation of precision electronic components on the PCB. Furthermore, the large stray inductance also increases circuit losses and reduces system energy efficiency. Secondly, connection methods such as bolt fastening are prone to poor contact, creating heat dissipation bottlenecks, while traditional adhesive connections suffer from low thermal conductivity, poor process stability, and aging failure over long-term use.

[0004] Therefore, there is an urgent need to design a structure that can improve the heat dissipation performance and operational reliability of embedded PCBs. Summary of the Invention

[0005] To address the aforementioned problems in the existing technology, an integrated structure of PCB and Pinfin heat dissipation substrate is provided.

[0006] The specific technical solution is as follows:

[0007] An integrated structure of a PCB and a pinfin heat dissipation substrate mainly includes: a PCB body and a pinfin heat dissipation substrate;

[0008] The back side of the PCB body is soldered to the pinfin heat dissipation substrate. The PCB body is provided with a heat-conducting through hole that penetrates the PCB body. One end of the heat-conducting through hole contacts the pinfin heat dissipation substrate, and the other end of the heat-conducting through hole extends to the front side of the PCB body.

[0009] The aforementioned integrated structure of a PCB and a pinfin heat dissipation substrate also has the following feature: the pinfin heat dissipation substrate includes a substrate body and pinfin units arrayed on one side of the substrate body, wherein the pinfin units are waist-shaped column structures.

[0010] The above-mentioned integrated structure of PCB and pinfin heat dissipation substrate also has the following characteristics: the major axis length of the pinfin unit is 2-5mm, the minor axis length of the pinfin unit is 1-3mm, the center distance between two adjacent pinfin units is 3-6mm, and the height of the pinfin unit is 1-4mm.

[0011] The aforementioned integrated structure of a PCB and a Pinfin heat dissipation substrate also has the following feature: a thermally conductive and insulating coating is applied to the other side of the substrate body.

[0012] The aforementioned integrated structure of a PCB and a pinfin heat dissipation substrate also has the following feature: the long axis of the pinfin unit is aligned with the flow direction of the heat dissipation medium.

[0013] In the above-mentioned integrated structure of PCB and pinfin heat dissipation substrate, there is also the following feature: the PCB body has an embedded cavity in the area where the pinfin unit is provided on the pinfin heat dissipation substrate, and a chip copper structure is embedded in the embedded cavity.

[0014] The aforementioned integrated structure of a PCB and a Pinfin heat dissipation substrate also has the following feature: the PCB body includes several layers of PCB boards, and the embedded cavity is formed between the two middle layers of the PCB boards.

[0015] The aforementioned integrated structure of a PCB and a Pinfin heat dissipation substrate also features that the inner wall of the heat-conducting via is plated with copper.

[0016] The aforementioned integrated structure of a PCB and a Pinfin heat dissipation substrate also features the following characteristic: a plurality of solder pads are provided on the back side of the PCB body, and the PCB body and the Pinfin heat dissipation substrate are soldered together through the solder pads.

[0017] The aforementioned integrated structure of a PCB and a Pinfin heat dissipation substrate also features that the solder pads are connected to the grounding line of the PCB body.

[0018] The positive effects of the above technical solution are:

[0019] This invention provides an integrated structure of a PCB and a pinfin heat sink substrate, directly soldering the back of the PCB body to the pinfin heat sink substrate. With the addition of thermal vias, heat generated by heat-generating components on the PCB is rapidly conducted to the pinfin heat sink substrate through these vias. The pinfin unit maintains full contact with the heat dissipation medium, quickly dissipating the heat. The waist-shaped design of the pinfin unit minimizes eddy current losses and reduces voltage drop as the heat dissipation medium flows through it. Simultaneously, the large heat exchange area ensures efficient heat dissipation. The grounding solder pad design significantly reduces stray inductance and circuit losses. Attached Figure Description

[0020] Figure 1 A schematic diagram of the overall structure of an integrated structure of a PCB and a pinfin heat dissipation substrate provided by the present invention;

[0021] Figure 2 This is a cross-sectional structural diagram of a PCB body provided by the present invention;

[0022] Figure 3 for Figure 2 A partial structural diagram;

[0023] Figure 4 This is a schematic diagram of the structure of the pinfin heat dissipation substrate provided by the present invention;

[0024] Figure 5 This is a schematic diagram of the back structure of a PCB body provided by the present invention.

