Wafer level package reflow soldering anti-warping self-adaptive reinforcement device and method
Patent Information
- Application Number
- CN202511731349.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-24
- Publication Date
- 2026-09-22
- Estimated Expiration
- 2045-11-24
AI Technical Summary
由于高温下真空密封较为困难,同时吸附力会导致基本那局部应力和变形,影响基板回流焊质量;传统刚性夹具无法适应基板在加热过程中的微小膨胀/收缩,反而引入额外应力,加剧局部损伤或导致夹具变形,压力分布不均,同时容易划伤基板表面器件
本发明通过将待回流焊晶圆级基板安装在支撑平台上,格栅式压紧机构通过压紧力施加机构的预紧力紧固晶圆级基板,底部碟簧浮动结构能够自适应补偿回流焊过程的局部热应力不均,有效抑制热应力引起的基板变形与翘曲,保持整体结构的平整度。本发明提出的加固装置能够解决晶圆级回流焊过程中由热应力引起的基板翘曲等失效,适配多种封装的晶圆级回流焊,拆装方便,提高晶圆级封装的焊接可靠性。
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Figure CN121607736B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of reflow soldering technology, and specifically relates to a wafer-level packaging reflow soldering anti-warping adaptive reinforcement device and method. Background Technology
[0002] As Moore's Law slows down and performance improvements in traditional single-chip applications become limited, technologies such as heterogeneous integration are reshaping the design paradigm for high-performance computing and AI accelerators. Wafer-level packaging (WLP) is an advanced packaging technology that enables wafer-level system integration. It integrates multiple chips, devices, and functional modules onto a single wafer-level substrate, breaking through the limitations of single-chip size and interconnection to achieve high-density heterogeneous integration.
[0003] In the core process flow of wafer-level packaging, reflow soldering is a critical step to ensure reliable connection between the chip and the substrate. The solder bumps on the bottom of the chip are melted, wetted, and solidified during reflow soldering, forming the electrical and mechanical interconnects between the chip and the wafer-level substrate. The composite structure formed by the silicon chip, the polymer dielectric / metal of the redistribution layer (RDL), the underfill material, and the wafer-level substrate is subjected to severe thermal loads (peak temperatures reaching 240℃~260℃) during reflow soldering. Due to the mismatch in the thermal expansion coefficients of the different materials, the overall structure generates significant thermomechanical stress. The 12-inch wafer-level substrate is a crucial carrier for devices and interconnects. When the thermal stress exceeds the material's yield strength, the organic substrate often exhibits a "V"-shaped warping under gravity due to the localized thermal stress contraction effect. This can lead to failures such as poor solder joints, excessive localized stress causing pin tearing, and other issues.
[0004] Wafer-level substrate warping leads to decreased mounting quality, poor solder joint coplanarity, and problems such as cold solder joints, bridging, and uneven solder ball height, resulting in reduced yield. Excessive stress concentration at weak points such as chip edges can cause brittle chip cracking, solder joint fatigue failure, and interconnect structure breakage. For substrates with complex structures, excessive local stress can cause substrate material tearing or delamination, posing a systemic and multi-layered severe challenge to subsequent precision manufacturing processes such as chip mounting. Conventional clamping structures include traditional rigid fixtures and vacuum adsorption carriers. Since vacuum sealing is difficult at high temperatures, and adsorption forces can cause localized stress and deformation, affecting the reflow soldering quality of the substrate, traditional rigid fixtures cannot adapt to the slight expansion / contraction of the substrate during heating. Instead, they introduce additional stress, exacerbating local damage or causing fixture deformation, uneven pressure distribution, and easily scratching devices on the substrate surface.
