JPS60208892A - Method of producing circuit board having protecting layer - 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 Field of Application] The present invention relates to a method of manufacturing a circuit board having a horizontal circuit protection layer on the same plane as a printed circuit.

[Prior art]

Conventionally, the method of forming a circuit on the surface of a laminated board is to print on a resistor or conductor paste whose main component is resin, dry it, and then
A method for obtaining a circuit wiring board by curing and, for example, as seen in Japanese Patent Publication No. 58891, a removable metal foil t carrier is used, a resistor and a conductor circuit τ are formed on the carrier, and a laminate is formed. A method of transferring a horizontal circuit board t4 by placing it on a horizontal circuit board and hot pressing it is used.

However, in both methods, the resistor and conductor parts are easily damaged by scratches during handling or assembly work, resulting in a change in resistance value or breakage of the conductor part. It often happens that fCv cannot be put to practical use. For these reasons, in order to form a protective layer for the purpose of protecting the circuit portion of a printed circuit board, it is necessary to protect the surface of the circuit board. In order to improve the tightness of the layer, it is carefully roughened using sandpaper, etc., or alkaline degreasing,
Alternatively, after performing a so-called degreasing treatment using an organic bath agent such as trichlorethylene, the protective layer had to be formed by coating or screen printing with a resin varnish or the like. However, these methods have many problems such as the addition of one step and deterioration of circuits, circuit boards, etc. due to alkaline or organic bath agents.

[Purpose of the invention]

The present invention was developed in view of these problems in the prior art.9 As a result of intensive studies to improve these shortcomings, for example, the horizontal circuit board disclosed in the above-mentioned Japanese Patent Publication No. 158891/1989 was developed. Horizontal protection J#'2 with the advantages of
A circuit board? This is what we have come to offer.

[Structure of the invention]

The present invention will be explained in detail below.

The present invention first uses means such as screen printing with a resin phenol to form a resin coating that will serve as a protective layer for resistors and conductors on the inkstone enclosure.
form. In this case, the mirror body serving as the carrier may be anything with a mirror surface, such as a synthetic resin film or metal foil, but the most preferred mirror body used in the present invention is Kanasu foil, which can be finally removed by etching. I want it. Generally, copper foil, aluminum foil, iron foil, etc. can be used, but aluminum foil is preferred in this paper because it has advantages in handling and is relatively inexpensive and easily available.

Next, is there a protective coating? Protection 4! It can be used in various ways as a resin varnish for membranes. However, it is preferable to use the same components as the 4'1JJl used in this paper to form the prepreg via, from the viewpoints of adhesion, reduction of warpage when used as a circuit board, and weight. Generally, in consideration of the above characteristics, phenol based on epoxy resin is preferably used.

By heating the protective layer formed by screen printing etc.,
Allow to be dry to touch or completely cured.

At this time, if necessary, ultraviolet curing, electron beam curing, and room temperature curing using a room temperature curing agent are also carried out as appropriate.

Next, any desired conductor or resistance circuit is formed on the protective layer.As the conductive and resistive paste, phenolic resin, epoxy resin, polyester resin, acrylic resin, alkyd melamine resin, polyimide, etc. Any so-called isoelectric or resistance paste can be used as long as it is a thermosetting resin binder such as a thermosetting resin, □, etc., and a conductive material such as carbon, silver powder, copper powder, or solder powder is mixed with it. A desired circuit is formed on the circuit protection JvI by applying these pastes alone or in combination.

Next, the circuit formation t6i1! For this purpose, a curing method by heating is generally used, but depending on the case, other curing methods such as ultraviolet curing, electron beam curing, and room temperature curing using a room temperature curing agent may also be used as appropriate.

Next, the metal foil t on which the desired circuit has been formed is laminated so that the circuit surface is in contact with the top layer of the laminate having adhesive properties. In this case, although there are many examples of non-consolidated materials, the point is that all materials can be used as long as they are heat-consolidable. -For example,
Thermosetting resin for various substrates: No.1 coating of thermosetting resin to the required thickness on the surface of plates, metal plates, ceramic plates, plastic films, laminates with copper foil etching circuits, etc., if necessary. d '1 m Semi-cured to the B-stage, one or more layers of so-called Gripreg installed on the above substrate, 71 or more layers of thermoformable uncured prepreg, etc. The laminate τ can be used as appropriate.

Next, the product 4'? 1J' is hot-pressed to form a laminate, but since the circuit has been hardened in advance, it is possible to mold it under desired hot-pressure conditions. That is, -@ is raised and n
For example, conventional circuit forming methods rarely have the disadvantage that they cannot be used for resins such as imide resins, which require a high temperature environment during curing. However, according to Kempo, for the reasons mentioned above, there is an advantage that the fc 1flll is completely black.

