Surface-mounted heat dissipation bonding pad and semiconductor packaging piece

Abstract

The utility model discloses a surface mount heat dissipation pad and a semiconductor package, and relates to the electronic technical field, the surface mount heat dissipation pad comprises a pad body and a solder mask layer, the pad body is provided with a welding surface and a heat dissipation surface which are arranged oppositely, the pad body is provided with a plurality of first heat dissipation via holes penetrating through the welding surface and the heat dissipation surface in an array mode, and the first heat dissipation via holes are communicated with the solder mask layer. The solder mask layer is located on the welding surface of the bonding pad body and is arranged around the edge area of the welding surface, so that in the packaging process of the surface-mounted device, tin materials sufficient to fill the heat dissipation via holes and the welding surface are arranged on the bonding pad body only through one-time tin brushing on the welding surface, the number of subsequent heating and welding times is reduced, and the surface-mounted device packaging efficiency is improved. Related process steps in the packaging process are saved, the product production cost is reduced, the product supporting efficiency is improved, and the production period is shortened.

Description

Technical Field

[0001] The utility model relates to the field of electronic technology, in particular to a surface mounted heat dissipation pad and a semiconductor package. Background Art

[0002] With the widespread use of surface-mount devices, the heat dissipation problem of high-power surface-mount devices directly affects the reliability of electronic equipment. Generally speaking, PCB boards (Printed Circuit Boards) use processes such as copper embedding and electroplated copper hole filling to meet the heat dissipation requirements of surface-mount devices.

[0003] Alternatively, tinning heatsink pads to dissipate heat for surface-mount components can be achieved. One method involves brushing tin onto the pad, allowing the tin to liquefy and fill the thermal vias. Then, tinning the pad again is repeated to complete the soldering of the surface-mount component. Another method involves combining reflow and wave soldering: first, using wave soldering to fill the thermal vias from the bottom of the PCB, then brushing tin onto the pad and soldering the surface-mount component using reflow.

[0004] However, the above traditional methods all require two tinning and two heating steps to complete the filling of tin material and the soldering of components, resulting in generally high production costs, low process efficiency and long production cycles. Utility Model Content

[0005] The purpose of the embodiments of the present invention is to provide a surface mount heat dissipation pad and a semiconductor package, which can solve the above-mentioned problems existing in the prior art.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] In a first aspect, a surface mount heat dissipation pad is provided, comprising:

[0008] A pad body, wherein the pad body is formed with a soldering surface and a heat dissipation surface disposed opposite to each other, and a plurality of first heat dissipation vias penetrating the soldering surface and the heat dissipation surface are arranged in an array on the pad body;

[0009] A solder resist layer is located on the soldering surface of the pad body and is arranged around an edge area of ​​the soldering surface.

[0010] As an optional implementation manner, the diameter of the first heat dissipation via is set to 0.2mm-0.3mm;

[0011] A heat dissipation copper layer is further provided around the first heat dissipation via hole, and the thickness of the heat dissipation copper layer is 0.025 mm.

[0012] As an optional implementation manner, the distance between the hole wall of the first heat dissipation via and the edge of the pad body is set to be ≥0.3 mm;

[0013] The hole wall spacing between any two adjacent first heat dissipation vias is set to be ≥0.3 mm.

[0014] As an optional implementation manner, the thickness of the solder resist layer protruding from the soldering surface is set to 0.01 mm-0.04 mm.

[0015] As an optional implementation, the width of the solder resist layer is set to 0.1 mm.

[0016] In a second aspect, a semiconductor package is provided, comprising:

[0017] The surface mount heat dissipation pad as described in the first aspect;

[0018] a substrate, wherein the pad body is embedded in one side of the substrate, the heat dissipation surface of the pad body faces the substrate, and the welding surface is flush with a surface of one side of the substrate, and the substrate is further provided with a plurality of second heat dissipation vias arranged in an array and correspondingly connected to each of the first heat dissipation holes, wherein the second heat dissipation vias penetrate two opposite side surfaces of the substrate; and

[0019] A surface mount device is provided with a heat dissipation pin. A side of the surface mount device provided with the heat dissipation pin is mounted on the substrate through the solder resist layer, so that the surface mount device, the solder resist layer and the soldering surface enclose a cavity structure, the cavity structure is connected to the first heat dissipation via and the second heat dissipation via, and the cavity structure and the first heat dissipation via and the second heat dissipation via are all filled with solder.

