A pick-up-free composite material for die bonding and a manufacturing method and a using method thereof

Abstract

The application provides a non-drawing composite material for die bonding and a manufacturing method and use method thereof, and belongs to the COB packaging technical field; the technical problem to be solved is that in the prior art, after the die bonding suction nozzle contacts the chip surface, the chip surface is rubbed and scratched or is damaged by pressure; the technical scheme for solving the technical problem is that modified polysiloxane resin 40-60 parts, nano silicon dioxide particles 5-10 parts, polytetrafluoroethylene nano powder 3-8 parts, amino silane coupling agent 1-3 parts and platinum gold catalytic curing agent 0.5-2 parts are used; the application is applied to a COB chip die bonding process.

Description

Technical Field

[0001] This application relates to the field of COB packaging technology, and in particular to a non-fudge composite material for die bonding and its manufacturing and application methods. Background Technology

[0002] In the COB chip die bonding process, the chip scratching phenomenon is a common pain point in the industry. The core cause is that when the die bonding nozzle comes into contact with the chip surface, the hardness and coefficient of friction of the contact material are too high, or the material itself is prone to generating dust or has poor adhesion, which leads to the chip surface being scratched by friction or damaged by pressure, thereby affecting the chip appearance and optoelectronic performance, reducing production yield and increasing production costs.

[0003] In existing technologies, solving the chip adhesion problem mostly relies on nozzle structure modification or process adjustment, failing to address the core issue of "contact materials." Current die-bonding nozzle contact materials are mostly ordinary silicone, ceramics, and rubber. Ordinary silicone has poor wear resistance, is easily worn, sheds powder, ages, softens and adheres to the die at high temperatures, contaminating the chip. Ceramic has high hardness (70–90 HRC) and a high coefficient of friction (0.3–0.6), easily causing chip adhesion, indentation, and edge chipping. Rubber easily generates dust and has insufficient adhesion. None of these technologies can simultaneously meet the core requirements of "low friction (≤0.03), low hardness, high adhesion, dust-free, high resilience, and high temperature resistance (≥200℃)," thus failing to solve the chip adhesion problem at its root. Currently, there is no dedicated composite material in the industry specifically designed for the contact surface of COB chip die-bonding nozzles that can completely eliminate chip adhesion. Therefore, a new technical solution that solves the chip adhesion phenomenon through material innovation is urgently needed. Summary of the Invention

[0004] To address the aforementioned technical problems, this application proposes a non-growth-absorbing composite material for crystal bonding, as well as its manufacturing and application methods.

[0005] The technical solution adopted in this application is: a non-gold-absorbing composite material for crystal fixation, which is prepared from the following components in parts by weight: 40-60 parts of modified polysiloxane resin, 5-10 parts of nano-silica particles, 3-8 parts of polytetrafluoroethylene nanopowder, 1-3 parts of aminosilane coupling agent, and 0.5-2 parts of platinum catalytic curing agent.

[0006] Furthermore, the modified polysiloxane resin is a polysiloxane resin with phenyl side chains.

[0007] Furthermore, a method for preparing the flower-free composite material as described above includes the following steps: Step 1: Stir the modified polysiloxane resin evenly at room temperature; Step 2: Add nano-silica particles and polytetrafluoroethylene nanopowder to the modified polysiloxane resin and stir until homogeneous. Step 3: Add aminosilane coupling agent and platinum catalyst curing agent and stir evenly; Step 4: Curing at room temperature, then cutting into shape after curing.

[0008] Further, in step two, the mixture is stirred at a speed of 2000–3000 r / min for 20–30 min.

[0009] Further, in step three, the mixture is stirred at a speed of 100–200 r / min for 5–10 min.

[0010] Furthermore, a method using the non-flower-absorbing composite material as described above includes the following steps: Step 1: Pre-treat the die bonding nozzle; Step 2: Cut the composite material into a patch that matches the adsorption end face of the die bonding nozzle, and attach the patch to the adsorption end face of the die bonding nozzle; Step 3: Install the bonded die bonding nozzle onto the die bonding machine and perform the die bonding operation according to the conventional process.

[0011] Furthermore, step 1 specifically includes: Step 1.1: Use anhydrous ethanol as a cleaning solution to perform ultrasonic cleaning on the die bonding nozzle; Step 1.2: Wipe the die bonding nozzle with a lint-free cloth dampened with anhydrous ethanol; Step 1.3: Purge the die bonding nozzle with nitrogen gas; Step 1.4: Place the die bonding nozzle in an oven for baking to remove residual adhesive and moisture from the surface of the die bonding nozzle.

