JPH0577104A - Drilling method of glass backing fluororesin substrate - Google Patents

Abstract

PURPOSE:To obtain a backing fluororesin substrate wherein the wall surface of a drilled hole possesses properties excellent in the performance of future plating without damaging a drill bit by using a drill of straight type wherein the shape of the drill bit is formed of a point angle 130-150 degrees and a twist angle 35-40 degrees. CONSTITUTION:A glass backing fluororesin substrate 1 having an internal layer circuit 6 is drilled with a drill whose diameter is 0.1-3.0mm. In this case, a drill of straight type whose drill bit is formed of a point angle 130-150 degrees, and a twist angle 35-40 degrees is used. Because of this, the glass backing fluororesin substrate 1 having such properties of the wall surface of the drilled hole as excellent in plating performance can be obtained without damaging the drill bit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a perforation method for a glass-based fluororesin substrate used for mounting electronic parts and electric parts.

[0002]

2. Description of the Related Art Glass-based fluororesin substrates, which are organic insulating materials having excellent dielectric loss tangent and dielectric constant high frequency characteristics and heat resistance, have been widely used in recent years in the fields of communication satellites and computers.

Conventionally, the shape of a drill bit used for drilling a resin substrate such as epoxy resin or polyimide resin has a tip angle of 110 to 1 at a drill diameter of 0.1 to 3.0 mm.
It was an undercut type of 30 ° and a twist angle of 25 to 35 °. The reason is that generally when drilling with a drill, if the tip angle becomes large, the shape of the cutting chips becomes a shear shape in the drill performance, which is good for dischargeability, burr, and cutting heat, but it is not straightforward. Have a bad influence. It is known that when the twisting angle becomes large, it has a good effect on the discharging property, burr, cutting heat, and wear resistance, but it has a bad influence on the straight running property and the biting property. If it is too large, straightness will be impaired and the drill will be damaged. In addition, the use of a straight type drill bit causes a smear problem of the multilayer printed wiring board.

The glass-based fluororesin substrate is thermoplastic and soft, and has the property of being difficult to cut in cutting. FIG. 4 shows a cross-sectional view of a glass-based fluororesin substrate perforated using the conventional drill bit (the glass fiber 4 is not shown in the left half). A glass cloth substrate made of glass fibers 4 is impregnated with a fluororesin 7 and dried, and a prepreg obtained by laminating is laminated to form a multilayer glass base fluororesin substrate 1 having an inner layer circuit 6 and the conventional drill bit. When the hole 2 is drilled by using it, there is a problem that the cutting powder is wrapped around the drill bit and the drill bit is damaged, and the glass fiber protrusions 5 are generated on the inner wall of the hole 2 so that the plating layer 3 does not adhere uniformly. Was there. FIG. 5 shows the SEM with the hole 2 enlarged further.
It was observed under the condition of 1. and it was observed that the glass fibers 4 were partially formed as protrusions 5 in the fluororesin 7.

[0005]

SUMMARY OF THE INVENTION Therefore, the present invention provides a method for boring a glass-based fluororesin substrate in which the wall surface of the bored hole has a property excellent in the subsequent plating property without damaging the drill bit. To do.

[0006]

The present invention has been made in view of the above problems, and its characteristic is that when a glass-based fluororesin substrate is drilled with a drill diameter of 0.1 to 3.0 mm,
The shape of the drill bit is to use a straight type having a tip angle of 130 to 150 ° and a screw angle of 35 to 40 °.

[0007]

[Operation] By increasing the tip angle and using a straight type drill bit, the shape of the cutting chips becomes a shearing shape, the cutting chips are not wrapped around, and the drill bits are not damaged. By increasing the tip angle, increasing the twist angle, and using a straight type drill bit, the machinability of the drill bit and the discharge of chips are improved, and a hole wall surface with excellent plating properties can be formed.

Even if such a drill bit shape is used, the glass-based fluororesin substrate is soft and is 270-350.
Since the temperature and Tg are high, straightness can be ensured, drilling with excellent hole position accuracy can be performed, and there is no damage to the drill bit, wear of the drill bit, no smear, etc.

[0009]

EXAMPLES The method for punching a glass-based fluororesin substrate of the present invention will be described below based on examples. The present invention is not limited to these examples.

As the glass-based fluororesin substrate, the fluororesin used for the laminated plate can be used as it is. Further, the fluororesin may contain an inorganic filler, an organic filler, bubbles, etc., either alone or in combination. As the glass substrate, a glass cloth or a non-woven cloth containing an organic fiber having an aromatic polyamideimide skeleton having excellent heat resistance can be used.