[0020] As an optional implementation, it also includes:

[0021] The bottom heat dissipation pad is embedded in the side of the substrate away from the pad body, and is also provided with a plurality of third heat dissipation vias arranged in an array and corresponding to the second heat dissipation holes.

[0022] As an optional implementation manner, a surface of the bottom heat dissipation pad facing away from the substrate and a side surface of the substrate facing away from the pad body are flush with each other.

[0023] As an optional embodiment, the substrate includes:

[0024] a substrate layer, wherein at least two substrate layers are provided, and the pad body is embedded in one of the substrate layers; and

[0025] The inner pad is arranged between any two adjacent base material layers, and the second heat dissipation via penetrates each base material layer and the inner pad.

[0026] As an optional implementation, it also includes:

[0027] Surface mount pads, the surface mount pads are provided in plurality, the plurality of surface mount pads are spaced apart and arranged on a side of the substrate where the pad body is provided and surround the periphery of the welding surface;

[0028] The surface mount device is further provided with a plurality of functional pins, and each functional pin is connected to each surface mount pad via solder.

[0029] The beneficial effects of the present invention are as follows: the surface mount heat dissipation pad is provided with a solder mask layer surrounding the edge area of ​​the soldering surface on the soldering surface of the pad body, thereby preventing the liquid tin from overflowing during the subsequent tin brushing and heating of the tin material. In this way, the tin material sufficient to fill the heat dissipation vias and the soldering surface can be arranged on the pad body by only brushing the tin on the soldering surface once, thereby reducing the number of subsequent heating and soldering times, saving related process steps in the packaging process, reducing product production costs, and improving product support efficiency and shortening the production cycle.

[0030] Since the solder mask layer is protruding from the soldering surface of the pad body, in the process of the tin material liquefying and flowing into the various heat dissipation vias, as the liquid tin level on the soldering surface drops, the surface mount device can also be mounted on the solder mask layer, thereby forming a vacuum area between the surface mount device and the soldering surface. In this way, under the action of atmospheric pressure, it is ensured that the tin material will not flow out of the various heat dissipation vias, ensuring that the filling effect of the tin material can meet the heat dissipation requirements of the device, that is, on the basis of meeting the packaging requirements of the device, the process steps can be simplified to achieve the purpose of reducing costs and increasing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

[0032] Figure 1 This is a schematic diagram of the structure of the surface mount heat dissipation pad according to an embodiment of the present utility model;

[0033] Figure 2 This is a schematic structural diagram of a semiconductor package according to an embodiment of the present utility model;

[0034] Figure 3 This is a flow chart of the surface mounting method described in an embodiment of the present utility model.

[0035] In the figure: 10, pad body; 11, welding surface; 12, heat dissipation surface; 13, first heat dissipation via; 20, solder mask layer; 30, substrate; 31, second heat dissipation via; 32, base material layer; 33, inner pad; 40, surface mount device; 41, heat dissipation pin; 42, functional pin; 50, bottom heat dissipation pad; 51, third heat dissipation via; 60, surface mount pad; 70, heat dissipation copper layer. DETAILED DESCRIPTION

[0036] To make the technical problems solved, the technical solutions adopted, and the technical effects achieved by the present invention more clearly understood, the technical solutions of the embodiments of the present invention are described in further detail below. Obviously, the embodiments described are only a portion of the embodiments of the present invention, not all of them. All other embodiments derived by those skilled in the art based on the embodiments of the present invention without creative effort are also within the scope of protection of the present invention.

[0037] In the description of this utility model, unless otherwise expressly specified or limited, the terms "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.

[0038] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0039] Surface Mounted Devices (SMD) are electronic components packaged using surface mount technology. Compared with traditional plug-in components, SMD has the advantages of small size, light weight, high mounting density, and good reliability. Therefore, it is also widely used in various electronic devices such as mobile phones, computers, televisions, and communication equipment.

[0040] SMDs come in a wide variety of shapes, including resistors, capacitors, inductors, diodes, transistors, and integrated circuits. The pins or solder terminals of these devices are typically designed to be flat, rectangular, or in other shapes to mate and connect with surface-mount pads on PCBs. With the increasing use of surface-mount devices, the heat dissipation of high-power surface-mount devices has a direct impact on the reliability of electronic equipment. Generally, PCBs (Printed Circuit Boards) utilize processes such as copper inlay and copper-plated hole filling to meet the heat dissipation requirements of surface-mount devices.