[0012] Furthermore, in step 2, the patch is attached to the adsorption end face of the die-bonding nozzle using high-temperature resistant silicone adhesive.

[0013] Furthermore, the conventional processes described in step 3 include eutectic bonding process, silver paste bonding process, and insulating adhesive bonding process.

[0014] The beneficial effects of this application compared to the prior art are as follows: 1. Solving the problem of chip adhesion: The core is to achieve low friction (friction coefficient 0.01-0.03), low hardness and high adhesion through the innovation of composite material formula, eliminating friction scratches and pressure damage from the source of contact materials. During the die bonding process, the chip surface has zero chip adhesion and zero damage, and the die bonding yield can be increased to more than 99.8%.

[0015] 2. Simple operation and controllable cost: No need to modify the existing die bonder and die bonder process. It can be used simply by attaching the composite material patch to the existing nozzle. The preparation process is simple, the material components are readily available and the cost is low, which facilitates industrial mass production and industry promotion, and greatly reduces the production cost of enterprises.

[0016] 3. Strong adaptability and long service life: The composite material has good high temperature resistance, wear resistance and stability, and can be adapted to COB chips of different specifications and surface materials (including Mini LED chips, power chips, etc.). It has a long service life, reduces the frequency of chip replacement, and further reduces the cost of consumables. At the same time, the material is dust-free and residue-free, and will not contaminate the chip and die bonding environment, meeting the high cleanliness requirements of COB packaging. Attached Figure Description

[0017] The following description, in conjunction with the accompanying drawings, further illustrates this application: Figure 1 This is a schematic diagram of the die-bonding nozzle in this application; In the diagram: 1 is the die bonding nozzle, 2 is the surface mount device, and 3 is the chip. Detailed Implementation

[0018] like Figure 1 As shown, this application provides a non-growth-absorbing composite material for crystal bonding, which is prepared from the following components in parts by weight: 40–60 parts of modified polysiloxane resin, as the core matrix of the composite material, adopts a polysiloxane main chain structure (high Si-O bond energy and strong stability), introduces phenyl side chains to improve the toughness of the material, avoids the material from cracking and generating dust, and at the same time has good high temperature resistance (can withstand crystal solidification environment above 200℃). Its Shore hardness is 10–25HA, tensile strength is 3–6MPa, and it is not brittle, does not powder, and leaves no residue. 5–10 parts of fumed silica nanoparticles, with a purity ≥99.9% and a particle size of 50–100 nm, are used as flexible modifiers and are uniformly dispersed in the matrix material to adjust the hardness of the composite material, reduce the rigidity of the material, and at the same time improve the wear resistance and elasticity of the material. This prevents the material from wearing out and aging during long-term use, ensures that it can adhere tightly to the surface of chip 3 during adsorption, disperses contact pressure, and avoids local stress concentration. 3–8 parts of polytetrafluoroethylene (PTFE) nanopowder with a particle size of 30–80 nm are uniformly dispersed in the composite material as the core anti-friction component. Its self-lubricating properties keep the surface friction coefficient of the composite material stable at 0.01–0.03. It can be cured at room temperature without dust precipitation, and at the same time has good high temperature resistance, avoiding additives from falling off and contaminating the chip 3. 1–3 parts of aminosilane coupling agent, preferably γ-aminopropyltriethoxysilane, to improve the dispersibility of inorganic powder and the adhesion strength to patch 2 or nozzle (ceramic, metal, etc.), prevent detachment and curling during use, and at the same time enhance the adhesion between the composite material and the surface of chip 3, reduce contact gaps, and avoid foreign matter residue. 0.5–2 parts of platinum catalyst curing agent, preferably platinum-vinylsiloxane complex, are used to achieve room temperature curing of composite materials. After curing, the material is residue-free, odorless, and dust-free, with a fast curing speed (complete curing in 1–2 hours at room temperature), meeting the requirements for high-cleanliness packaging.

[0019] In summary, the key performance indicators of the composite material are: coefficient of friction 0.01–0.03, hardness 10–25HA, high temperature resistance (no deformation at 220℃ for 2 hours), no sticking, bonding strength ≥0.8Mpa, resilience ≥90%, no visible dust in a Class 100 cleanroom, and thickness specifications of 0.10mm, 0.15mm, and 0.20mm.