[0005] With the increasing demand for wafer-level packaging, there is an urgent need for a reinforcement technology that can adaptively apply uniform and controllable pressure in high-temperature environments and provide effective structural support to effectively suppress wafer-level substrate warpage while avoiding the introduction of additional stress, thereby reducing the risk of warpage failure during the reflow soldering process. Summary of the Invention
[0006] The purpose of this invention is to provide a wafer-level packaging reflow soldering anti-warping adaptive reinforcement device and method. This invention applies a controllable and uniform bearing force to the wafer-level substrate assembly during reflow soldering to compensate for and counteract thermal stress caused by mismatched coefficients of thermal expansion. This effectively suppresses warping deformation of the wafer-level substrate caused by thermal stress during reflow soldering, ensuring the coplanarity and stability of the solder interface. This reinforcement device is compatible with existing reflow soldering equipment, is easy to operate and disassemble, and reduces the risk of damage to devices on the substrate surface.
[0007] To address the aforementioned technical problems, this invention provides a wafer-level packaging reflow soldering anti-warpage adaptive hardening device, comprising: A support platform is used to support a wafer-level substrate assembly to be reflow soldered; the wafer-level substrate assembly to be reflow soldered includes a substrate and components to be soldered. A spring-loaded floating support mechanism is arranged at multiple points within the cavity of the support platform to provide support for the wafer-level substrate assembly to be reflow soldered, and has a certain floating stroke. Each spring-loaded floating support mechanism is composed of multiple elastic elements, each elastic element including: a high-temperature resistant disc spring, a high-temperature resistant pin, and a support block. One end of the high-temperature resistant pin is floatingly inserted into the bottom wall of the cavity, and the other end is threaded and locked onto the support block. The high-temperature resistant disc spring is sleeved on the high-temperature resistant pin, and the upper and lower ends of the high-temperature resistant disc spring abut against the support block and the cavity, respectively. The grid-type clamping mechanism, located above the support platform, consists of multiple orthogonal rigid pressure bars, forming a grid-like clamping surface that covers the effective area of the substrate.
[0008] Preferably, the support platform is an octagonal base with a central cavity, and its material is 304 stainless steel; its bottom is a flat surface that can integrate a heat dissipation plate.
[0009] Preferably, the bottom of the cavity of the support platform is provided with a plurality of cylindrical countersunk holes for inserting the high-temperature resistant pins, and the high-temperature resistant pins and the cylindrical countersunk holes are positioned with negative tolerance to ensure that the high-temperature resistant pins can float vertically.
[0010] Preferably, each of the spring floating support mechanisms consists of 5 elastic elements distributed in a "four corners and center point" manner, wherein each support point has an independent floating stroke of 0~5mm, and the high-temperature resistant disc spring adopts a bimetallic compensating spring, which can compensate for the influence of temperature on the spring stiffness.
[0011] Preferably, the grid-type clamping mechanism includes: a transverse clamping rod, a longitudinal clamping rod, and a tail fin clamping rod; two spaced transverse clamping rods and two spaced longitudinal clamping rods are orthogonally clamped together, and four tail fin clamping rods are respectively clamped to the ends of the transverse clamping rods and the longitudinal clamping rods. Through the cross arrangement between the transverse clamping rods, the longitudinal clamping rods, and the tail fin clamping rods, a multi-grid grid-type clamping structure is formed.
[0012] Preferably, it further includes flexible gaskets, which are disposed at the bottom of the lateral pressure bar, the longitudinal pressure bar, and the tail fin pressure bar, and are made of Mylar sheet with high temperature resistance, low modulus, and high elasticity; the lateral pressure bar, the longitudinal pressure bar, and the tail fin pressure bar are made of ceramic matrix composite material with high strength, low coefficient of thermal expansion, and high temperature resistance.
[0013] Preferably, it also includes U-shaped grooves and through holes. Each of the transverse pressure rods, the longitudinal pressure rods, and the tail fin pressure rods is linearly provided with a plurality of U-shaped grooves. The through holes are provided in the U-shaped grooves. The transverse pressure rods and the longitudinal pressure rods, the transverse pressure rods and the tail fin pressure rods, and the longitudinal pressure rods and the tail fin pressure rods are snapped and locked together through the U-shaped grooves and the through holes. At the same time, the diameter of the multi-grid of the grid-type clamping structure can be flexibly adjusted according to the area where the components to be soldered on the wafer-level substrate assembly to be reflow soldered are required to be placed.