[0025] In the attached diagram: 1. PCB body; 101. Embedded cavity; 102. Soldering pad; 2. Pinfin heat dissipation substrate; 201. Substrate body; 202. Pinfin unit; 3. Chip copper structure; L2. Second layer; L3. Third layer. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0027] The serial numbers assigned to components in this document, such as "first," "second," etc., are merely used to distinguish the described objects and have no sequential or technical meaning. The terms "connection" and "linkage" used in this application, unless otherwise specified, include both direct and indirect connections (linkages). In the description of this invention, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention.

[0028] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0029] Please see Figures 1 to 5 The present invention discloses an integrated structure of PCB and pinfin heat dissipation substrate, comprising: PCB (Printed Circuit Board) body 1 and pinfin heat dissipation substrate 2;

[0030] The back side of the PCB body 1 is soldered to the pinfin heat dissipation substrate 2. The PCB body 1 is provided with a heat-conducting through hole (not shown in the figure) that penetrates the PCB body 1. One end of the heat-conducting through hole contacts the pinfin heat dissipation substrate 2, and the other end of the heat-conducting through hole extends to the front side of the PCB body 1.

[0031] The front side of PCB body 1 is where the circuit is located, and the side of PCB body 1 opposite to the front side is the back side.

[0032] Specifically, the pinfin heat dissipation substrate 2 includes a substrate body 201 and pinfin units 202 arrayed on one side of the substrate body 201. Each pinfin unit 202 has an oblong column structure. In other words, the pinfin unit 202 is a column structure with an oblong cross-sectional shape. More specifically, the cross-sectional shape of the pinfin unit 202 includes a rectangle and a first semicircle and a second semicircle disposed at both ends of the rectangle, a major axis, and a minor axis. The major axis is along the direction of the long side of the rectangle, and the minor axis is along the direction of the short side of the rectangle.

[0033] Optionally, the pinfin units 202 are evenly arranged on the substrate body 201. The pinfin array formed by the evenly arranged pinfin units 202 can avoid heat dissipation dead zones, improve heat dissipation uniformity, and further ensure the working stability of the PCB body 1.

[0034] Optionally, in this embodiment, the major axis length of the pinfin unit 202 is 2-5mm, the minor axis length of the pinfin unit is 1-3mm, the center distance between two adjacent pinfin units is 3-6mm, and the height of the pinfin unit is 1-4mm.

[0035] The integrated structure of PCB and pinfin heat dissipation substrate provided by this invention has the following advantages: First, the surface area of ​​the waist-shaped structure is 15-25% larger than that of a circular pinfin of the same volume, which can significantly increase the heat exchange area and enhance the heat dissipation efficiency. Second, the waist-shaped structure can optimize the flow state of the heat dissipation medium, reduce eddy current losses when the fluid flows through, and reduce the pressure drop of the heat dissipation medium. Compared with the traditional circular pinfin heat dissipation substrate, the heat dissipation efficiency can be improved by more than 25%, and the pressure drop of the heat dissipation medium can be reduced by more than 20%.

[0036] Preferably, the long axis of the pinfin unit 202 is aligned with the flow direction of the heat dissipation medium (air or coolant) to optimize the flow state and reduce pressure drop.

[0037] Optionally, the PCB body 1 has an embedded cavity 101 in the area where the pinfin unit 202 is located on the pinfin heat dissipation substrate 2, and the embedded cavity 101 contains a chip copper structure 3. The chip copper structure 3 is a copper sheet structure with a chip.

[0038] Optionally, the PCB body 1 includes a multilayer PCB board. For example, in this embodiment, the PCB body 1 includes a four-layer PCB board, with an embedded cavity 101 provided between the second layer L2 and the third layer L3.

[0039] Optionally, the back of the PCB body 1 is provided with a plurality of solder pads 102, and the PCB body 1 and the Pinfin heat dissipation substrate 2 are soldered together through the solder pads 102. Specifically, the PCB body 1 is soldered to the other side of the substrate body 201.

[0040] Preferably, the solder pad 102 is connected to the grounding line of the PCB body 1.

