PCB structure with heat dissipation bonding pad

Abstract

The utility model discloses a PCB structure with a heat radiation pad, comprising a PCB substrate, a metal foil sheet arranged on a welding surface of the PCB substrate, and a solder mask layer covering the PCB substrate and the metal foil sheet, the solder mask layer is provided with a first solder mask window exposing at least part of the metal foil sheet and part of the PCB substrate, and the first solder mask window is provided with a second solder mask window exposing at least part of the metal foil sheet and part of the PCB substrate. The part, exposed out of the metal foil, of the first solder mask window forms a heat dissipation bonding pad suitable for welding a device, the part, exposed out of the PCB substrate, of the first solder mask window forms a gas guide groove, and gas at the heat dissipation bonding pad is suitable for being exhausted outwards through the gas guide groove. According to the design, the part, exposed out of the metal foil, of the first solder mask window forms a heat dissipation bonding pad suitable for welding a device, and the part, exposed out of the PCB substrate, of the first solder mask window forms an air guide groove; in the reflow soldering process of the device, volatile gas generated by welding flux on the heat dissipation bonding pad can be exhausted outwards through the gas guide groove, so that the phenomena of insufficient soldering and welding spot cavity of the heat dissipation bonding pad are reduced, and the welding yield and the welding spot reliability are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductor packaging, in particular to a PCB structure with a heat dissipation pad. Background Art

[0002] In board design, in order to reduce the space occupied by the device on the PCB board, pinless package devices are sometimes used. The difference between pinless package devices and common pinned package devices is that the pins used for electrical connection to the PCB board are located on the bottom surface of the device body, rather than extending outward from the device body. Since the conductive path between the internal pins of the pinless package device and the pads on the PCB board is short, the self-inductance coefficient and the wiring resistance in the package body are very low, it can provide excellent electrical performance and occupy a small area, so the packaging application of pinless package devices on PCB boards is becoming more and more extensive.

[0003] However, due to the small size and poor heat dissipation performance of the pinless packaged devices on the PCB board, it will greatly affect the normal use of the product, such as freezing and restarting. Therefore, it is generally necessary to set a heat dissipation pad for heat dissipation at the center position below the pinless packaged device to improve the heat dissipation performance of the device.

[0004] In the prior art, PCB boards with heat dissipation pads such as Figure 1 As shown, it includes a PCB board 01, a pin pad 02 and a heat dissipation pad 03, and a metallized via 04 is provided on the heat dissipation pad 03; wherein the PCB board 01 is the substrate layer of the PCB structure. These metallized vias 04 are used to connect to the GND network or the power network on the one hand, and to connect to the copper foil of the inner layer or the bottom layer on the other hand to improve the heat dissipation problem of the device. Although the method of punching metallized vias solves the heat dissipation problem, during the reflow soldering process of the device, on the one hand, the solder on the heat dissipation pad 03 easily flows into the metallized via 04, resulting in a reduction in solder, and on the other hand, the gas generated by the volatilization of the flux in the solder is difficult to be discharged to the outside, which will cause the solder joints between the device and the heat dissipation pad 03 to have problems of cold solder joints or solder joint voids, affecting the reliability of the product. Utility Model Content

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the defects of the soldering structure of the pinless packaging device in the prior art, that is, the existence of cold solder joints or solder joint voids, which in turn affects the reliability of the product, thereby providing a PCB structure with a heat dissipation pad.

[0006] In order to solve the above technical problems, the technical solution of the utility model is as follows:

[0007] A PCB structure with a heat dissipation pad comprises a PCB substrate, a metal foil arranged on a welding surface of the PCB substrate, and a solder resist layer covering the PCB substrate and the metal foil, wherein the solder resist layer is provided with a first solder resist window exposing at least a portion of the metal foil and a portion of the PCB substrate, the portion of the first solder resist window exposing the metal foil forms a heat dissipation pad suitable for welding devices, the portion of the first solder resist window exposing the PCB substrate forms an air guide groove, and the gas at the heat dissipation pad is suitable for being discharged outward through the air guide groove.

[0008] Furthermore, the area of ​​the welding surface of the PCB substrate covered by the device is the first area, and the area of ​​the welding surface of the PCB substrate not covered by the device is the second area, and the gas guide groove allows gas to be discharged from the first area to the second area.

[0009] Furthermore, at least a portion of the air guide groove is exposed outside the second area.

[0010] Furthermore, at least two metal foils are provided, and at least two of the metal foils are arranged at intervals; the air guide groove includes a middle part of the air guide groove and an end part of the air guide groove, the middle part of the air guide groove is arranged corresponding to a part of the PCB substrate exposed between at least two of the metal foils, and the end part of the air guide groove is arranged corresponding to a part of the PCB substrate outside the area enclosed by at least two of the metal foils.

[0011] Furthermore, the direction from the middle part of the air guide groove to the end part of the air guide groove is the length direction of the air guide groove, the direction perpendicular to the length direction of the air guide groove is the width direction of the air guide groove, and in the width direction of the air guide groove, the size of the end part of the air guide groove is larger than the size of the middle part of the air guide groove.

[0012] Furthermore, there are two metal foils, namely a first metal foil and a second metal foil, and the first metal foil and the second metal foil are symmetrically arranged along a center line at interval positions thereof.

[0013] Furthermore, the first metal foil and the second metal foil are both in a triangular shape, and the longest side of the first metal foil and the longest side of the second metal foil are arranged to face each other.

[0014] Furthermore, a plurality of pin foils are provided on the welding surface of the PCB substrate and are located at the periphery of the metal foil, a second solder resist window is opened on the solder resist layer to partially expose the pin foil, and the portion of the pin foil leaking out of the second solder resist window forms a pin pad suitable for welding device pins; and the plurality of pin pads are located in the second area.

[0015] Furthermore, the pin pad is in the shape of a right-angled pentagon, and the hypotenuse of the pin pad faces the outer side of the heat dissipation pad.

[0016] Furthermore, the second area on the PCB substrate is provided with at least one external heat dissipation structure connected to the heat dissipation pad via a heat transfer structure, and the external heat dissipation structure is used to dissipate heat from the heat dissipation pad.

[0017] Furthermore, the external heat dissipation structure includes an external metal foil located on the surface of the PCB substrate, and the external metal foil is provided with a metallized through hole. The heat transfer structure includes a first metal trace connected between the metal foil and the pin foil, and a second metal trace connected between the pin foil connected to the first metal trace and the external metal foil.

[0018] Furthermore, the external metal foil is provided with a metallized through hole, and the metallized through hole is connected to the ground foil of the PCB structure.

[0019] Furthermore, a third solder resist window partially exposing the external metal foil is provided on the solder resist layer.

[0020] The technical solution of the utility model has the following advantages:

[0021] 1. The utility model provides a PCB structure with a heat dissipation pad, wherein the portion of the metal foil exposed by the first solder resist opening forms a heat dissipation pad suitable for welding components, and the portion of the PCB substrate exposed by the first solder resist opening forms an air guide groove; during the reflow soldering process of the component, the volatile gas generated by the solder on the heat dissipation pad can be discharged to the outside through the air guide groove, thereby reducing the cold solder joints and solder joint voids of the heat dissipation pad, and improving the soldering yield and solder joint reliability.

[0022] 2. The utility model provides a PCB structure with a heat dissipation pad. During the reflow soldering process of the device, the volatile gas generated by the solder can be discharged from the first area covered by the device to the second area not covered by the device through the gas guide groove, which is beneficial to reducing the cold solder joints and solder joint voids during the reflow soldering process.

[0023] 3. In the PCB structure with the heat dissipation pad provided by the utility model, the air guide groove is partially exposed in the second area of ​​the PCB welding surface, which is more conducive to the outward discharge of the gas in the first area.

[0024] 4. The PCB structure with the heat dissipation pad provided by the utility model has at least two metal foils arranged at intervals, and the gap between the metal foils can form an air guide channel of the air guide groove on the PCB substrate, which is convenient for the volatile gas to be discharged outwardly.

[0025] 5. In the PCB structure with a heat dissipation pad provided by the utility model, the size of the end portion of the air guide groove is larger than the size of the middle portion of the air guide groove in the width direction of the air guide groove; such an arrangement facilitates the discharge of gas through the air guide groove.

[0026] 6. In the PCB structure with a heat dissipation pad provided by the utility model, the first metal foil and the second metal foil are symmetrically arranged along the center line of the two at the interval position, which further facilitates the rapid discharge of volatile gases generated in the central area of ​​the heat dissipation pad, and ensures that there is a large welding contact area between the middle of the bottom of the device and the heat dissipation pad, so as to improve the heat dissipation performance of the device.

[0027] 7. In the PCB structure with a heat dissipation pad provided by the utility model, the first metal foil and the second metal foil are both triangular, and the longest side of the first metal foil and the longest side of the second metal foil are arranged opposite to each other; such an arrangement facilitates providing sufficient wiring width and wiring spacing on the PCB substrate, which is conducive to realizing the miniaturized packaging design of the device.

[0028] 8. The PCB structure with the heat dissipation pad provided by the utility model can provide a heat dissipation path for the heat on the heat dissipation pad to be quickly dissipated outward through the heat transfer structure, thereby improving the heat dissipation capacity.

[0029] 9. The PCB structure with heat dissipation pad provided by the utility model, the metallized through hole on the external metal foil can not only provide a better heat dissipation path, but the metallized through hole can also be connected to the grounding foil on the bottom layer of the PCB substrate, thereby increasing the heat dissipation area and enhancing the heat dissipation effect.

[0030] 10. The PCB structure with the heat dissipation pad provided by the utility model and the setting of the third solder resist window on the external metal foil can print solder on the part of the external metal foil exposed by the third solder resist window and then reflow soldering to enhance the heat dissipation effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0032] Figure 1 is a PCB structure diagram corresponding to the X2SON device in the prior art;

[0033] Figure 2 is a perspective view of an X2SON device in the prior art;

[0034] Figure 3 This is a PCB structure diagram corresponding to the X2SON device in the embodiment of the utility model;

[0035] Figure 4 for Figure 3 Schematic diagram of the first solder mask opening;

[0036] Figure 5 for Figure 3 Schematic diagram of the middle air guide slot;

[0037] Figure 6 This is a schematic diagram of the PCB structure corresponding to the X2SON device in one implementation of an embodiment of the utility model.

[0038] Explanation of the reference numerals: 1. PCB substrate; 2. heat dissipation pad; 21. first solder resist window; 22. air guide groove; 221. middle part of air guide groove; 222. end part of air guide groove; 23. first metal foil; 24. second metal foil; 3. pin pad; 31. pin foil; 32. second solder resist window; 4. external heat dissipation structure; 41. external metal foil; 42. metallized through hole; 43. third solder resist window; 5. first metal trace; 6. second metal trace; 7. device; 71. heat dissipation pin; 72. device pin. DETAILED DESCRIPTION

[0039] The technical solution of the utility model will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0040] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the 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 orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0041] 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, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0042] The utility model discloses a PCB structure with a heat dissipation pad. The PCB packaging structure is used for packaging pinless packaged devices. In the present application, pinless devices specifically refer to devices whose device pins are located on the bottom surface of the device, such as QFN (Quad Flat No-leads Package, square flat no-lead package) devices, DFN (Dual Flat No-lead Package, double-sided flat no-lead package) devices, and X2SON (ultra-small outline no-lead package) devices. The PCB packaging structure corresponding to the X2SON device is taken as an example to specifically explain the PCB packaging structure for which protection is requested in the present application.

[0043] The structure of X2SON device is as follows Figure 2 As shown, the device 7 includes a heat dissipation pin 71 located in the middle of the bottom surface of the device 7 and four device pins 72 located at the four corners of the device 7. The four device pins 72 are respectively an OUT pin, a GND pin, an EN pin and an IN pin.

[0044] PCB packaging structure such as Figure 3 As shown in Figure 6, the PCB packaging structure includes a PCB substrate 1, a heat dissipation pad 2, four pin pads 3 and an external heat dissipation structure 4; wherein the PCB substrate 1 is the base material layer of the PCB structure. When the device 7 is welded on the PCB substrate 1, the area of ​​the welding surface of the PCB substrate 1 covered by the device 7 is the first area, and the area of ​​the welding surface of the PCB substrate 1 not covered by the device 7 is the second area. The heat dissipation pad 2 and the four pin pads 3 are both located in the first area, the four pin pads 3 are located at the four corners of the first area, and the heat dissipation pad 2 is located in the middle of the four pin pads 3. The heat dissipation pad 2 is used to weld with the heat dissipation pin 71 in the middle of the bottom surface of the device 7, and the pin pad 3 is used to weld with the device 7 pins corresponding to the periphery of the bottom surface of the device 7. The external heat dissipation structure 4 is located in the second area, and the external heat dissipation structure 4 is connected to the heat dissipation pad 2 through a heat transfer structure, and is used to dissipate heat from the heat dissipation pad 2.

[0045] Among them, the heat dissipation pad 2 is a HSMD PAD (semi-enclosed solder mask defined pad) structure, which specifically refers to a structure in which a portion of the copper foil and the substrate are covered with solder mask, and another portion of the copper foil and the substrate are exposed, and the copper foil exposed by the solder mask opening is used as a pad. The four pin pads 3 are all the same SMD PAD (solder mask defined pad) structure, which specifically refers to a structure in which a portion of the copper foil is covered with solder mask, and the copper foil exposed by the solder mask opening is used as a pad.

[0046] In some embodiments, the welding surface of the PCB substrate 1 is mounted with a first metal foil 23 and a second metal foil 24 arranged at intervals, and the first metal foil 23, the second metal foil 24 and the PCB substrate 1 are covered with a solder resist layer, and the solder resist layer is provided with a first solder resist window 21 that exposes a portion of the first metal foil 23 and the second metal foil 24, and a portion of the PCB substrate 1. The portion of the first solder resist window 21 that exposes the first metal foil 23 and the second metal foil 24 forms a heat dissipation pad 2, and the portion of the first solder resist window 21 that exposes the PCB substrate 1 (that is, the portion of the first solder resist window 21 that does not correspond to the first metal foil 23 and the second metal foil 24) forms a gas guide groove 22, and the gas guide groove 22 is used to discharge gas from the first area to the second area. In an alternative embodiment, the heat dissipation pad 2 can also include three, four or more metal foils, as long as there is a gap between the multiple metal foils that is located in the first solder resist window 21 and exposes the PCB substrate 1.

[0047] In some embodiments, the exhaust direction of the gas guide groove 22 is perpendicular to the thickness direction of the PCB substrate 1. The gas guide groove 22 extends from the first area to the second area on the welding surface of the PCB substrate 1. After the device 7 is welded on the welding surface of the PCB substrate 1, the gas guide groove 22 is located in the second area that is not blocked by the device 7 but is exposed outside the device 7. In an alternative embodiment, the gas guide groove 22 can also be completely located in the first area below the device 7, as long as the gas can be exhausted to the outside.

[0048] In some embodiments, the air guide groove 22 is in the shape of an elongated strip and is one in number. The air guide groove 22 includes an air guide groove middle portion 221 and an air guide groove end portion 222. The air guide groove middle portion 221 is arranged correspondingly to a portion of the PCB substrate 1 exposed between the first metal foil 23 and the second metal foil 24, and the air guide groove end portion 222 is arranged correspondingly to a portion of the PCB substrate 1 outside the area enclosed by the first metal foil 23 and the second metal foil 24. In this way, the gap between the first metal foil 23 and the second metal foil 24 can form an air guide channel of the air guide groove 22, so that the volatile gas generated at the heat dissipation pad 2 can be discharged outward through the air guide groove 22. In an alternative embodiment, the number of the air guide grooves 22 can also be multiple, and the multiple air guide grooves 22 can be arranged crosswise or independently. The air guide grooves 22 can extend in a straight line or in a curved manner.

