JPS61225894A - Manufacture of multilayer printed interconnection 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 Field of Application) The present invention relates to a method of manufacturing a substrate for a multilayer printed wiring board.

(Prior art) A multilayer printed wiring board consists of an inner layer circuit board on which an inner layer circuit is formed,
If necessary, align and overlap multiple sheets through prepreg, then overlay single-sided copper-clad laminates or steel foil on both sides or one side through prepreg, and heat and press to form a single skin. After that, expose the marking guide marks provided at at least two corners of the inner layer circuit board, mark the reference position display mark position of the inner layer circuit using the marking guide mark as a reference, and use the marked position as a guide by cutting with an end mill, etc. The reference position display mark is exposed, a hole is drilled in the center of the reference position display mark, and this hole is used as a reference to form through holes and circuits in the double-sided steel clad laminate.

(Problems to be Solved by the Invention) Conventionally, the hole #JA for the reference position display mark was aimed at the center of the mark, which caused the following problems. Since the inner layer circuit board shrinks by approximately α11Iffl per 500ff1m, the pattern of the inner layer circuit board should be zoomed in advance.
The design value (the value of the pattern required for the final product) is made larger at a ratio of about 0.11111!1 per m,
It is necessary to ensure that the pattern is accurately finished after lamination, but the amount of shrinkage of the inner layer circuit board varies depending on the pattern shape, and on the other hand, determining the amount of shrinkage requires a large number of experiments. The accuracy of ff1 in the inner layer circuit becomes extremely poor, and when through-holes are drilled using an NC drilling machine, reliable conduction or insulation between the through-holes and the inner layer pattern may not be expected. This will be explained in detail using FIG.

Hole drilled in the reference position display mark ykGo, Gt, %Go as the origin, straight line IV51 connecting Go and Gtf
If the X coordinate is G1 (a, o), then the through hole is G. Holes are drilled (necessary circuit processing) using this as the starting point.

Here, if the amount of shrinkage of the inner layer circuit board is smaller than that of the child side, then
Should be (design value) G.

Gs pitch: A is smaller than GoG pitch a of the product.

As a result, in the pattern farthest from Go, the amount of deviation between the through-hole hole and the pattern is maximum, resulting in 94 lines or insulation becomes uncertain.

The present invention provides manufacturability of a multilayer printed wiring board in which circuit processing close to design values can be easily performed.

(Means for Solving the Problems) The present invention provides reference position display marks on a multilayer printed wiring board substrate equipped with an inner layer circuit board and an inner layer circuit board on which at least two reference position display marks are formed using %X-rays. Measure the pitch between the reference position display marks, compare it with the design value, add a correction value to the position of the reference position display mark, drill a hole, and perform the necessary circuit processing using this hole as a reference.1r: This is a characteristic feature.

In other words, in the case shown in Figure 2, the design value A is smaller than the actual measurement value a, so the Go hole is (a-A)/2 in the G1 direction.
By moving and drilling (drilling with a drilling machine set according to the design value), the frt between the through-hole hole and the pattern, iN is [F]t-(oyo). If it is clear, it is possible to halve it by comparison.

The moving distance is preferably (a-A)/2 to (a-A)/4.

FIG. 2 shows an apparatus used in the present invention, which will be explained below with reference to the drawings.

1 is an XY table with a length measurement function such as Magnescale, and the table surface on which the product 2 is mounted is made of glass plastic, etc., which has low X-ray attenuation. In order to roughly position the product 2 and the table, a lJ# (or guide) parallel to the XY axes is installed on the table In, and the central axis of the XWI irradiation tube 4 and the image pickup tube are placed on the perpendicular to the XY table 1. Both tubes are arranged so that the center axis of the image pickup tube 5 rests thereon and the XY table is sandwiched therebetween, and a drill 6 is arranged parallel to the image pickup tube 5 at the same pressure l1ill in the X-axis direction.

Furthermore, it is determined in advance where the center position of the image pickup tube 5 will be on the display surface of the monitor television 7.

In such a device, a product 2 is placed on an XY table 1 with the end face of the product aligned with the marked line, the product is fixed with a clamp 3, the XY table 1 is moved, and a separate product is placed directly under the image pickup tube 5. Make sure that the scribing guide marks shown are aligned. °The relative position of the gauge line and the marking guide mark is as follows:
Since the marking guide marks are predetermined at the stage of forming the inner layer circuit, rough positioning can be easily determined by measuring the length with a Magnescale.

Next xI! 11' was irradiated, a guide mark for marking was projected on the monitor TV, and the XY table 1 was finely adjusted on the monitor TV 7 so that the guide mark was placed at the position that had been determined in advance as the center position of the image pickup tube 5. rear,
Display the reference position and find the coordinates of the mark.

The coordinates of the other reference position display mark are determined in the same manner.

The direction of correction is determined by the pitch tat between the reference position display marks - the design value A and the illumination correction value 1a - AI/2. For simplicity, it is assumed that the product 2 is in a state as shown in Fig. 2 with a>A, the intersection of the center point of the image pickup tube 5 with the XY table 1 is (0,0), and the intersection between the drill 6 and the XY table 1. Intersection t-(j, o
) and a〉I, then KGo(o, o), Gt(a
, o), then make a hole and make a hole for Gl (a-1,
o) or n −A a+A (a−12), that is, (−# +−T−, O). Various conditions have been added for the sake of simplicity, but the magnitude, direction, and coordinate values of the correction value Fi can be easily determined by linking with an electronic computer.

Set n to match the set Ct value using the Go hole as a reference.
After drilling the holes, perform drilling and necessary circuit processing.

(Effects of the Invention) In the method of the present invention, or even in a multilayer printed wiring board board using the same inner layer circuit board, by appropriately correcting and drilling the hole of the reference position display mark, the inner layer pattern and the through hole can be adjusted. It is possible to reduce the amount of n111 by half with the hole 9,
Accuracy can be improved.

Furthermore, since the reference position display mark is directly viewed through X-rays, the work of exposing the mark using an end mill or the like becomes unsuitable.

[Brief explanation of the drawing]

FIG. 1 is a side view of a device for drilling a reference position indicating mark used in the present invention, and FIG. 2 is a plan view showing a state in which through-holes are drilled in a substrate for a multilayer printed wiring board. Explanation of symbols I XY table 2 Product 3 Clamp 4 X# irradiation tube 5 Image tube
6 Drill 7 Monitor TV

Claims (1)

[Claims] 1. A multilayer printed circuit board equipped with an inner layer circuit board on which at least two reference position display marks are formed, see through the reference position display marks using X-rays, and measure the pitch between the reference position display marks. A method for manufacturing a substrate for a multilayer printed wiring board, which comprises: checking the design value, adding a correction value to the position of the reference position display mark, drilling a hole, and performing necessary circuit processing using the hole as a reference.