[0014] Preferably, it further includes four fixing screws with self-locking structures: a first fixing screw, a second fixing screw, a third fixing screw, and a fourth fixing screw. The first fixing screw is inserted sequentially from the bottom into a pre-drilled hole in the substrate and into the through hole in the U-shaped groove at the connection point between the transverse and longitudinal pressure rods. A nut is tightened at the end of the first fixing screw to pre-tighten the transverse and longitudinal pressure rods and the substrate. An elastic washer is also included between the first fixing screw and the longitudinal pressure rod. The second fixing screw is inserted sequentially from the top into the through hole at the connection point between the tail wing pressure rod and the transverse pressure rod. The through holes on the U-shaped groove, the preset holes on the substrate, and the locking screw holes on the support platform are used to pre-tighten the transverse pressure rod, the tail wing pressure rod, and the substrate; the four fixing screws are used to be inserted sequentially from the top into the through holes on the U-shaped groove, the preset holes on the substrate, and the locking screw holes on the support platform at the connection points between the tail wing pressure rod and the longitudinal pressure rod, to pre-tighten the longitudinal pressure rod, the tail wing pressure rod, and the substrate; the ends of the transverse pressure rod, the longitudinal pressure rod, and the tail wing pressure rod are pre-tightened to the locking screw holes on the support platform by the three fixing screws.
[0015] Preferably, the device further includes a clamping force application mechanism, which is a fastening fixture driven by a servo motor, used to apply pre-tightening action to the first fixing screw, the second fixing screw, the third fixing screw, and the fourth fixing screw; the fastening fixture driven by the servo motor also includes a force measurement sensor to determine whether the clamping force reaches a preset threshold; it also includes limiting blocks, a plurality of which are respectively arranged on the substrate and used to abut against the bottom ends of the transverse pressure bar and the longitudinal pressure bar to prevent excessive clamping force from damaging the wafer-level substrate.
[0016] This invention also provides a reinforcement method for a wafer-level packaging reflow soldering anti-warpage adaptive reinforcement device, employing the wafer-level packaging reflow soldering anti-warpage adaptive reinforcement device as described above, comprising: Place the component to be soldered at the corresponding location on the wafer-level substrate; A spring-loaded floating support mechanism is installed on a support platform, and a clamping force application mechanism is used to press the wafer-level substrate onto the grid-type clamping mechanism. A grid-type clamping mechanism that clamps the wafer-level substrate is placed on a support platform, and a pre-tightening force is applied by a clamping force application mechanism to complete the pre-tightening with the support platform. The high-temperature resistant disc spring is compressed to a predetermined working stroke, so that the bottom surface of the grid-type clamping mechanism is in uniform contact with the substrate surface to ensure flat constraint in the initial state.
[0017] Compared with the prior art, the present invention has the following beneficial effects: This invention mounts the wafer-level substrate to be reflow soldered onto a support platform. A grid-type clamping mechanism secures the wafer-level substrate with the preload of a clamping force application mechanism. A bottom disc spring floating structure adaptively compensates for uneven local thermal stress during the reflow soldering process, effectively suppressing substrate deformation and warping caused by thermal stress and maintaining the overall structural flatness. The reinforcement device proposed in this invention can solve failures such as substrate warping caused by thermal stress during wafer-level reflow soldering, is compatible with wafer-level reflow soldering for various packages, is easy to install and remove, and improves the soldering reliability of wafer-level packages. Attached Figure Description
[0018] Figure 1 This is a three-dimensional structural view of a wafer-level packaging reflow soldering anti-warping adaptive reinforcement device according to the present invention.
[0019] Figure 2 This is a top view of the structure of a wafer-level packaging reflow soldering anti-warping adaptive reinforcement device according to the present invention.
[0020] Figure 3 This is a top view of the structure of a wafer-level packaging reflow soldering anti-warping adaptive reinforcement device according to the present invention.
