Bonding device suitable for bonding silicon and glass
By using a support pad assembly of stacked silicon nitride insulating plates and graphite conductive plates in the bonding device, combined with a power conductive assembly, the insulation reliability and interference problems when high-voltage electrodes are introduced into the cavity in the bonding device are solved, realizing high-strength bonding of silicon wafers and glass sheets and stable operation of automated production.
Patent Information
- Application Number
- CN202511556831.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-29
- Publication Date
- 2026-01-20
AI Technical Summary
In the prior art, when high-voltage electrodes are introduced into the cavity of the bonding device, there are problems such as insufficient insulation reliability, easy high-temperature oxidation or creep, interference with the cavity structure, and difficulty in ensuring the conductivity, thermal conductivity and high-temperature insulation of the wafer support plate, which affects the material handling and safety of automated production.
The system employs a support plate assembly, which includes stacked silicon nitride insulating plates and graphite conductive plates. External power is stably introduced through a power conductive assembly to ensure that voltage is applied to the silicon wafer and glass plate. The conductive plates are designed to avoid interference with the movement path of the robotic arm.
This enables stable introduction of high-voltage electricity, avoids interference and insufficient insulation in the electrode structure, improves the smoothness of automated production and equipment reliability, and ensures high-strength bonding between silicon wafers and glass sheets.
Smart Images
Figure CN121361762A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of vacuum wafer bonding equipment, in particular to a bonding device suitable for silicon and glass bonding. BACKGROUND
[0002] In the chip manufacturing industry, anodic bonding technology is a key core technology in wafer level packaging (WLP) and micro-electro-mechanical system (MEMS) manufacturing. Anodic bonding is a key technology for realizing high-strength, high-airtightness, and low-stress permanent sealing between silicon wafers and glass, silicon wafers and silicon wafers, or other materials under the combined action of an electric field and temperature.
[0003] In the prior art, anodic bonding technology is a key process for realizing permanent sealing of glass and silicon materials. The basic operating principle is as follows: the glass and silicon wafer in the bonding cavity are heated to 300-450℃ by a heating table, the activity of alkali metal ions (such as Na + ) in the glass is significantly enhanced, a voltage of 500-1000V is applied, the positive electrode is connected to the silicon wafer through an electrode, and the negative electrode is connected to the heating table supporting the glass. In this configuration, the entire system forms a static electric field loop. The active positive ions in the glass migrate away from the silicon wafer towards the cathode (heating table) under the driving of the electric field, resulting in the accumulation of stable negative charge at the glass interface adjacent to the silicon wafer, thereby generating strong electrostatic attraction between the two, allowing the interface to achieve atomic-level tightness at high temperature, and finally forming a firm Si-O-Si covalent bond through chemical reaction, completing the permanent sealing of high strength and high airtightness.
[0004] In the prior art, in the high-temperature and vacuum bonding environment, it is a technical problem in the field to safely and reliably introduce external high-voltage electricity into the cavity and apply it to the wafer. Direct connection of metal wires has problems of insufficient insulation, creep or oxidation at high temperatures, and interference with the cavity structure; anodic bonding requires the establishment of an electric field between the heated silicon wafer and the glass, which requires a high-quality wafer supporting pad; in addition, in the automatic production line, the robot needs to enter the cavity to take and place the wafer. If the electrode structure is not properly designed, it will invade the movement space of the robot, making it difficult to take and place the material and increasing the risk of collision. SUMMARY
[0005] The present application provides a bonding device suitable for silicon and glass bonding to solve the technical problems of insufficient insulation reliability, easy high-temperature oxidation or creep, and interference with the cavity structure when introducing high-voltage electrodes into the cavity in the existing bonding device; at the same time, the wafer supporting pad cannot simultaneously have good electrical conductivity, thermal conductivity, and high-temperature insulation, which cannot stably establish the required electric field for bonding; in addition, the rigid electrode structure invades the movement space of the robot, making it difficult to automatically take and place the material and increasing the risk of collision.
