A method for metal film peeling using double-layer negative adhesive as a mask.

Abstract

This invention discloses a method for metal thin film stripping using a double-layer negative adhesive as a mask, comprising the following steps: 1) Spin-coating a base adhesive with a CP value of 25±1 onto a cleaned substrate, followed by a first baking of the substrate coated with the base adhesive, with the baking temperature controlled between 115-125℃ and the baking time controlled between 100±2s; 2) Spin-coating a top adhesive with a CP value of 12±1 onto the base adhesive, followed by a second baking, with the baking temperature controlled between 120-130℃ and the baking time controlled between 100s+ / -2s; 3) Exposure using UV light on an exposure machine, with an exposure dose of 120mJ / cm. 2 4) After PEB and development, a metal film is deposited in a coating machine using electron beam evaporation; 5) Peeling is performed in NMP solvent at a temperature of 75±3℃ and a pressure of standard atmosphere. The base adhesive is a photocrosslinking negative adhesive, and the top adhesive is a photopolymerizing negative adhesive. This peeling method is stable, yields a product with low fragmentation, and the adhesive layer is less prone to collapse, resulting in superior interdigitated stripe edges.

Description

Technical Field

[0001] This invention relates to the fields of electrical and nanofabrication technology, specifically to a method for metal thin film peeling using a double-layer negative adhesive as a mask. Background Technology

[0002] With the advent of the new generation of mobile communication, surface acoustic wave (SAWF) filters are widely used in radio frequency mobile communication. SAW chip technology is developing rapidly, and new research and discoveries in the technology have become an important focus.

[0003] Traditional metal film peeling processes employ either single-layer or double-layer adhesives. Existing single-layer negative adhesives, due to the need for high resolution, require a sufficiently thin adhesive layer. When thick metal film layers are required, complete adhesive removal becomes difficult, or even impossible. Double-layer adhesive peeling processes, on the other hand, [see...]. Figure 3 As shown, the specific peeling steps include applying a base adhesive 2' to the substrate 1'. This base adhesive is typically a common negative photoresist. Then, a top adhesive 3' is applied over the base adhesive 2'. This top adhesive 3' is generally a non-photosensitive adhesive. After exposure, PEB baking, development, and then depositing a metal film 4', the substrate is finally peeled off. Because the base adhesive is non-photosensitive, it reacts readily with the developer. The PEB baking temperature is very high (reaching 250-260℃). Due to our product's technical requirements, the substrate is very thin (0.2-0.25μm). Baking at 250℃ or higher makes it brittle, especially when producing 0.2μm substrates, and during hot plate handling. Experimental verification (approximately 2000 samples) shows a fragmentation rate of 15%-20%. Furthermore, the base adhesive is generally more than twice the price of the negative photoresist, resulting in extremely high production costs. Additionally, due to performance limitations, the non-photosensitive adhesive layer has low process tolerance and is prone to severe delamination due to differences in development time or temperature, or excessive development, leading to collapse of the upper adhesive layer (e.g., ...). Figure 4 As shown in the figure, this results in the inability to peel off. The aforementioned technical problem is something that those skilled in the art are dedicated to solving. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for metal film peeling using a double-layer negative adhesive as a mask.

[0005] To achieve the above objectives, the technical solution adopted by this invention is: a method for metal thin film peeling using a double-layer negative adhesive as a mask, comprising the following steps: 1) Spin-coat a primer with a CP value of 25±1 onto the cleaned substrate, and then bake the substrate coated with primer for the first time. The baking temperature is controlled between 115-125℃ and the baking time is controlled between 100±2s. 2) Spin coat the base coat with a top coat with a CP value of 12±1 and bake it a second time. The baking temperature is controlled between 120-130℃ and the baking time is controlled between 100s+ / -2s. 3) Exposure was performed using UV light on an exposure machine at a dose of 120 mJ / cm. 2 ; 4) After PEB and development, a metal film is deposited on the upper surface of the adhesive using electron beam evaporation in a coating machine; 5) Metal film peeling was performed in NMP solvent at a temperature of 75±3℃ and a pressure of standard atmosphere. The base adhesive uses a photocrosslinking negative adhesive, and the top adhesive uses a photopolymerization negative adhesive.

[0006] In one specific implementation, the base adhesive is any one of the photoresists manufactured by FUTURREX, namely NR9-250PY, NR9-500PY, NR9-1000PY, and NR9-3000PY.

[0007] As one specific implementation, the adhesive used is AZ5510 photoresist produced by Jiangsu Hantuo Optical Materials Co., Ltd.

[0008] In one specific implementation, the spin coating speed in step 1) is 2000 r / min-3000 r / min.