[0021] Figure 4 This is a cross-sectional view of the structure of a wafer-level packaging reflow soldering anti-warpage adaptive reinforcement device according to the present invention. Figure 1 .
[0022] Figure 5 This is a cross-sectional view of the structure of a wafer-level packaging reflow soldering anti-warpage adaptive reinforcement device according to the present invention. Figure 2 .
[0023] Figure 6 This is a structural diagram of the support platform, spring floating support mechanism, and grid-type clamping mechanism of the present invention.
[0024] Figure 7 This is a top view of the structure of the spring floating support mechanism and the grid-type clamping mechanism of the present invention.
[0025] Figure 8 This is a top view of the structure of the spring floating support mechanism and the grid-type clamping mechanism of the present invention.
[0026] Figure 9 This is a structural diagram of the U-shaped groove and through hole of the present invention.
[0027] Figure 10 This is an exploded top view of the structure of a wafer-level packaging reflow soldering anti-warping adaptive reinforcement device of the present invention.
[0028] Figure 11 This is an exploded bottom view of the structure of a wafer-level packaging reflow soldering anti-warping adaptive reinforcement device according to the present invention.
[0029] Figure 12 This is a flowchart illustrating the reinforcement process of an adaptive reinforcement device for preventing warpage during reflow soldering in wafer-level packaging, as described in this invention.
[0030] In the diagram: 1-Support platform, 11-Cavity, 12-Columnar countersunk hole, 2-Wafer-level substrate assembly to be reflow soldered, 21-Substrate, 22-Components to be soldered, 3-Spring floating support mechanism, 31-Elastic element, 311-High temperature resistant pin, 312-Support block, 4-Grid-type clamping mechanism, 41-Transverse pressure bar, 42-Vertical pressure bar, 43-Tail wing pressure bar, 44-U-shaped pressure groove, 45-Through hole, 46-Fixing screw one, 461-Nut, 462-Elastic washer, 47-Fixing screw two, 48-Fixing screw three. Detailed Implementation
[0031] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The advantages and features of the present invention will become clearer from the following description. It should be noted that the drawings are all in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the present invention.
[0032] like Figures 1-12 As shown, this embodiment of the invention specifically provides a wafer-level packaging reflow soldering anti-warpage adaptive hardening device, comprising: Support platform 1 is used to support wafer-level substrate assembly 2 to be reflow soldered; wafer-level substrate assembly 2 to be reflow soldered typically includes substrate 21 and components 22 to be soldered. The spring floating support mechanism 3 is arranged in multiple points within the cavity 11 of the support platform 1. In this embodiment of the invention, eight spring floating support mechanisms 3 are specifically arranged to provide support for the wafer-level substrate assembly 2 to be reflow soldered and have a certain floating stroke. Each spring floating support mechanism 3 is composed of elastic elements 31 arranged in multiple points. Each elastic element 31 includes: a high-temperature resistant disc spring, a high-temperature resistant pin 311, and a support block 312. One end of the high-temperature resistant pin 311 is floatingly inserted into the bottom wall of the cavity 11, and the other end is threaded and locked onto the support block 312. A high-temperature resistant disc spring is sleeved on the high-temperature resistant pin 311, and the upper and lower ends of the high-temperature resistant disc spring abut against the support block 312 and the cavity 11, respectively. The grid-type clamping mechanism 4 is located above the support platform 1 and consists of multiple orthogonal rigid pressure bars, forming a grid-like clamping surface that covers the effective area of the substrate 21.
[0033] As a further explanation of the embodiments of the present invention, the support platform 1 is an octagonal base with a central cavity 11, which is made of 304 stainless steel; the surface is treated with oxidation and corrosion resistance, and the bottom is a flat surface that can integrate heat dissipation devices such as heat dissipation plates.
[0034] As a further explanation of the embodiments of the present invention, the bottom of the cavity 11 of the support platform 1 is provided with a plurality of cylindrical countersunk holes 12 for inserting high-temperature resistant pins 311. The high-temperature resistant pins 311 and the cylindrical countersunk holes 12 are positioned with negative tolerance to ensure that the high-temperature resistant pins 311 can float vertically and avoid jamming.
