JPS6184096A - Manufacture of multilayer printed board - 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 multilayer printed boards.

(Prior Art) Multilayer printed wiring boards are generally manufactured as follows.

7. Overlap one or more insulating plates (hereinafter referred to as inner layer plates) having conductor circuits on both sides or one side with Gripreg in between. Overlay shells or single-sided steel-clad laminates on both sides of the structure. These are stacked alternately with the end plate for the intermediate plate, and the required number of sets are stacked. After this alternate stacking, flat metal plates (hereinafter referred to as multilayer bonding jig plates) having a smooth and uniform thickness of about 3 to 20 mm are stacked on top and bottom. At this time, in order to align the circuits on the inner layer board, through holes are drilled in advance at the same positions in each material, mirror plate, and multilayer bonding jig plate, and the holes are fixed with alignment bottles. If necessary, place cushioning material on the outside of the curtain. This is heat-integrated in a press capable of heating and cured. (Hereinafter, this process will be referred to as multilayer adhesion.)
Thereafter, the board for the plate-shaped multilayer printed board is separated from the end plate, the jig plate for multilayer adhesion, and the positioning pins to complete the process.

The materials of the multilayer bonding jig used here and the end plate for the intermediate plate (hereinafter referred to as ``other'') used between the products are generally metals such as stainless steel and iron.In addition, the prepreg used for multilayer bonding is generally made of metal such as stainless steel or iron. A thermosetting resin is impregnated into a glass cloth base material to bring it to a B-stage state.The thermosetting resin used for the prepreg at a temperature of Alternatively, research has been conducted to firmly bond a single-sided copper-clad laminate to an inner layer.

In the multilayer adhesion process, the resin of the prepreg melts and flows out due to heating and pressure, filling the voids in the conductor circuit. In general, the amount of resin attached to the prepreg is about 2 to 20 times the volume of the gap, because in order to completely fill the gap in the circuit section, it is necessary to push out the air present in the gap.

Therefore, a portion of the resin that melted and flowed out due to heating and pressurization was pushed out of the substrate by 5 degrees, and the resin that flowed out came into contact with the above-mentioned jigs and hardened.

Thereafter, it must be cooled, taken out from the press, and the substrate and jigs must be separated. However, the resin that has flowed out strongly adheres to the multilayer bonding jig plate, making it difficult to separate it and making the work extremely difficult.

Generally, to prevent adhesion of such jigs and spilled resin,
Is the resin leaking part V in advance? - A method of applying a mold release agent and overlapping the molds is used.

The mold release agent used is silicone-based, such as KS.
-707 (trade name of Shin-Etsu Chemical Co., Ltd.) and QZ-13 (trade name of Dow Chemical Co., Ltd.) are used by diluting them 2 to 30 times in a solvent (toluene, acetone, methyl ethyl ketone).

Even in small amounts, this type of mold release agent is sufficiently effective and can completely prevent adhesion between jigs and spilled resin. However, when applying mold release agent in the multilayer bonding process, even if it slightly adheres to some of the constituent materials of the copper foil, single-sided copper-clad laminate, inner layer board, or prepreg, or penetrates through the pin holes, Do not adhere to the resin of Woma Prepreg (・.

In a multilayer printed board, such unbonded areas are only a few minutes. In the later board processing process, short circuits may occur due to penetration of plating liquid, etc., and blistering and peeling may occur in the heating process using a solder leveler, etc., and the function as a multilayer printed board cannot be obtained.

(Objective of the Invention) The object of the present invention is to eliminate the occurrence of defective adhesion of multilayer printed boards (・method for manufacturing multilayer printed boards and to improve the causes of defects in multilayer printed boards due to adhesion and penetration of mold release agents). The present invention provides a method for manufacturing a multilayer printed board that completely eliminates the need for manufacturing.

(Structure of the invention) The present invention is an inner layer plate of a loquat edge plate having a conductor circuit.

A jig for multilayer adhesion of flat/temporary metal plates on the top and bottom, by alternately overlapping the outer layer of copper foil or single-sided @f-wavy laminate with prepreg interposed between them and the mirror plate for the intermediate plate. In a manufacturing method that relies on multilayer printing, in which plates are arranged and aligned, and heated and pressed using a press, a mold release agent is fixed to at least the edge of the end plate for the intermediate plate and/or the jig plate for multilayer adhesion. This is a method for manufacturing a multilayer printed board, characterized in that the layers are formed in a fixed manner.

