Bonding fixing device and method for device with uneven bottom surface

Abstract

The invention discloses a bonding fixing device and method for a device with an uneven bottom surface. A glass sheet is used as a bearing substrate, a first UV film, a double-sided adhesive film and a second UV film are sequentially arranged on the surface of the glass sheet, and a device is bonded on the second UV film to form a bonding fixing device; the bonding fixing device is arranged in a vacuum hole array area of a hot seat of bonding equipment, and a glass sheet is fixed by using vacuum adsorption force; and after bonding is completed, ultraviolet light is irradiated from the bottom surface of the glass sheet, so that the first UV film and the second UV film are subjected to UV decomposition, and after the bonding force between the first UV film and the glass sheet and the bonding force between the second UV film and the device are reduced to a weak state, the device is separated. According to the bonding fixing method, the vacuum adsorption function of the bonding equipment is effectively utilized, meanwhile, low-stress separation of the bonded device after bonding is achieved, and low-temperature bonding of the device with the uneven bottom face and the structure prone to damage is achieved.

Description

Technical Field

[0001] This invention relates to the field of semiconductor integrated circuit packaging and testing, and specifically to a bonding and fixing device and method for devices with uneven bottom surfaces. Background Technology

[0002] In semiconductor packaging and testing, the devices to be bonded must be stably fixed to the hot mount of the bonding equipment before wire bonding. This is a fundamental requirement to ensure the smooth progress of the bonding process. Devices with uneven bottom surfaces or low mechanical strength are difficult to reliably fix using existing methods, and subsequent separation is prone to damage or residual adhesive issues, affecting packaging reliability and yield.

[0003] Currently, there are three main types of fixing methods: vacuum adsorption, which uses a microporous array of heated bases to create negative pressure to adsorb the bottom surface of the device, suitable for devices with flat bottom surfaces and certain dimensions and rigidity, and has advantages such as high positioning accuracy, good repeatability, and no residue; mechanical clamping, which relies on external mechanical structures to apply pressure and clamp the edges or specific areas of the device, suitable for scenarios where vacuum adsorption is not possible; and adhesive bonding, which uses double-sided tape for fixing, is simple to operate, highly adaptable, and widely used in small-batch pilot production and bonding of irregularly shaped devices. Existing solutions are not suitable for devices with uneven bottom surfaces and low mechanical strength: vacuum adsorption fails because it cannot form an effective sealed cavity; clamping requires customized fixtures, has poor versatility, and is prone to deformation and damage to fragile devices; while adhesive bonding can fix the device, peeling after bonding requires a large tearing force, which can easily cause device cracking, solder ball detachment, and other problems, and the adhesive layer is prone to residue, causing contamination and affecting the reliability and yield of subsequent packaging. Therefore, there is an urgent need for a new bonding and fixing solution that can be compatible with devices with uneven bottom surfaces and achieve low-stress separation and zero adhesive residue. Summary of the Invention

[0004] This invention addresses the problems of damage risk and adhesive residue contamination during device separation caused by existing device fixing methods, and proposes a bonding and fixing device and method for devices with uneven bottom surfaces.

[0005] To achieve the above objectives, the present invention provides the following technical solution: The present invention provides a bonding and fixing device for a device with an uneven bottom surface, comprising a glass sheet, on which a first UV film, a double-sided adhesive film and a second UV film are sequentially bonded. The top of the second UV film is used to bond the receiving bonding device. The bonding and fixing device is placed in the vacuum hole array area of ​​the hot seat of the bonding equipment.

[0006] Furthermore, the diameter of the vacuum holes 2 in the vacuum hole array of the bonding device hot seat is 0.2~0.4mm, and the hole spacing is 1.5~3.0mm.

[0007] Furthermore, the glass sheet has a thickness of 1.0~2.0mm, a light transmittance of ≥85%, and a surface roughness Ra≤0.02μm.

[0008] Furthermore, before UV light irradiation, the adhesion between the first UV film and the second UV film is not less than 4N / 20mm; after UV light irradiation, the adhesion between the first UV film and the second UV film can be reduced to less than 0.2N / 20mm.

[0009] Furthermore, the thickness of both the first UV film and the second UV film is 0.06~0.17mm.

[0010] Furthermore, the double-sided adhesive film is a light-transmitting film with a thickness of 25~50μm and a transmittance of ≥85% for 365nm ultraviolet light.