[0041] As can be seen from the background technology, in addition to using the above-mentioned process to solve the heat dissipation problem of surface-mount devices, the existing technology also uses a method of filling the heat dissipation pad with tin to achieve the purpose of providing heat dissipation for the surface-mount devices. One method of achieving this is to brush tin on the heat dissipation pad once, so that the tin material is heated and liquefied to meet the requirements of filling the heat dissipation vias, and then brush tin on the heat dissipation pad a second time to complete the soldering of the surface-mount device. The second method of achieving this is to use reflow soldering combined with wave soldering, first filling the heat dissipation vias with tin from the bottom of the PCB through wave soldering, then brushing tin on the heat dissipation pad and soldering the surface-mount device through reflow soldering.

[0042] However, the above traditional methods all require two tinning and two heating steps to complete the filling of tin material and the soldering of components, resulting in generally high production costs, low process efficiency and long production cycles.

[0043] In view of this, this embodiment provides a surface mount heat dissipation pad, which solves a series of technical problems such as the difficulty and complexity of the surface mount assembly process by improving the structure of the solder mask layer on the heat dissipation pad.

[0044] Please refer to the instruction manual Figure 1-Figure 2 The surface mount heat dissipation pad includes a pad body 10. The pad body 10 plays the role of connecting the surface mount device 40 and the PCB board during the process of surface mount technology (SMT) to effectively conduct the heat generated by the surface mount device 40 to the surrounding environment, thereby maintaining the normal operating temperature of the surface mount device 40 and improving its service life and stability.

[0045] To facilitate a more comprehensive understanding of this embodiment, the two opposing surfaces of the pad body 10 are defined as a soldering surface 11 and a heat dissipation surface 12, respectively. The soldering surface 11 is the side of the pad body 10 facing the external environment of the PCB board and is used for soldering to the surface-mount device 40 to achieve heat transfer. Its design aims to maximize the heat dissipation path between the surface-mount device 40 and the pad body 10, thereby more effectively transferring heat generated by the surface-mount device 40 to the pad body 10. Opposite to the heat dissipation surface 12, the soldering surface 11 is the surface of the pad body 10 that directly contacts the PCB board or other substrate.

[0046] On the basis that the above-mentioned pad body 10 is formed with a welding surface 11 and a heat dissipation surface 12 arranged opposite to each other, a plurality of first heat dissipation vias 13 penetrating the welding surface 11 and the heat dissipation surface 12 are arranged in an array on the pad body 10. The first heat dissipation vias 13 can provide an effective heat dissipation path for the pad body 10, so that after the heat is transferred to the pad body 10 through the welding surface 11, the pad body 10 can quickly transfer the heat to the heat dissipation surface 12 through the first heat dissipation vias 13, thereby improving the heat transfer efficiency between the pad body 10 and the air or the above-mentioned carrier board components, and effectively reducing the temperature of the surface mount device 40.

[0047] Based on the structural form of the above-mentioned pad body 10, the surface mount heat dissipation pad also includes a solder mask layer 20. The main purpose of the solder mask layer 20 is to protect the circuit structure on the PCB board and prevent the solder from overflowing during the soldering process, thereby avoiding problems such as short circuit of the PCB board. At the same time, the solder mask layer 20 can also effectively confine the solder to a specific welding area to ensure that the solder can cover the welding surface 11 and fill the first heat dissipation via 13, thereby improving the heat transfer efficiency between the surface mount device 40 and the pad body 10 and ensuring the welding stability of the surface mount device 40.

[0048] It should be understood that the material generally used for the solder resist layer 20 is a polymer material. In some cases, resin is the main component of the solder resist layer 20. These polymer materials have good moisture resistance and temperature resistance and are non-conductive. Therefore, they can effectively protect the PCB board and prevent solder from flowing into areas where soldering is not required during the soldering process.

[0049] Please refer to the attached Figure 1-Figure 2 The solder resist layer 20 is located on the soldering surface 11 of the pad body 10 and is arranged around the edge area of ​​the soldering surface 11. It should be noted that the edge area of ​​the soldering surface 11 refers to the area near the edge of the soldering surface 11. The range of this area can usually be limited by the width of the solder resist layer 20. The solder resist layer 20 continuously arranged in the edge area of ​​the soldering surface 11 can define the layout area of ​​the solder on the soldering surface 11 and can confine the solder to the area of ​​the soldering surface 11 surrounded by the solder resist layer 20, so as to avoid overflow of liquid solder.