That is, the present invention has a layer fixed with a solid mold release agent that can be used repeatedly on a part of the jigs or the foot surface in order to prevent adhesion between the jigs and the resin that has flowed out. Further, since this fixed layer of mold release agent can withstand repeated use, the conventional work of applying a liquid mold release agent is unnecessary. There are various methods for forming a solid mold release agent layer on jigs, but from the viewpoint of precision, ease of formation, and repeated workability of the mold release layer, fluororesins (obtained from fluorine-containing olefins) are preferred. A good method is to hold the synthetic resin (n) on the surface of the jig.

There are two main ways to do this: one is to fix the fluorine level (fat) in the cracks and gaps on the metal surface, and the other is to use other resins and liquids that easily bond the fluororesin to the metal. This method involves dissolving or dispersing the resin in a bath, applying it to jigs, and then evaporating the volatile liquid by heating to fix the 2-noresin and other resins on the surface layer.

One of the former methods is Tenlock processing ■ (Omori Chrome Plating Co., Ltd.). Temperature processing ■ is a method in which a fluororesin such as Teflon (DuPont Co., Ltd.) is embedded in a hard coating of chrome or other material plated on the surface of a jig, and becomes part of the coating. .

A bag-like fine skewer is chemically made on a metal surface and heated to about 200 degrees Celsius to enlarge the cracks, whereas Teflon is cooled to about -70 degrees Celsius and shrinks. Shrunken Teflon is inserted into the heated crack using a special method. Since Teflon has a very large coefficient of thermal expansion, the Teflon particles warm up inside the crack and expand rapidly, and the crack cools and contracts, causing the Teflon to remain permanently sealed inside the crack. Since it has a metal surface that has the characteristics of a metal and that of Teflon, a strong layer with good mold releasability can be obtained. There is also a method similar to this called Nidax treatment (Metal Surface Chemical Co., Ltd.).

The latter method is provided by Mitsui Toatsu ■.
Powdered Teflon and polyether sulfone are mixed, dispersed in N-methyl-2-pyrrolidone, and applied to jigs.

Thereafter, it is pre-dried to temporarily fix the thickness to a constant value, and then N-methyl-2-pyrrolidone is completely removed by evaporation at a high temperature. Since polynytail sanphon has good adhesion to Teflon and metal, a layer containing Teflon can be formed on the surface of jigs and can be used as a mold release layer.

Although the processing methods for the former and latter are different, the purpose of mold release is the same, and the layer thickness is 2 μm or more, preferably 5 to 50 μm, for good durability (repeated use) and mold release properties. f. The part to be processed can be the entire surface of the jig, but the smooth surface of the product part that will become the multilayer printed board makes it easier to form circuits later, so a VC weave pattern is required as shown in Figure 1. It is desirable to form the portion only on the edge. When a layer is further formed partially, the valley ゛2ν
It is preferable to form it so that it has the same thickness as the jigs, as shown in the cross-sectional view of j.

In Figure L1 and Figure 2 V, 1 is a jig for multi-node formation N.
2 is the pin hole for the stand, 3+'! This is a mold release agent layer.

(Effect of the invention) In the method V of the present invention, -fsjH':I is performed n
When applying a liquid release agent, there will be no adhesion failure caused by the release agent layering or soaking into the multilayer print/temporary structure bottom material f4. nte(
・Since it can be used repeatedly, there is no need to apply a template agent during multilayer bonding, improving work efficiency.

[Brief explanation of the drawing]

FIG. 1 is a plan view of the multilayer receiving jig, and FIG. 2 is a sectional view. Explanation of symbols

Claims (1)

[Claims] 1. Inner layer plate of insulating plate with conductor circuit 1 A structure in which the outer layer plate of copper foil or single-sided copper-clad laminate is laminated with prepreg interposed therebetween is alternately layered with intermediate mirror plates, and flat plate-shaped upper and lower layers are layered. In a method of manufacturing a multilayer printed board in which a jig plate for multilayer bonding of metal plates is arranged and aligned, and then heated and pressed using a press machine, at least the edge of the end plate for the intermediate plate and/or the jig plate for multilayer bonding. A method for manufacturing a multilayer printed board, characterized in that a solid mold release agent layer is fixedly formed on a portion of the board.