Heat dissipation cover and heat dissipation structure for blocking indium sheet reflow soldering leakage
By designing a heat dissipation cap and structure with reflow grooves and solder layers during the chip packaging process, the indium wafer sputtering problem is solved, ensuring connection stability and heat transfer, and protecting the chip and electronic components.
Patent Information
- Application Number
- CN202520108618.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-17
- Publication Date
- 2026-01-09
- Estimated Expiration
- 2035-01-17
AI Technical Summary
During chip packaging, indium wafers are prone to scattering and sputtering after melting at high temperatures during vacuum reflow soldering, which can contaminate the chip or other electronic components and affect product performance.
Design a heat sink and heat dissipation structure, including an inner wall reflow groove and a solder layer. The reflow groove blocks indium wafer sputtering, the solder layer ensures connection stability, and the outer ring and blocking protrusion further reduce the risk of sputtering.
It effectively reduces the possibility of indium wafers sputtering to the surrounding area during reflow soldering, protecting the chip and other electronic components, and ensuring connection quality and heat transfer efficiency.
Smart Images
Figure CN223786518U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical field of heat dissipation structures for chip packaging, and in particular to a heat dissipation cover and heat dissipation structure for blocking leakage during reflow soldering of indium wafers. Background Technology
[0002] In encapsulated products, indium foil is often regarded as a substitute for traditional thermal interface materials due to its excellent thermal conductivity. Its thermal conductivity is higher than that of traditional adhesives, providing an ideal material basis for efficient thermal management.
[0003] Unlike the traditional process of applying adhesive to the chip surface, attaching a cover, and then curing, after the indium wafer is mounted, a cover is attached, and then vacuum reflow soldering is used to achieve curing, ensuring efficient heat conduction between the indium wafer, the chip, and the heat sink.
[0004] However, during vacuum reflow soldering, the edges of the indium wafer melt at high temperatures and then scatter and sputter everywhere, which may contaminate the chip or spill over into electronic components such as capacitors, causing their electrical performance to fail and affecting product performance. Utility Model Content
[0005] To reduce the possibility of indium sheets sputtering during reflow soldering, this application provides a heat sink and heat dissipation structure for preventing leakage during indium sheet reflow soldering.
[0006] In a first aspect, this application provides a heat dissipation cover for blocking reflow soldering leakage of indium sheets, which adopts the following technical solution: A heat dissipation cover for blocking reflow soldering leakage of indium sheets includes a heat dissipation shell, the inner wall of the heat dissipation shell has a first contact surface for connection, the inner wall of the heat dissipation shell has a reflow groove, the reflow groove surrounds the first contact surface, and the distance between the first contact surface and the inner edge of the reflow groove is x, where x is greater than or equal to 0.
[0007] By adopting the above technical solution, if the edge of the indium sheet becomes scattered after melting at high temperature during the reflow soldering process, it will fall or splash into the reflow tank under the action of gravity, reducing the possibility of the molten indium sheet splashing to the outside.
[0008] Preferably, x equals 0, and the inner wall of the heat dissipation housing has a solder layer, which includes at least a first part and a second part. The first part covers the first contact surface, and the second part is connected to the outside of the first part and fits and covers the inner wall of the return channel.
[0009] Preferably, the inner wall of the heat dissipation housing, located outside the return groove, is an outer annular surface, and the solder layer further includes a third part connected to the outside of the second part and attached to and covering the inner side of the outer annular surface.
[0010] By adopting the above technical solution, the solder layer can be operated on a single plane during the solder layer construction process, and the solder layer can be extended to the outer ring surface. If the indium foil overflows slightly outward, it can also come into contact with the solder layer.
[0011] Secondly, this application provides a heat dissipation structure for blocking reflow soldering leakage of indium sheets, adopting the following technical solution: A heat dissipation structure for blocking reflow soldering leakage of indium sheets includes a package and a heat dissipation shell as described above. The side of the package facing the heat dissipation shell is a second contact surface. An indium sheet is provided between the package and the solder layer. The edge of the indium sheet is located within the projection of the reflow groove in a first direction. The direction perpendicular to the second contact surface is the first direction. The projections of the second contact surface and the first contact surface in the first direction at least partially overlap.
[0012] Preferably, the projection of the second contact surface onto the first contact surface in the first direction coincides.
[0013] Preferably, the outer edge of the indium sheet extends away from the center to the outside of the second contact surface.
[0014] Preferably, the vertical distance between the first contact surface and the second contact surface is c, and the vertical distance between the outer annular surface and the second contact surface is d, where c is greater than d.
[0015] By adopting the above technical solution, during the reflow soldering process, due to the higher height of the outer ring surface, when the indium wafer sputters outward, a portion of it can be blocked by the higher outer ring surface.
[0016] Preferably, the indium sheet has a trapezoidal vertical cross-section, and the bottom surface of the smaller side of the vertical cross-section is close to the first contact surface.
[0017] By adopting the above technical solution, under the action of gravity, when the indium sheet melts, the side of the indium sheet closer to the second contact surface is more likely to flow towards the side of the return tank.
