阅读说明：本技术 一种硬盘驱动器悬架保护材料的制备方法 (Preparation method of hard disk drive suspension protection material ) 是由 周雨薇 于 2021-09-02 设计创作，主要内容包括：本发明涉及一种硬盘驱动器悬架保护材料的制备方法,属于高分子材料制造领域。该方法先制备聚酰亚胺前体树脂,然后将酸性光敏树脂涂抹到脱模聚酯薄膜上,固化后再将制备的聚酰亚胺前体树脂涂抹到光敏树脂上,之后将聚酯薄膜/光敏树脂/聚酰亚胺前驱体树脂3层材料按照聚酰亚胺前驱体树脂在下聚酯薄膜在上的方式层压到硬盘驱动器悬架电路板上,执行曝光,用乳酸水溶液刻蚀掉未曝光部分的光敏树脂,使用氢氧化钾水溶液刻蚀掉未曝光部分的聚酰亚胺前驱体树脂,再用乳酸水溶液刻蚀掉剩余的光敏树脂,最后进行高温固化,得到硬盘驱动器悬架聚酰亚胺保护材料。本发明制备的硬盘驱动器悬架保护材料具有很高的可靠性和耐久性,制造成本廉价。(The invention relates to a preparation method of a hard disk drive suspension protection material, belonging to the field of polymer material manufacture. Preparing polyimide precursor resin, coating acid photosensitive resin on a demoulding polyester film, curing, coating the prepared polyimide precursor resin on the photosensitive resin, laminating the 3 layers of the polyester film/photosensitive resin/polyimide precursor resin on a hard disk drive suspension circuit board in a mode that the polyimide precursor resin is on the lower polyester film, performing exposure, etching the unexposed part of the photosensitive resin by using lactic acid aqueous solution, etching the unexposed part of the polyimide precursor resin by using potassium hydroxide aqueous solution, etching the rest of the photosensitive resin by using lactic acid aqueous solution, and finally performing high-temperature curing to obtain the hard disk drive suspension polyimide protective material. The hard disk drive suspension protection material prepared by the invention has high reliability and durability and low manufacturing cost.)

1. A preparation method of a hard disk drive suspension protection material is characterized by comprising the following steps:

(1) mixing binary aminobenzene and tetracarboxylic dianhydride in a molar ratio of 1: 1, adding the mixture into dimethylacetamide, and reacting at room temperature for 2-8 h to obtain a polyimide precursor solution, wherein the diaminobenzene is 4,4 '-diaminobenzenecarboxanilide or 4, 4' -diaminodiphenyl ether, the tetracarboxylic dianhydride is pyromellitic dianhydride or 3,3 ', 4, 4' -benzophenone tetracarboxylic dianhydride, and the mass ratio of the diaminobenzene to the dimethylacetamide is 1: 10-20;

(2) coating photosensitive resin on a demoulding polyester film with the thickness of 50-100 mu m, coating the photosensitive resin with the thickness of 5-20 mu m, and drying for 5-10 minutes at the temperature of 50-100 ℃; smearing the polyimide precursor resin obtained in the step (1) on the cured photosensitive resin, smearing the resin with the thickness of 5-10 microns, and drying at 110-150 ℃ for 2-8 minutes to obtain a laminated board with a 3-layer structure of a polyester film/photosensitive resin/polyimide precursor resin;

(3) laminating the laminated plate with the 3-layer structure of the polyester film/photosensitive resin/polyimide precursor resin obtained in the step (2) on a hard disk drive suspension circuit board with the line width of 30-100 microns/line according to the mode that the polyimide precursor resin is on the lower polyester film, and then removing the polyester film;

(4) according to the circuit arrangement pattern on the hard disk drive suspension circuit board, the photosensitive resin in the step (3) is at 80-200 mJ/cm²Is exposed to light at an exposure intensity of 1 to 3min in a 0.1% aqueous solution of lactic acid at a liquid temperature of 25 ℃ and a pressure of 1 to 4Kgf/cm²Developing for 1-4 min by using a horizontal transportation type shower device under the shower pressure, and removing the photoresist on the unexposed part;

