JPH0354804A - laser trimming method - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention is directed to adjusting the resistance value of an electronic circuit to a set value.
The present invention relates to a resistor trimming method.

BACKGROUND OF THE INVENTION In recent years, laser trimming methods have been required to be highly functional as a technology essential to the spread of HICs as electronic circuit boards become more densely packaged and more highly functional.

The conventional laser trimming method described above will be described below with reference to the drawings.

FIG. 4 shows a schematic diagram of a resistor cut by a conventional laser trimming method. In Figure 4, 13
．． 14 is a conductor electrode which functions as a resistance terminal. 15 is a resistor, 16 is a trace of laser processing, and 17 is a laser beam irradiation spot.

The principle of the laser trimming method configured as described above will be explained below.

The resistance value of the resistor 15 is lower than the target value, and a laser beam is irradiated from the outside of the resistor to scan the spot 17 in the direction of the arrow. At that time laser trace 16
Since the cross-sectional area of the resistor decreases, the resistance value increases. Eventually, when the target resistance value and the current resistance value match, this operation is stopped.

Problems to be Solved by the Invention However, the trimming method described above burns out the resistor and narrows the area where the current flows, so it is possible to increase the resistance value, but it is not possible to decrease it. It had

In view of the above problems, the present invention provides a laser trimming method that can lower the resistance value.

Means for Solving the Problems In order to solve the above problems, the laser trimming method of the present invention includes a step of scanning a laser beam in the longitudinal direction of the object to be trimmed, that is, the resistor.

Effect of the present invention The above-mentioned structure enables partial firing of a part of the object to be trimmed, that is, a part of the resistor in the longitudinal direction, so that a part exhibiting a low resistance value can be partially formed, so that the resistance value can be reduced in the lower direction. It is possible to trim to.

EXAMPLE Hereinafter, a laser trimming method according to an example of the present invention will be explained with reference to the drawings.

FIG. 1 shows a main structural diagram of a laser trimming device for realizing a laser trimming method according to an embodiment of the present invention. In Figure 1, 1 is the object to be trimmed, that is, a resistor, 2 is a substrate for shaping the resistor, 3 is a YAG laser oscillator for processing, 4 is a galvanometer optical system for scanning the laser beam, and 5 is a laser oscillator. and a laser controller for controlling the optical system; 6 is a resistance measuring device for measuring the resistance value of the resistor; 7 is a main controller for controlling the entire apparatus.

The operation of the laser trimming device configured as described above will be described below with reference to FIGS. 1 and 2.

First, FIG. 2 shows the state of trimming of a resistor, in which 8 is a resistor, 9 and 10 are conductor patterns, 1l is a laser beam irradiation spot, and 2 is a scanning trace of a laser beam.

Furthermore, FIG. 3 shows the characteristics of the resistor material and shows the relationship between the firing temperature and the resistance value in the firing process, which is the main step in forming the resistor.

As described above, according to this embodiment, when the resistance value of the resistor burnt out at temperature T1 in FIG. By heating, the same effect as firing at the firing temperature T2 is obtained, and the resistance value becomes R2, which is lower than R, and resistance 1 rimming can be performed to lower the resistance value.

Effects of the Invention As described above, in the present invention, by scanning the laser beam in the longitudinal direction of the resistor, it is possible to partially advance firing and trim the resistance value to a low value.

[Brief explanation of drawings]

FIG. 1 is a main configuration diagram of a laser trimming device according to an embodiment of the present invention, FIG. 2 is an explanatory diagram of a resistor body trimmed by a laser trimming method according to an embodiment of the present invention, and FIG. FIG. 4 is a diagram showing the relationship between firing temperature and resistance value of a resistor, and is an explanatory diagram of a resistor trimmed by a conventional laser trimming method. 1...Resistor, 2...Circuit board, 3.
...Laser oscillator, 4...Scanning optical system, l2...Laser trace.

Claims (2)

[Claims] (1) A laser trimming method for trimming the resistance value of an object to be trimmed formed in an electronic circuit to a predetermined resistance value, the method comprising firing a part of the resistor with a laser beam. (2) The laser trimming method according to claim 1, wherein the laser beam is scanned in the longitudinal direction of the resistor.