JPS6120947A - Photoresist peeling agent - Google Patents

Abstract

PURPOSE:To obtain a photoresist peeling agent good in stability and superior in peeling performance and especially, giving hardly an adverse influence to metallic materials in manufacturing printed circuits by using methylene chloride, alcohol, and dichloroethane as essential components. CONSTITUTION:The photoresist peeling agent contains the mixture of methylene chloride and alcohol in an amt. of >=90wt%, preferably, >=95wt%, e.g., in a methylene chloride:methanol wt. ratio of about 13:1 or when isopropanol is used in place of methanol as alcohol, in a methylene chloride:isopropanol wt. ratio of about 12:1, each having an azeotropic compsn. Further, 1,2-dichloroethane is mixed with said azeotropic mixture in an amt. of 0.2-7wt% as an essential component, thus permitting the obtained peeling agent to be incombustible, low in toxicity, and high in peeling speed, and it does not adversely affect plating metallic materials to be used for printed circuits in manufacturing them.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a photoresist stripper with improved stripping performance.

Printed wiring boards on which various parts are mounted and connecting wiring formed in the form of wiring diagrams on an insulator are known in various shapes such as single-sided, nine-sided, and multilayer wiring boards. When creating patterns for printed wiring boards, when the pattern density is high, a photographic method using a photoresist is said to be preferable to a screen printing method. The photoresist must undergo steps such as exposure, development, etching, and finally be stripped off. A mixture of methylene chloride and methanol described in Japanese Patent Publication No. 52-45241 is known as such a photoresist stripping agent. There are more than 10 manufacturing processes for printed wiring boards, so efforts are being made to improve productivity by simplifying or speeding up various processes. Improvement in power is desired.

In order to meet these demands, the present invention provides a new photoresist stripping agent with high photoresist stripping ability, and it is an object of the present invention to provide a novel photoresist stripping agent with high photoresist stripping ability.
It contains dichloroethane as an essential component.

The total blending ratio of methylene chloride and alcohol in the photoresist stripping agent of the present invention is suitably at least 110 wt%, preferably at least 1115 wt%.

If it is less than this, sufficient photoresist stripping ability cannot be obtained.It is preferable to select a blending ratio of methylene chloride and alcohol that is close to an azeotropic composition of both, but it is substantially non-flammable. It is also important that flammable alcohols be used in small amounts compared to methylene chloride, which has no flash point. For example, methylene chloride and methanol have approximately 13
: 1. , about +2 for methylene chloride and isopropyl/-
A blending ratio of 1:1 forms an azeotropic composition and is substantially nonflammable, causing no problem, but for ethanol, 95 wt % or more is required; rather, an azeotropic composition is not preferred. Use at or near an azeotropic composition has the advantage that the composition ratio does not fluctuate greatly during distillation regeneration and that the stripping performance can be kept constant. Usually, the mixing ratio of methylene chloride and alcohol is 7:l.
~25:l may be used. Suitable examples of other alcohols include lower alcohols such as n-propyl alcohol, n-butyl alcohol, isobutyl alcohol, sec-butyl alcohol, and tertiary-butyl alcohol. These alcohols may be used as long as they do not impede the purpose of the present invention.
Two or more types can also be combined and used.

The stripping agent of the present invention contains methylene chloride and alcohol,
! , 2-dichloroethane in an amount of 0.2 to 7 wt%, preferably 0.5 to 5 wt%, which improves the peeling performance and increases the peeling speed. Although 1.2-dichloroethane has a flash point comparable to that of methanol and isopropanol, it is effective when added in smaller amounts to methylene chloride than these alcohols; However, it can be made substantially nonflammable.

The insulating portion of the printed wiring board is made of a composite material of epoxy resin or phenol resin and paper, glass fiber, or the like. Furthermore, tin-lead plating, copper coating, or gold plating with a nickel base is used for the surface plating of the wiring board. The photo 1/cyst stripping agent is required not to have an adverse effect on the various materials constituting these printed wiring boards, and the stripping material itself is also required not to decompose, particularly due to the influence of metals and the like. The stripping agent of the present invention has excellent stripping power, is substantially nonflammable, and has low toxicity, and does not have the above-mentioned adverse effects in normal use.

When the stripping agent of the present invention is used under severe conditions and stabilization is required, stabilization can be well achieved by incorporating epoxides and/or amines.

Epoxides include at least one adjacent epoxy in the molecule, such as propylene oxide, 1.2--!
f 7 oxide, 2,3-butylene oxide, -
Epichlorohydrin, styrene oxide, butyl glycidyl ether, phenyl glycidyl ether, glycidol and the like are preferred. Particularly preferred epoxides are epichlorohydrin and propylene oxide. Although the amount of epoxides is not particularly limited,
0.02-3 wt% in the release agent, preferably 0.0
A small amount of 5 to 0.8 wt% has a sufficient stabilizing effect.

Diisopropylamine is an amine.

Cyclohexylamine, diallylamine, N-methylbenzylamine, N,N-dimethylbenzylamine, N
-Alkylmorpholine and the like are preferred, and particularly preferred are diisopropylamine, sialylamine, and N-methylbenzylamine. Similar to epoxides, the amount of amines added is not particularly limited, and is 0.001 to 0.1 wt%, preferably 0.01 wt% in the release agent.
A very small amount of ~0.06 wt % may be added, and even if more than this is added, it will only become uneconomical and there will be no significant difference in the effect.

The photoresist that can be removed by the removal composition of the present invention is not limited in any way, and examples include positive or negative photoresists, deep ultraviolet exposure resists, and X-ray or electron beam resists. . Materials for resists for light exposure include quinone diazide based on phenol and cresol novolac resins, cyclized rubber based on cis-1,4-polyisoprene, and polycinnamic acid. Resists include polymethyl methacrylate, polymethyl isopropenyl ketone, etc.
Although polymethyl methacrylate, glycidyl methacrylate-ethyl acrylate copolymer, methyl methacrylate-methac4-noric acid copolymer, etc. are known as X-ray resists, the stripping agent of the present invention is effective for all of them. '-ru.

The stripping agent of the present invention is particularly suitable for stripping photoresists during the production of printed wiring boards, but is also suitable for other photoresist application fields, such as semiconductors.

It is extremely effective as a release agent in the field of electronic components such as lead frames and TV shadow masks, as well as in the field of etching metals, ceramics, glass, etc.

Examples of the present invention will be described in more detail below.

Example 1 [Peeling Performance] 80 cc of the stripping agent of the present invention was prepared in a 100 cc beaker, and a test piece (M-light 1 item) cut into 5 cm squares was immersed. The liquid temperature was 18°C. After soaking 2
The peeling state after 0 seconds and 40 seconds was evaluated according to the following criteria. The results are shown in Table 1.

Claims (1)

[Claims] A photoresist stripping agent characterized by containing methylene chloride, alcohol and 1,2-dichloroethane as essential components.