[0011] The present invention also provides a bonding and fixing method for devices with uneven bottom surfaces, comprising the following steps: The bonding equipment is equipped with a heated mount with a vacuum array; The assembly is completed using the bonding and fixing device described in any one of claims 1-6; With the vacuum closed, place the glass plate of the bonding fixture in the vacuum array area of ​​the hot seat of the bonding equipment, ensuring that the glass plate covers the vacuum hole; Turn on the vacuum system of the bonding equipment and perform the bonding operation; After bonding is completed, the vacuum system is turned off and the bonding fixing device is removed. Ultraviolet light is applied from the underside of the glass plate of the bonding fixing device to reduce the adhesion between the first UV film and the second UV film to below 0.2N / 20mm. The device is then separated.

[0012] Furthermore, the ultraviolet light wavelength is 365nm, the irradiation intensity is (100-300)mW / cm², and the irradiation time is 10-20 seconds.

[0013] Furthermore, the method is applicable to low-temperature bonding processes with bonding temperatures ranging from room temperature to 80°C.

[0014] Furthermore, the method is applicable to aluminum wire bonding.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: The bonding and fixing device provided by this invention uses a glass sheet as a flat, rigid carrier, which is fixed to the bonding equipment's heated seat via vacuum adsorption. A UV film composite structure with double-sided adhesion is set on the glass sheet. The first UV film is fixed to the glass sheet with its adhesive side facing down, and the second UV film is fixed to the device with its adhesive side facing up. The upper and lower UV film surfaces are connected by double-sided adhesive film. The UV film composite structure reduces the requirement for the flatness of the device's bottom surface, achieving effective fixing without requiring a completely flat bottom surface. Simultaneously, during the bonding process, the UV film acts as a temporary adhesive layer, relying on its high adhesion to achieve tight fixing between the device and the glass sheet before light irradiation. After bonding, the UV is removed by UV irradiation, causing a sharp drop in adhesion, allowing easy peeling of the device. This ensures bonding accuracy while avoiding mechanical damage and residual contamination.

[0016] The bonding and fixing method provided by this invention achieves bonding between a flat glass sheet and an uneven device by using a double-layer UV film, and then fixes the glass sheet by vacuum adsorption to achieve device fixation. After bonding, the strong adhesion between the UV film, the device, and the glass sheet is reduced to a weak adhesion state by UV irradiation, and then the device is separated. The weak force experienced during device separation significantly reduces the risk of device damage during the separation process. Separating the device under the weak adhesion state after UV removal leaves virtually no adhesive residue on the device surface, reducing or eliminating the risk of device contamination or residual waste. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0018] Figure 1 This is a schematic diagram of the bonding and fixing device of the present invention; Figure 2 This is a schematic diagram of the UV film composite structure of the bonding and fixing device of the present invention; Figure 3 This is a schematic diagram of the hot mount of the bonding device of the present invention; Figure 4 This is a diagram showing the state of the glass plate in the bonding and fixing device of the present invention being placed in the vacuum array region of the heated seat in the bonding and fixing method of the present invention. Figure 5 This is a diagram showing the state of the bonding and fixing device being vacuum-adsorbed in the bonding and fixing method of the present invention; Figure 6 This is a state diagram of ultraviolet light irradiation after bonding is completed in the bonding and fixing method of the present invention; In the diagram: 1. Heating seat; 2. Vacuum hole; 3. Glass plate; 4. First UV film; 5. Double-sided adhesive film; 6. Second UV film; 7. Device; 8. Ultraviolet light. Detailed Implementation

[0019] 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 typically be arranged and designed in various different configurations.

[0020] 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. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0021] 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.

[0022] In the description of the embodiments of this application, it should be noted that if terms such as "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" 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, terms such as "first" and "second" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0023] Furthermore, the use of the term "horizontal" does not imply that the component must be absolutely horizontal, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0024] In the description of the embodiments of this application, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "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 according to the specific circumstances.

[0025] The technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. The components of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. 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 represents selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application. It should be noted that similar reference numerals and letters in the following drawings indicate similar items; therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. Furthermore, in the description of this application, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0026] In existing technologies, devices with uneven bottom surfaces, such as PCBs with solder balls or metal tubes with slotted bottoms, cannot form an effective sealing cavity with the vacuum hole array of the hot seat of the bonding equipment, causing the vacuum adsorption method to fail. The fixture method requires customized design and is prone to mechanical damage. Although the conventional bonding method can fix the components, a large tearing force is required during peeling, which can lead to damage such as solder ball detachment, substrate warping, and tube indentation, as well as the risk of glue residue, which seriously affects the packaging yield and reliability.

