JPH01187902A - Thin film resistor - Google Patents

Abstract

PURPOSE:To slightly vary the resistance value of a thin film resistor and to accurately trim it in a short time by trimming it from the end which is the nearest to an electrode wiring layer of a trimming land in a direction of obliquely cutting the land. CONSTITUTION:A thin film resistor 1 having a trimming land 11 and an electrode wiring layer 2 adhered to the part of the resistor 1 are provided, an the resistor 1 is trimmed from the end which is the nearest to the layer 2 of the land 11 in a direction of obliquely cutting the land 11. For example, a voltage applied to both the ends of the original resistor 1 is measured while continuously supplying a constant current from a constant-current source 3 to the resistor 1. Then, the land 11 of the resistor 1 is cut by a laser beam. In this case, the resistor 1 is cut from the end which is the nearest to the layer 2 of the land 11 in a direction of the cutting oblique to the direction of a current. When the read of a voltmeter becomes a value to be obtained, the trimming is finished.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a trimming structure for a thin film resistor formed on a substrate.

Conventional technology In recent years, A/D and D/A converters have come into widespread use, and in order to improve the relative accuracy between resistors, thin film resistors formed on semiconductor substrates are trimmed using laser beams. This method has come to be used.

The conventional method of trimming a thin film resistor and the shape of the thin film resistor after trimming will be described below with reference to the conceptual plan view of FIG. 5 is a thin film resistor, 6 is an electrode wiring layer, 7 is a current source, and 8 is a voltmeter. Below, the steps of the conventional method will be explained.

First, while continuing to supply a constant current into the thin film resistor 5 with a constant current source 7 connected to an electrode wiring layer bonded to a part of the thin film resistor, the voltage applied across the initial thin film resistor is measured. Next, while keeping the current of the constant current source constant and looking at the scale of the voltmeter, use a laser beam to cut the end of the trimming land of the thin film resistor closest to the electrode layer parallel to the current. .When the voltmeter scale reaches the desired value, finish trimming with the laser beam.

Problems to be Solved by the Invention However, in the conventional method described above, as shown in Figure 2, in order to make cuts in the thin film resistor parallel to the direction of the current, the resistance value can be changed simply by irradiating it with a laser beam. There is a problem in that trimming by the laser beam must be completed at a voltage value that is significantly smaller than the desired voltage value.

The present invention solves the above-mentioned conventional problems, and aims to provide a trimming structure that can gradually change the resistance value of a thin film resistor.

Means for Solving the Problems To achieve this object, the present invention provides a structure in which the trimming land of the thin film resistor is trimmed diagonally from the end of the trimming land of the thin film resistor that is closest to the electrode wiring layer. It is.

Effect: According to the present invention, accurate trimming can be performed in a short time.

EXAMPLE An example of the present invention will be described below with reference to the drawings.

FIG. 1 is a conceptual plan view showing a trimming structure of a thin film resistor using a laser beam in one embodiment of the present invention. In FIG. 1, 1 is a thin film resistor, 2 is an electrode wiring layer, 3 is a current source, and 4 is a voltmeter.

Next, the procedure for trimming the thin film resistor of this embodiment will be explained below. First, while continuing to supply a constant current to the thin film resistor 1 from the constant current source 3 connected to the electrode wiring layer 2 bonded to a part of the thin film resistor 1, the initial voltage applied to both ends of the thin film resistor 1 is adjusted. Measure. Next, while keeping the current of the constant current source constant and watching the voltmeter, cut into the trimming land 11 of the thin film resistor 1 using a laser beam. Starting from the end closest to the electrode wiring layer 2 of No. 11, make a cut in a direction diagonal to the direction of current flow. is directly proportional to the distance of the notch.

When the voltmeter scale reaches the desired value, trimming with the laser beam is finished.

Effects of the Invention As described above, according to the present invention, when trimming a thin film resistor, the direction in which the trimming land of the thin film resistor is cut diagonally from the end of the trimming land of the thin film resistor that is closest to the electrode wiring layer. By trimming with , you can achieve accurate trimming in a short time.

[Brief explanation of the drawing]

FIG. 1 is a conceptual plan view showing a trimming structure of a thin film resistor in an embodiment of the present invention, and FIG. 2 is a conceptual plan view of a trimming structure of a conventional thin film resistor. 1.5... thin film resistor, 2,6... electrode wiring layer, 3,7... constant current source, 4,8...
...Voltmeter, 11...Trimming land. Name of agent: Patent attorney Toshio Nakao and 1 other person
! , vL body 2- with pole arrangement tIL/% 3-m constant current source Fig. 2

Claims (1)

[Claims] A thin film resistor having a trimming land and an electrode wiring layer bonded to a part of the thin film resistor are provided, and the trimming land of the thin film resistor is connected from the end of the trimming land of the thin film resistor closest to the electrode wiring layer. A thin film resistor characterized by being trimmed in a diagonal direction.