JP2002284924A - Method for treating member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for decomposing and removing a polyimide resin by which cost, accuracy and productivity causing problems in perforation processing, waste disposal, etc., are solved. SOLUTION: This method for treating a member comprises decomposing a member having the polyimide resin in a part thereof under conditions of >=200 and <=400 deg.C under the supersaturated steam pressure at the temperature in an autoclave containing water placed therein.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a through-hole in the manufacture of various circuit boards typified by flexible substrates used for LCDs (liquid crystal displays), cameras, portable terminals, AV equipment, medical electronic equipment, and various sensors. A resin called the flying lead structure, which is required for drilling holes that require via holes and blind holes, and materials for CSP (chip size package) and HDD (hard disk drive) suspensions Process for removing the entire surface, etching of polyimide used on the surface of integrated circuits such as ICs and LSIs, and decomposition treatment of polyimide resin used for waste treatment and recycling of members that partially contain polyimide resin. It is about.

[0002]

2. Description of the Related Art Conventionally, in a flexible substrate formed by laminating copper foil on both surfaces of a polyimide resin, a drilling machine called NC drilling, punching, plasma etching, There are various types of laser drilling such as excimer, carbon dioxide, and YAG, and chemical etching using an alkali. However, in drilling, the diameter of the hole is at most about 0.3 mm, which is not suitable for the current high-density circuit design. In addition, punching has a drawback in that it is not possible to form a hole called a blind hole that does not penetrate. In addition, plasma etching
Since the equipment cost is high, the degree of vacuum in the apparatus and the gas to be used are difficult to manage, and the running cost is extremely high, the use cases are limited. Further, in laser drilling, there is a problem that productivity is inferior because multi-hole processing is difficult, and a thermal decomposition product of a resin called smear is generated at the time of processing and needs to be removed in a later step.
Furthermore, although chemical etching is excellent in terms of cost and workability, the currently used etching solution is a mixture of a strong alkali such as alkali hydroxide, phenol, hydrazine, etc. There is a problem in the treatment of waste liquid and waste liquid, which is not industrially preferable. In recent years, circuit materials using polyimides with excellent heat resistance, combustion resistance, and chemical resistance have been increasing, and from the viewpoint of waste disposal of such materials, the purpose is to recycle various metal members used. However, there is no effective method at present.

[0003]

The present invention provides a method for decomposing and removing a polyimide resin, which solves the cost, accuracy, and productivity problems that occur in the above-described drilling and waste treatment.

[0004]

Means for Solving the Problems The present invention is a method for decomposing a polyimide resin, which is used for processing a circuit board using a polyimide resin or treating wastes of circuit members and the like. That is, the present invention provides: (1) a method for treating a member, which comprises decomposing and removing at least a part of the polyimide resin of a member having a polyimide resin in a part thereof in an autoclave filled with water. The method according to (1), wherein the temperature in the autoclave is 200 ° C. or more and 400 ° C. or less, and the pressure in the autoclave is equal to or higher than the saturated vapor pressure of water at that temperature. (3) The method for treating a member according to (1) or (2), wherein the polyimide-based resin contains polyimide and / or polyamideimide as a main component. (4) A method for manufacturing an electronic circuit board, comprising etching a polyimide resin by the method according to any one of (1) to (3). About.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is characterized in that the solvent used is water and the equipment used is simple, so that the work is easy and simple, and the equipment cost is low. Here, the water used is preferably ion-exchanged water or distilled water when used for materials used in the fields of electronics, electricity and semiconductors. The temperature in the autoclave containing water is preferably from 200 ° C to 400 ° C, more preferably from 250 ° C to 400 ° C. Here, when the temperature is lower than 200 ° C., the hydrolysis of the polyimide hardly proceeds and has a disadvantage that the etching time is prolonged. The member after processing may not be preferable as a circuit board because of the possibility of thermal decomposition. The pressure in the autoclave at each temperature is preferably equal to or higher than the saturated vapor pressure of water at that temperature, and the autoclave container needs to be completely sealed. When the pressure is equal to or higher than the saturated water vapor pressure, a structure in which a back pressure is applied by a pump or the like may be employed, and other general methods can be used. The autoclave used here is not particularly limited as long as it has sufficient heat resistance and pressure resistance in the above-mentioned usage range, and a general device can be used. As the polyimide-based resin, those containing polyimide and / or polyamideimide as a main component are preferable, and there is no particular restriction on the resin component, but it is used for those requiring high-precision processing such as small-diameter drilling. In such a case, it is preferable that inorganic components such as various reinforcing agents and fillers are not contained. Although there is no restriction on the thickness of the polyimide resin, when used for a circuit board,
It is preferably from 0.1 μm to 125 μm, more preferably from 3 μm to 50 μm. In addition, the etching time in the autoclave depends on the structure and thickness of the resin used and the temperature in the autoclave, and the optimal etching time is determined. The thicker and more rigid the resin, the higher the temperature and the longer the time. Processing is necessary, but conversely, in the case of a thin resin having a flexible skeleton such that the structure contains many ether bonds, etching can be performed in about several minutes.