[0006] The application adopts the following technique to achieve the above-mentioned purposes: The application provides a bonding device suitable for silicon and glass bonding, comprising: A support pad assembly is arranged in a bonding cavity and mounted on a lower heating cover for carrying and heating silicon wafers and glass wafers to be bonded; the support pad assembly comprises stacked silicon nitride insulating plates and graphite conductive plates, the graphite conductive plates carry the silicon wafers and glass wafers to be bonded; the silicon nitride insulating plates are positioned in cooperation with the lower heating cover; a power supply conductive assembly is used for leading and applying the voltage of an external power supply to the support pad assembly; the power supply conductive assembly comprises an adapter, an adapter plate and a conductive sheet, the adapter plate is sealingly clamped and fixed on the side wall opening of the cavity, the adapter is mounted on the adapter plate and used for connecting the external power supply, one end of the conductive sheet is fixed to the end of the adapter and electrically connected with the adapter, and the other end of the conductive sheet is press-fitted between the silicon nitride insulating plate and the graphite conductive plate and electrically connected with the graphite conductive plate.
[0007] In the implementation, the support pad assembly is arranged in a bonding cavity and mounted on a lower heating cover for carrying and heating silicon wafers and glass wafers to be bonded; the support pad assembly comprises stacked silicon nitride insulating plates and graphite conductive plates, the graphite conductive plates carry the silicon wafers and glass wafers to be bonded; the silicon nitride insulating plates are positioned in cooperation with the lower heating cover; specifically, the silicon nitride insulating plate is provided with two positioning pin holes for limiting the position of the lower heating cover; the silicon nitride insulating plate is uniformly provided with through holes in the circumferential direction, the graphite conductive plate is provided with counterbores at the corresponding positions, and the graphite conductive plate and the silicon nitride insulating plate are mounted on the lower heating cover in sequence through the counterbores and the through holes by screws, The power supply conductive assembly is used for leading and applying the voltage of an external power supply to the support pad assembly; the power supply conductive assembly comprises an adapter, an adapter plate and a conductive sheet, the adapter plate is sealingly clamped and fixed on the side wall opening of the cavity, the adapter plate is clamped and fixed on the side wall opening of the cavity by circumferentially distributed fasteners, and the two sides of the adapter plate are provided with sealing rings; specifically, one end of the adapter plate is attached to the outside of the side wall opening of the cavity, and the other end is connected with a ring-shaped pressing plate; the adapter plate is clamped between the ring-shaped pressing plate and the side wall of the cavity and locked and fixed by circumferentially distributed bolts.
[0008] The adapter is bolted to the adapter plate, and the adapter and the adapter plate are connected by conventional assembly; the conductive sheet is in the shape of U, one end of the conductive sheet is a fixed end and is fixed to the end of the adapter and electrically connected with the adapter, and the other end is a crimping end, the end of the conductive sheet away from the adapter plate is bent outward to form the crimping end, the crimping end is crimped between the silicon nitride insulating plate and the graphite conductive plate and electrically connected with the graphite conductive plate, the end of the crimping end is provided with an elastic contact part, a square groove for accommodating the crimping end is formed on the surface of the silicon nitride insulating plate facing the graphite conductive plate, the top of the elastic contact part is 1-2mm higher than the upper surface of the silicon nitride insulating plate in the state of not installing the graphite conductive plate, and the elastic contact part is compressed and tightly electrically connected with the graphite conductive plate after installation; the conductive sheet is provided with conductive sheet mounting holes at both ends, and the conductive sheet mounting hole on the side of the crimping end is formed between the elastic contact part and the bent corner.