[0020] A method for preparing the flower-free composite material as described above includes the following steps: Step 1: Use a double planetary mixer to stir the modified polysiloxane resin at room temperature at a speed of 300–500 r / min for 10–15 min until it is uniform and free of bubbles; Step 2: Add nano-silica particles and polytetrafluoroethylene nanopowder to the modified polysiloxane resin and stir at high speed of 2000–3000 r / min for 20–30 min. Degas under vacuum of -0.08 to -0.095 MPa to ensure no agglomeration. Step 3: Add aminosilane coupling agent and platinum catalyst curing agent and stir at low speed of 100-200 r / min for 5-10 min, and continue vacuum degassing for 3-5 min; Step 4: Inject it into a precision mold and cure it at room temperature for 1-2 hours. After curing, demold it and laser-die-cut it into a round or square patch 2 with a size that matches the suction end face of the nozzle. The size tolerance is ±0.02mm, and the edges are free of burrs and defects.

[0021] A method using the non-flower-absorbing composite material as described above includes the following steps: Step 1: Pre-treat the die bonding nozzle 1. The pre-treatment includes the following steps: use anhydrous ethanol as a cleaning solution to ultrasonically clean the die bonding nozzle 1 for 5 minutes; wipe the die bonding nozzle 1 with a lint-free cloth soaked in anhydrous ethanol; purge the die bonding nozzle 1 with nitrogen gas; place the die bonding nozzle 1 in an oven for baking at 100℃ for 10 minutes to remove residual adhesive and moisture from the surface of the die bonding nozzle 1. After pre-treatment, the adsorption end face Ra ≤ 0.02μm, with no adhesive residue, scratches, burrs, or dust, thereby avoiding foreign matter from affecting the bonding effect of the composite material patch 2.

[0022] Step 2: Cut the composite material into patches 2 that match the adsorption end face of the die bonding nozzle 1. Apply a small amount of high-temperature resistant silicone adhesive (high-temperature resistant single-component silicone, temperature resistance ≥200℃, adhesive thickness 5–10μm) in dots to the adsorption end face of the die bonding nozzle 1. Align the patches 2 concentrically with the adsorption end face of the die bonding nozzle 1, and then apply a light pressure of 0.01–0.02Mpa for 5–10s to ensure tight adhesion, no air bubbles, and no misalignment. Ensure that the surface of the patches 2 is completely adhered to the adsorption end face of the nozzle. Then let it stand at room temperature for 30 minutes to ensure that there are no air bubbles, no misalignment, and no curling edges.

[0023] Step 3: Install the bonded die bonding nozzle 1 onto the die bonding machine and perform the die bonding operation according to the conventional process (eutectic die bonding process, silver paste die bonding process, insulating adhesive die bonding process); when the composite material patch 2 contacts the surface of the chip 3, it disperses the contact pressure due to its low friction, low hardness and high adhesion characteristics, eliminates friction scratches and solves the problem of chip adhesion.

[0024] In the embodiments of this application, the parameters of the die bonder are: adsorption pressure 0.02–0.05 MPa (preferably 0.03 MPa), nozzle descent speed 5–10 mm / s (preferably 8 mm / s), and adsorption time 50–120 ms. After use, the composite material patch 2 needs to be maintained regularly. Every 2–3 hours of operation, the surface of the composite material patch 2 should be cleaned with anhydrous ethanol to remove residual adhesive residue and dust. When the patch 2 has a friction coefficient >0.03, or shows wear, scratches, warping, or detachment, or has been used continuously for ≥100 hours, a new composite material patch 2 should be replaced in time. After replacement, it needs to be re-cured for 30 minutes before being put back into operation to ensure the continuous and stable anti-scratching effect.

[0025] Example 1: A non-scratching composite material for die bonding of COB chips In this embodiment, the composite material is made of the following components in parts by weight: 50 parts modified polysiloxane resin, 8 parts nano silica particles (particle size 80nm), 5 parts polytetrafluoroethylene nanopowder, 2 parts aminosilane coupling agent, and 1 part platinum catalytic curing agent.

[0026] Preparation method: 50 parts of modified polysiloxane resin were placed in a stirring device and stirred at room temperature for 12 minutes until uniform; 8 parts of nano silica particles and 5 parts of polytetrafluoroethylene nano powder were added in sequence and stirred at high speed for 25 minutes (stirring speed 2500r / min); then 2 parts of aminosilane coupling agent and 1 part of platinum catalyst curing agent were added and stirred at low speed for 8 minutes. After mixing evenly, the mixture was poured into a mold and cured at room temperature for 1.5 hours. After removal, it was cut into circular patches 2 with a diameter of 1.2mm (fitting COB chip 3 die bonding nozzle 1 with a size of 1mm×1mm) to obtain non-flake composite material patch 2.

