JPS6241027A - Manufacture of substrate for wiring - Google Patents

Abstract

PURPOSE:To prevent the shrink of a substrate at the later etching process and soldering resist process or even at plating resist process, by using a paper as the base material to be heated to the almost completely shrinked extent, then by heating and pressing it which include resin with copper foils placed on both up and down surfaces. CONSTITUTION:While a paper 2 is controlled by driving roller controlling part 23 so as not to exceed the position of a sensor 22 to making a condition that the paper 2 sags in a U letter between the driving roller 20 and a roller 3, whereby it shrinks sufficiently when passing through a heater 21. Namely because tension is not applied to the paper 2 when passing through a heater 21, the paper becomes sufficiently shrinkable by heat without internal stress. Here the heating temperature of the heater 21 is preferably 100 deg.C-200 deg.C. Therefore, the shrink of the substrate at the later processes can be prevented by shrinking the paper almost completely by heating it before including the resin.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field The present invention relates to a method of manufacturing a wiring board such as a phenol board or a paper epoxy board using paper mixed with resin as the material of the board.

(bl Prior Art and Its Disadvantages) Conventionally, wiring boards such as paper phenol boards and paper epoxy boards use a sheet of paper wound around a roller 1 as a starting base material, as shown in FIG. While conveying the paper with rollers 3.4, resin is mixed with the white paper through a resin tank 4.5, and then sent to a drying process via rollers 7 to be dried, and furthermore, the dried paper is cut,
They were stacked in multiple layers and copper foil was placed on both the top and bottom surfaces to heat and pressurize them. FIG. 3 shows a cross-sectional view of the wiring board manufactured in this manner. In the figure, reference numeral 10 indicates a sheet of paper stacked in multiple stages, and copper foils 11 and 12 are adhesively fixed to the upper and lower surfaces of the paper. A phenol resin is used for the resin of the Mio phenol board, and an epoxy resin is used for the resin of the Mio epoxy board. The wiring board manufactured in this manner is then sent to a circuit pattern forming process and an etching process.

Conventionally, however, wiring boards manufactured in this manner have had the disadvantage that the entire board shrinks during the subsequent etching process or when forming a solder resist or Menki resist film, resulting in errors in pattern alignment. In particular, there was the problem that the film thickened (shrank) during etching, and also gradually shrunk when forming a solder resist film or a mesochyresist film. The reason for the shrinkage of the entire board is that paper mixed with resin is stacked in multiple layers and copper foil is pressed from both the top and bottom surfaces.
Due to the presence of the copper foil, the paper itself cannot be shrunk even when heat is applied from the outside, and when it is etched afterwards, the area of the copper foil decreases due to etching.
This is because the force that tries to suppress the shrinkage of the paper rapidly decreases. Furthermore, when a solder resist film or a metal resist film is formed, the resist film is baked to a temperature of 100-odd degrees, and the paper further shrinks due to the heat.

In this way, in the conventional method of manufacturing Mio phenol substrates and Mio epoxy substrates for wiring, the entire substrate shrinks during etching for circuit formation and when forming resist patterns, making it difficult to accurately position the pattern. If pattern alignment is to be performed accurately, it is necessary to take photographs to realign the patterns many times during the process.

(C) Purpose of the Invention An object of the present invention is to provide a method for manufacturing a wiring board that can eliminate the above-mentioned drawbacks by adding simple steps.

(d1 Structure and effect of the invention This invention uses paper as a starting base material, heats the paper until it almost completely shrinks, then mixes resin, places copper foil on both the top and bottom, and heats and pressurizes the paper. It is characterized by

With this configuration, according to the present invention, the paper is heated until it almost completely shrinks before being mixed with the resin.
When copper foil is placed on both the top and bottom and heated and pressurized, the paper is not fully stretched. In other words, the copper foil is bonded to both the upper and lower surfaces of the paper in a substantially completely shrunk state.

Therefore, the substrate will not shrink in the subsequent etching process (and will not shrink in the soldering resist process or plating resist process. Positioning can be performed, and there is an advantage that there is no need to take photographs or the like to realign the pattern midway.

TELE EXAMPLE FIG. 1 is a diagram showing a part of the method for manufacturing a phenol substrate according to the present invention.

In the figure, a sheet-shaped rug 2 wound around a roller 1 is conveyed forward by a driving roller 20, passed through a heater 21, and is conveyed to a position of a roller 3.

The rear part of the roller 3 is similar to the apparatus shown in FIG. 2, and the resin is immersed in resin tanks 5 and 6 and transported to the drying process.

A sheet of paper 2 is held hanging down in a U-shape between the drive roller 20 and the roller 3. Maintaining this U-shaped state is controlled by the photosensor 22 and a drive roller control section 23 that controls the drive roller 20. When the bulge 2 has not reached the position of the sensor 22, the drive roller control unit 23 increases the amount of pupil 2 carried by the drive roller 20. Further, when the paper 2 exceeds the position of the sensor 22, the amount of conveyance of the paper 2 by the drive roller 20 is reduced. By continuously performing such control, the lowest position of the U-shaped shidagi 2 coincides with the position of the sensor 22. Between the drive roller 20 and the roller 3, the G2 is
By hanging down in the shape of a letter, when the gill 2 passes through the heater 21, it is sufficiently contracted. That is, heater 2
Since no tension is applied to the wire 2 when the paper passes through the paper 1, no internal stress is generated in the white paper, and it is able to sufficiently shrink due to heat. Note that the heating temperature of the heater 21 is preferably about 100°C to 200°C. Also heater 2
1 may use a heater or have a structure that radiates hot air (or may be configured by other known means).

By heating the paper to almost completely shrink it before mixing the resin as described above, it is possible to prevent the substrate from shrinking when etching is performed later or when a resist film is formed.

[Brief explanation of the drawing]

FIG. 1 is a diagram illustrating a part of the manufacturing method according to the present invention. Also, Fig. 2 is a diagram explaining the conventional manufacturing method, and Fig. 3 is a diagram explaining the conventional manufacturing method.
The figure is a cross-sectional view of a wiring board using paper as a starting base material. 2-paper, 11.12-copper foil, 21-heater.

Claims (1)

[Claims] (1) Manufacturing a wiring board using paper as a starting base material, heating the paper until it almost completely shrinks, then mixing resin with it, placing copper foil on the top and bottom surfaces, and heating and pressurizing it. Method.