[0035] As a further explanation of the embodiments of the present invention, each spring floating support mechanism 3 is composed of 5 elastic elements 31 distributed in a "four corners and center point" manner, wherein the support point of each spring floating support mechanism 3 has an independent floating stroke of 0~5mm, and the high temperature resistant disc spring adopts a bimetallic compensating spring, which can compensate for the influence of temperature on the spring stiffness.
[0036] As a further explanation of the embodiments of the present invention, the grid-type pressing mechanism 4 includes: a transverse pressing rod 41, a longitudinal pressing rod 42, and a tail wing pressing rod 43; two spaced transverse pressing rods 41 and two spaced longitudinal pressing rods 42 are orthogonally clamped together, and four tail wing pressing rods 43 are respectively clamped to the ends of the transverse pressing rods 41 and the longitudinal pressing rods 42. Through the cross arrangement between the transverse pressing rods 41, the longitudinal pressing rods 42, and the tail wing pressing rods 43, a multi-grid grid-type pressing structure is formed.
[0037] As a further illustration of the embodiments of the present invention, flexible gaskets are also included. The flexible gaskets are arranged at the bottom of the transverse pressure bar 41, the longitudinal pressure bar 42, and the tail fin pressure bar 43. The flexible gaskets are made of Mylar sheet, which is resistant to high temperature, has low modulus, and is highly elastic. They can buffer the surface pressing force and prevent the rigid connection from damaging the surface of the wafer-level substrate 21. Moreover, the Mylar sheet has the same shape as the pressure bar size to maintain flexible pressing on the wafer-level substrate 21. The transverse pressure bar 41, the longitudinal pressure bar 42, and the tail fin pressure bar 43 are made of ceramic matrix composite material with high strength, low coefficient of thermal expansion, and high temperature resistance.
[0038] As a further explanation of the embodiments of the present invention, it also includes U-shaped pressure grooves 44 and through holes 45. Each transverse pressure bar 41, longitudinal pressure bar 42 and tail wing pressure bar 43 is linearly provided with a plurality of U-shaped pressure grooves 44. Through holes 45 are provided on the U-shaped pressure grooves 44. The transverse pressure bar 41 and longitudinal pressure bar 42, the transverse pressure bar 41 and tail wing pressure bar 43, and the longitudinal pressure bar 42 and tail wing pressure bar 43 are snapped and locked together by the U-shaped pressure grooves 44 and through holes 45. At the same time, the diameter of the multi-grid of the grid-type clamping structure can be flexibly adjusted according to the area where the components 22 to be soldered on the wafer-level substrate assembly 2 to be reflow soldered are required to be placed. The grid is a spliced assembly and can be freely disassembled and assembled according to the layout of the components 22 of the on-chip system.
[0039] As a further explanation of the embodiments of the present invention, it also includes a first fixing screw 46, a second fixing screw 47, a third fixing screw 48, and a fourth fixing screw with a self-locking structure; the first fixing screw 46 is used to be inserted from the bottom into the pre-set hole of the substrate 21, the through hole 45 on the U-shaped pressure groove 44 at the connection point between the transverse pressure bar 41 and the longitudinal pressure bar 42, and the nut 461 is locked at the end of the first fixing screw 46 to pre-tighten the transverse pressure bar 41, the longitudinal pressure bar 42 and the substrate 21; at the same time, an elastic washer 462 is also included between the first fixing screw 46 and the longitudinal pressure bar 42 to avoid damaging the surface of the substrate 21; the second fixing screw 47 is used to be inserted from the top into the tail fin pressure bar The through hole 45 on the U-shaped groove 44 at the connection point between rod 43 and transverse pressure rod 41, the preset hole of substrate 21, and the locking screw hole of support platform 1 are used to pre-tighten the transverse pressure rod 41, tail wing pressure rod 43, and substrate 21; fixing screw four is used to be inserted from the top into the through hole 45 on the U-shaped groove 44 at the connection point between tail wing pressure rod 43 and longitudinal pressure rod 42, the preset hole of substrate 21, and the locking screw hole of support platform 1 to pre-tighten the longitudinal pressure rod 42, tail wing pressure rod 43, and substrate 21; the ends of transverse pressure rod 41, longitudinal pressure rod 42, and tail wing pressure rod 43 are pre-tightened to the locking screw hole of support platform 1 by fixing screw three 48.
