JPH08290286A - Method for dividing circuit board - Google Patents

Abstract

PURPOSE: To dispense with exclusive split dies, in dividing a circuit board with electronic parts mounted into pieces of a prescribed size each, to prevent dust from generating from the end face of the circuit board thus divided or to prevent the insulation of the circuit board from deteriorating. CONSTITUTION: A condenser lens 3 is provided by which a circuit board 1 with electronic parts mounted is irradiated with a laser beam 4, and also a blowing nozzle 6 is provided by which an oxygen gas containing glass powder is blown to the laser machining part. As a result, exclusive dies are no longer required for dividing the circuit board 1. In addition, carbon dust is prevented from generating from the end face of the circuit board 1 on account of the heating by the laser beam, or the deterioration of the insulation is also prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of dividing a circuit board, and more particularly to a method of dividing a circuit board such as a hybrid IC for mounting the electronic parts on the board and then forming the board into a predetermined size.

[0002]

2. Description of the Related Art Conventionally, when a circuit board made of epoxy resin containing glass fiber used for a hybrid IC or the like is divided, it is carried out by a division mold as shown in FIG. 1 was set, the circuit board 1 was pressed by the upper die pad 13, and then punching was performed by the punch 14.

Further, as shown in FIG. 5, there is also a method in which the circuit board 1 is locally heated by the laser beam 4 and compressed air is blown to the heating portion to perform the division processing.

[0004]

In the conventional method of dividing and processing a circuit board by a division die, the division die must be made every time the outer dimensions of the board on which electronic components such as a hybrid IC are mounted are changed. However, there are drawbacks such as requiring a long period of time for making the split mold and being expensive.

In the method of dividing a circuit board by a laser beam, since the epoxy resin is carbonized by heating by the laser beam, carbon dust is generated from the end face of the circuit board on which the electronic components are mounted, or a mixed IC or the like is not provided. There were problems such as deterioration of insulation properties (see FIG. 6).

[0006]

The circuit board dividing method according to the present invention uses a laser beam as a heating means, and has means for blowing oxygen gas containing glass powder to the portions of the circuit board to be divided.

[0007]

The present invention will be described below with reference to the drawings.

FIG. 1 shows a first embodiment of a circuit board dividing method according to the present invention, and is a sectional view showing a divided state of a circuit board. In this embodiment, first, the circuit board 1 made of epoxy resin containing glass fiber is set on the stage 2.
Next, while irradiating a predetermined position on the circuit board 1 with the laser beam 4 condensed by the condenser lens 3, oxygen gas containing glass powder is fed from the gas introduction port 5, and the laser processing part of the circuit board 1 is ejected from the blowing nozzle 6. To blow away the locally melted portion by the laser beam 4,
It is possible to make a hole. Further, by moving the stage 2 on which the circuit board 1 is set at a predetermined speed in the horizontal direction, the circuit board 1 can be divided into a predetermined size.

More specifically, a circuit board 1 generally used for a hybrid IC or the like is an epoxy board containing glass fiber having a thickness of about 0.6 to 1.6 mm, and has an outer shape of 100 × 15.
Dozens of hybrid ICs of about 20 × 30 mm are formed from a circuit board of about 0 mm. In the process of manufacturing a hybrid IC, surface mount components such as ICs, transistors, and diodes are soldered on the circuit board 1 and then divided into a predetermined size as the hybrid IC, and external leads are attached to the hybrid IC. Is completed. When the present invention is applied to the hybrid IC, the stage 2 is fixed to the circuit board 1 to which the surface mount components are soldered in advance by vacuum suction or the like.
Next, through a condenser lens 3, a YAG laser (wavelength 1,06
μm) with an output of 50 to 200 W. At this time, oxygen gas (oxygen concentration of 50% or more, pressure of 3 to 5 × 10 ⁵ Pa) containing glass powder (having a particle size of 10 to 100 μm) with a volume ratio of about 0.01 to 1 ppm is supplied from the gas inlet 5. It is introduced and blown onto the circuit board 1 from the blowing nozzle 6.
If the glass powder is smaller than 10 μm, the glass powder will fall off, so that it will not easily adhere to the substrate. If it is larger than 100 μm, it is difficult to adhere uniformly, and the surface of the cross section becomes rough,
In addition, there is a disadvantage that welding is difficult. That is, it is preferable that the particle diameter of the glass powder is 10 μm or more and 100 μm or less in order to uniformly adhere the glass film. The processed part locally melted by the laser beam 4 of the circuit board 1 is blown off while being oxidized by the blown gas, and a hole is formed. At this time, the circuit board 1 can be divided into a predetermined size as a hybrid IC by moving the stage 2 at a speed of 1 to 10 mm / sec.