[0009] In one specific implementation, the spin coating speed in step 2) is 5500-2500 r / min.

[0010] In one specific implementation, the thickness ratio of the base adhesive to the top adhesive is between 2:1 and 3:1; the thickness ratio of the base adhesive to the metal film plated in step 5) is between 1.5:1 and 2.5:1.

[0011] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art: In this invention, the base adhesive uses a photocrosslinking type negative adhesive, and the top adhesive uses a photopolymerizing type negative adhesive. The baking temperatures of the two adhesive layers are similar. The base adhesive is more soluble in TMAH solution than the top adhesive. The use of the above two layers of negative photoresist solves the problem of insufficient thickness of a single adhesive film, which causes incomplete or even impossible peeling. At the same time, compared with the existing technology that uses a double-layer adhesive (one layer of negative adhesive and one layer of non-photosensitive adhesive), the product of this invention has stable process and low breakage rate. Production verification (sample of 15,000 pieces) shows that the breakage rate is less than 1‰ below 150°C. It has low cost, the adhesive layer is not easy to collapse, and the interdigitated strip shape edge is better. Attached Figure Description

[0012] Appendix Figure 1This is a process flow diagram of the method for metal thin film peeling using a double-layer negative adhesive as a mask according to the present invention; Appendix Figure 2 This is a schematic diagram of the process for the method of metal thin film peeling using a double-layer negative adhesive as a mask according to the present invention; Appendix Figure 3 This is a schematic diagram of a prior art method for metal film peeling using a double-layer adhesive. Appendix Figure 4 For the appendix Figure 3 In the diagram, the gel collapses after development; Wherein: 1, substrate; 2, base adhesive; 3, top adhesive; 4, metal film; 1', substrate; 2', base adhesive; 3', top adhesive; 4', metal film. Detailed Implementation

[0013] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0014] Example 1 This example provides a method for metal thin film peeling using a double-layer negative adhesive as a mask. (See also...) Figure 1 , 2 As shown, it includes the following steps: S01: Spin coat a base coater 2 with a CP value of 25±1 onto the cleaned substrate 1. The base coater 2 used here is NR9-250PY photoresist manufactured by FUTURREX. The spin coating speed is 2000r / min and the thickness is 0.4μm. Then, the substrate 1 coated with base coater 2 is baked for the first time at a temperature of 120℃ and a baking time of 100±2s. S02: Spin coat the base adhesive 2 with a top adhesive 3 having a CP value of 12±1. Here, the top adhesive 3 is a photoresist of model AZ5510 produced by Jiangsu Hantuo Optical Materials Co., Ltd. The spin coating speed is 5500r / min, the thickness is 0.3μm, and a second baking is performed. The baking temperature is 125℃, and the baking time is controlled within 100s+ / -2s. S03: Exposure using UV light on an exposure machine, with an exposure dose of 120 mJ / cm². 2 ; S04: Developed with PEB and developer; S05: A metal film 4 is deposited on the upper surface of the adhesive 3 using electron beam evaporation in a coating machine. The thickness of the metal film 4 is 750 nm. S06: The metal film 4 was peeled off in NMP solvent at a temperature of 75±3℃ and a pressure of standard atmosphere.

[0015] Production verification (sample size 15,000 pieces) showed a breakage rate of less than 1‰ at temperatures below 150℃.

[0016] Example 2 This example provides a method for metal thin film peeling using a double-layer negative adhesive as a mask. (See also...) Figure 1 , 2 As shown, it includes the following steps: S01: Spin-coat a base coat 2 with a CP value of 25±1 onto the cleaned substrate 1. The base coat 2 used here is NR9-500PY photoresist manufactured by FUTURREX. The spin-coating speed is 2000r / min and the thickness is 0.7μm. Then, the substrate 1 coated with base coat 2 is baked for the first time at a temperature of 115℃ and a baking time of 100±2s. S02: Spin coat the base adhesive 2 with a top adhesive 3 having a CP value of 12±1. The top adhesive 3 is a photoresist of model AZ5510 produced by Jiangsu Hantuo Optical Materials Co., Ltd. The spin coating speed is 4500r / min and the thickness is 0.45μm. Then, a second baking is performed at a baking temperature of 120℃ and a baking time of 100s+ / -2s. S03: Exposure using UV light on an exposure machine, with an exposure dose of 120 mJ / cm². 2 ; S04: Developed with PEB and developer; S05: A metal film 4 is deposited on the upper surface of the adhesive 3 using electron beam evaporation in a coating machine. The thickness of the metal film 4 is 0.5 μm. S06: The metal film 4 was peeled off in NMP solvent at a temperature of 75±3℃ and a pressure of standard atmosphere.