(5) drying the product obtained in the step (4) at 80-150 ℃ for 1-4 min, and using 10% potassium hydroxide aqueous solution at 25 ℃ and 0.5-2 Kgf/cm²Etching for 4 to 15 seconds under the spraying pressure of (3), and then using hot water at a temperature of 40 ℃ under a pressure of 5 to 15kgf/cm²Spraying for 1-4 min to completely remove the polyimide precursor resin layer exposed from the patterned photosensitive resin layer;

(6) using 10% lactic acid aqueous solution at 25 deg.C and 1-4 Kgf/cm²Spraying the product obtained in the step (5) for 20-60 s under the spraying pressure to remove the residual photosensitive resin, then placing the obtained product in a hot air furnace, and carrying out treatment at 130 DEG CAnd (3) carrying out heat treatment for 8-15 min, carrying out heat treatment for 2-6 min at 160 ℃, carrying out heat treatment for 1-4 min at 200 ℃, carrying out heat treatment for 1-4 min at 270 ℃ to completely solidify the polyimide precursor into polyimide, and using the obtained polyimide layer with the thickness of 5-10 micrometers as a protective layer of the hard disk drive suspension.

Technical Field

The invention relates to a preparation method of a hard disk drive suspension protection material, belonging to the application field of high polymer materials in electronic information.

Background

As the amount of data in personal computers in conjunction with multimedia penetration processing has increased dramatically, the capacity of hard disk drives (hard disk drives) has correspondingly increased rapidly. As one of the techniques for increasing the capacity, a method of directly forming a signal line on a suspension has been proposed as a technique that can be used instead of using a signal line. In this method, a protective film for insulating and protecting a conductor layer formed on the suspension is indispensable, and materials suitable for this portion are now being sought. In previous studies, photosensitive polyimide was mainly used as a material for the protective film. However, such photosensitive polyimide generally has an inherent problem of poor light transmittance, and therefore, has a problem that it is difficult to pattern a thick film. Further, since such photosensitive polyimide generally has to be developed using an organic solvent, there are problems of working environment, and further, inherent heat resistance of polyimide cannot be expressed due to volatilization of photosensitive groups during heat treatment.

Accordingly, an object of the present invention is to provide a method for producing a protective film material for a suspension of a hard disk drive, which is excellent in workability and reliability and has high processing accuracy.

Disclosure of Invention

The invention aims to provide a method for manufacturing a protective film material for a hard disk drive suspension, which has excellent workability and reliability and high processing precision, and aims to solve the problems that the conventional protective film material for the hard disk drive suspension has poor light transmittance, photosensitive polyimide usually needs to use an organic solvent and the like, and the method realizes high-precision application of the protective film material for the hard disk drive suspension. Has great significance for the application field of large-capacity hard disk drives. Firstly preparing polyimide precursor resin, then coating acid photosensitive resin on a demoulding polyester film, coating the prepared polyimide precursor resin on the photosensitive resin after curing, then laminating the 3 layers of the polyester film/photosensitive resin/polyimide precursor resin on a hard disk drive suspension circuit board in a mode that the polyimide precursor resin is on the lower polyester film, carrying out exposure, etching the unexposed part of the photosensitive resin by using lactic acid aqueous solution, etching the unexposed part of the polyimide precursor resin by using potassium hydroxide aqueous solution, etching the rest of the photosensitive resin by using lactic acid aqueous solution, and finally carrying out high-temperature curing to obtain the hard disk drive suspension polyimide protective material.