FIG. 3 shows a hybrid I formed separately according to the present invention.
The cross section of the laser-processed portion C is shown. In the present invention, since the oxygen gas containing the glass powder is blown while irradiating the laser beam at the time of dividing the substrate, it can be easily processed by the oxidizing action by oxygen and the glass powder is contained. As a result, the surface of the carbonized layer of the epoxy resin of 50 to 200 μm is covered with the glass layer of 10 to 100 μm.

FIG. 2 shows a circuit board dividing method according to a second embodiment of the present invention.
FIG. 3 is a cross-sectional view illustrating a positional relationship among a circuit board, a blowing nozzle, a condenser lens, and a laser beam. The difference from the first embodiment of FIG. 1 is that the blow-out nozzle 6 ′ is provided separately from the exit of the laser beam 4. By doing so, the direction of the blowing nozzle 6 'can be freely changed regardless of the direction of the laser beam 4, so that the glass powder can be sprayed in the optimum direction. Further, the condenser lens is not contaminated by the glass powder.

Although the glass fiber-containing epoxy substrate of the hybrid IC has been described in this embodiment, it goes without saying that the circuit substrate can be divided into circuit substrates for other purposes as long as the circuit substrate is a plastic substrate.

[0013]

As described above, the method for dividing a circuit board according to the present invention uses a laser beam as a heating means and can blow oxygen gas containing glass powder onto a portion of the circuit board to be divided. Therefore, a punching die for dividing the circuit board is not required, and the development period of the hybrid IC or the like is short, and the cost can be reduced. In addition, a hybrid IC is added to the carbonized layer generated by heating as in the conventional laser beam processing method.
This has the effect of not causing the generation of carbon dust from the package or the deterioration of insulation.

[Brief description of drawings]

FIG. 1 is a sectional view of a first embodiment according to the present invention.

FIG. 2 is a sectional view of a second embodiment according to the present invention.

FIG. 3 is a cross-sectional view of a laser-processed portion of a hybrid IC formed separately according to the present invention.

FIG. 4 is a cross-sectional view showing a divided state of a circuit board by a conventional split mold.

FIG. 5 is a sectional view of a conventional method of blowing compressed air.

FIG. 6 is a cross-sectional view of a laser processing portion of a hybrid IC divided and formed by a conventional method of blowing compressed air.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Circuit board 2 Stage 3 Condenser lens 4 Laser beam 5, 5 'Gas inlet 6, 6' Blow-out nozzle 7 Hybrid IC 8 Epoxy resin carbonized layer 9 Glass layer 10 Lower mold 11 Upper mold 12 Surface mount parts 13 Pads 14 Punch 15 Compressed air inlet

Claims (6)

[Claims] 1. A method for dividing a circuit board, comprising: performing laser processing while blowing oxygen gas containing glass powder onto a portion of the circuit board where the circuit board is to be divided. 2. The method for dividing a circuit board according to claim 1, wherein the circuit board is made of epoxy resin. 3. The glass powder has a particle size of 10 to 100 μm.
The method for dividing a circuit board according to claim 1, wherein m is m. 4. The method for dividing a circuit board according to claim 1, wherein laser processing is performed so that a divided cross section of the circuit board is covered with a glass layer in which the glass powder is melted. 5. The method for dividing a circuit board according to claim 1, wherein the blowing direction of the oxygen gas containing the glass powder and the laser direction of the laser processing are in the same direction and on the same axis. 6. The method for dividing a circuit board according to claim 1, wherein the blowing direction of the oxygen gas containing the glass powder and the direction of the laser beam in the laser processing are on different axes in different directions.