JPH04129263A - Trimming of semiconductor element - Google Patents

Abstract

PURPOSE:To make it possible to cut another resistor while one resistor is cooled after the resistor is trimmed by a method wherein identical trimming resistors are arranged on the both ends of a thick film circuit board, with the resistors being divided into two parts and alternately undergo laser trimming. CONSTITUTION:At first, a hybrid IC is set to operation, and one thick film resistor 3a is cut only a little by a laser while the voltage value on the position to be adjusted is monitored, thereby increasing the resistance value of the thick film resistor 3a and changing the voltage value at the position to be adjusted. A thick film circuit board 1 is heated by the laser in this instance, and then, another thick film resistor 3a is burned off only a little bit by a laser while the heat near the resistor 3a is radiated. By alternately repeating the operation stated above, the trimming will be terminated when the voltage value on the position to be adjusted reaches the target value.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for laser trimming a hybrid IC.

[Conventional technology]

FIG. 2 is a plan view showing a conventional laser trimming method for a hybrid IC. In FIG. This is a thick film resistor for trimming formed on a thick film substrate 1.

Next, the operation will be explained. First, the hybrid IC is brought into operation, and while monitoring the voltage value at the adjustment point, the thick film resistor 3 is slightly burned out with a laser. As a result, the resistance value of the thick film resistor 3 increases, and the voltage value at the adjustment location changes.

Next, the IC on the thick film substrate 1 is heated by the laser.
In order to prevent the chip 2 from being heated and changing its characteristics, one or more operations are repeated to burn out the thick film resistor 3 again after the heat of the thick film substrate 1 has decreased and the characteristics of the IC chip 2 have stabilized. , trimming is completed when the voltage value at the adjustment point reaches the target value.

[Problem to be solved by the invention]

In the conventional laser trimming method, a small amount of trimming is performed as described above, and then a small amount of trimming is performed again after waiting for the temperature of the hybrid IC to decrease, which takes a very long time.

This invention was made to solve the above-mentioned problems, and aims to reduce the waiting time until the temperature of a hybrid IC becomes stable.

[Means to solve the problem]

In the hybrid IC laser trimming method according to the present invention, the same trimming resistor is divided into two parts and arranged at both ends of a thick film substrate, and laser trimming is performed alternately.

[Effect]

In the laser trimming method for a hybrid IC configured as described above, after trimming one resistor, the other resistor can be cut while dissipating heat, so the waiting time is shorter than in the conventional method. becomes less,
Laser trimming can be done in a short time.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
3a is a plan view showing the laser trimming method for a hybrid IC according to the present invention.

Reference numeral 3b denotes a thick film resistor for trimming divided into two pieces formed at both ends of the thick film substrate 1.

Incidentally, the same parts as in the conventional example are denoted by the same reference numerals, and the explanation thereof will be omitted.

Next, the operation will be explained. First, the hybrid IC is put into operation, and while monitoring the voltage value at the adjustment point, one thick film resistor 3a is slightly burnt out with a laser. As a result, the resistance value of the thick film resistor 3a increases, and the voltage value at the adjustment point Mm changes. At this time, the thick film substrate 1 is heated by the heat of the laser, and while the heat in the vicinity of the thick film resistor 3a is being radiated, the other thick film resistor 3b is then slightly burned off by the laser. From this, thick film resistor 3b
The resistance value increases, and the voltage value at the adjustment point changes further. Further, while heat is being dissipated near the thick film resistor 3b, next, the thick film resistor 3a is slightly burnt out by a laser. By repeating the above operations alternately, trimming is completed when the voltage value at the adjustment location reaches the target value.

〔Effect of the invention〕

As described above, according to the present invention, the trimming resistor is divided into two parts and the trimming is performed alternately, so there is no need to insert an extra waiting time while the thick film resistor is burned out by the laser, and the trimming resistor can be trimmed in half. It has the effect of being able to shorten the time.

[Brief explanation of drawings]

FIG. 1 is a plan view showing a hybrid IC laser trimming method according to an embodiment of the present invention, and FIG. 2 is a plan view showing a conventional hybrid IC laser trimming method. In the figure, 1 is a thick film substrate, 2 is an IC 53a, and 3b is a thick film resistor. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] A method for laser trimming a hybrid IC, which comprises dividing a thick film resistor to be trimmed into two parts and baking them onto a thick film substrate, and cutting the two resistors alternately.