High heat dissipation packaging structure and semiconductor device
By machining grooves and setting metal layers on the surface of the grains to form a mechanical interlocking structure, the problems of lateral diffusion and splashing after the indium heat sink melts are solved, thereby improving the bonding force between the heat sink and the grains and the heat dissipation efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- FOREHOPE SEMICONDUCTOR (NINGBO) CO LTD
- Filing Date
- 2025-06-26
- Publication Date
- 2026-07-10
AI Technical Summary
In existing flip-chip packaging technology, indium heat sinks are prone to melting and volatilization during reflow soldering, resulting in abnormal voids at the contact surface, reducing heat transfer efficiency, and potentially causing device failure.
Multiple grooves are machined on the second surface of the grain, and a first metal layer is set between the heat sink and the grain to form a mechanical interlocking structure to enhance the bonding force. At the same time, deep grooves are set at the edge of the grain to limit the lateral diffusion of liquid metal.
This increases the contact area and bonding force between the heat sink and the die, enhances heat dissipation efficiency, reduces liquid metal splashing, and ensures the stability and reliability of the packaging structure.
Smart Images
Figure CN224482054U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of semiconductor processing technology, and more specifically, to a high heat dissipation packaging structure and semiconductor device. Background Technology
[0002] With the development of the microelectronics industry towards lightweighting, thinning, miniaturization, and functional diversification, traditional wire bonding interconnect technology can no longer meet the requirements of high density. Flip chip packaging technology has emerged to address this need. To meet the high heat dissipation requirements of chips, existing flip chip packaging technology requires, after soldering the die onto the substrate, to attach a heat sink to the die's surface facing away from the substrate, and then hot-pressing a heat sink cap onto the substrate's adhesive. Flux is applied between the die and the heat sink, and between the heat sink and the heat sink cap. During reflow soldering, the flux melts, connecting the die, heat sink, and heat sink cap together.
[0003] Currently, indium heat sinks are widely used in the industry. The melting point of indium heat sinks is significantly lower than the reflow soldering temperature. Therefore, indium heat sinks melt during reflow soldering and may be carried away by volatile flux, causing voids at the contact surfaces between the indium heat sink and the die, and between the indium heat sink and the heat sink cap, thus reducing heat transfer efficiency. Molten metal spatter can also overflow from the edges of the contact surfaces, leading to device failure. Utility Model Content
[0004] The purpose of this application is to address the shortcomings of the prior art by providing a high heat dissipation packaging structure and semiconductor device, which can effectively suppress the lateral diffusion after the heat sink melts and reduce liquid metal splashing.
[0005] To achieve the above objectives, the technical solutions adopted in the embodiments of this application are as follows:
[0006] In one aspect of this application, a high heat dissipation packaging structure is provided, including: a substrate, a die disposed on the substrate, and a heat sink, wherein a first surface of the die is connected to the substrate, a second surface opposite to the first surface is provided with a plurality of grooves, and the heat sink covers the grooves.
[0007] Optionally, the edge of the second surface of the grain is provided with a deep groove, the depth of which is greater than the depth of the groove.
[0008] Optionally, there are multiple deep grooves, which are distributed in a ring and surround all the recesses.
[0009] Optionally, multiple grooves cover 70% or more of the second surface of the grain.
[0010] Optionally, a first metal layer is provided between the heat sink and the die, the first metal layer being used to enhance the bonding force between the die and the heat sink.
[0011] Optionally, the first metal layer is a nickel layer, and the heat sink is an indium heat sink.
[0012] Optionally, it also includes a heat sink cover, which covers the outside of the die and the heat sink, and the surface of the heat sink facing away from the die is thermally connected to the inner surface of the heat sink cover.
[0013] Optionally, the inner surface of the heat sink is provided with a second metal layer, which is attached to the surface of the heat sink and is used to enhance the bonding force between the heat sink and the heat sink.
[0014] Optionally, the end face of the heat sink is bonded to the surface of the substrate with adhesive.
[0015] In another aspect of the embodiments of this application, a semiconductor device is provided, including a high heat dissipation packaging structure as described in any of the above claims.
