JPS60183791A - Method of producing insulating film of printed board for circuit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for manufacturing an insulating film.

[Prior art]

Currently, the manufacturing method of insulating film for circuit printed circuit boards, which is generally popular, involves forming a thermosetting insulating film in a desired pattern on a circuit printed board by screen printing, and then thermosetting this film. method is known. Although it is easy to use this method to form single-color insulation 11r and i on the bulb board, it is also easy to color the insulation film differently for each wiring pattern that is created by insulating each other.
i+L, yes. A talented friend of mine, a woman who helped me find broken wires and short circuits.

[Purpose of the invention]

Therefore, in order to eliminate all of the above-mentioned defects in the present invention, a colored insulation layer 111r- made of a polymer and a dye selectively electrodeposited on the interconnection patterns of the circuit printed circuit board, which are insulated from each other, is applied. At the same time, it is intended to be useful in discovering disconnections and short circuits in wiring patterns.

[Structure of the invention]

Hereinafter, the method of forming a colored layer by electrodeposition of a polymer, which is the key point of the present invention, will be described. One way to conduct electricity on a polymer chemical pole is to electrochemically polymerize it on a single @ body (r'+,'tt pole. As an example of this method, various vinyl There is a report that polymer keratin metal 47 was obtained by electrochemically polymerizing all compounds (Metal Surface Technology Vol. 19.Ban 12゜1968).Recently, dege, pyrrole, thiophene, etc. were also electrochemically polymerized. Research has been actively conducted to create electroconductive polymers such as polypyrrole and polythenylene by electrolytic polymerization.However, this method of directly electrochemically polymerizing monomers There are many problems in using it in the present invention, such as the efficiency is still not good, the obtained film is already colored, and the coloring is not arbitrary.
Another method for depositing Tf is to completely insolubilize and precipitate the polymer from a polymer solution onto the electrode. As an example of this, a method called electrocoating is known industrially, in which a pigment is dispersed in an aqueous polymer solution, a metal is immersed in it, and used as an electrode, and a colored layer is electrodeposited on the metal. It is used for blur coating, etc. The principle of this method is to introduce a hydrophilic group, such as a carboxyl group, into a polymer, and then neutralize the carboxyl group with an inorganic alkali, an organic amine, etc. to make it water-soluble. Then, when the electrode is immersed in an aqueous solution of the water-soluble polymer and a voltage is applied, the carboxyl anions dissociated in the aqueous solution electrophores toward the anode and react with protons generated by water electrolysis on the electrode. As a result, the polymer becomes insolubilized and precipitates out.

That is, the reaction shown in the following formula occurs on the anode, and polymer precipitation is observed.

2H70→4H"-1-021+40-Also, if a basic group (for example, polyamine) is used as the hydrophilic group and it is neutralized and made water-solubilized with an acid, polymer precipitation will be observed on the electrode. Become.

If the electrodeposited polymer is electrically insulating, the current decreases as the electrode is coated with the polymer, preventing further coating, so no increase in film thickness can be expected. However, in reality, water Due to the oxygen bubbles generated by electrolysis, complete coverage at the initial stage is avoided, and a certain degree of film thickness can be obtained by the time it becomes an insulating layer.

Polymers for anionic electrodeposition include adducts of natural drying oil tomaleic acid, alkyd trees with carboxyl groups introduced, adducts of epoxy resin and maleic acid, carboxyl-
A copolymer of acrylic acid or meccrylic acid and its ester, etc., is used, and depending on the characteristics of the electrodeposited film, other polymers or organic compounds with functional groups are added to the polymer skeleton. Sometimes it is introduced inside.

In addition, the amount of hydrophilic functional groups such as carboxyl groups and hydroxyl groups in the polymer is important; if there are too many hydrophilic groups, the insolubilization of the electrodeposited layer will not be sufficient, resulting in an uneven film. Water solubility during neutralization becomes insufficient. As a solvent for polymers, water is the main component 1', but ingrohanol, n-
Phthyl alcohol, t-butyl alcohol, methyl cellosolve, ethyl seronlube, inpropyl cellosolve,
Butyl cellosol, cyethylene glycol methyl ether.

Hydrophilic solvents such as diethylene glycol ethyl needle and diacetone alcohol are included as solvents for polymerization of polymers. Type of hydrophilic solvent contained.

1 also greatly influences the film thickness and uniformity of the electrodeposited layer.

Further, as a method for coloring the electrical tension layer, a method can be employed in which a dye or pigment is first dispersed in a fully polymerized polymer solution, and the dye is incorporated into the film together with the polymer.

Hereinafter, the present invention will be explained in detail based on examples.

〔Example〕

(1) As shown in the figure, let us consider the case where insulating films with different colors are formed on the wiring patterns 2, 5, 4.5 of the circuit printed/printed board 1.

An electrodeposition bath having the following composition is prepared using Shimoki Kinunari's coating Xi (Nisvia, mD-30 (IQ Shinto Nuri Sashi Co., Ltd.) and Nisvia ED-1000).