[0017] Example 3 This example provides a method for metal film stripping using a double-layer negative adhesive as a mask, including the following steps: S01: Spin-coat a base coat 2 with a CP value of 25±1 onto the cleaned substrate 1. The base coat 2 used here is NR9-1000PY photoresist manufactured by FUTURREX. The spin-coating speed is 3000r / min and the thickness is 1.2μm. Then, the substrate 1 coated with base coat 2 is baked for the first time at a temperature of 122℃ and a baking time of 100±2s. S02: Spin coat the base adhesive 2 with a top adhesive 3 having a CP value of 12±1. The top adhesive 3 is a photoresist of model AZ5510 produced by Jiangsu Hantuo Optical Materials Co., Ltd. The spin coating speed is 3000r / min and the thickness is 0.70μm. Then, a second baking is performed at a baking temperature of 128℃ and a baking time of 100s+ / -2s. S03: Exposure using UV light on an exposure machine, with an exposure dose of 120 mJ / cm².2 ; S04: Developed with PEB and developer; S05: A metal film 4 is deposited on the upper surface of the adhesive 3 using electron beam evaporation in a coating machine. The thickness of the metal film 4 is 0.75 μm. S06: The metal film 4 was peeled off in NMP solvent at a temperature of 75±3℃ and a pressure of standard atmosphere.

[0018] Example 4 This example provides a method for metal film stripping using a double-layer negative adhesive as a mask, including the following steps: S01: Spin coat a base coat 2 with a CP value of 25±1 onto the cleaned substrate 1. The base coat 2 used here is NR9-3000PY photoresist manufactured by FUTURREX. The spin coat speed is 4500r / min and the thickness is 2μm. Then, the substrate 1 coated with base coat 2 is baked for the first time at a temperature of 125℃ and a baking time of 100±2s. S02: Spin coat the base adhesive 2 with a top adhesive 3 having a CP value of 12±1. The top adhesive 3 is a photoresist of model AZ5510 produced by Jiangsu Hantuo Optical Materials Co., Ltd. The spin coating speed is 2500r / min and the thickness is 1μm. Then, a second baking is performed at a baking temperature of 130℃ and a baking time of 100s+ / -2s. S03: Exposure using UV light on an exposure machine, with an exposure dose of 120 mJ / cm². 2 ; S04: Developed with PEB and developer; S05: A metal film 4 is deposited on the upper surface of the adhesive 3 using electron beam evaporation in a coating machine. The thickness of the metal film 4 is 1.2 μm. S06: The metal film 4 was peeled off in NMP solvent at a temperature of 75±3℃ and a pressure of standard atmosphere.

[0019] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for metal thin film peeling using a double-layer negative adhesive as a mask, characterized in that, Includes the following steps: 1) Spin-coat a primer with a CP value of 25±1 onto the cleaned substrate, and then bake the substrate coated with primer for the first time. The baking temperature is controlled between 115-125℃ and the baking time is controlled between 100±2s. 2) Spin coat the base coat with a top coat with a CP value of 12±1 and bake it a second time. The baking temperature is controlled between 120-130℃ and the baking time is controlled between 100s+ / -2s. 3) Exposure was performed using UV light on an exposure machine at a dose of 120 mJ / cm. 2 ; 4) After PEB and development, a metal film is deposited on the upper surface of the adhesive using electron beam evaporation in a coating machine; 5) Metal film peeling was performed in NMP solvent at a temperature of 75±3℃ and a pressure of standard atmosphere. The base adhesive uses a photocrosslinking negative adhesive, and the top adhesive uses a photopolymerization negative adhesive. The thickness ratio of the base adhesive to the top adhesive is between 2:1 and 3:

1. The thickness ratio of the base adhesive to the metal film deposited in step 4) is between 1.5:1 and 2.5:

1.

2. The method for metal thin film peeling using a double-layer negative adhesive as a mask according to claim 1, characterized in that, The base adhesive is any one of the following photoresists manufactured by FUTURREX: NR9-250PY, NR9-500PY, NR9-1000PY, and NR9-3000PY.

3. The method for metal thin film peeling using a double-layer negative adhesive as a mask according to claim 1, characterized in that, The adhesive used is AZ5510 photoresist produced by Jiangsu Hantuo Optical Materials Co., Ltd.

4. The method for metal thin film peeling using a double-layer negative adhesive as a mask according to claim 1, characterized in that, In step 1), the spin coating speed is 2500 r / min.

5. The method for metal thin film peeling using a double-layer negative adhesive as a mask according to claim 1, characterized in that, In step 2), the spin coating speed is 3000 r / min.

Images