[0018] Preferably, the depth of the reflux groove gradually decreases from the inside to the outside.
[0019] By adopting the above technical solution, after the indium sheet flows downwards, it is easier for it to accumulate inwards, reducing the possibility of indium sheet splashing outwards.
[0020] Preferably, the outer ring surface has a blocking protrusion along the extension direction of the return groove, and there is a gap between the third part and the blocking protrusion.
[0021] By adopting the above technical solution, the indium sheet can be sputtered outward by blocking the protrusion ring. At the same time, the indium sheet will remain inside the blocking protrusion ring after being blocked. The structure of having a blocking protrusion ring but not contacting the solder layer can avoid the need to perform back gold on the blocking protrusion ring part during back gold.
[0022] In summary, this application includes at least one of the following beneficial technical effects: during the reflow soldering process, if the edge of the indium sheet becomes scattered after melting at high temperature, it will fall or sputter into the reflow tank under the action of gravity, reducing the possibility of the molten indium sheet sputtering to the outside. Attached Figure Description
[0023] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of this application;
[0024] Figure 2 yes Figure 1 A magnified view of part A in the middle;
[0025] Figure 3 This is a partial structural diagram of the solder layer in Embodiment 1 of this application;
[0026] Figure 4 This is a schematic diagram of the structure of Embodiment 2 of this application;
[0027] Figure 5 A magnified view of part B in the middle section;
[0028] Figure 6 This is a partial structural diagram of Embodiment 3 of this application;
[0029] Figure 7 This is a partial structural diagram of Embodiment 4 of this application.
[0030] Explanation of reference numerals in the attached drawings: 100, package; 110, heat sink housing; 111, indium sheet; 112, solder layer; 113, reflow groove; 114, second contact surface; 115, first contact surface; 116, first part; 117, second part; 118, third part; 120, outer annular surface; 121, blocking protrusion. Detailed Implementation
[0031] The present application will be further described in detail below with reference to the accompanying drawings, which are for structural illustration only.
[0032] Example 1: Refer to Figure 1 , Figure 2Embodiment 1 of this application discloses a heat dissipation cover for preventing leakage during reflow soldering of indium sheet 111, including a heat dissipation shell 110. The inner wall of the heat dissipation shell 110 has a first contact surface 115 for connection, and the inner wall of the heat dissipation shell 110 has a reflow groove 113. The reflow groove 113 surrounds the first contact surface 115. Specifically, in this embodiment, the first contact surface 115 is rectangular, and the distance between the first contact surface 115 and the inner edge of the reflow groove 113 is x, where x is greater than or equal to 0.
[0033] In this embodiment, x is 0, meaning that the inner edge of the return channel 113 is connected to the edge of the first contact surface 115. The inner wall of the heat sink 110 has a solder layer 112, which is formed on the inner wall of the heat sink 110 by a back gold process. Generally, it is a back gold layer, which allows for better connection between the indium sheet 111 and the heat sink cover. The solder layer 112 has a uniform thickness.
[0034] Reference Figure 2 , Figure 3 The solder layer 112 includes a first part 116, a second part 117, and a third part 118. The first part 116 covers the first contact surface 115, and the second part 117 is connected to the outside of the first part 116 and adheres to and covers the inner wall of the return channel 113. The inner wall of the heat sink housing 110, located outside the return channel 113, is an outer annular surface 120, and the third part 118 adheres to and covers the inner side of the outer annular surface 120.
[0035] Example 2: Based on Example 1, Example 2 of this application discloses a heat dissipation structure for blocking leakage during indium sheet reflow soldering, referring to... Figure 4 , Figure 5 The package includes a package 100 and the aforementioned heat sink 110. The side of the package 100 facing the heat sink 110 is the second contact surface 114. In this embodiment, the second contact surface 114 is parallel to the first contact surface 115. In other embodiments, the two may be inclined to each other.
[0036] In this embodiment, the direction perpendicular to the second contact surface 114 is defined as the first direction. The projections of the second contact surface 114 and the first contact surface 115 in the first direction at least partially overlap, and in this embodiment, they coincide. The edge of the indium sheet 111 is located within the projection of the return groove 113 in the first direction. Specifically, in this embodiment, the outer edge of the indium sheet 111 extends away from the center to the outside of the second contact surface 114. The length of the outer edge of the indium sheet 111 extending to the outside of the second contact surface 114 is a, and the width of the return groove 113 is b, where a is not greater than 0.5b.
[0037] The implementation principle of Embodiment 2 of this application is as follows: During reflow soldering, after the indium sheet 111 melts at high temperature, its edge will overflow outwards, thus preferentially overflowing into the reflow tank 113, reducing the possibility of splashing affecting electrical components. A larger indium sheet covering the first contact surface 114 and the second contact surface 115 can also ensure the connection effect and the efficiency of heat transfer.