[0016] The beneficial effects of this application include:
[0017] This application provides a high heat dissipation packaging structure, including: a substrate, a die disposed on the substrate, and a heat sink. A first surface of the die is connected to the substrate, and a second surface opposite to the first surface has multiple grooves, with the heat sink covering the grooves. The high heat dissipation packaging structure has multiple grooves processed on the second surface of the die, creating a rough, uneven surface. When the heat sink melts into liquid metal due to excessive reflow soldering temperature, the liquid metal fills the grooves. After solidification, the liquid metal increases the contact area between the heat sink and the die, forming a mechanical interlocking structure between them, thereby improving heat dissipation efficiency and significantly enhancing the bonding force between the heat sink and the die. Simultaneously, the rough second surface enhances capillary action, promoting the filling of liquid metal into the grooves and inhibiting its lateral diffusion, thus reducing liquid metal splashing. Attached Figure Description
[0018] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0019] Figure 1 This is a schematic diagram of the high heat dissipation packaging structure provided in the embodiments of this application;
[0020] Figure 2 This is a schematic diagram of the die structure in the high heat dissipation packaging structure provided in the embodiments of this application;
[0021] Figure 3This is one of the schematic diagrams illustrating the fabrication process of the high heat dissipation packaging structure provided in the embodiments of this application;
[0022] Figure 4 This is the second schematic diagram illustrating the fabrication process of the high heat dissipation packaging structure provided in the embodiments of this application;
[0023] Figure 5 This is the third schematic diagram illustrating the fabrication process of the high heat dissipation packaging structure provided in the embodiments of this application;
[0024] Figure 6 Fourth schematic diagram of the fabrication process of the high heat dissipation packaging structure provided in the embodiments of this application;
[0025] Figure 7 Fifth schematic diagram illustrating the fabrication process of the high heat dissipation packaging structure provided in the embodiments of this application;
[0026] Figure 8 This is the sixth schematic diagram illustrating the fabrication process of the high heat dissipation packaging structure provided in the embodiments of this application.
[0027] Icons: 100 - High heat dissipation package structure; 110 - Substrate; 120 - Die; 121 - Groove; 122 - Deep trench; 130 - Heat sink; 140 - First metal layer; 150 - Heat sink cap; 160 - Second metal layer; 170 - Adhesive; 180 - Copper pillar; 190 - Bottom filler adhesive; 200 - Wafer. Detailed Implementation
[0028] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.
[0029] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. It should be noted that, unless otherwise specified, the various features in the embodiments of this application can be combined with each other, and the combined embodiments are still within the protection scope of this application.
[0030] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.
[0031] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this application is in use. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.
[0032] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.
[0033] Regarding one aspect of the embodiments of this application, please refer to Figure 1 and Figure 2 A high heat dissipation packaging structure 100 is provided, including: a substrate 110, a die 120 disposed on the substrate 110 and a heat sink 130, wherein a first surface of the die 120 is connected to the substrate 110, and a second surface opposite to the first surface is provided with a plurality of grooves 121, and the heat sink 130 covers the grooves 121.
[0034] The multiple grooves 121 on the second surface of the grain 120 create an uneven, roughened surface. When the heat sink 130 melts into liquid metal due to excessive reflow soldering temperature, the liquid metal fills the grooves 121. After solidification, the liquid metal increases the contact area between the heat sink 130 and the grain 120, forming a mechanical interlocking structure between them. This improves heat dissipation efficiency and significantly enhances the bonding force between the heat sink 130 and the grain 120. Simultaneously, the roughened second surface enhances capillary action, promoting the filling of liquid metal into the grooves 121 and inhibiting its lateral diffusion, thereby reducing liquid metal splashing.
[0035] Alternatively, the groove 121 can be obtained by micro-etching the second surface of the grain 120. By micro-etching, a random recessed structure is formed on the second surface, thereby roughening the second surface.
[0036] Optionally, the plurality of grooves 121 cover 70% or more of the second surface of the grain 120.
[0037] The second surface has grooves 121 in more than 70% of its area, which can further increase the contact area between the heat sink 130 and the grain 120, improve the bonding force between the heat sink 130 and the grain 120, and better suppress the lateral diffusion of liquid metal and reduce the splashing of liquid metal.
[0038] Optionally, the edge of the second surface of the grain 120 is provided with a deep groove 122, the depth of the deep groove 122 being greater than the depth of the groove 121.
[0039] A deeper trench 122 can locally form a "liquid reservoir" on the second surface of the grain 120, using surface tension to confine the liquid metal within the trench 122, further reducing the risk of splashing. The trench 122 forms a physical barrier at the edge of the grain 120, restricting the liquid metal from flowing outwards and preventing the risk of short circuits caused by liquid metal overflow.
[0040] Optionally, the second surface is roughened by forming random recesses through micro-etching to obtain multiple grooves 121. Then, the grooves 121 near the edge are laser-processed to increase the depth of the grooves 121, making them deep grooves 122.
[0041] Optionally, there are multiple deep grooves 122, which are arranged in a ring and surround all the recesses 121.
[0042] The deep groove 122 is distributed in a ring shape near the edge of the second surface, which can form a "liquid pool" on the second surface to better limit the diffusion of liquid metal and make the bonding force between the heat sink 130 and the grain 120 stronger, resulting in better heat dissipation.
[0043] Alternatively, there may be one deep groove 122, which is annular and surrounds all the recesses 121.
[0044] This also better restricts the diffusion of liquid metal and increases the bonding force between the heat sink 130 and the grain 120, resulting in better heat dissipation.
[0045] Optionally, a first metal layer 140 is provided between the heat sink 130 and the die 120, and the first metal layer 140 is used to enhance the bonding force between the die 120 and the heat sink 130.
[0046] One surface of the first metal layer 140 is bonded to the heat sink 130, and the opposite surface is bonded to the grain 120. The first metal layer 140 is used to promote the bonding between the heat sink 130 and the grain 120, thereby improving the interfacial adhesion.
[0047] It is understandable that in order for the liquid metal formed by the melting of the heat sink 130 to fill the groove 121 and the deep groove 122 smoothly, the surface of the first metal layer 140 should also be an uneven and rough surface.
[0048] Optionally, a metal material is deposited onto the second surface of the grain 120 by means of material deposition to form a first metal layer 140, and the surface of the first metal layer 140 formed in this way is also a rough surface.
[0049] Optionally, the first metal layer 140 is a nickel layer, and the heat sink 130 is an indium heat sink.
[0050] Indium heat sinks possess high thermal conductivity, effectively transferring heat. Simultaneously, their soft texture and good plasticity allow them to conform closely to various irregular surfaces, further enhancing thermal conductivity. Indium heat sinks also exhibit high chemical stability, resisting oxidation, corrosion, or other chemical reactions, thus maintaining excellent thermal conductivity over long periods. The nickel layer, acting as an intermediate transition layer, effectively promotes the bonding between the indium heat sink and the backing material of the 120 grain, thereby improving the adhesion and thermal conductivity between the indium heat sink and the 120 grain.
[0051] Optionally, the high heat dissipation package structure 100 further includes a heat sink 150, which covers the die 120 and the heat sink 130. The surface of the heat sink 130 facing away from the die 120 is thermally connected to the inner surface of the heat sink 150. In this way, the heat generated by the die 120 can be conducted and released through the heat sink 130 and the heat sink 150.
[0052] Optionally, the inner surface of the heat sink 150 is provided with a second metal layer 160, which is attached to the surface of the heat sink 130. The second metal layer 160 is used to enhance the bonding force between the heat sink 150 and the heat sink 130.
[0053] Optionally, the second metal layer 160 is a nickel layer, and the heat sink 130 is an indium heat sink.
[0054] Optionally, the end face of the heat sink 150 is bonded to the surface of the substrate 110 by adhesive 170.
[0055] The heat sink 150 is bonded to the substrate 110 using adhesive 170, a simple and convenient process. Adhesive 170 is typically an AD adhesive.
[0056] Optionally, the first surface of the die 120 is provided with copper pillars 180, and the die 120 is soldered to the substrate 110 through the copper pillars 180.