[0009] During assembly, the silicon nitride insulating plate is positioned by the two positioning pin holes and the positioning pins on the lower heating cover to realize initial positioning, the crimping end of the conductive sheet is placed into the square groove on the surface of the silicon nitride insulating plate, the graphite conductive plate is covered, the countersunk hole on the graphite conductive plate is aligned with the through hole on the silicon nitride insulating plate, and the through hole is sequentially threaded by the countersunk hole and the through hole and screwed into the lower heating cover to complete the fixing, the crimping end of the conductive sheet is electrically connected with the graphite conductive plate, the fixed end of the conductive sheet is fixed and electrically connected with the end of the adapter, and the adapter plate is clamped between the cavity side wall and the annular pressing plate by bolts to realize sealing connection between the adapter plate and the cavity side wall, so that the adapter plate becomes part of the cavity sealing and the assembly is completed.
[0010] During use, after the cavity is closed, the mechanical hand sends the silicon and glass to be bonded into the cavity and places them on the graphite conductive plate, the U-shaped structure of the conductive sheet can avoid the mechanical hand, facilitates the mechanical hand to take and feed, and avoids motion interference. After heating and vacuumizing, the bonding is realized by electrifying, specifically, the upper heating plate is pressed down to the glass sheet, the heat of the lower heating cover is conducted to the graphite conductive plate through the silicon nitride insulating plate, the silicon sheet and the glass sheet are heated to a set temperature, the current of the external high-voltage power supply is transmitted to the graphite conductive plate through the conductive sheet through the adapter, the graphite conductive plate is connected to the positive electrode, and then transmitted to the silicon sheet, the upper heating plate is connected to the negative electrode to form a cathode loop, a strong electrostatic field is formed at the silicon-glass interface, the anode bonding is completed, and the bonding is completed.
[0011] Compared with the prior art, the present application has the following advantages: The bonding device designed in the present application is suitable for bonding of silicon and glass, an external power supply is introduced into the cavity of the device through the power supply conductive assembly, and the power supply and the support pad assembly are connected through the conductive sheet in the power supply conductive assembly. The voltage applied by the external power supply can be applied to the silicon and glass sheet, and the bonding of the silicon and glass can be completed under the action of heating and vacuumizing.
[0012] The application realizes stable introduction of external high-voltage electricity into the cavity through the adapter, the adapter plate and the conductive sheet, avoids stress concentration or loose connection caused by thermal expansion and cold shrinkage, at the same time, the structure of the conductive sheet reserves sufficient non-interference movement space for the mechanical hand to enter the cavity to take and place the wafer, completely solves the difficulty in taking and placing the material caused by the electrode structure invading the path and the collision risk, fundamentally solves the problems of insufficient insulation, high temperature creep and structure interference, and improves the operation fluency of the automatic production line and the equipment reliability.
[0013] In the support pad assembly, the upper graphite conductive plate ensures excellent conductivity to provide uniform electric field and temperature field for the silicon wafer; the lower silicon nitride insulating plate has excellent high-temperature insulation performance, isolates the high-voltage graphite plate from the lower heating cover of the grounded metal, and thus stably and reliably establishes the high-strength electrostatic field required for bonding between the silicon wafer and the glass.
[0014] When silicon and glass bonding is not required, the support pad assembly in the application can be compatible with the production of other products, significantly improving the equipment utilization rate and production flexibility. BRIEF DESCRIPTION OF DRAWINGS
[0015] Figure 1 It is a schematic diagram of the overall structure of the application.
[0016] Figure 2 It is a schematic diagram of the structure of the support pad assembly.
[0017] Figure 3 It is a schematic diagram of the structure of the power supply conductive assembly.
[0018] Figure 4 It is a schematic diagram of the structure of the silicon nitride insulating plate.
[0019] Figure 5 It is a schematic diagram of the structure of the conductive sheet.
[0020] In the figure: 1, support pad assembly; 2, power supply conductive assembly; 3, silicon nitride insulating plate; 301, positioning pin hole; 302, via hole; 303, square groove; 4, graphite conductive plate; 401, countersunk hole; 5, adapter; 6, adapter plate; 7, conductive sheet; 701, fixed end; 702, crimped end; 71, conductive sheet mounting hole. DETAILED DESCRIPTION
[0021] The specific embodiments of the application will be described in detail below with reference to the accompanying drawings.