[0027] To solve the above problems, such as Figure 1 and Figure 2 As shown, the present invention provides a bonding and fixing device for a device with an uneven bottom surface, including a glass sheet 3, on which a first UV film 4, a double-sided adhesive film 5 and a second UV film 6 are sequentially bonded. The top of the second UV film 6 is used to bond a receiving bonding device 7. The bonding and fixing device is placed in the vacuum hole array area of ​​the hot seat 1 of the bonding equipment.

[0028] The bonding and fixing device of the present invention forms a multi-layer composite structure of glass sheet-UV film-double-sided adhesive film-UV film-device; vacuum adsorption fixing is achieved through glass sheet, and the multi-layer composite structure transforms non-adsorbable devices into an adsorbable whole; the requirements for the flatness of the bottom surface of the device are reduced, and the UV film can avoid the risks of mechanical damage and adhesive residue during device separation by UV photolysis.

[0029] In some specific embodiments, the glass sheet 3 has a thickness of 1.0~2.0mm, a light transmittance of ≥85%, and a surface roughness Ra≤0.02μm to ensure the sealing performance of vacuum adsorption, ultraviolet transmission efficiency, and the effect of vacuum adsorption. If the glass sheet is too thin, its rigidity will be insufficient, and it will easily undergo micro-deformation during vacuum adsorption, affecting the positioning accuracy of the device; if it is too thick or the light transmittance is insufficient, the ultraviolet light transmission will be severely attenuated, resulting in insufficient unbonding of the upper UV film; if the surface roughness is too large, it may make the vacuum adsorption unstable.

[0030] In some specific embodiments, the thickness of both the first UV film 4 and the second UV film 6 is 0.06~0.17mm. Before UV irradiation, the adhesion between the first UV film 4 and the second UV film 6 is not less than 4N / 20mm; after UV irradiation, the adhesion can be reduced to below 0.2N / 20mm. The adhesion before UV irradiation needs to be sufficient to firmly fix the device to the glass sheet, and the adhesion after UV irradiation needs to be low enough to reduce the difficulty of device separation.

[0031] In some specific embodiments, the double-sided adhesive film is a light-transmitting film with a thickness of 25~50μm and a transmittance of ≥85% for 365nm ultraviolet light; and it maintains dimensional stability at 80℃. The double-sided adhesive film is the intermediate layer connecting the first UV film and the second UV film and ensuring ultraviolet transmission. If the transmittance is insufficient, it will affect the UV removal effect of the first UV film and the second UV film.

[0032] In some specific implementation methods, such as Figure 3 As shown, the diameter of the vacuum holes 2 in the vacuum hole array of the bonding device's hot seat is 0.2~0.4mm, and the hole spacing is 1.5~3.0mm. The glass plate 3 covers the entire vacuum hole area, forming an effective negative pressure sealing cavity. The vacuum adsorption effect depends on the integrity of the sealing cavity; insufficient glass plate coverage or too small edge margin will lead to air leakage and insufficient adsorption force. This structure ensures that a fully enclosed negative pressure cavity is formed between the glass plate and the hot seat, which is a prerequisite for stable vacuum adsorption.

[0033] like Figure 4-6 As shown, the present invention also provides a bonding and fixing method for devices with uneven bottom surfaces, comprising the following steps: The bonding equipment is equipped with a hot mount 1 with a vacuum array; Complete the assembly of the above-mentioned bonding and fixing device; With the vacuum closed, place the glass plate of the bonding fixing device in the vacuum array area of ​​the hot seat 1 of the bonding equipment, ensuring that the glass plate covers the vacuum hole 2; Turn on the vacuum system of the bonding equipment and perform the bonding operation; After bonding is completed, the vacuum system is turned off and the bonding fixing device is removed; ultraviolet light is applied from the underside of the glass plate of the bonding fixing device to debond the first UV film 4 and the second UV film 6; then the device 7 is separated.