The preparation method of the hard disk drive suspension protection material comprises the following steps:

(1) mixing binary aminobenzene and tetracarboxylic dianhydride in a molar ratio of 1: 1, adding the mixture into dimethylacetamide, and reacting at room temperature for 2-8 h to obtain a polyimide precursor solution, wherein the diaminobenzene is 4,4 '-diaminobenzenecarboxanilide or 4, 4' -diaminodiphenyl ether, the tetracarboxylic dianhydride is pyromellitic dianhydride or 3,3 ', 4, 4' -benzophenone tetracarboxylic dianhydride, and the mass ratio of the diaminobenzene to the dimethylacetamide is 1: 10-20;

(2) coating photosensitive resin on a demoulding polyester film with the thickness of 50-100 mu m, coating the photosensitive resin with the thickness of 5-20 mu m, and drying for 5-10 minutes at the temperature of 50-100 ℃; smearing the polyimide precursor resin obtained in the step (1) on the cured photosensitive resin, smearing the resin with the thickness of 5-10 microns, and drying at 110-150 ℃ for 2-8 minutes to obtain a laminated board with a 3-layer structure of a polyester film/photosensitive resin/polyimide precursor resin;

(3) laminating the laminated plate with the 3-layer structure of the polyester film/photosensitive resin/polyimide precursor resin obtained in the step (2) on a hard disk drive suspension circuit board with the line width of 30-100 microns/line according to the mode that the polyimide precursor resin is on the lower polyester film, and then removing the polyester film;

(4) according to the circuit arrangement pattern on the hard disk drive suspension circuit board, the photosensitive resin in the step (3) is at 80-200 mJ/cm²Is exposed to light at an exposure intensity of 1 to 3min in a 0.1% aqueous solution of lactic acid at a liquid temperature of 25 ℃ and a pressure of 1 to 4Kgf/cm²Developing for 1-4 min by using a horizontal transportation type shower device under the shower pressure, and removing the photoresist on the unexposed part;

(5) drying the product obtained in the step (4) at 80-150 ℃ for 1-4 min, and using 10% potassium hydroxide aqueous solution at 25 ℃ and 0.5-2 Kgf/cm²Etching for 4 to 15 seconds under the spraying pressure of (3), and then using hot water at a temperature of 40 ℃ under a pressure of 5 to 15kgf/cm²Spraying for 1-4 min to completely remove the polyimide precursor resin layer exposed from the patterned photosensitive resin layer;

(6) using 10% lactic acid aqueous solution at 25 deg.C and 1-4 Kgf/cm²Spraying the product obtained in the step (5) for 20-60 s under the spraying pressure to remove the residual photosensitive resin, then placing the obtained product in a hot air furnace, performing heat treatment at 130 ℃ for 8-15 min, 160 ℃ for 2-6 min, 200 ℃ for 1-4 min, and 270 ℃ for 1-4 min to completely remove the polyimide precursorCuring the polyimide to obtain polyimide, and using the obtained polyimide layer with the thickness of 5-10 mu m as a protective layer of a hard disk drive suspension.

The invention has the beneficial effects that: the protective film material of the hard disk drive suspension of the present invention can stably cover the conductive layer of the hard disk drive suspension, and can ensure good filling performance for details and simultaneously perform high-precision polyimide pattern fabrication. Further, the patterned polyimide obtained according to the present invention has excellent heat resistance in terms of characteristics because it is substantially free of components that volatilize at high temperatures, such as photosensitive groups, and is suitable for hard disk drive suspensions. Therefore, a hard disk drive suspension using the hard disk drive suspension protective film material of the present invention has high reliability and durability, such as electrical characteristics, and hardly generates exhaust gas. Meanwhile, in the manufacturing method, the protective layer of the suspension having excellent pattern accuracy can be easily and inexpensively formed.

Drawings

FIG. 1 is a schematic plan view of a 3-layer film of a polyester film/photosensitive resin/polyimide precursor resin

FIG. 2 is a plan view of a suspension circuit board of a hard disk drive

FIG. 3 is a schematic view of a plane view of a product obtained after step (3) in example 1

FIG. 4 is a schematic view of a plane view of a product obtained after the step (4) in example 1

FIG. 5 is a schematic view of a plane view of a product obtained after step (5) in example 1

FIG. 6 is a schematic view of a plane view of a product obtained after step (6) in example 1

Detailed Description

The present invention is further described in the following description of the specific embodiments, but the present invention is not limited thereto, and those skilled in the art can make various modifications or alterations based on the basic idea of the present invention without departing from the scope of the present invention.

