Colloid quick-change type soft pressing head for silver sintering

Abstract

The invention discloses a colloid quick-change type soft pressing head for silver sintering, which comprises a pressing head seat body, silica gel, a rubber hanging plate, a pressing ring and a piston ring, a rubber plate is arranged in the pressing head seat body and is connected with the pressing head seat body, the silica gel is adhered to the outer wall of the rubber plate, the pressing ring is sleeved on the periphery of the silica gel, and the piston ring is connected with the rubber hanging plate. A mounting groove is formed in the outer wall of the pressing ring, and the piston ring is arranged in the mounting groove. Through the application of the colloid quick-change type soft pressing head for silver sintering, the colloid quick-change type soft pressing head for silver sintering can evenly transmit pressure, and the phenomenon that pressure concentration is prone to being generated by a traditional hard pressing head is effectively relieved; meanwhile, in the high-temperature and high-pressure environment in the sintering process, the nano-silver paste cannot be chemically reacted with the nano-silver paste, so that the adverse conditions that the pressure head is polluted, the performance of the nano-silver paste is degraded and the like are avoided; in addition, the device can adapt to sintered workpieces of different sizes and different shapes, and is high in universality and wide in adaptation range.

Description

Technical Field

[0001] This invention relates to the field of silver sintering technology for power semiconductor packaging, and more particularly to a colloidal quick-change soft pressure head for silver sintering. Background Technology

[0002] Silver sintering technology is a high-temperature resistant encapsulation and connection technology that utilizes nano-silver paste under certain temperature and pressure. Its core principle is that the organic components in the nano-silver paste decompose and volatilize during the sintering process, ultimately forming a silver connection layer. This technology can meet the high-temperature service requirements of third-generation semiconductor power module packaging interconnection and has been widely used in the manufacturing process of power devices.

[0003] During the silver sintering process, specific pressures and temperatures must be applied to the sintering material to ensure sintering quality. Traditional sintering heads are mostly made of hard materials such as metals and ceramics. However, these hard heads are prone to chemical reactions with nano-silver paste under high temperature and pressure, leading to head contamination, degradation of nano-silver paste performance, and even sintering failure. The rigidity of these hard heads can also cause uneven pressure distribution, resulting in cracks in the chip or DBC board, seriously affecting the stability and consistency of sintering quality. In addition, traditional sintering heads require a dedicated model for each product, resulting in extremely poor versatility. Summary of the Invention

[0004] In view of this, in order to solve the above problems, the purpose of this invention is to provide a colloidal quick-change soft pressure head for silver sintering, comprising: a pressure head base body, silicone, a hanging plate, a pressure ring, and a piston ring. The hanging plate is disposed in the pressure head base body and connected to the pressure head base body. The silicone is bonded to the outer wall of the hanging plate. The pressure ring is sleeved around the silicone. An installation groove is formed on the outer wall of the pressure ring, and the piston ring is disposed in the installation groove.

[0005] In another preferred embodiment, the pressure head seat includes a connecting plate and a mounting base. The mounting base is connected to the lower end of the connecting plate, and a pressure head cavity is formed through the middle of the mounting base. The hanging rubber plate, the silicone rubber, the pressure ring, and the piston ring are all disposed in the pressure head cavity.

[0006] In another preferred embodiment, it further includes: pressure plates and set screws, wherein a plurality of pressure plates are provided at the lower end of the mounting base, the plurality of pressure plates are evenly arranged along the circumferential direction of the mounting base, each pressure plate is connected to the mounting base by a set screw, and the lower end of the pressure ring is operably in contact with the pressure plate.

[0007] In another preferred embodiment, the lower end of the hanging plate is provided with a plurality of locking grooves, and the silicone is bonded to the inner wall of the locking grooves.

[0008] In another preferred embodiment, the adhesive groove is T-shaped.

[0009] In another preferred embodiment, the connecting plate has a plurality of first threaded holes, and the hanging plate has a plurality of second threaded holes. Each first threaded hole is directly opposite to a second threaded hole. Hanging plate screws are provided in the first threaded holes and the second threaded holes, and the hanging plate and the connecting plate are connected by the hanging plate screws.

[0010] In another preferred embodiment, the piston ring is an open ring.

[0011] The present invention, by employing the above-mentioned technical solution, has the following positive effects compared with the prior art: By applying the present invention, a colloidal quick-change soft pressure head for silver sintering is proposed. By incorporating silicone, it can uniformly transmit pressure, effectively alleviating the pressure concentration phenomenon easily caused by traditional hard pressure heads, thereby effectively reducing the risk of cracks in chips and DBC boards due to excessive local stress. Simultaneously, silicone possesses excellent corrosion resistance and chemical stability, and will not chemically react with nano-silver paste under the high temperature and high pressure environment of the sintering process, thus helping to avoid adverse conditions such as pressure head contamination and nano-silver paste performance degradation. Furthermore, silicone, by utilizing its own elastic deformation characteristics, can adapt to sintering workpieces of different sizes and shapes, eliminating the need for a separate pressure head for each specification of product, thus improving the versatility and adaptability of the pressure head. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structure of a colloidal quick-change soft pressure head for silver sintering according to the present invention;

[0013] Figure 2 This is a schematic diagram of the structure of a colloidal quick-change soft pressure head for silver sintering according to the present invention from another perspective.