[0022] A bonding device suitable for silicon and glass bonding, as shown in Figures 1-5 , comprises: The support base plate assembly is arranged in a bonding cavity and mounted on the lower heating cover for bearing and heating the silicon wafer and glass wafer to be bonded; the support base plate assembly comprises a stacked silicon nitride insulating plate and graphite conductive plate, and the silicon wafer and glass wafer to be bonded are placed on the graphite conductive plate; the silicon nitride insulating plate is positioned in cooperation with the lower heating cover (not shown in the figure); specifically, two positioning pin holes are formed in the silicon nitride insulating plate for limiting position with the lower heating cover, in the embodiment, the diameter of the positioning pin hole is 6 mm, and two positioning pin holes are provided; the silicon nitride insulating plate is uniformly provided with through holes in the circumferential direction, the graphite conductive plate is provided with counterbores at the corresponding positions, and the graphite conductive plate and the silicon nitride insulating plate are mounted on the lower heating cover in sequence through the counterbores and the through holes by screws, in the embodiment, the through holes and the counterbores are all provided with three holes, matched with three M3 screws. The power supply conductive assembly is used for guiding and applying the voltage of an external power supply to the support base plate assembly; the power supply conductive assembly comprises an adapter, an adapter plate and a conductive sheet, the adapter plate is sealingly clamped and fixed on the side wall opening of the cavity, the adapter plate is clamped and fixed on the side wall opening of the cavity by circumferentially distributed fasteners, and both sides of the adapter plate are provided with sealing rings, specifically, one end of the adapter plate is attached to the outside of the side wall opening of the cavity, and the other end is connected with the annular pressing plate; the adapter plate is clamped between the annular pressing plate and the side wall of the cavity and is locked and fixed by circumferentially distributed bolts.
[0023] The adapter is mounted on the adapter plate and is used for connecting the external power supply, the conductive sheet is in a whole U shape, one end of the conductive sheet is a fixed end and is fixed to the end of the adapter and is electrically connected with the adapter, the other end is a crimping end, the end of the conductive sheet away from the adapter plate is bent outward to form the crimping end, the crimping end is crimped between the silicon nitride insulating plate and the graphite conductive plate and is electrically connected with the graphite conductive plate, the end of the crimping end is provided with an elastic contact part, a square groove for accommodating the crimping end is formed in the surface of the silicon nitride insulating plate facing the graphite conductive plate, the square groove is provided with two, the crimping end is inserted into one of the two square grooves, in the state that the graphite conductive plate is not mounted, the top of the elastic contact part is 1-2 mm higher than the upper surface of the silicon nitride insulating plate, after the graphite conductive plate is mounted, the elastic contact part is compressed and forms a close electrical contact with the graphite conductive plate; the conductive sheet is provided with conductive sheet mounting holes at both ends, the conductive sheet mounting hole on the side of the crimping end is formed between the elastic contact part and the bent corner.
[0024] When assembling, the silicon nitride insulation plate is initially positioned by cooperating with the positioning pins on the lower heating cover through the two positioning pin holes, the crimping end of the conductive sheet is placed into the square groove on the surface of the silicon nitride insulation plate, the graphite conductive plate is covered, the countersunk hole on the graphite conductive plate is aligned with the via hole on the silicon nitride insulation plate, and the M3 screw is sequentially threaded through the countersunk hole, the via hole and screwed into the lower heating cover to complete the fixation, the crimping end of the conductive sheet is electrically connected with the graphite conductive plate; the fixed end of the conductive sheet is fixed and electrically connected with the end of the adapter, the adapter plate is clamped between the cavity side wall and the annular pressing plate through the bolts, the adapter plate is sealingly connected with the cavity side wall and becomes part of the cavity seal, and the assembly is completed.