[0050] Through the above-mentioned arrangement, the filling of the first heat dissipation via 13 of the surface mount heat dissipation pad and the soldering with the surface mount device 40 can be completed by only one tinning and one heating. In the actual process flow, the operator or organization needs to calculate the amount of solder used to fill the first heat dissipation via 13 and arranged on the welding surface 11, and after one tinning, arrange the tin material sufficient to fill the heat dissipation via and the welding surface 11 on the pad body 10. Because the amount of tin is larger than the amount used in the traditional tinning in batches, when the surface mount device 40 is subsequently placed on the heat dissipation pad, the surface mount device 40 will be supported by the solder. As the solder liquefies during the subsequent heating, the liquid solder (liquid tin) will also fill and flow into each heat dissipation via. In the process, the liquid level of the liquid solder on the welding surface 11 will gradually decrease. And because the solder mask 20 is protruding from the welding surface 11 of the pad body 10, the surface mount device 40 will eventually drop to the level of the solder mask 20. 0, so that the surface mount device 40 and the welding surface 11 cooperate to form a vacuum area that is connected to the external environment only through the first heat dissipation vias 13, and because the first heat dissipation vias 13 have been filled during the solder liquefaction process, under the action of atmospheric pressure, the tin material is ensured to be "absorbed" by the vacuum area and will not flow out from the first heat dissipation vias 13, ensuring that the filling effect of the tin material can meet the heat dissipation requirements of the device, that is, on the basis of meeting the packaging requirements of the device, the process steps can be simplified to achieve the purpose of reducing costs and increasing efficiency, thereby reducing the number of subsequent heating and welding times, saving related process steps in the packaging process, reducing product production costs, and improving product support efficiency and shortening the production cycle.

[0051] It is worth mentioning that in some embodiments, the PCB board will be placed on the heating plate through the heat dissipation surface 12 for heating and soldering. Therefore, during the above-mentioned heating process, the temperature of the end of the first heat dissipation via 13 close to the heat dissipation surface 12 will be higher than the end close to the soldering surface 11. Therefore, the end of the first heat dissipation via 13 with a relatively higher temperature can also attract liquid solder, so that the liquid solder can not only be affected by the atmospheric pressure but also be attracted by the fourth heat dissipation via, so as to further ensure that the liquid tin material is in a state of completely filling the first heat dissipation via 13 without overflowing.

[0052] Please continue to refer to the attached Figure 1-Figure 2It is understood that the diameter and spacing of the first heat dissipation vias 13 have a direct impact on the heat dissipation effect of the heat dissipation pad. The diameter of the first heat dissipation vias 13 should not be too large, so as not to increase manufacturing costs and process difficulty, nor too small, so as not to affect the heat dissipation effect. In this example, the diameter of the first heat dissipation vias 13 is set to 0.2mm-0.3mm, preferably 0.25mm, to ensure that the liquid solder can flow smoothly into the first heat dissipation vias 13 and effectively transfer the heat from the solder on the soldering surface 11 to the end of the heat dissipation surface 12 of the pad body 10 after the solder re-solidifies.

[0053] Optionally, a material with good thermal conductivity can be provided in the first heat dissipation via 13 to cooperate with the solder to further improve the heat transfer efficiency. For example, by providing a heat dissipation copper layer 70 around the first heat dissipation via 13, when the solder in the first heat dissipation via 13 receives heat, the solder can not only transfer the heat toward the heat dissipation surface 12, but also exchange heat with the heat dissipation copper layer 70, thereby improving the heat transfer speed through copper or other metals with good thermal conductivity, so as to quickly discharge the heat accumulated in the heat dissipation pad, thereby avoiding the situation where the surface mount device 40 accumulates heat on the heat dissipation pad during continuous heating, and ensuring that the surface mount device 40 can operate normally.

[0054] In one embodiment, the thickness of the heat dissipation copper layer 70 is 0.025 mm. It should be noted that since this embodiment requires a heat dissipation copper layer 70 with a certain thickness to be set in the first heat dissipation via 13, in order to ensure that the tin material filled in the first heat dissipation via 13 can meet the heat dissipation requirements of the surface mount device 40, the aperture size of the first heat dissipation via 13 also needs to reserve sufficient space for the heat dissipation copper layer 70.

[0055] For example, when the heat dissipation copper layer 70 is not provided in the first heat dissipation via 13, if the diameter of the solder in the first heat dissipation via 13 is to be maintained at 0.2 mm, the first heat dissipation via 13 needs to be opened to 0.2 mm. In an embodiment in which the heat dissipation copper layer 70 is provided in the first heat dissipation via 13, in order to allow the solder to still maintain a diameter of 0.2 mm in the first heat dissipation via 13, the first heat dissipation via 13 needs to be set to 0.25 mm, so that after the heat dissipation copper layer 70 with a thickness of 0.025 mm is provided on the hole wall of the first heat dissipation via 13, the inner diameter of the hole still remains at a size of 0.2 mm.

[0056] It is worth mentioning that by setting the heat dissipation copper layer 70 in the first heat dissipation via 13, when the liquid tin flows into the first heat dissipation via 13, the first heat dissipation via 13 can also use the metal properties of the heat dissipation copper layer 70 to attract the liquid tin, so as to further improve the stability of the liquid tin in the first heat dissipation via 13.

[0057] Optionally, the first heat dissipation vias 13 of this embodiment should all be opened in the area defined by the solder resist layer 20 so that the heat can be better transferred to the solder located in the first heat dissipation vias 13. In addition, in order to leave sufficient heat absorption space between each first heat dissipation via 13 and avoid the heat between each first heat dissipation via 13 affecting each other, resulting in a decrease in heat transfer efficiency, this embodiment sets the hole wall spacing between any two adjacent first heat dissipation vias 13 to ≥0.3mm.

[0058] Of course, under the above-mentioned limited conditions, in order to ensure that more first heat dissipation vias 13 are set in a limited area to achieve a good heat dissipation effect, the first heat dissipation vias 13 can be arrayed on the pad body 10 under the constraint of a hole wall spacing of 0.3 mm to achieve a balance in a certain sense.

[0059] Furthermore, in order to prevent the heat transferred by the solder in the first heat dissipation via 13 arranged near the edge of the pad body 10 from affecting other related components in the PCB board, this embodiment also sets the distance between the hole wall of the first heat dissipation via 13 and the edge of the pad body 10 to ≥0.3mm.

[0060] In addition, based on any of the above-mentioned embodiments, in order for the solder resist layer 20 to effectively provide a solder blocking function for the pad body 10 and prevent solder overflow, the solder resist layer 20, while surrounding the outer edge area of ​​the welding surface 11, also needs to constrain and limit its thickness dimension protruding from the welding surface 11 and its width dimension perpendicular to its extension direction on the welding surface 11.

[0061] The thickness of the solder resist layer 20 protruding from the soldering surface 11 is set to 0.01 mm-0.04 mm, preferably 0.03 mm, so that the solder resist layer 20 has a sufficient height to block the liquid tin accumulated on the soldering surface 11 .

[0062] Optionally, the width of the solder resist layer 20 is set to 0.1 mm to prevent excessive tin from accumulating on the soldering surface 11 and easily passing over the solder resist layer 20 to cause solder overflow.

[0063] Please continue to refer to the attached Figure 1-Figure 2 This embodiment further provides a semiconductor package, which, based on the surface mount heat dissipation pad provided in any of the above embodiments, further includes:

[0064] Substrate 30 provides support and protection for surface-mount device 40 and also provides a conductive path for electrical connection between surface-mount device 40 and external circuitry. Substrate 30 can be a composite of various materials, such as metal, ceramic, or composite materials, depending on the specific application scenario and requirements. For example, in the power amplifier device of this embodiment, substrate 30 needs to have good thermal conductivity to ensure timely heat dissipation and prevent device damage from overheating. It also needs to have a certain degree of mechanical strength and stability to withstand the vibration and impact generated by the device during operation.

[0065] In some embodiments, the substrate 30 can be configured as a PCB board, thereby reducing the difficulty of installing the surface-mount device 40 and other related devices, and also improving the space utilization of the substrate 30, making the power amplifier module structure more compact and more integrated.

[0066] The pad body 10 provided in the above embodiment is embedded in one side of the substrate 30, so that the pad body 10 can be regarded as forming an integral plate with the substrate 30, the heat dissipation surface 12 of the pad body 10 faces the substrate 30, and the welding surface 11 is flush with the surface of one side of the substrate 30, so as to ensure that the surface mount device 40 can be smoothly soldered to the PCB board using surface mount technology and connected to the pad body 10 through solder.

[0067] Optionally, the pad body 10 can be set on the substrate 30 through different process methods, including but not limited to welding process, bonding process, pressing process, etc. This embodiment does not make strict limitations and requirements on this, and only needs to ensure that the welding surface 11 of the pad body 10 is set flush with the surface of the substrate 30.