[0057] The number of copper pillars 180 can be multiple, and multiple copper pillars 180 can be simultaneously welded to the substrate 110, thereby improving the reliability of the connection between the die 120 and the substrate 110.
[0058] After multiple copper pillars 180 are soldered to the substrate 110, gaps exist between the copper pillars 180. To further improve the reliability of the connection between the die 120 and the substrate 110, optionally, an underfill adhesive 190 is filled between the die 120 and the substrate 110, and the underfill adhesive 190 wraps around the copper pillars 180. The underfill adhesive 190 tightly adheres the die 120, the copper pillars 180, and the substrate 110 together.
[0059] The fabrication process of the above-mentioned high heat dissipation packaging structure 100 is as follows: Please refer to... Figure 3 and Figure 4 Micro-etching is performed on wafer 200 to roughen its surface and form grooves 121; please refer to the reference. Figure 2 Laser processing is performed on the grooves 121 near the edges of each die 120 in wafer 200 to create deep grooves 122, the depth of which is greater than the depth of the grooves 121; please refer to Figure 5 A nickel layer is formed on the back side of wafer 200 using PVD (Physical Vapor Deposition); please refer to... Figure 6 The wafer 200 is diced into individual dies 120 by electroplating copper pillars 180 using a bumping process, and then the individual dies 120 are mounted onto the substrate 110. Finally, the bottom of the copper pillars 180 is filled. Please refer to [reference needed]. Figure 7 Spray flux onto the back side (second surface) of die 120, and attach the indium heat sink to the back side of die 120; please refer to... Figure 8 Apply adhesive (170) to the outermost ring of substrate 110; please refer to... Figure 1 Flux is sprayed onto the indium heat sink, and the nickel-plated metal cover is hot-pressed onto the adhesive 170 on the substrate 110. The bonding of the die 120, the indium heat sink, and the heat sink cover 150 is achieved by reflow soldering.
[0060] This embodiment also provides a semiconductor device, including the high heat dissipation packaging structure 100 as described above.
[0061] This semiconductor device includes the same structure and beneficial effects as the high heat dissipation package structure 100 in the foregoing embodiments. The structure and beneficial effects of the high heat dissipation package structure 100 have been described in detail in the foregoing embodiments and will not be repeated here.
[0062] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. A high heat dissipation packaging structure, characterized in that, include: The substrate, the die disposed on the substrate, and the heat sink, wherein the first surface of the die is connected to the substrate, the second surface opposite to the first surface is provided with a plurality of grooves, and the heat sink covers the grooves.
2. The high heat dissipation packaging structure as described in claim 1, characterized in that, The edge of the second surface of the grain is provided with a deep groove, the depth of which is greater than the depth of the groove.
3. The high heat dissipation packaging structure as described in claim 2, characterized in that, The number of deep grooves is multiple, and the multiple deep grooves are distributed in a ring and surround all the grooves.
4. The high heat dissipation packaging structure as described in claim 1, characterized in that, The plurality of grooves cover 70% or more of the second surface of the grain.
5. The high heat dissipation packaging structure as described in claim 1, characterized in that, A first metal layer is provided between the heat sink and the grain, and the first metal layer is used to enhance the bonding force between the grain and the heat sink.
6. The high heat dissipation packaging structure as described in claim 5, characterized in that, The first metal layer is a nickel layer, and the heat sink is an indium heat sink.
7. The high heat dissipation packaging structure as described in claim 1, characterized in that, It also includes a heat dissipation cover, which covers the outside of the chip and the heat sink, and the surface of the heat sink facing away from the chip is thermally connected to the inner surface of the heat dissipation cover.
8. The high heat dissipation packaging structure as described in claim 7, characterized in that, The inner surface of the heat sink cover is provided with a second metal layer, which is attached to the surface of the heat sink fin. The second metal layer is used to enhance the bonding force between the heat sink cover and the heat sink fin.
9. The high heat dissipation packaging structure as described in claim 7, characterized in that, The end face of the heat sink is bonded to the surface of the substrate with adhesive.
10. A semiconductor device, characterized in that, Includes the high heat dissipation packaging structure as described in any one of claims 1 to 9.