JPH0666702A - Method for inspecting dust attached to prepreg - Google Patents

Abstract

PURPOSE:To inspect the amount of attached dust simply over a wide range by scanning with an adhesive hand roller, and measuring the weight of the adhesive hand roller before and after the scanning. CONSTITUTION:Drill holes 2 for inserting guide pins at the time of multilayer formation press are formed at a peripheral part 3 of a prepreg (glass epoxy prepreg) for a multilayer printed wiring board. The prepreg is heated to the diffusing temperature of resin. The prepreg is lightly compressed with a roll, and a resin-powder-generation preventing product is formed. The peripheral part 3 including the holes 2 and an inner part 4 are scanned with an adhesive roller. Thus, dust can be inspected simply and positively only by measuring the weight of the adhesive hand roller before and after the scanning regardless of the size of the measuring area.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for inspecting the amount of dust attached to a prepreg.

[0002]

2. Description of the Related Art A copper-clad laminate used as a substrate of a printed wiring board is manufactured by stacking a plurality of prepregs, copper foil on one or both sides, sandwiching them with end plates, and heating and pressing. The multilayer copper-clad laminate is manufactured by stacking prepregs on both sides of the inner layer printed wiring board, copper foils on the outside of the prepregs, and heating and pressing.

This prepreg is obtained by impregnating a long base material with a liquid thermosetting resin and then drying the resin so as to be B-staged. Since the prepreg is cut into a predetermined size in use, dust (mainly resin powder or base material powder generated by cutting) is attached. If this dust is not removed, not only will the environment of the next laminating step be adversely affected, but also defects called dents will occur on the copper foil surface, causing defects in the product. In addition, dust is transferred from the prepreg to the end plate, and it takes a lot of time and effort to remove it.

For this reason, an adhesive tape was attached to the prepreg surface, peeled off, and the weight thereof was measured to inspect the dust adhesion state.

[0005]

In the conventional method, there is no particular problem when inspecting a narrow area, but when inspecting over a wide area, a long adhesive tape is required, and the weight of the adhesive tape before the inspection is required. In order to measure, the pressure-sensitive adhesive tape must be folded, and when it is folded, it cannot be expanded to measure. For this reason, it was necessary to use a short tape and to inspect it several times. The present invention solves these drawbacks and provides a wide range of dimensions for easily inspecting the amount of deposited dust.

[0006]

According to the present invention, a method for inspecting dust adhering to a prepreg is characterized by scanning the surface of a prepreg with an adhesive hand roller and measuring the weight of the adhesive hand roller before and after scanning. Is. As the adhesive hand roller, a commercially available one for removing dust such as clothes can be used, and it can be repeatedly used until the adhesive force on the roller surface is lost.

[0007]

EXAMPLE A drill hole 2 for inserting a guide pin at the time of multilayer press was drilled in a peripheral edge portion 3 of a prepreg (glass epoxy prepreg) 1 for a multilayer printed wiring board having a thickness of 0.1 mm (see FIG. 1). This prepreg was heated to the melting temperature of the resin and lightly pressed by a roll to manufacture a resin powder generation preventing product. The obtained resin powder generation-preventing products and general products not subjected to such treatment were scanned with an adhesive hand roller to examine the amount of dust adhesion. The results are shown in Table 1. The scanned locations are the peripheral portion 2 (a portion including the drill hole 2 and having a width of 20 mm) and the inner portion 4 (see FIG. 1).

[0008]

[Table 1]

[0009]

The method for inspecting dust adhering to a prepreg according to the present invention is simple and reliable irrespective of the measurement area because it only uses an adhesive hand roller to measure its weight. The development and improvement of the resin powder drop prevention method for prepregs used in printed wiring boards with ever-increasingly high density and finer wiring is applied to the shipment control of prepregs, and it is a major contribution to the stability and improvement of quality.

[Brief description of drawings]

FIG. 1 is a plan view of a prepreg for a multilayer printed wiring board according to an embodiment of the present invention.

[Explanation of symbols]

 1 Prepreg 2 Drill hole 3 Edge 4 Inner part

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Claims (1)

[Claims] 1. A method for inspecting dust adhering to a prepreg, comprising scanning the surface of the prepreg with an adhesive hand roller, and measuring the weight of the adhesive hand roller before and after scanning.