[0034] The bonding and fixing method provided by this invention involves placing the entire bonding and fixing device in the vacuum hole array area of ​​the hot seat of the bonding equipment, turning on the machine vacuum, and using vacuum adsorption force to fix the glass sheet, thereby achieving stable fixation of the device during the bonding process. After bonding is completed, the vacuum is turned off, and the composite structure is removed. Ultraviolet light is irradiated from the bottom side of the glass sheet, allowing the ultraviolet light to penetrate the glass sheet, the lower UV film, the light-transmitting double-sided adhesive film, and the upper UV film in sequence, simultaneously reducing the adhesion force between the upper and lower UV films and the glass sheet and the device. After the adhesion force decays to a weak state, the device is separated from the glass sheet, achieving clean detachment with low stress and zero adhesive residue.

[0035] In some specific embodiments, the wavelength of the ultraviolet light is 365nm, the irradiation intensity is 100~300mW / cm², and the irradiation time is 10~20 seconds. These parameters can achieve a good debonding effect, significantly reducing the adhesion between the first UV film and the second UV film, thereby facilitating their smooth separation from the glass sheet or device.

[0036] In some specific implementations, the method is suitable for low-temperature bonding processes with bonding temperatures ranging from room temperature to 80°C, such as aluminum wire bonding, but not for processes requiring hot pressing above 80°C. The thermal stability of the UV film is a determining factor for process applicability. This limitation ensures the stability and reliability of the solution within the target process window.

[0037] After separation by ultraviolet light irradiation, there is no visible adhesive residue on the surface of the glass sheet, which can be reused for the next round of device bonding. The reusable nature of the glass sheet reduces the material cost of bonding operations and effectively improves the economic efficiency of the process.

[0038] This solution reduces the requirement for the flatness of the device's bottom surface and can be applied to devices with uneven bottom surfaces. In this application, devices with uneven bottom surfaces include ball-mounted PCB substrates and metal tube shell devices with bottom slots.

[0039] To make the technical problem to be solved, the technical solution, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0040] The following examples use instruments and equipment conventional in the art. Experimental methods in the following examples, unless otherwise specified, are generally performed under standard conditions or as recommended by the manufacturer. All raw materials used in the following examples are conventional commercially available products with specifications standard in the art. The front side of the UV film in the following examples is the adhesive side.

[0041] Example 1 For PCB substrate devices with pre-placed balls, the device size is 2cm x 2cm, aluminum wires are bonded to the front side of the device, and the bonding temperature is room temperature. The specific implementation steps are as follows: Step 1: Install the heat mount 1 with vacuum array in the bonding area of ​​the aluminum wire bonding machine. The surface of the heat mount 1 is flat. Step 2: Select a flat glass sheet 3. The glass sheet 3 is 5cm x 5cm in length and width and 1.2mm in thickness. On it, attach the front side of the first UV film 4, the back side of the double-sided adhesive film 5 and the second UV film 6 in sequence, with the front side of the second UV film 6 facing up. The thickness of the UV film is 0.85mm and the thickness of the double-sided adhesive film is 50μm.

[0042] Step 3: Adhere the bonding device 7 to the top of the second UV film 6. During the bonding process, press the bonding device 7 firmly and check to ensure that the bonding device and the UV film are firmly bonded. Step 4: With the vacuum system of the aluminum wire machine hot seat closed, place the glass plate of the bonding and fixing device in the vacuum array area of ​​the hot seat 1, and cover all the vacuum holes with the glass plate 3. Step 5: Turn on the vacuum system of the aluminum wire machine to firmly vacuum-adhere the glass sheet 3; Step 6: Perform aluminum wire bonding; Step 7: After bonding is complete, turn off the vacuum system and remove the bonding fixing device; Step 8: Place the bonding and fixing device into the UV de-UV device and apply 365nm ultraviolet light from the glass plate side of the bonding and fixing device to de-UV the first UV film 4 and the second UV film 6. Step 9: Separate the device, UV film, and glass plate; Step 10: Proceed to the next round of operations.

[0043] Example 2 For metal-cased devices with uneven bottom surfaces that cannot attract vacuum, the device dimensions are 2.5cm x 2.5cm. The device contains internal aluminum wire bonding at room temperature. The specific implementation steps are as follows: Step 1: Install the heat mount 1 with vacuum array in the bonding area of ​​the aluminum wire bonding machine. The surface of the heat mount 1 is flat. Step 2: Select a flat glass sheet 3. The glass sheet 3 is 6cm x 6cm in length and width and 1.5mm in thickness. On it, attach the front side of the first UV film 4, the back side of the double-sided adhesive film 5 and the second UV film 6 in sequence, with the front side of the second UV film 6 facing up. The thickness of the UV film is 1mm and the thickness of the double-sided adhesive film is 30μm.