The material of the drill bit is not particularly limited, and the material normally used for laminated plates can be used as it is.

Example 1 A 10-layer plate having a thickness of 3.2 mm was used as a glass substrate fluororesin substrate, and a 0.4 mm laminated plate was laminated on the upper side of this substrate and a 1.6 mm laminated plate was laminated on the lower side thereof. Then, it was perforated with the next drill bit. The shape of the drill bit is 1.0m in diameter.
Use a straight type with a tip angle of 130 ° and a twist angle of 37 ° at m, and drilling conditions of 60000r.pm and 50μm / rev.
Drilled up to 600 hits. As a result, no glass fiber protrusion was observed on the wall surface of the hole. FIG. 1 shows an SEM observation of the state of the inner wall of the hole at this time. A bundle of glass fibers 4 is arranged above and below the inner layer circuit 6 using the fluororesin 7 as a binder. The hole clogging was not 0/600, and the wrapping amount of cutting chips was 2 mm for L and 0.5 mm for H. The evaluation method for each result is as follows.

The inner wall of the hole is observed by SEM. The clogging of holes is observed visually. The wrapping amount of the cutting chips was measured with the length L of the cutting chips and the width H.

Example 2 Example 1 was repeated except that the shape of the drill bit of Example 1 was changed to a straight type shape having a drill diameter of 1.0 mm, a tip angle of 150 ° and a screw angle of 40 °. As a result, no glass fiber protrusion was observed on the wall surface of the hole. The hole clogging was not 0/600, and the wrapping amount of the cutting chips was L 1 mm and H 0.5 mm.

Comparative Example 1 The same procedure as in Example 1 was carried out except that the shape of the drill bit of Example 1 was changed to a straight type having a drill diameter of 1.0 mm, a tip angle of 118 ° and a screw angle of 30 °. As a result, glass fiber protrusions were observed on the wall surfaces of the holes. FIG. 2 shows an SEM observation of the wall surface state of the holes at this time. A bundle of glass fibers 4 is arranged above and below the inner layer circuit 6 using the resin 7 as a binder, and a part of the glass fibers 4 has protrusions 5 at some places.
As it was standing up remarkably. Most of the other glass fibers 4 also tended to stand. The hole clogging is 39/600,
The amount of cutting chips wrapped around was 10 mm for L and 5 mm for H.

Comparative Example 2 The procedure of Example 1 was repeated except that the shape of the drill bit of Example 1 was changed to an undercut type having a drill diameter of 1.0 mm, a tip angle of 118 ° and a screw angle of 35 °. As a result, glass fiber protrusions were observed on the wall surfaces of the holes. FIG. 3 shows an SEM observation of the wall surface state of the holes at this time.
A bundle of glass fibers 4 was arranged above and below the inner layer circuit 6 using the resin 7 as a binder, and a part of the glass fibers 4 was remarkably erected as a protrusion 5 in comparison with Comparative Example 1. Most of the other glass fibers 4 also tended to stand. 28 / hole clogging
600, the amount of shavings wrapped around is 13 mm for L and H
Was 7 mm.

From the above, it was confirmed that the glass fiber of the example did not protrude from the wall surface of the hole, the hole was not clogged, and the amount of the cutting dust was smaller than that of the comparative example.

[0018]

According to the present invention, it is possible to obtain a glass-based fluororesin substrate in which the wall surface of the drilled hole has a property excellent in the subsequent plating property without damaging the drill bit.

[Brief description of drawings]

FIG. 1 is an enlarged view showing a wall surface of a hole punched in an embodiment of the present invention.

FIG. 2 is an enlarged view showing a wall surface of a perforated hole of a comparative example.

FIG. 3 is an enlarged view showing a wall surface of a hole punched in another comparative example.

FIG. 4 is a cross-sectional view showing a glass-based fluororesin substrate punched in a conventional example.

FIG. 5 is an enlarged view showing a wall surface of a hole drilled in a conventional example.

[Explanation of symbols]

 1 Glass Base Fluororesin Substrate 2 Hole 3 Plating Layer 4 Glass Fiber 5 Protrusion of Glass Fiber 6 Inner Layer Circuit 7 Fluororesin

Claims (1)

[Claims] 1. A glass-based fluororesin substrate having a drill diameter
A drilling method for a glass-based fluororesin substrate, characterized in that, when drilling with a diameter of 0.1 to 3.0 mm, the drill bit is a straight type having a tip angle of 130 to 150 ° and a screw angle of 35 to 40 °.