The oil-soluble dyes used are limited to those soluble in hydrophilic solvents, and preferably have a metal complex salt structure with very good light resistance. For example, some molecules have the following molecular structure: (The product name is Aizen 5pilon,
01eoeoi li'ast etc.) C! H3 Color index number 5olvent Red 8
In the bath preparation step 111tl, Nisbia ED-3000 is dissolved in water. Next, dissolve the dye in methyl cellosolve. At this time, the dye weight f# ratio X is arbitrarily selected within a range that does not affect the solubility of the dye in methyl cellosolve. Add all of the dissolved methyl cellosolve to the above aqueous solution,
Distribute the dye evenly.

At this time, methyl cellosolve acts as a dispersion film, but if the amount added or the amount of carbon in the alkyl group of cellosolve increases, the amount of film 7 will increase, and the printed circuit board 1 will not be placed in the solution 110. Pickle. inside the printed circuit board,
Red insulation film? A voltage of 10't/ is applied for a total of 3 minutes as an anode to the power line 2, which is the part to be electrodeposited. At this time, the current value shows a large value immediately after energization, but gradually decreases and eventually approaches almost zero. Next, the circuit printed circuit board is removed from the fixing solution, and the solution adhering to areas where no voltage is applied is washed away with water. Thereafter, by repeating the same operation in the electrodeposition solution in which black dye 7 was dispersed, in the fixing solution in which green dye was completely dispersed, and in the H1 swamp solution in which yellow dye was dispersed, a ground line 6° wiring pattern/ 4. All black, green, and yellow insulating films are formed on the wiring pattern 5, respectively. Next, the polyester resin in the insulating film formed using the foil and melamine # were subjected to a fat total condensation reaction (175°C, 50°C).
cure by 1 minute).

Through the rc process described above, it was possible to fabricate an insulating film colored in multiple colors on the wiring butter of a printed circuit board.

In addition, when there is a break in the wiring patterns 2, 3, 4.5, the insulating film is formed only in the part close to the anode when viewed from the break point, and polymer deposition does not occur from the break point first. It is extremely easy to find the location of the disconnection. On the other hand, if there is a '/iodine between the patterns, the insulating film is formed on the pattern that is not connected to the anode, so it can be detected immediately.

(2) In Example 1), by using an aqueous solution of a cationic polymer as the electrodeposition bath and connecting each of the wiring patterns to the cathode, a multicolored ZET! P, H! 1
was created. The bath had the following composition:

The bath preparation procedure is described below. Mix some of the acrylic resin, some of the ethyl cellosolve, and all of the pigment.
This mixture was processed using a 3X roll mill (newly manufactured by Kodaira Seisaku) in the laboratory.
Disperse until the pigment particle size becomes 0.4μI11 or less.

To this dispersed mixture, the remaining acrylic resin, the remaining ethyl cellosolve, and Inglovir alcohol are all mixed. Then, all of the neutralizing agent acetic acid was gradually added dropwise, and then diluted with water to prepare an electrodeposition bath.

〔Effect of the invention〕

As described above in detail in the examples, the method for manufacturing an insulating film for a printed circuit board according to the present invention consists of selectively forming a polymer with an angle of L. 1 piece of colored insulation is formed, and from then on, the same ψ operation sound 1 is formed.
Because the process involves completely dispersing the colored dye and repeating it with the FC Hatake Molecule Irrigation Solution, the color classification is 1] and insulation III.
This method is extremely effective in easily producing large quantities of i. Mafko, the wiring pattern is broken! , it is also effective for discovering short circuits.

[Brief explanation of drawings]

l.>, 1 indicates a printed circuit board. 1. Circuit print, J^ board 2゛°power source...ground line 4...-wiring pattern for electrodepositing green insulating film 5...k
"The wiring pattern for attaching the colored insulating film" = Applicant: Seiko Electronics Industries Co., Ltd. (and 1 other person) Patent attorney: Mogami, 41st attorney Continued from page 1 ■ Inventor: Mitsuru Suginoya Tokyo Company @ Inventor: Temple 1) Yumiko Tokyo Company ■ Inventor Kato Menka Tokyo Company @ Inventor Precious wood A2 Zushi @ Inventor Atsushi Yasuyo - Kayake @ Inventor Toyokazu Nomura Naushi @ Inventor Far 1) Soma Tokyo [Sou] Inventor Shinji Ito 6-31-1 Kameido, Koto-ku, Narashito Seiko Electronic Industries Co., Ltd. 6-31-1 Kameido, Koto-ku Seiko Electronic Industries Co., Ltd. 6-31-1 Kameido, Koto-ku Seiko Electronic Industries Co., Ltd. 3-1 Ichikawanone No. 7: 2-1 Minami Higashikawa, Saki-shi No. 13: 5-1-1 Higashi-Narashino, No-shi 6-6-14 Kanamachi, Katsushika-ku, Miyako

Claims (1)

[Claims] In printed circuit boards, a colored insulating film made of selectively electrodeposited polymers and dyes is formed on wiring patterns that are insulated from each other, and the same process is then repeated in different colors. A method for manufacturing an insulating film for a printed circuit board.