[0027] Example 2: A method for using COB chip 3 die bonding to a non-scratching composite material This embodiment is based on the composite material of Embodiment 1 and is applied to the die bonding of a COB chip 3 with a size of 1mm × 1mm and a fluorescent coating on the surface. The specific steps are as follows: 1. Nozzle pretreatment: Wipe the adsorption end face of the existing ceramic nozzle with a lint-free cloth dampened with anhydrous ethanol to remove surface dust and adhesive residue, ensuring that the adsorption end face is flat and free of burrs.

[0028] 2. Composite material patch bonding: The circular composite material patch 2 prepared in Example 1 is bonded to the suction end face of the nozzle with high-temperature resistant silicone adhesive to ensure tight bonding, no air bubbles, and no misalignment. After bonding, it is left at room temperature for 30 minutes to ensure that the adhesive cures.

[0029] 3. Die bonding application: Install the nozzle with the attached patch 2 on the die bonder, set the adsorption pressure to 0.03MPa and the nozzle descent speed to 8mm / s, and perform chip 3 adsorption, transfer and die bonding operations according to the conventional die bonding process; when the composite material patch 2 contacts the chip 3 surface, the coefficient of friction is 0.02, the fit is tight, and there are no friction scratches or pressure damage.

[0030] 4. Regular maintenance: Clean the surface of composite material patch 2 with a lint-free cloth every 2.5 hours of operation; after 8 hours of continuous operation, check that patch 2 is free from wear and detachment, and continue to use it; when patch 2 has been used for 100 hours and the surface friction coefficient rises to 0.04, replace it with a new composite material patch 2 in time.

[0031] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A non-growth-absorbing composite material for crystal bonding, characterized in that: It is prepared from the following components in parts by weight: 40-60 parts modified polysiloxane resin, 5-10 parts nano silica particles, 3-8 parts polytetrafluoroethylene nanopowder, 1-3 parts aminosilane coupling agent, and 0.5-2 parts platinum catalytic curing agent.

2. The non-growth-absorbing composite material for crystal bonding according to claim 1, characterized in that: The modified polysiloxane resin is a polysiloxane resin with phenyl side chains.

3. A method for preparing the non-flowering composite material as described in claim 2, characterized in that: Includes the following steps: Step 1: Stir the modified polysiloxane resin evenly at room temperature; Step 2: Add nano-silica particles and polytetrafluoroethylene nanopowder to the modified polysiloxane resin and stir until homogeneous. Step 3: Add aminosilane coupling agent and platinum catalyst curing agent and stir evenly; Step 4: Curing at room temperature, then cutting into shape after curing.

4. The method for preparing a non-growth-absorbing composite material for crystal bonding according to claim 3, characterized in that: In step two, stir at a speed of 2000–3000 r / min for 20–30 min.

5. The method for preparing a non-growth-absorbing composite material for crystal bonding according to claim 3, characterized in that: In step three, stir at a speed of 100–200 r / min for 5–10 min.

6. A method for using the non-flowering composite material as described in claim 2, characterized in that: Includes the following steps: Step 1: Pre-treat the die bonding nozzle (1); Step 2: Cut the composite material into a patch (2) that matches the adsorption end face of the die bonding nozzle (1), and attach the patch (2) to the adsorption end face of the die bonding nozzle (1); Step 3: Install the bonded die bonding nozzle (1) onto the die bonding machine and perform the die bonding operation according to the conventional process.

7. The method of using a non-growth-absorbing composite material for crystal bonding according to claim 6, characterized in that: Step 1 specifically also includes: Step 1.1: Use anhydrous ethanol as a cleaning solution to perform ultrasonic cleaning on the die bonding nozzle (1); Step 1.2: Wipe the die bonding nozzle (1) with a lint-free cloth dampened with anhydrous ethanol; Step 1.3: Purge the die bonding nozzle (1) with nitrogen gas; Step 1.4: Place the die bonding nozzle (1) in an oven for baking to remove residual adhesive and moisture from the surface of the die bonding nozzle (1).

8. The method of using a non-growth-absorbing composite material for crystal bonding according to claim 7, characterized in that: In step 2, the patch (2) is attached to the adsorption end face of the die-bonding nozzle (1) using high-temperature resistant silicone adhesive.

9. The method of using a non-growth-absorbing composite material for crystal bonding according to claim 8, characterized in that: The conventional processes described in step 3 include eutectic bonding process, silver paste bonding process, and insulating adhesive bonding process.

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