[0040] As a further explanation of the embodiments of the present invention, a clamping force application mechanism is also included. The clamping force application mechanism adopts a fastening fixture driven by a servo motor, which is used to apply pre-tightening action to fixing screw 46, fixing screw 47, fixing screw 48, and fixing screw 4. At the same time, the fastening fixture driven by the servo motor also includes a force value measuring sensor, which is used to determine whether the clamping force reaches a preset threshold, ensuring that the grid-type clamping mechanism 4 and the support platform 1 tightly press the wafer-level substrate 21 together. It also includes limiting blocks, with multiple limiting blocks respectively arranged on the substrate 21, which are used to abut against the bottom ends of the transverse pressure bar 41 and the longitudinal pressure bar 42 to prevent excessive clamping force from damaging the wafer-level substrate 21. The limiting blocks and the force value measuring sensor ensure the accuracy of the pre-tightening force. At the same time, the fixing screws include a self-locking structure to prevent the fixing screws from loosening and falling off due to thermal stress during reflow soldering.
[0041] This invention also provides a reinforcement method for a wafer-level packaging reflow soldering anti-warpage adaptive reinforcement device, employing the aforementioned wafer-level packaging reflow soldering anti-warpage adaptive reinforcement device, comprising: Place the component 22 to be soldered at the corresponding position on the wafer-level substrate 21; The spring floating support mechanism 3 is installed on the support platform 1, and the wafer-level substrate 21 is pressed onto the grid-type clamping mechanism 4 by the clamping force application mechanism; The grid-type clamping mechanism 4, which clamps the wafer-level substrate 21, is placed on the support platform 1, and a pre-tightening force is applied by the clamping force application mechanism to complete the pre-tightening with the support platform 1. The high-temperature resistant disc spring is compressed to a predetermined working stroke, so that the bottom surface of the grid-type clamping mechanism 4 is in uniform contact with the surface of the substrate 21 to ensure flat constraint in the initial state.
[0042] As a further illustration of an embodiment of the present invention, the wafer to be reflowed is placed in a reflow oven. As the temperature rises, the organic substrate 21 begins to warp due to thermal stress (local areas attempt to bulge upwards or downwards). When a certain area of the substrate 21 attempts to bulge upwards: the pressure head corresponding to that area (i.e., the pressing area of the Mylar sheet) feels increased pressure. If the pressure exceeds a preset safety threshold, the spring floating support mechanism 3 below it is compressed, allowing the support point in that area to move slightly downwards, thereby releasing some pressure and preventing excessive compression that could damage the device or tear the substrate 21. The reaction force of the spring provides sufficient constraint to suppress excessive upward bulging.
[0043] When a certain area of the substrate 21 attempts to be recessed: the pressure of the pressure head corresponding to that area decreases. At this time, the spring floating support mechanism 3 corresponding to that area extends, pushing the support point slightly upward, restoring or maintaining the clamping force on that area, and preventing it from being excessively recessed.
[0044] Throughout the entire heating-holding-cooling reflow soldering temperature profile, the device, through the linkage support of the spring floating support mechanism 3, achieves adaptive following of the warpage deformation of the substrate 21 and dynamic compensation of the clamping force. It maintains a relatively uniform and safe constraint force on the substrate 21 as a whole, effectively suppressing warpage while avoiding localized stress concentration. It can flexibly adapt to various wafer-level substrate 21 reflow soldering packaging layouts, improving the soldering quality and packaging reliability of wafer-level reflow soldering.