[0041] Furthermore, a thermally conductive and insulating coating 203 is coated on the other side of the substrate body 201. The thermally conductive and insulating coating 203 can be made of ceramic insulating and thermally conductive material, which can achieve insulation isolation between the pinfin heat sink substrate 2 and the internal circuitry of the PCB body 1, avoiding short-circuit faults, while ensuring thermal conductivity. The connection between the PCB body 1 and the pinfin heat sink substrate 2 adopts a low-temperature reflow soldering process. The specific process is as follows: first, Sn-Bi-based lead-free solder (melting point 145℃) is applied to the soldering pads 102. The edge of the pinfin heat sink substrate 2 is aligned with the soldering pads 102. Then, the whole assembly is placed in a reflow oven and soldered according to a preset temperature profile. The soldering temperature is controlled at 210-220℃, and the holding time is 3-5 minutes. After soldering, the assembly is allowed to cool naturally to room temperature, achieving a firm connection between the two. This soldering process will not cause thermal damage to the PCB body 1 and its internal electronic components, and the thermal conductivity of the solder joint can reach over 80W / (m·K), which is far superior to traditional adhesive connections.

[0042] This invention provides an integrated structure of a PCB and a pinfin heat dissipation substrate. The back side of the PCB body 1 is directly soldered to the pinfin heat dissipation substrate 2. With the addition of thermal vias, heat generated by heat-generating components on the PCB is rapidly conducted to the pinfin heat dissipation substrate through these vias. The pinfin unit maintains full contact with the heat dissipation medium, quickly dissipating the heat. The waist-shaped design of the pinfin unit minimizes eddy current losses and reduces voltage drop as the heat dissipation medium flows through it. Simultaneously, the large heat exchange area ensures efficient heat dissipation. The grounding solder pad design significantly reduces stray inductance and circuit losses.

[0043] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0044] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. An integrated structure of a PCB and a pinfin heat dissipation substrate, characterized in that, include: PCB body and pinfin heat sink; The back side of the PCB body is soldered to the pinfin heat dissipation substrate. The PCB body is provided with a heat-conducting through hole that penetrates the PCB body. One end of the heat-conducting through hole contacts the pinfin heat dissipation substrate, and the other end of the heat-conducting through hole extends to the front side of the PCB body.

2. The integrated structure of PCB and pinfin heat dissipation substrate according to claim 1, characterized in that, The pinfin heat dissipation substrate includes a substrate body and pinfin units arrayed on one side of the substrate body, wherein the pinfin unit is a waist-shaped column structure.

3. The integrated structure of PCB and pinfin heat dissipation substrate according to claim 2, characterized in that, The major axis of the pinfin unit is 2-5mm, the minor axis of the pinfin unit is 1-3mm, the center distance between two adjacent pinfin units is 3-6mm, and the height of the pinfin unit is 1-4mm.

4. The integrated structure of PCB and pinfin heat dissipation substrate according to claim 2, characterized in that, The other side of the substrate body is coated with a thermally conductive and insulating coating.

5. The integrated structure of the PCB and pinfin heat dissipation substrate according to claim 3, characterized in that, The long axis of the pinfin unit is aligned with the flow direction of the heat dissipation medium.

6. The integrated structure of PCB and pinfin heat sink according to any one of claims 2 to 5, characterized in that, The PCB body has an embedded cavity in the area where the pinfin unit is located on the pinfin heat dissipation substrate, and a chip copper structure is embedded in the embedded cavity.

7. The integrated structure of the PCB and the pinfin heat dissipation substrate according to claim 6, characterized in that, The PCB body comprises several layers of PCB boards, and the embedded cavity is formed between the two middle layers of the PCB boards.

8. The integrated structure of PCB and pinfin heat sink according to any one of claims 1 to 5, characterized in that, The inner wall of the heat-conducting through hole is plated with copper.

9. The integrated structure of PCB and pinfin heat sink according to any one of claims 1 to 5, characterized in that, The back of the PCB body is provided with several solder pads, and the PCB body and the Pinfin heat dissipation substrate are soldered together through the solder pads.

10. The integrated structure of PCB and pinfin heat dissipation substrate according to claim 9, characterized in that, The solder pads are connected to the grounding line of the PCB body.

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