[0014] Figure 3 This is a schematic diagram of the structure of the hanging plate of a colloidal quick-change soft pressure head for silver sintering according to the present invention;

[0015] Figure 4 This is a cross-sectional view of the hanging plate of a colloidal quick-change soft pressure head for silver sintering according to the present invention.

[0016] In the attached image:

[0017] 1. Pressure head seat; 2. Silicone; 3. Hanging plate; 4. Pressure ring; 5. Piston ring; 6. Pressure plate; 7. Set screw; 8. Hanging plate screw; 11. Connecting plate; 12. Mounting base. Detailed Implementation

[0018] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] In the description of this invention, it should be understood that the orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", "inner", "outer", "front", "rear", "lateral", and "vertical" are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or component referred to must have a specific orientation, and therefore should not be construed as a limitation of this invention.

[0020] It should be noted that the terms "horizontal" and "vertical" in this invention are used to describe approximate positional relationships, and not strictly "horizontal plane" or "vertical plane".

[0021] like Figure 1-4 The figure shows a preferred embodiment of a colloidal quick-change soft pressure head for silver sintering, comprising: a pressure head base 1, silicone rubber 2, a hanging plate 3, a pressure ring 4, and a piston ring 5. The hanging plate 3 is disposed inside the pressure head base 1 and is connected to the pressure head base 1. The silicone rubber 2 is bonded to the outer wall of the hanging plate 3. The silicone rubber 2 can directly contact the sintered workpiece, and it can transmit uniform pressure and avoid pressure concentration. At the same time, the silicone rubber 2 has excellent high temperature resistance and corrosion resistance, and it will not react with the nano silver paste, which helps to avoid contaminating the nano silver paste. The pressure ring 4 is sleeved around the silicone rubber 2, and an installation groove is opened on the outer wall of the pressure ring 4. The piston ring 5 is disposed in the installation groove.

[0022] Furthermore, as a preferred embodiment, the pressure head seat 1 includes a connecting plate 11 and a mounting base 12. The mounting base 12 is connected to the lower end of the connecting plate 11, and a pressure head cavity is formed through the middle of the mounting base 12. The hanging rubber plate 3, silicone rubber 2, pressure ring 4 and piston ring 5 are all disposed in the pressure head cavity.

[0023] Furthermore, in a preferred embodiment, the upper end of the connecting plate 11 is provided with a positioning hole, and a bolt is installed in the positioning hole. The connecting plate 11 is connected to the heating plate of the sintering machine by the bolt. Furthermore, the heat generated by the heating plate can be conducted through the connecting plate 11 to the mounting base 12, and then from the mounting base 12 to the hanging plate 3 and the silicone 2, and finally from the silicone 2 to the sintering workpiece, forming a uniform heat conduction path from the heating plate to the sintering workpiece.

[0024] Furthermore, in a preferred embodiment, it further includes: a pressure plate 6 and a set screw 7. A plurality of pressure plates 6 are provided at the lower end of the mounting base 12, and the pressure plates 6 are evenly arranged along the circumference of the mounting base 12. Each pressure plate 6 is connected to the mounting base 12 by a set screw 7. The lower end of the pressure ring 4 is operably in contact with the pressure plate 6. Furthermore, by the pressure plate 6 abutting against the lower end face of the pressure ring 4, the axial displacement of the pressure ring 4 can be restricted, preventing the pressure ring 4 from dislodging from the pressure head cavity.

[0025] Furthermore, as a preferred embodiment, the pressure ring 4 and the inner wall of the pressure head cavity are in clearance fit, and the pressure ring 4 can move flexibly along the axial direction of the pressure head cavity, thereby adapting to the pressure transmission and sealing compensation requirements during the sintering process.

[0026] Furthermore, in a preferred embodiment, the lower end of the hanging plate 3 is provided with several locking grooves, and the silicone 2 is bonded to the inner wall of the locking grooves. Further, the locking grooves are used to enhance the bonding strength between the silicone 2 and the hanging plate 3, preventing the silicone 2 from falling off or dropping under high-temperature sintering conditions.

[0027] Furthermore, as a preferred embodiment, the adhesive groove is T-shaped.

[0028] In another embodiment of the present invention, the adhesive groove is V-shaped.

[0029] Furthermore, in a preferred embodiment, the connecting plate 11 has a plurality of first threaded holes, and the hanging plate 3 has a plurality of second threaded holes. Each first threaded hole is aligned with a second threaded hole. A hanging plate screw 8 is installed in each of the first and second threaded holes, and the hanging plate 3 and the connecting plate 11 are connected by the hanging plate screw 8. Furthermore, the silicone 2 and the hanging plate 3 can be manufactured as an integrated functional component. When the silicone 2 needs to be replaced, simply unscrew the hanging plate screw 8 to remove the old functional component from the pressure head seat 1, align the new functional component with the first threaded hole of the connecting plate 11, and tighten the hanging plate screw 8 to complete the replacement. The entire process does not require on-site silicone pouring or complex adjustments, which improves replacement efficiency.

[0030] Furthermore, in a preferred embodiment, the piston ring 5 is an open circular ring. Further, during assembly, the piston ring 5 needs to be fitted into the mounting groove of the pressure ring 4 using a special tool to close the opening, and then placed into the pressure head cavity along with the pressure ring 4. After releasing the special tool, the piston ring 5 can open due to its own elastic tension, and its outer circumferential surface tightly fits against the inner wall of the pressure head cavity, blocking the gas flow between the pressure head cavity and the outside, forming a radial seal.

[0031] In another embodiment of the present invention, when the soft pressure head is applied to the low-pressure sintering process, the piston ring 5 and the corresponding mounting groove can be eliminated. At this time, the clearance fit between the pressure ring 4 and the pressure head cavity can meet the low-pressure sealing requirements, which is beneficial to simplify the structure and reduce the cost of use.

[0032] The working principle of this invention is as follows: During the sintering operation, the sintering machine can drive the pressure head seat 1 to move downward, so that the pressure ring 4 and the silicone 2 can be in close contact with the sintering fixture. As the sintering machine continues to apply pressure downward to the pressure head seat 1, a completely sealed cavity will be formed between the pressure head cavity of the pressure head seat 1, the sintering fixture, and the silicone 2. The pressure applied by the sintering machine is transmitted to the sealed cavity through the pressure head seat 1, so that a stable pressure is generated inside the sealed cavity. Since the silicone 2 has excellent flexibility and elasticity, the pressure will be evenly transmitted to the surface of the sintered workpiece below through the silicone 2, forming an isotropic uniform pressure field. This pressure field can effectively avoid the pressure concentration problem caused by traditional hard pressure heads, ensuring that the nano silver paste is evenly spread and densified during the sintering process, which is beneficial to improving the bonding strength and consistency of the silver bonding layer.

[0033] The above description is merely a preferred embodiment of the present invention and does not limit the implementation and protection scope of the present invention. Those skilled in the art should realize that any equivalent substitutions and obvious changes made based on the description and illustrations of the present invention should be included within the protection scope of the present invention.

Claims

1. A colloidal quick-change soft pressure head for silver sintering, characterized in that, include: The pressure head base body, silicone, a hanging plate, a pressure ring, and a piston ring are provided. The hanging plate is disposed in the pressure head base body and connected to the pressure head base body. The silicone is bonded to the outer wall of the hanging plate. The pressure ring is sleeved around the silicone and has an installation groove on its outer wall. The piston ring is disposed in the installation groove.

2. The colloidal quick-change soft pressure head for silver sintering according to claim 1, characterized in that, The pressure head seat includes a connecting plate and a mounting base. The mounting base is connected to the lower end of the connecting plate. A pressure head cavity is formed through the middle of the mounting base. The hanging rubber plate, the silicone rubber, the pressure ring, and the piston ring are all disposed in the pressure head cavity.

3. The colloidal quick-change soft pressure head for silver sintering according to claim 2, characterized in that, Also includes: The mounting base has a plurality of pressure plates at its lower end, which are evenly arranged along the circumference of the mounting base. Each pressure plate is connected to the mounting base by a set screw. The lower end of the pressure ring is operably in contact with the pressure plate.

4. The colloidal quick-change soft pressure head for silver sintering according to claim 1, characterized in that, The lower end of the hanging plate is provided with several locking grooves, and the silicone is bonded to the inner wall of the locking grooves.

5. The colloidal quick-change soft pressure head for silver sintering according to claim 4, characterized in that, The locking groove is T-shaped.

6. The colloidal quick-change soft pressure head for silver sintering according to claim 1, characterized in that, The connecting plate has a plurality of first threaded holes, and the hanging plate has a plurality of second threaded holes. Each first threaded hole is directly opposite to a second threaded hole. Hanging plate screws are provided in the first threaded holes and the second threaded holes. The hanging plate and the connecting plate are connected by the hanging plate screws.

7. The colloidal quick-change soft pressure head for silver sintering according to claim 1, characterized in that, The piston ring is an open circular ring.

Images