[0044] Step 3: Two devices 7 to be bonded are bonded on the top of the second UV film 6 at one time. During the bonding process, the devices 7 to be bonded are pressed firmly, and the bonding between the devices and the UV film is checked to ensure that the bonding is firm. Step 4: With the vacuum system of the aluminum wire machine hot seat closed, place the glass plate of the bonding and fixing device in the vacuum array area of ​​the hot seat 1, and cover all the vacuum holes with the glass plate 3. Step 5: Turn on the vacuum system of the aluminum wire machine to firmly vacuum-adhere the glass sheet 3; Step 6: Perform aluminum wire bonding; Step 7: After bonding is complete, turn off the vacuum system and remove the bonding fixing device; Step 8: Place the bonding and fixing device into the UV de-UV device and apply 365nm ultraviolet light from the glass plate side of the bonding and fixing device to de-UV the first UV film 4 and the second UV film 6. Step 9: Separate the device, UV film, and glass plate; Step 10: Proceed to the next round of operations.

[0045] The above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art can still make modifications or equivalent substitutions to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention are within the protection scope of the claims of the present invention pending approval.

Claims

1. A bonding and fixing device for components with uneven bottom surfaces, characterized in that, The device includes a glass plate (3), on which a first UV film (4), a double-sided adhesive film (5) and a second UV film (6) are sequentially bonded. The top of the second UV film (6) is used to bond the bonding device (7). The bonding fixing device is placed in the vacuum hole array area of ​​the hot seat (1) of the bonding equipment.

2. The bonding and fixing device for devices with uneven bottom surfaces according to claim 1, characterized in that, The diameter of the vacuum holes 2 in the vacuum hole array of the hot seat of the bonding device is 0.2~0.4mm, and the hole spacing is 1.5~3.0mm.

3. The bonding and fixing device for devices with uneven bottom surfaces according to claim 1, characterized in that, The glass sheet (3) has a thickness of 1.0~2.0 mm, a light transmittance of ≥85%, and a surface roughness Ra≤0.02 μm.

4. The bonding and fixing device for devices with uneven bottom surfaces according to claim 1, characterized in that, Before UV light exposure, the adhesion between the first UV film (4) and the second UV film (6) is not less than 4N / 20mm; After being irradiated with UV light, the adhesion between the first UV film (4) and the second UV film (6) can be reduced to below 0.2N / 20mm.

5. The bonding and fixing device for devices with uneven bottom surfaces according to claim 1, characterized in that, The thickness of the first UV film (4) and the second UV film (6) is 0.06~0.17mm.

6. The bonding and fixing device for devices with uneven bottom surfaces according to claim 1, characterized in that, The double-sided adhesive film is a light-transmitting film with a thickness of 25~50μm and a transmittance of ≥85% for 365nm ultraviolet light.

7. A bonding and fixing method for a device with an uneven bottom surface, characterized in that, Includes the following steps: The bonding equipment is equipped with a hot mount with a vacuum array (1); The assembly is completed using the bonding and fixing device described in any one of claims 1-6; With the vacuum off state, place the glass plate of the bonding fixing device in the vacuum array area of ​​the bonding equipment hot seat (1) to ensure that the glass plate covers the vacuum hole (2). Turn on the vacuum system of the bonding equipment and perform the bonding operation; After bonding is completed, the vacuum system is turned off and the bonding fixing device is removed. Ultraviolet light is applied from the underside of the glass plate of the bonding fixing device to debond the first UV film (4) and the second UV film (6). Then the device (7) is separated.

8. The bonding and fixing method for devices with uneven bottom surfaces according to claim 7, characterized in that, The ultraviolet light wavelength is 365nm, the irradiation intensity is (100~300)mW / cm², and the irradiation time is 10~20 seconds.

9. The bonding and fixing method for devices with uneven bottom surfaces according to claim 7, characterized in that, The method is applicable to low-temperature bonding processes with bonding temperatures ranging from room temperature to 80°C.

10. The bonding and fixing method for devices with uneven bottom surfaces according to claim 7, characterized in that, The method is applicable to aluminum wire bonding.

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