[0068] Furthermore, a plurality of second heat dissipation vias 31 corresponding to and connected to the first heat dissipation holes are arranged in an array on the substrate 30. The second heat dissipation vias 31 pass through two opposite side surfaces of the substrate 30. Each first heat dissipation via 13 is connected to each second heat dissipation via 31 one by one, so that the solder can flow into the second heat dissipation via 31 through the first heat dissipation via 13 after liquefaction, and completely fill each first heat dissipation via 13 and the second heat dissipation via 31, thereby dissipating heat from the side of the substrate 30 away from the pad body 10, rather than just transferring heat to the substrate 30 through the solder in the first heat dissipation via 13.

[0069] Based on the above embodiment, the semiconductor package also includes the surface mount device 40 mentioned above. The surface mount device 40 is provided with a heat dissipation pin 41 on one side thereof for welding with the pad body 10 (i.e., the side thereof for mounting on the substrate 30). The heat dissipation pin 41 can effectively transfer the heat generated by the surface mount device 40. In one embodiment, a plurality of heat dissipation pins 41 are provided. The plurality of heat dissipation pins 41 can increase the heat dissipation path of the surface mount device 40, so that when the surface mount device 40 is soldered to the pad body 10 through the heat dissipation solder foot, the heat transfer efficiency between the surface mount device 40 and the heat dissipation pad is ensured.

[0070] Please refer to the attached Figure 1-Figure 3 As described above for the mounting process of the surface mount device 40, during the heating process of the substrate 30, the solder on the pad body 10 will gradually liquefy and flow into the second heat dissipation via 31 through the first heat dissipation via 13 until the first heat dissipation via 13 and the second heat dissipation via 31 are filled. The liquid tin on the soldering surface 11 will be flush with the solder resist layer 20 or slightly lower than the thickness of the solder resist layer 20. In this way, the side of the surface mount device 40 with the heat dissipation pin 41 will eventually drop to a state where it is mounted on the substrate 30 through the solder resist layer 20. The surface mount device 40, the solder resist layer 20 and the welding surface 11 are surrounded to form a cavity structure. Since the welding surface 11 and the first and second heat dissipation holes are all filled with solder in this state, air can only enter the cavity structure through the second heat dissipation vias 31 and the first heat dissipation vias 13. However, due to the presence of solder, the solder cannot overflow from the second heat dissipation holes under the action of the atmosphere, so that air cannot enter the cavity structure, thereby ensuring that the solder will not overflow, so that the solder filling effect meets the packaging requirements and heat dissipation requirements of the semiconductor package.

[0071] Please continue to refer to the attached Figure 1-Figure 2 The semiconductor package also includes a bottom heat dissipation pad 50, which is embedded in the side of the substrate 30 away from the pad body 10 and is consistent with the pad body 10. The bottom heat dissipation pad 50 can be, but is not limited to, set on the side of the substrate 30 away from the pad body 10 using the above-mentioned process method to form a whole with the substrate 30.

[0072] The bottom heat dissipation pad 50 is also provided with an array of third heat dissipation vias 51 that are connected to the second heat dissipation holes. The first heat dissipation vias 13, the second heat dissipation vias 31, and the third heat dissipation vias 51 are connected one-to-one. This allows liquid tin to flow into the third heat dissipation vias 51 through the first heat dissipation vias 13 and the second heat dissipation vias 31 during heating of the substrate 30, and then connect to the bottom heat dissipation pad 50 after solidification. By further providing the bottom heat dissipation pad 50 on the side of the substrate 30 facing away from the pad body 10, the heat dissipation surface 12 on the bottom side of the substrate 30 (the side facing away from the pad body 10) is effectively increased, allowing heat to pass through the heat dissipation vias and be transferred to the bottom heat dissipation pad 50, thereby dissipating heat to the outside through the bottom heat dissipation pad 50, eliminating the need for heat dissipation solely through the solder in the heat dissipation vias. This improves the heat dissipation efficiency of the semiconductor package.

[0073] Based on the above principles, to further improve the heat dissipation efficiency of the substrate 30 (PCB), the substrate 30 in this embodiment further includes at least two substrate layers 32 and inner pads 33. The pad body 10 is embedded in one of the substrate layers 32. In the aforementioned embodiment including the bottom heat dissipation pad 50, the bottom heat dissipation pad 50 and the pad body 10 are embedded in two separate substrate layers 32. The inner pads 33 are disposed between any two adjacent substrate layers 32, and the second heat dissipation vias 31 extend through each substrate layer 32 and the inner pads 33.

[0074] In this embodiment, the number of substrate layers 32 can be determined based on the design requirements of the semiconductor package and the heat dissipation needs of the surface-mount device 40. It can be set to two, three, four, etc. In addition, when there are two substrate layers 32, there is one inner layer pad 33, and when there are three substrate layers 32, there are two inner layer pads 33, and so on. In other words, it can be understood that the number of substrate layers 32 is n, where n ≥ 2, and the number of inner layer pads 33 is n-1.

[0075] Of course, in the PCB board, the base material layers 32 can also be integrally formed. It is only necessary to place the inner layer pads 33 therein at one time during the processing of the substrate 30 so that the inner layer pads 33 are separated by the base material layer 32.

[0076] In this way, when heat is transferred to the solder in the second heat dissipation via 31 through the solder in the first heat dissipation via 13, the heat can not only be transferred in the direction away from the first heat dissipation via 13 (the direction close to the third heat dissipation via 51), but also be dispersed to the inner layer pad 33, so as to alleviate the heat transfer burden of each heat dissipation via and avoid excessive heat accumulation in the heat dissipation via.

[0077] It should be understood that to ensure effective connection between the surface-mount device 40 and other related components, the semiconductor package further includes surface-mount pads 60. A plurality of surface-mount pads 60 are provided, spaced apart on one side of the substrate 30 where the pad body 10 is provided, and surrounding the periphery of the soldering surface 11. Accordingly, the surface-mount device 40 is further provided with a plurality of functional pins 42, each of which is connected to a corresponding surface-mount pad 60 via solder.

[0078] In the above embodiment in which the heat dissipation copper layer 70 is provided, the heat dissipation copper layer 70 may be provided in the first heat dissipation via 13 , the second heat dissipation via 31 and the third heat dissipation via 51 that are interconnected.

[0079] Please refer to the attached Figure 3 This embodiment further provides a surface mounting method, which is applied to the above-mentioned semiconductor package. The surface mounting method includes the following steps:

[0080] S10, placing solder paste in a receiving groove formed by the soldering surface 11 and the solder resist layer 20. The receiving groove is part of the subsequent cavity structure, and the solder paste can generally be placed by opening a window with a steel mesh and brushing the tin.

[0081] S20, placing the surface mount device 40 on the substrate 30 and positioning the heat dissipation pins 41 in the corresponding positions of the receiving grooves. Since the amount of solder paste is larger than the space defined by the soldering surface 11 and the solder resist layer 20, the solder paste will be higher than the solder resist layer 20 after tinning, so that the surface mount device 40 is supported by the solder paste in this state.

[0082] S30, heating the solder paste and liquefying it. The liquid tin gradually fills the receiving tank and flows through the first heat dissipation vias 13 to the second heat dissipation vias 31 under the action of gravity. The liquid tin level in the receiving tank gradually decreases to be flush with the solder resist layer 20. While the liquid tin fills the first heat dissipation vias 13 and the second heat dissipation vias 31, the surface mount device 40 is mounted on the solder resist layer 20.

[0083] S40, cooling and solidifying the liquid tin to complete the packaging process of the semiconductor package.

[0084] It should be noted that in order for the solder paste (solder) to accurately fill the heat dissipation vias and the cavity structure formed between the surface mount device 40 and the welding surface 11 after liquefaction, the operator or organization should calculate the volume of the above-mentioned cavity structure and each heat dissipation via before brushing the solder. Moreover, after calculating the above-mentioned volume, further calculation is required based on the ratio between the tin and the flux in the solder paste, so that after the solder paste is liquefied and the flux is discharged, the remaining tin can meet the above-mentioned filling requirements.

[0085] In the above embodiment, taking the case where the ratio of tin material to flux in the solder paste is 1:1 as an example, the calculation of the amount of solder paste should satisfy the following relationship:

[0086] V={πr2*h*n+(a-2w)*(b-2w)*e}*2.

[0087] Among them, the length of the pad body 10 is a, the width of the pad body 10 is b, the width of the solder resist layer 20 is w, the thickness of the solder resist layer 20 is e, the radius of the heat dissipation via (including the first heat dissipation via 13, the second heat dissipation via 31 and the third heat dissipation via 51) is r, the number of heat dissipation vias is n, and the thickness of the substrate 30 is h.