[0049] In some embodiments, the direction from the middle part 221 of the air guide groove to the end part 222 of the air guide groove is the length direction of the air guide groove 22, and the direction perpendicular to the length direction of the air guide groove 22 is the width direction of the air guide groove 22. In the width direction of the air guide groove 22, the size of the end part 222 of the air guide groove is larger than the size of the middle part 221 of the air guide groove. This arrangement facilitates the rapid discharge of gas through the air guide groove 22.

[0050] In this PCB packaging structure with a heat dissipation pad, the first solder resist window 21 exposes the portion of the PCB substrate 1 to form an air guide groove 22. During the reflow soldering process of the device 7, the volatile gas generated by the solder on the heat dissipation pad 2 can be discharged from the first area covered by the device 7 to the second area not covered by the device 7 through the air guide groove 22, thereby reducing cold solder joints and solder joint voids and improving the soldering yield and solder joint reliability.

[0051] In some embodiments, the first metal foil 23 and the second metal foil 24 have the same shape, both of which are isosceles right triangles or acute triangles, and the corners of the first metal foil 23 and the second metal foil 24 can be designed as rounded structures. The first metal foil 23 and the second metal foil 24 are symmetrically arranged along the center line of the two at the interval position, and the longest side of the first metal foil 23 and the longest side of the second metal foil 24 are arranged facing each other. Such an arrangement not only facilitates the rapid discharge of volatile gases generated in the central area of ​​the heat dissipation pad 2, but also ensures that the middle of the bottom of the device 7 and the heat dissipation pad 2 have a larger welding contact area, which is convenient for improving the heat dissipation performance of the device 7.

[0052] In some embodiments, four pin foils 31 located on the periphery of the metal foil are mounted on the welding surface of the PCB substrate 1, and a second solder resist window 32 partially exposing the pin foil 31 is opened on the solder resist layer, and the portion of the second solder resist window 32 exposing the pin foil 31 forms a pin pad 3, and the size of the second solder resist window 32 is smaller than the size of the pin foil 31. The four pin pads 3 are all right-angled pentagons, and the hypotenuse of the pin pad 3 faces the outer side of the heat dissipation pad 2. Such a configuration facilitates providing sufficient wiring width and wiring spacing on the PCB substrate 1, which is conducive to realizing the miniaturized packaging design of the device 7. It can be understood here that the number and position distribution of the pin pads 3 can be selected according to the type of device 7.

[0053] In some embodiments, the external heat dissipation structure 4 is connected to the metal foil through a heat transfer structure, and the number of the external heat dissipation structures 4 can be one or more. The external heat dissipation structure 4 includes an external metal foil 41 located on the surface of the PCB substrate 1. The external metal foil 41 is square, and the external metal foil 41 can dissipate heat through the copper foil on its surface. A circular metallized through hole 42 is provided in the middle of the external metal foil 41. The metallized through hole 42 can not only provide a better heat dissipation path, but also the metallized through hole 42 can be connected to the ground foil of the PCB structure, thereby increasing the heat dissipation area and enhancing the heat dissipation effect. The solder resist on the external metal foil 41 is provided with a third solder resist window 43, and the printed solder on the part of the external metal foil 41 exposed by the third solder resist window 43 can be reflowed to further enhance the heat dissipation effect.

[0054] In summary, the utility model provides a PCB packaging structure with a heat dissipation pad, the heat dissipation pad 2 adopts a semi-enclosed solder resist structure, and the first solder resist window 21 exposes the portion of the PCB substrate 1 to form an air guide groove 22. During the reflow soldering process of the device 7, the volatile gas generated by the solder on the heat dissipation pad 2 can be discharged from the first area covered by the device 7 to the second area not covered by the device 7 through the air guide groove 22, thereby reducing the cold solder joints and solder joint voids, and improving the welding yield and solder joint reliability; and by setting an external heat dissipation structure 4, the heat dissipation performance of the packaging structure can meet the requirements.

[0055] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention of the utility model.