[0045] The above description is merely a description of preferred embodiments of the present invention and is not intended to limit the scope of the present invention in any way. Any changes or modifications made by those skilled in the art based on the above disclosure shall fall within the protection scope of the claims.
Claims
1. A wafer-level packaging reflow soldering anti-warpage adaptive reinforcement device, characterized in that, include: A support platform (1) is used to support a wafer-level substrate assembly (2) to be reflow soldered; the wafer-level substrate assembly (2) to be reflow soldered includes a substrate (21) and components (22) to be soldered. A spring floating support mechanism (3) is arranged in multiple points in the cavity (11) of the support platform (1) to provide support for the wafer-level substrate assembly (2) to be reflow soldered, and has a certain floating stroke; wherein each spring floating support mechanism (3) is composed of multiple points arranged elastic elements (31), each elastic element (31) includes: a high temperature resistant disc spring, a high temperature resistant pin (311) and a support block (312); one end of the high temperature resistant pin (311) is floatingly inserted into the bottom wall of the cavity (11), and the other end is threaded and locked onto the support block (312). The high temperature resistant disc spring is sleeved on the high temperature resistant pin (311), and the upper and lower ends of the high temperature resistant disc spring abut against the support block (312) and the cavity (11) respectively; The grid-type pressing mechanism (4) is located above the support platform (1) and consists of multiple orthogonal rigid pressure bars, forming a grid-like pressing surface that covers the effective area of the substrate (21).
2. The wafer-level packaging reflow soldering anti-warpage adaptive reinforcement device as described in claim 1, characterized in that, The support platform (1) is an octagonal base with a cavity (11) in the center, and its material is 304 stainless steel. Its bottom is flat and can be integrated with a heat dissipation plate.
3. The wafer-level packaging reflow soldering anti-warpage adaptive reinforcement device as described in claim 2, characterized in that, The bottom of the cavity (11) of the support platform (1) is provided with several cylindrical countersunk holes (12) for inserting the high-temperature resistant pin (311). The high-temperature resistant pin (311) and the cylindrical countersunk holes (12) are positioned with negative tolerance to ensure that the high-temperature resistant pin (311) can float vertically.
4. The wafer-level packaging reflow soldering anti-warpage adaptive reinforcement device as described in claim 1, characterized in that, Each of the spring floating support mechanisms (3) consists of 5 elastic elements (31) distributed in a "four corners and center point" manner, wherein each support point has an independent floating stroke of 0~5mm. The high temperature resistant disc spring adopts a bimetallic compensating spring, which can compensate for the influence of temperature on the spring stiffness.
5. The wafer-level packaging reflow soldering anti-warpage adaptive reinforcement device as described in claim 1, characterized in that, The grid-type pressing mechanism (4) includes: a transverse pressing rod (41), a longitudinal pressing rod (42), and a tail fin pressing rod (43); two spaced transverse pressing rods (41) and two spaced longitudinal pressing rods (42) are orthogonally clamped together, and four tail fin pressing rods (43) are respectively clamped to the ends of the transverse pressing rods (41) and the longitudinal pressing rods (42). Through the cross arrangement between the transverse pressing rods (41), the longitudinal pressing rods (42), and the tail fin pressing rods (43), a multi-grid grid-type pressing structure is formed.
6. The wafer-level packaging reflow soldering anti-warpage adaptive hardening device as described in claim 5, characterized in that, It also includes flexible pads, which are arranged at the bottom of the transverse pressure bar (41), the longitudinal pressure bar (42) and the tail fin pressure bar (43), and are made of Mylar sheet with high temperature resistance, low modulus and high elasticity; the transverse pressure bar (41), the longitudinal pressure bar (42) and the tail fin pressure bar (43) are made of ceramic matrix composite material with high strength, low thermal expansion coefficient and high temperature resistance.