[0038] Example 3: Reference Figure 6 The difference from Embodiment 2 is that the vertical distance between the first contact surface 115 and the second contact surface 114 is c, and the vertical distance between the outer ring surface 120 and the second contact surface 114 is d, where c is greater than d. This causes the middle part of the heat sink housing 110 to be concave, thereby making the outer ring surface 120 relatively convex. Simultaneously, the vertical cross-section of the indium sheet 111 is trapezoidal, with the smaller bottom side of the indium sheet 111 closer to the first contact surface 115. In this embodiment, the depth of the return groove 113 gradually decreases from the inner to the outer side.
[0039] In this embodiment, during the reflow soldering process, the indium sheet 111, with its trapezoidal vertical cross-section, flows more easily towards the reflow tank 113 from the side closer to the second contact surface 114. This allows the indium sheet 111 to enter the reflow tank 113 more effectively. Furthermore, after entering the reflow tank 113, due to the change in depth, the indium sheet 111 will flow as inwards as possible. Simultaneously, due to the distance difference between the second contact surface 114 and the first contact surface 115, the portion of the second part 117 near the outer ring surface 120 can effectively prevent the indium sheet 111 from splashing outwards.
[0040] Example 4: Reference Figure 7 The difference from Embodiment 1 is that a blocking protrusion 121 is provided on the outer annular surface 120 along the extension direction of the return groove 113, and a gap exists between the third portion 118 and the blocking protrusion 121. Firstly, the blocking protrusion 121 can prevent the indium sheet 111 from sputtering outwards. Simultaneously, the indium sheet 111, after being blocked, will remain inside the blocking protrusion 121. The gap between the blocking protrusion 121 and the third portion 118 can also serve as a channel for retaining the indium sheet, thereby ensuring that the edge of the indium sheet 111 remains in contact with the solder layer 112. Furthermore, during the back-golding operation in the first direction, since there is a predetermined distance between the blocking protrusion 121 and the third portion 118, it is not necessary to perform back-golding on the blocking protrusion 121 portion.
[0041] The embodiments described in this specific implementation are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.
Claims
1. A heat sink cover for preventing leakage during reflow soldering of indium sheets, comprising a heat sink housing (110), characterized in that: The inner wall of the heat dissipation housing (110) has a first contact surface (115) for connection, and the inner wall of the heat dissipation housing (110) has a return groove (113) that surrounds the first contact surface (115). The distance between the first contact surface (115) and the inner edge of the return groove (113) is x, where x is greater than or equal to 0.
2. A heat dissipation cap for preventing leakage during reflow soldering of indium sheets according to claim 1, characterized in that: x equals 0, and the inner wall of the heat dissipation housing (110) has a solder layer (112). The solder layer (112) includes at least a first part (116) and a second part (117). The first part (116) covers the first contact surface (115), and the second part (117) is connected to the outside of the first part (116) and fits and covers the inner wall of the return groove (113).
3. A heat dissipation cap for preventing leakage during reflow soldering of indium sheets according to claim 2, characterized in that: The inner wall of the heat sink housing (110) and located outside the return groove (113) is an outer ring surface (120). The solder layer (112) also includes a third part (118) connected to the outside of the second part (117) and attached to and covering the inner side of the outer ring surface (120).
4. A heat dissipation structure for preventing leakage during reflow soldering of indium sheets, characterized in that: The package includes a package (100) and a heat dissipation housing (110) as described in any one of claims 1-3, wherein the side of the package (100) facing the heat dissipation housing (110) is a second contact surface (114), and an indium sheet (111) is provided between the package (100) and the solder layer (112), wherein the edge of the indium sheet (111) is located within the projection of the return groove (113) in a first direction; The direction perpendicular to the second contact surface (114) is the first direction, and the projections of the second contact surface (114) and the first contact surface (115) in the first direction have at least partial overlap.
5. A heat dissipation structure for blocking leakage during reflow soldering of indium sheets according to claim 4, characterized in that: The projection of the second contact surface (114) and the first contact surface (115) in the first direction coincides.
6. A heat dissipation structure for blocking leakage during reflow soldering of indium sheets according to claim 5, characterized in that: The outer edge of the indium sheet (111) extends away from the center to the outside of the second contact surface (114).
7. A heat dissipation structure for blocking leakage during reflow soldering of indium sheets according to claim 6, characterized in that: The vertical distance between the first contact surface (115) and the second contact surface (114) is c, and the vertical distance between the outer ring surface (120) and the second contact surface (114) is d, where c is greater than d.
8. A heat dissipation structure for blocking leakage during reflow soldering of indium sheets according to claim 7, characterized in that: The vertical cross-section of the indium sheet (111) is trapezoidal, and the bottom surface of the smaller side of the vertical cross-section of the indium sheet (111) is close to the first contact surface (115).
9. A heat dissipation structure for blocking leakage during reflow soldering of indium sheets according to claim 8, characterized in that: The depth of the reflux groove (113) gradually decreases from the inside to the outside.
10. A heat dissipation structure for blocking leakage during reflow soldering of indium sheets according to claim 6, characterized in that: The outer annular surface (120) has a blocking protrusion (121) along the extension direction of the return groove (113), and there is a gap between the third part (118) and the blocking protrusion (121).