Claims

1. A PCB structure with a heat dissipation pad, characterized in that: The invention comprises a PCB substrate (1), a metal foil sheet arranged on a welding surface of the PCB substrate (1), and a solder resist layer covering the PCB substrate (1) and the metal foil sheet, wherein the solder resist layer is provided with a first solder resist window (21) exposing at least a portion of the metal foil sheet and a portion of the PCB substrate (1), the portion of the first solder resist window (21) exposing the metal foil sheet forms a heat dissipation pad (2) suitable for welding a device (7), the portion of the first solder resist window (21) exposing the PCB substrate (1) forms an air guide groove (22), and the gas at the heat dissipation pad (2) is suitable for being discharged to the outside through the air guide groove (22).

2. The PCB structure with a heat dissipation pad according to claim 1, characterized in that: The area of ​​the welding surface of the PCB substrate (1) covered by the device (7) is the first area, the area of ​​the welding surface of the PCB substrate (1) not covered by the device (7) is the second area, and the gas guide groove (22) allows gas to be discharged from the first area to the second area.

3. The PCB structure with a heat dissipation pad according to claim 2, characterized in that: At least a portion of the air guide groove (22) is exposed outside the second area.

4. The PCB structure with a heat dissipation pad according to claim 1, characterized in that: At least two metal foils are provided, and at least two of the metal foils are arranged at intervals; the air guide groove (22) comprises an air guide groove middle portion (221) and an air guide groove end portion (222); the air guide groove middle portion (221) is arranged corresponding to a portion of the PCB substrate (1) exposed between at least two of the metal foils, and the air guide groove end portion (222) is arranged corresponding to a portion of the PCB substrate (1) outside an area enclosed by at least two of the metal foils.

5. The PCB structure with a heat dissipation pad according to claim 4, characterized in that: The direction from the middle part (221) of the air guide groove to the end part (222) of the air guide groove is the length direction of the air guide groove (22), and the direction perpendicular to the length direction of the air guide groove (22) is the width direction of the air guide groove (22). In the width direction of the air guide groove (22), the size of the end part (222) of the air guide groove is larger than the size of the middle part (221) of the air guide groove.

6. The PCB structure with a heat dissipation pad according to claim 4, characterized in that: There are two metal foils, namely a first metal foil (23) and a second metal foil (24). The first metal foil (23) and the second metal foil (24) are symmetrically arranged along a center line at interval positions.

7. The PCB structure with a heat dissipation pad according to claim 6, characterized in that: The first metal foil (23) and the second metal foil (24) are both triangular in shape, and the longest side of the first metal foil (23) and the longest side of the second metal foil (24) are arranged facing each other.

8. The PCB structure with a heat dissipation pad according to claim 2, characterized in that: A plurality of pin foils (31) are provided on the welding surface of the PCB substrate (1) and are located on the periphery of the metal foil; a second solder resist window (32) partially exposing the pin foil (31) is provided on the solder resist layer; a portion of the second solder resist window (32) that leaks out of the pin foil (31) forms a pin pad (3) suitable for welding device pins; and the plurality of pin pads (3) are located in the first area.

9. The PCB structure with a heat dissipation pad according to claim 8, characterized in that: The pin pad (3) is in the shape of a right-angled pentagon, and the oblique side of the pin pad (3) faces the outer side of the heat dissipation pad (2).

10. The PCB structure with a heat dissipation pad according to claim 8, characterized in that: The second area on the PCB substrate (1) is provided with at least one external heat dissipation structure (4) connected to the heat dissipation pad (2) via a heat transfer structure, and the external heat dissipation structure (4) is used to dissipate heat from the heat dissipation pad (2).

11. The PCB structure with a heat dissipation pad according to claim 10, characterized in that: The external heat dissipation structure (4) comprises an external metal foil (41) located on the surface of the PCB substrate (1), and the heat transfer structure comprises a first metal trace (5) connected between the metal foil and the pin foil (31), and a second metal trace (6) connected between the pin foil (31) connected to the first metal trace (5) and the external metal foil (41).

12. The PCB structure with a heat dissipation pad according to claim 11, characterized in that: The external metal foil (41) is provided with a metallized through hole (42), and the metallized through hole (42) is connected to the ground foil of the PCB structure.

13. The PCB structure with a heat dissipation pad according to claim 11, characterized in that: The solder resist layer is provided with a third solder resist window (43) partially exposing the external metal foil (41).

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