[0006]

EXAMPLES Example 1 1,3-Bis (3-aminophenoxy) benzene was prepared as follows.
00 mol and 0.975 mol of 3,3 ′, 4,4′-biphenyltetracarboxylic acid were weighed, and N, N′-dimethylacetamide was added so as to have a solid concentration of 31 wt%. For 15 hours to obtain a polyamic acid solution as a polyimide precursor. This was coated on USLP-18 manufactured by Nippon Electrolyte so that the thickness after drying was 5 μm, and was applied at 115 ° C. for 15 minutes, 150 ° C. for 15 minutes, and 200 ° C. for 15 minutes.
Minutes, dried at 260 ° C. for 15 minutes, and is a circuit board material.
The single-sided copper-polyimide laminate shown in FIG. 1 was obtained. this,
Place in a stainless steel autoclave containing ion-exchanged water, treat at a temperature of 280 ° C. and a pressure of 6.6 MPa for 30 minutes,
As a result of cooling and observation, it was confirmed that the polyimide resin was completely removed, and only the copper foil could be separated.

Example 2 USLP-18 copper foil was similarly laminated on the polyimide surface of the single-sided copper-polyimide laminate used in Example 1 and heated and pressed at 280 ° C., 50 kgf / cm ² for 1 hour. By doing so, a double-sided copper-polyimide laminate shown in FIG. 2 was obtained. Then, a resist is applied and dried, and is exposed and developed using a mask pattern so as to have a form as shown in FIG. 3. After the development, the exposed copper foil portion is removed by etching with iron chloride, and the remaining resist is removed. It was removed with 3% by weight of sodium hydroxide, washed with water, and dried to obtain a circuit board material shown in FIG.
This circuit board material was placed in a stainless steel autoclave containing ion-exchanged water, at a temperature of 280 ° C and a pressure of 6.6M.
After treatment with Pa for 30 minutes, the mixture was cooled and observed. As a result, it was confirmed that a 100 μmφ through hole, a 100 μmφ blind hole, and a 2 mm flying lead structure shown in FIG. 4 were formed.

Comparative Example 1 The same procedure as in Example 1 was carried out except that the processing conditions in the autoclave were changed to a temperature of 190 ° C. and a pressure of 2.5 MPa for 120 minutes, but polyimide remained after the processing.
Could not be removed.

Comparative Example 2 The same procedure as in Example 2 was carried out except that the processing conditions in the autoclave were changed to a temperature of 190 ° C. and a pressure of 2.5 MPa for 120 minutes, but polyimide remained after the processing.
Through holes, blind holes, and flying lead structures could not be formed.

[0010]

According to the present invention, since the polyimide resin can be easily decomposed and removed at low cost, it can be effectively used at the time of processing a circuit board or treating a waste of a circuit board, and has high industrial value.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a single-sided copper-polyimide laminate according to the present invention.

FIG. 2 is a schematic sectional view of a double-sided copper-polyimide laminate according to the present invention.

FIG. 3 is a schematic sectional view of a copper-etched product of a double-sided copper-polyimide laminate according to the present invention.

FIG. 4 is a schematic cross-sectional view after the polyimide etching of FIG. 3;

[Explanation of symbols]

1 copper foil, 2 polyimide, 3 through hole, 4 blind hole, 5 flying lead

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masahisa Kobayashi 580-32 Nagaura, Sodegaura-shi, Chiba Mitsui Chemicals Co., Ltd. Reference) 4F301 AA27 CA09 CA24 CA51 CA72 CA73

Claims (4)

[Claims] 1. A method for treating a member, comprising: decomposing and removing at least a part of the polyimide resin in a member partially having the polyimide resin in an autoclave filled with water. 2. The temperature inside the autoclave is 200 ° C. or more and 400 ° C.
2. The method according to claim 1, wherein the pressure in the autoclave is not higher than the saturated vapor pressure of water at the temperature.
A method for treating a member as described in the above. 3. The method according to claim 1, wherein the polyimide resin is polyimide and / or
The method for treating a member according to claim 1 or 2, wherein the member is mainly composed of polyamideimide. 4. A method for manufacturing an electronic circuit board, comprising etching a polyimide resin by the method according to claim 1.