Example 1

(1) 154.4g (0.60mol) of 4,4 '-diaminobenzanilide and 80.1g (0.40mol) of 4, 4' -diaminodiphenyl ether were added to a 5L flask containing 2560g of dimethylacetamide, and dissolved with stirring; then, the solution was cooled in an ice bath, and 218.1g (1mol) of pyromellitic dianhydride was added to a nitrogen stream; then, the solution is returned to the room temperature, and is continuously stirred for 3 hours, and polymerization reaction is carried out, so as to obtain viscous polyimide precursor solution;

(2) coating an acidic developing/peeling type photosensitive resin on a release polyester film with the thickness of 100 mu m, coating the photosensitive resin with the thickness of 10 mu m, and drying the photosensitive resin for 8 minutes at 80 ℃; smearing the polyimide precursor resin obtained in the step (1) on the cured photosensitive resin, smearing the resin with the thickness of 5 microns, and drying at 130 ℃ for 4 minutes to obtain a laminated board with a 3-layer structure of a polyester film/photosensitive resin/polyimide precursor resin;

(3) laminating the laminated plate with the 3-layer structure of the polyester film/photosensitive resin/polyimide precursor resin obtained in the step (2) on a hard disk drive suspension circuit board with the line width of 50 microns/line according to the mode that the polyimide precursor resin is on the lower polyester film, and then removing the polyester film;

(4) aligning the photosensitive resin in step (3) at 100mJ/cm according to the circuit arrangement pattern on the suspension circuit board of the hard disk drive²Exposure is carried out for 1min at an exposure intensity of (2) under conditions of 0.1% aqueous lactic acid solution, liquid temperature of 25 ℃ and 2Kgf/cm²Using a horizontal transport type shower apparatus for development for 60 seconds under the shower pressure of (1), removing the photoresist of the unexposed portion;

(5) drying the product obtained in step (4) at 100 deg.C for about 2 minutes using 10% aqueous potassium hydroxide at 25 deg.C and 1Kgf/cm²Is etched for 8 seconds under a spray pressure of 8kgf/cm, and then hot water at a temperature of 40 deg.c is used²Spraying for 2min to completely remove the polyimide precursor resin layer exposed from the patterned photosensitive resin layer;

(6) using 10% lactic acid aqueous solution at 25 deg.C and 2Kgf/cm²Spraying the product obtained in the step (5) for 30 seconds under the spraying pressure to remove the residual photosensitive resin, and then placing the obtained product in a hot air furnace for heat treatment at 130 ℃ for 10min, 160 ℃ for 4min and 200 ℃ for 2min, heat treatment at 270 ℃ for 2min to completely cure the polyimide precursor into polyimide, and the resulting polyimide layer having a thickness of 5 μm as a protective layer for the conductor layer, when the cross section thereof was observed with a microscope, the circuit was covered with a uniform thickness without gaps.

Example 2

(1) Stirring 200.2g (1mol) of 4,4 ' -diaminodiphenyl ether in a 5L separable flask, adding 2650g of dimethylacetamide, then cooling the solution in an ice bath, and adding 161.1g (0.5mol) of 3,3 ', 4,4 ' -benzophenone tetracarboxylic dianhydride and 109.1g (0.5mol) of pyromellitic dianhydride in a nitrogen stream to the solution, after which the solution is returned to room temperature, stirring is continued for 3 hours, and polymerization is carried out to obtain a viscous polyimide precursor solution;

(2) same as in step (2) of example 1;

(3) same as in step (3) of example 1;

(4) same as in step (4) of example 1;

(5) same as in step (5) of example 1;

(6) the resulting suspension had a polyimide layer of 5 μm as a protective layer for the conductor layer as in step (6) of example 1, and when the cross section thereof was observed with a microscope, the circuit was covered with a uniform thickness without gaps.