[0025] When in use, after the cavity is closed, the mechanical hand sends the silicon and glass to be bonded into the cavity and places them on the graphite conductive plate, the U-shaped structure of the conductive sheet can avoid the mechanical hand, facilitates the mechanical hand to take and feed, and avoids motion interference. After heating and vacuumizing, the bonding is realized by electrifying, specifically, the upper heating plate (not shown in the figure) is pressed down to the glass sheet, the heat of the lower heating cover is conducted to the graphite conductive plate through the silicon nitride insulation plate, the silicon sheet and the glass sheet are heated to a set temperature, the external high-voltage power supply starts the current to be transmitted to the graphite conductive plate through the conductive sheet through the adapter, the graphite conductive plate is connected with the positive electrode, and then transmitted to the silicon sheet, the upper heating plate is connected with the negative electrode to form a cathode loop, a strong electrostatic field is formed at the silicon-glass interface, the anode bonding is completed, and the bonding is completed.
[0026] The scope of protection of the present application is not limited to the above specific embodiments, and the present application can have various modifications and changes for those skilled in the art, and any modification, improvement and equivalent replacement within the concept and principle of the present application should be included in the scope of protection of the present application.
Claims
1. A bonding apparatus suitable for silicon and glass bonding, characterized by, The utility model relates to a support pad assembly which is arranged in a bonding cavity and mounted on a lower heating cover for bearing and heating silicon wafers and glass sheets to be bonded, the support pad assembly comprising a silicon nitride insulating plate and a graphite conductive plate stacked together, the graphite conductive plate bearing the silicon wafers and glass sheets to be bonded, and the silicon nitride insulating plate being positioned in cooperation with the lower heating cover. The utility model relates to a power supply conductive assembly for leading and applying voltage from an external power supply to the support pad assembly, the power supply conductive assembly comprising an adapter, an adapter plate and a conductive sheet, the adapter plate being sealingly clamped and fixed on a side wall opening of the cavity, the adapter being mounted on the adapter plate for connecting the external power supply, one end of the conductive sheet being fixed at the end of the adapter and electrically connected with the adapter, and the other end being press-fitted between the silicon nitride insulating plate and the graphite conductive plate and electrically connected with the graphite conductive plate. The conductive sheet is in a U shape as a whole, one end of the conductive sheet away from the adapter plate is outwardly bent to form a press-fitting end, and an elastic contact portion is arranged at the end of the press-fitting end.
2. A bonding apparatus suitable for silicon and glass bonding according to claim 1, characterized in that: When the graphite conductive plate is not mounted, the top of the elastic contact portion is 1-2 mm higher than the upper surface of the silicon nitride insulating plate, and after the graphite conductive plate is mounted, the elastic contact portion is compressed and forms a close electrical contact with the graphite conductive plate.
3. A bonding apparatus suitable for silicon and glass bonding according to claim 2, characterized in that: Two ends of the conductive sheet are provided with conductive sheet mounting holes, and the conductive sheet mounting hole on the side of the press-fitting end is arranged between the elastic contact portion and the bent corner.
4. A bonding apparatus suitable for silicon and glass bonding according to claim 2, characterized in that: The silicon nitride insulating plate is provided with two positioning pin holes for limiting the position of the lower heating cover, and the silicon nitride insulating plate is uniformly provided with through holes in the circumferential direction.
5. A bonding apparatus suitable for silicon and glass bonding as claimed in claim 1, wherein: The graphite conductive plate is provided with a counterbore hole at the corresponding position, and the graphite conductive plate and the silicon nitride insulating plate are mounted on the lower heating cover in sequence through the counterbore hole and the through hole by means of a screw. The adapter plate is clamped and fixed on the side wall opening of the cavity by means of circumferentially distributed fasteners, and the adapter plate is provided with sealing rings on both sides.
6. A bonding apparatus suitable for silicon and glass bonding as claimed in claim 1, wherein: One end of the adapter plate is attached to the outside of the side wall opening of the cavity, and the other end is connected with a ring-shaped pressing plate, the adapter plate is clamped between the ring-shaped pressing plate and the side wall of the cavity, and is locked and fixed by means of circumferentially distributed bolts.
7. A bonding apparatus suitable for silicon and glass bonding according to claim 6, characterized in that: