JPH07105585B2 - Laser processing method for electronic circuit board - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit pattern processing by a laser on a copper foil-clad insulating substrate used for an electronic circuit substrate.

[0002]

2. Description of the Related Art Electronic circuit boards for trial production or small-scale production before the start of mass production are manufactured by etching or cutting.

However, the etching process requires the same steps and time as those in mass production, and the cutting process cuts more than the thickness of the copper foil to process the insulating substrate in order to avoid insulation failure. In the case of an insulating substrate having a high hardness as described above, there is a problem that the processing speed cannot be increased in view of the tool life.

On the other hand, there is a method of removing the copper foil on the insulating substrate by using the thermal energy of a YAG laser having a high absorption property for copper. FIG. 4 is a block diagram of a processing apparatus based on this method, and FIG. 5 is an explanatory view of a circuit pattern processing method by this method. In FIG. 4, 1 is a YAG laser oscillator, 2 is a Q switch, 3 is an XY table, 4 is a copper foil-bonded insulating substrate, and 5 is an XY table motor drive device.
Is a numerical controller for the XY table. In FIG. 4, 8 is a circuit pattern, 9 is a scanning line of a laser beam, 10 is a position where the laser output is stopped by the Q switch, and 11 is a position where the laser output is started. In this way, opening and closing of the laser output is alternately repeated on the scanning line, and the scanning line is moved at a constant pitch in the Y-axis direction to form a circuit pattern. This method does not require pretreatment such as etching, and unlike cutting, there is no need to change the processing speed depending on the hardness of the insulating substrate.

However, as shown in FIG. 5, in the conventional numerical control method, the circuit pattern is processed by alternately outputting the XY table movement command and the laser output control command.
At the start and end positions of the circuit pattern, the XY table is in the decelerating, stopping and accelerating states as shown in the velocity diagram of 16, so that the energy per unit time becomes larger than that in the constant velocity state and the insulating substrate is It had the drawback of being damaged.

[0006]

The problem to be solved is that, in the circuit pattern forming process of the copper foil-clad insulating substrate using the laser oscillator and the XY table, the start and end positions of the circuit pattern are The damage is even to the insulating substrate.

[0007]

In the present invention, in order to prevent damage to the insulating substrate, the laser energy is uniformly applied to the copper foil removed portion other than the circuit pattern.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram of the device of the present invention, showing a signal input / output system. 1 to 6 are the same as those in FIG. 4, and 7 is a computer.

Pulses from the rotary encoder of the motor are transmitted from the XY table drive unit, and command signals indicating the start and end of the scanning are transmitted from the numerical control unit to the computer. Sends a laser output control command signal to the gate of the Q switch.

FIG. 2 shows a processing method according to the present invention, and 8 to 11 are the same as those in FIG. The pulses 12 input from the rotary encoder in proportion to the feed amount of the XY table 3 in the X-axis direction are counted by a computer and the absolute value of the position data 13 converted into the number of pulses in advance is calculated. It is judged whether or not the start position and end position of the pattern have been reached by comparing with the value, and if the sign of the position data is negative, the laser output is stopped to the Q switch 2, and if the sign is positive, the output start signal. 14 is sent.

With the above method, the copper foil other than the circuit pattern is uniformly irradiated with the laser light. However, since the peeling of the copper foil is not sufficient with this alone, after the scanning of the entire surface of the substrate is completed, the process shown in FIG. As described above, trimming is performed by irradiating a laser beam along the circuit pattern to promote peeling of the removed copper foil portion other than the pattern portion and complete removal by buffing.

In this example, the lamp current is 30.6-3.
0.8A laser output, 96 table feed speed in X direction
mm / sec, Y-direction feed pitch of 0.8 mm, Q switch frequency of 5 KHz, and then full-scale scanning, then lamp current of 28.0
When trimming was performed at A and Q switch frequencies of 5 KHz and a feed rate of 20 mm / sec, and further finishing was performed with a buff, the laser irradiation part was peeled off and a circuit pattern with little damage was obtained.

As described above, in the circuit pattern processing of the copper foil-clad insulating substrate according to the present invention, it is not necessary to provide a pre-process for making a mask such as etching, and immediately based on the processing information created from the design information. It has the advantage of being put into processing. Moreover, since there is no problem of quality control of chemicals and waste liquid treatment, this method is suitable for small-scale production such as production of prototype boards.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration and a signal system of a circuit pattern processing device according to the present invention.

FIG. 2 is an explanatory diagram showing the principle of circuit pattern formation according to the present invention.

FIG. 3 is an explanatory diagram showing the principle of circuit pattern formation according to the present invention.

FIG. 4 is a diagram showing a configuration and a signal system of a conventional circuit pattern processing device that does not use the present invention.

FIG. 5 is an explanatory diagram showing the principle of circuit pattern formation by a conventional method.

[Explanation of symbols]

 1 Laser Oscillator 2 Q Switch 3 XY Table 4 Copper Foil Insulated Substrate 5 XY Table Motor Drive Device 6 XY Table Numerical Control Device 7 Computer 8 Circuit Pattern 9 Laser Beam Scan Line 10 Laser Output Stop Position 11 Laser Output Start Position 12 Pulse from Rotary Encoder 13 Circuit Pattern Position Data 14 Laser Output Control Command Signal 15 XY Table Velocity Diagram

Claims (1)

[Claims] 1. A YAG laser oscillator, a Q switch, and an X-
For laser processing machine consisting of Y table and computer
In the laser processing method of the electronic circuit board according to the above, by counting the position data of the circuit pattern created based on the information from the electronic circuit CAD or the image scanner in advance and the pulse output from the rotary encoder of the XY table, By comparing the position data of the obtained table and controlling the opening and closing of the laser output with the Q switch, the thickness of the copper foil other than the circuit pattern of the copper foil-clad insulating substrate is uniformly reduced, and then the thickness is buffed. by removing the reduced copper foil, an electronic circuit which is characterized in that the circuit pattern formed without damaging the insulating substrate supporting the copper foil
Laser processing method for substrates .