Embodiment 3

(1) Same as in step (1) of example 1;

(2) coating the acid developing/peeling type photosensitive resin on a demoulding polyester film with the thickness of 80 mu m, coating the acid developing/peeling type photosensitive resin with the thickness of 8 mu m, and drying for 6 minutes at 80 ℃; smearing the polyimide precursor resin obtained in the step (1) on the cured photosensitive resin, smearing the resin with the thickness of 8 microns, and drying at 130 ℃ for 6 minutes to obtain a laminated board with a 3-layer structure of a polyester film/photosensitive resin/polyimide precursor resin;

(3) same as in step (3) of example 1;

(4) same as in step (4) of example 1;

(5) same as in step (5) of example 1;

(6) the obtained suspension had a polyimide layer of 8 μm as a protective layer of the conductor layer as in the step (6) of example 1, and when the cross section thereof was observed with a microscope, the circuit was covered with a uniform thickness without a gap.

Example 4

(1) Same as in step (1) of example 1;

(2) same as in step (2) of example 1;

(3) laminating the laminated plate with the 3-layer structure of the polyester film/photosensitive resin/polyimide precursor resin obtained in the step (2) on a hard disk drive suspension circuit board with the line width of 80 microns/line according to the mode that the polyimide precursor resin is on the lower polyester film, and then removing the polyester film;

(4) same as in step (4) of example 1;

(5) same as in step (5) of example 1;

(6) the obtained polyimide layer having a thickness of 5 μm as a protective layer of the conductor layer was covered with a uniform thickness without a gap when the cross section thereof was observed with a microscope, as in the step (6) of example 1.

Example 5

(1) Same as in step (1) of example 1;

(2) same as in step (2) of example 1;

(3) same as in step (3) of example 1;

(4) according to the circuit arrangement pattern on the hard disk drive suspension circuit board, the photosensitive resin in the step (3) is at 150mJ/cm²Exposure is carried out for 1min at an exposure intensity of (1), in a 0.1% aqueous solution of lactic acid, at a liquid temperature of 25 ℃ and at a pressure of 4Kgf/cm²Using a horizontal transport type shower apparatus for 30 seconds under the shower pressure of (1), removing the photoresist of the unexposed portion; (ii) a

(5) Same as in step (5) of example 1;

(6) the obtained polyimide layer having a thickness of 5 μm as a protective layer of the conductor layer was covered with a uniform thickness without a gap when the cross section thereof was observed with a microscope, as in the step (6) of example 1.

Example 6

(1) Same as in step (1) of example 1;

(2) same as in step (2) of example 1;

(3) same as in step (3) of example 1;

(4) same as in step (4) of example 1;

(5) drying the product obtained in step (4) at 100 deg.C for about 2 minutes using 10% aqueous potassium hydroxide at 25 deg.C and 2Kgf/cm²Is etched for 8 seconds under a spray pressure of (3), and then hot water at a temperature of 40 ℃ is used under a pressure of 15kgf/cm²Spraying for 1min to completely remove the polyimide precursor resin layer exposed from the patterned photosensitive resin layer;

(6) the obtained polyimide layer having a thickness of 5 μm as a protective layer of the conductor layer was covered with a uniform thickness without a gap when the cross section thereof was observed with a microscope, as in the step (6) of example 1.

Example 7

(1) Same as in step (1) of example 1;

(2) same as in step (2) of example 1;

(3) same as in step (3) of example 1;

(4) same as in step (4) of example 1;

(5) same as in step (5) of example 1;

(6) using 10% lactic acid aqueous solution at 25 deg.C and 4Kgf/cm²Spraying the product obtained in the step (5) for 20 seconds under the spraying pressure to remove the remaining photosensitive resin, then placing the obtained product in a hot air oven, performing heat treatment at 130 ℃ for 15min, 160 ℃ for 6min, 200 ℃ for 4min, and 270 ℃ for 4min to completely cure the polyimide precursor into polyimide, and obtaining a polyimide layer having a thickness of 5 μm as a protective layer for the conductor layer, wherein when the cross section of the circuit is observed with a microscope, the circuit is covered with a uniform thickness without gaps.