Next, only the amount of metal is removed by purple etching from the integrated thermo-pressure laminate () in which the metal foil on which the recirculation layer has been formed is removed.

The etching removal method has the advantage that no external force is applied to the peeling of the circuit part, layer A, and printed circuit from the Y6, so there is no hot water and no deterioration of the circuit board. arise.

[Efficacy of invention] Thus, Kama Genus? h The beads obtained by removing 1llll by K etching. In addition to these parts being smooth, the circuit board has a completely V-embedded case on the board surface.
Because it is a horizontal circuit with
Under positive conditions, +'pj grows δ7, and by Mei4↓,
I was hit by an ambiguous first circuit board for a female rat.

〔Example〕

An example of the invention will be described below, but the invention is not limited thereto.

Example 1 (1) Using epoxy resin on the mirror surface of aluminum foil with a thickness of 20 μm, a circuit was formed only on the necessary parts of the rice board using the star line printing method, and this was heated in a τ Toguchi heat oven for 1,500 yen.
Treat for 1 hour to harden. Next, a carbon resistance paste made with a phenolic 41 B'tt F binder was screen printed on the necessary parts on this protective layer, and a resistance circuit was printed at 170°C for 1 hour under an atmosphere of feces. Hardened with a 6 cry.

Furthermore, a circuit was formed by screen printing on the necessary parts using silver paste with a phenolic binder.
Similarly, a 170" circuit printed aluminum foil was prepared by curing in an atmosphere for 0.1 hour.

(2) Next, paper base epoxy f (fat prepreg 'f
Place the printed aluminum foil on the top of a part of the 10-layer sheet so that the printed surface is in contact with it, and use the m method to
It was hardened by heating and pressing at 0°C at 18:00 for 10J.

(3) In (2), when the aluminum foil was removed by etching from the surface of the NFL-recording layer, the circuit with the circuit protection layer was completely embedded and transferred, and the circuit part and the board were transferred. A circuit board was obtained that had horizontal edges and sharp edges.

Actual flow ifU 2 tL) A circuit protective layer was formed on the mirror surface of an aluminum tank with a thickness of 50 μm using the screen printing method of amideimide'+AIJltf'K N-methylpyrrolidone 1ζ varnish, and then heated at 100°C. Leave it for 10 minutes to evaporate the bath water. Next, the hair was heated at 250° C. for 15 minutes to completely remove the bog agent and form a 14-layer hair.

Meanwhile, using an imide resin T binder and a carbon resistance paste F, a resistance circuit τ was formed by screen printing.
Forming and protecting the circuit using the same 'JZ' process as in No. 1 and using 1 process k x 2 to form a circuit τ. In the history, use the imide side H@τ binder and silver paste to form the desired part of the '-polar circuit τ, and apply a drying process similar to that of the holding layer and the resistor circuit.
The obtained printing proboscis was further baked at 80θ°C for 1 hour to completely harden it.

(2) A glass-based polyimide resin J4,+ whose surface was completely sanded was coated with a heat-resistant epoxy resin varnish on a layer plate and heated to a B-stage state. This contact enclosure and the circuit surface formed on the aluminum stop were stacked facing each other, and heated and pressed using a knife IJ for 2 hours under the conditions of 150°C and 50°C. In this way, I asked f
When the aluminum foil was removed from the laminated surface by etching, a circuit board having a horizontal circuit protection layer with excellent M4 resistance as in Example 17111 was obtained.

Claims (1)

[Scope of Claims] (1) By a face made of a thermosetting resin and an organic preservative or a reactive diluent, etc. on a sharp surface that can be finally removed,
A circuit protective layer is formed by coating or printing, and on the protective layer obtained by curing, a circuit is further formed using a resistive paste and a conductive paste in a thermosetting resin vehicle, and the circuit is dried. A thermosetting resin is coated on the circuit surface of the circuit formed product obtained by curing with paper, T6 cloth, etc.
Impregnated into base material such as glass cloth, '84HY! Component IB - Manufacture of a circuit board having a tensile strength of d7dτ obtained by kneading one or more sheets of prepreg cured to the IB stage and integrating them by heating and pressure, and removing the mirror body of the molded product. Method. (2) The heat-resistant varnish has an epoxy-based resin, a urethane-based resin, and a multi-ring system.
Phenol (fat, silicone, polysulfone, polyester, polyamide 11)
(8) The conductive and resistive paste contains a thermosetting II resin as a main component. The method for manufacturing a circuit board according to claim 1, wherein one or a combination of two or more selected from carbon paste, copper paste, silver paste, and solder paste.