7. The wafer-level packaging reflow soldering anti-warpage adaptive hardening device as described in claim 5, characterized in that, It also includes U-shaped pressure grooves (44) and through holes (45). Each of the transverse pressure rods (41), the longitudinal pressure rods (42) and the tail fin pressure rods (43) is linearly provided with several U-shaped pressure grooves (44). The through holes (45) are provided on the U-shaped pressure grooves (44). The transverse pressure rods (41) and the longitudinal pressure rods (42), the transverse pressure rods (41) and the tail fin pressure rods (43), and the longitudinal pressure rods (42) and the tail fin pressure rods (43) are snapped and locked together through the U-shaped pressure grooves (44) and the through holes (45). At the same time, the diameter of the multi-grid of the grid-type pressing structure can be flexibly adjusted according to the area where the components (22) to be soldered on the wafer-level substrate assembly (2) to be reflow soldered are required to be placed.
8. The wafer-level packaging reflow soldering anti-warpage adaptive reinforcement device as described in claim 7, characterized in that, It also includes a first fixing screw (46), a second fixing screw (47), a third fixing screw (48), and a fourth fixing screw with a self-locking structure; the first fixing screw (46) is used to be inserted from the bottom into the pre-set hole of the base plate (21), the through hole (45) on the U-shaped groove (44) at the connection point between the transverse pressure rod (41) and the longitudinal pressure rod (42), and the nut (461) is locked at the end of the first fixing screw (46) to pre-tighten the transverse pressure rod (41), the longitudinal pressure rod (42), and the base plate (21); at the same time, an elastic washer (462) is also included between the first fixing screw (46) and the longitudinal pressure rod (42); the second fixing screw (47) is used to be inserted from the top into the through hole (45) on the U-shaped groove (44) at the connection point between the tail wing pressure rod (43) and the transverse pressure rod (41). The through hole (45) on the U-shaped groove (44), the preset hole of the base plate (21) and the locking screw hole of the support platform (1) are used to pre-tighten the transverse pressure rod (41), the tail wing pressure rod (43) and the base plate (21); the four fixing screws are used to be inserted from the top into the through hole (45) on the U-shaped groove (44), the preset hole of the base plate (21) and the locking screw hole of the support platform (1) at the connection point between the tail wing pressure rod (43) and the longitudinal pressure rod (42) to pre-tighten the longitudinal pressure rod (42), the tail wing pressure rod (43) and the base plate (21); the ends of the transverse pressure rod (41), the longitudinal pressure rod (42) and the tail wing pressure rod (43) are pre-tightened to the locking screw hole of the support platform (1) by the three fixing screws (48).
9. The wafer-level packaging reflow soldering anti-warpage adaptive reinforcement device as described in claim 8, characterized in that, It also includes a clamping force application mechanism, which is a fastening fixture driven by a servo motor, used to apply pre-tightening action to the first fixing screw (46), the second fixing screw (47), the third fixing screw (48) and the fourth fixing screw; at the same time, the fastening fixture driven by the servo motor also includes a force value measurement sensor, used to determine whether the clamping force reaches a preset threshold; it also includes limit blocks, a plurality of the limit blocks are respectively arranged on the substrate (21), used to abut against the bottom of the ends of the transverse pressure bar (41) and the longitudinal pressure bar (42), so as to prevent excessive clamping force from damaging the wafer-level substrate (21).
10. A method for strengthening a wafer-level packaging reflow soldering anti-warpage adaptive strengthening device, comprising the wafer-level packaging reflow soldering anti-warpage adaptive strengthening device as described in any one of claims 1 to 9, characterized in that, include: Place the component to be soldered at the corresponding location on the wafer-level substrate; A spring-loaded floating support mechanism is installed on a support platform, and a clamping force application mechanism is used to press the wafer-level substrate onto the grid-type clamping mechanism. A grid-type clamping mechanism that clamps the wafer-level substrate is placed on a support platform, and a pre-tightening force is applied by a clamping force application mechanism to complete the pre-tightening with the support platform. The high-temperature resistant disc spring is compressed to a predetermined working stroke, so that the bottom surface of the grid-type clamping mechanism is in uniform contact with the substrate surface to ensure flat constraint in the initial state.
Citation Information
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