[0088] It should be understood that in order to meet the demand for solder paste usage, in the implementation of tin brushing through the steel mesh, the thickness of the steel mesh should also be calculated according to the amount of solder paste, and the calculation of the steel mesh thickness should satisfy the following formula:

[0089] t=V / {(a-2w)*(b-2w)}.

[0090] In the description herein, it should be understood that the terms "upper," "lower," "left," "right," and other positions or relationships are used solely for ease of description and simplified operation, and are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meaning.

[0091] Throughout this specification, references to terms such as "one embodiment" and "example" indicate that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example.

[0092] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0093] The technical principles of the present invention have been described above with reference to specific embodiments. These descriptions are intended solely to illustrate the principles of the present invention and should not be construed in any way as limiting the scope of protection of the present invention. Based on the explanations herein, those skilled in the art will be able to devise other specific implementations of the present invention without inventive effort, and such implementations will fall within the scope of protection of the present invention.

Claims

1. A semiconductor package, characterized in that: include: Surface mount thermal pads, including: A pad body (10), the pad body (10) being formed with a soldering surface (11) and a heat dissipation surface (12) disposed opposite to each other, and a plurality of first heat dissipation vias (13) penetrating the soldering surface (11) and the heat dissipation surface (12) being arranged in an array on the pad body (10); A solder resist layer (20), the solder resist layer (20) being located on the soldering surface (11) of the pad body (10) and being arranged around an edge region of the soldering surface (11); A substrate (30), wherein the pad body (10) is embedded in one side of the substrate (30), the heat dissipation surface (12) of the pad body (10) faces the substrate (30), and the welding surface (11) is flush with the surface of one side of the substrate (30), and the substrate (30) is further provided with a plurality of second heat dissipation vias (31) arranged in an array and correspondingly connected to each of the first heat dissipation vias (13), and the second heat dissipation vias (31) pass through two opposite side surfaces of the substrate (30); and A surface mount device (40) is provided with a heat dissipation pin (41); one side of the surface mount device (40) provided with the heat dissipation pin (41) is mounted on the substrate (30) through the solder resist layer (20), so that the surface mount device (40), the solder resist layer (20) and the welding surface (11) enclose a cavity structure, the cavity structure is connected to the first heat dissipation via (13) and the second heat dissipation via (31), and the cavity structure and the first heat dissipation via (13) and the second heat dissipation via (31) are all filled with solder.

2. The semiconductor package according to claim 1, wherein The diameter of the first heat dissipation hole (13) is set to 0.2mm-0.3mm; A heat dissipation copper layer (70) is also provided around the first heat dissipation via hole (13), and the thickness of the heat dissipation copper layer (70) is 0.025 mm.

3. The semiconductor package according to claim 1 or 2, wherein: The distance between the hole wall of the first heat dissipation via (13) and the edge of the pad body (10) is set to be ≥0.3 mm; The hole wall spacing between any two adjacent first heat dissipation holes (13) is set to be ≥0.3 mm.

4. The semiconductor package according to claim 1, wherein The thickness of the solder resist layer (20) protruding from the soldering surface (11) is set to 0.01 mm-0.04 mm.

5. The semiconductor package according to claim 1, wherein The width of the solder resist layer (20) is set to 0.1 mm.

6. The semiconductor package according to claim 1, wherein Also includes: A bottom heat dissipation pad (50) is embedded in a side of the substrate (30) away from the pad body (10), and a plurality of third heat dissipation vias (51) corresponding to and connected to each of the second heat dissipation vias (31) are arranged in an array on the bottom heat dissipation pad (50).

7. The semiconductor package according to claim 6, wherein: A side surface of the bottom heat dissipation pad (50) facing away from the substrate (30) is flush with a side surface of the substrate (30) facing away from the pad body (10).

8. The semiconductor package according to claim 3, wherein The substrate (30) comprises: A base material layer (32), wherein the base material layers (32) are provided in at least two pieces, and the pad body (10) is embedded in one of the base material layers (32); and The inner layer pad (33) is arranged between any two adjacent base material layers (32), and the second heat dissipation via (31) passes through each base material layer (32) and the inner layer pad (33).

9. The semiconductor package according to claim 1, wherein Also includes: A surface mount pad (60), wherein the surface mount pad (60) is provided in plurality, and the plurality of surface mount pads (60) are arranged at intervals on a side of the substrate (30) provided with the pad body (10) and surround the outer periphery of the welding surface (11); The surface mount device (40) is further provided with a plurality of functional pins (42), and each functional pin (42) is connected to a corresponding surface mount pad (60) via solder.

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