JPS61152055A - Resistance adjusting method for thick-film resistance element - Google Patents

Abstract

PURPOSE:To accomplish high-precision, high-reliability adjustment toward decreasing the resistance value of a thick-film resistance element, once subjected to a baking process, by a method wherein a DC voltage is applied across both ends of the once- baked thick-film resistance element and the current generated by the voltage is subjected to measurement during the application of a beam to raise the temperature of the resistance element. CONSTITUTION:A voltage is applied to a trimming laser 7 for increasing the resistance of a resistance element 2 or 8 positioned on a substrate 1 or for a beam 4 for decreasing the resistance of the same. The mechanism is so arranged as to determine the value of resistance by measuring the current generated by an applied voltage whereunder the value will increase or decrease. A DC voltage out of a power source 5 is applied across conductors 3 made of silver-palladium or the like connected to both ends of the thick-film resistance element 2. The resistance presented by the resistance element 2 is determined by measuring the current through the resistance element 2 by means of the ammeter 6. The elevated temperature attributable to the resistance- decreasing beam 4 thrown upon the element 2 causes silver out of the silver-palladium combination constituting the electrodes 3 to diffuse into the resistance element 2, which decreases the resistance to a target value.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to fine adjustment of a thick film resistor, and particularly relates to a thick film resistor that can be used when adjusting the resistance value from a high value to a low value. I was inspired by the way the body adjusts its resistance.

[Background of the invention]

Such a conventional resistance value adjusting device is disclosed in Japanese Patent Publication No. 47-2593.
As described in Japanese Patent No. 9, a high pulsed voltage is applied to a resistor to change its resistance value. However, according to this method, the resistance value can only be changed digitally, and since the amount of change in the resistance value with respect to one pulse is not constant, stable adjustment cannot always be performed. Furthermore, in terms of the reliability of the resistor, high voltage is applied to the resistor in pulses and shock is applied, which puts the resistor in a destructive mode. As described above, in the conventional technology, consideration has not been given to highly accurate adjustment and reliability.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for adjusting the resistance value of a thick film resistor, which can adjust the resistance value of a fired thick film resistor with high accuracy and reliability in a direction in which the resistance value decreases.

[Summary of the invention]

The outline of the present invention is to apply a DC voltage to both ends of a fired thick film resistor, and use the resulting current to measure the resistance value and at the same time cause ions to move. The silver in the conductor, such as silver parasilum, is made to diffuse easily, and the temperature of the resistor is raised to 800°C or the temperature at which glass melts using the beam method, causing the diffusion of silver. In this way, the resistance value of the thick film resistor is lowered.

Note that the color of the resistor is preferably black.

[Embodiments of the invention]

The present invention will now be described in detail with reference to the drawings.

FIG. 1 is a perspective view showing one embodiment of the present invention, and FIG. 2 is a perspective view showing one embodiment of the present invention.
It is an A-AM sectional view in a figure.

In these figures, 1 is the substrate, 2 is the thick paper antibody, and 3
is a conductor, 4 is a laser beam, 5 is a power supply, 6 is an ammeter, 7
8 is a trimming laser, and 8 is a thick film resistor.

First, this device shown in FIG. 1 is for finely adjusting the resistance value of a resistor. This device uses two types of beams: a trimming laser 7 to increase the resistance value of the resistor, and a beam 4 (for example, a laser beam, a light beam, an infrared beam) to lower the resistance value, and a trimming laser 7 to increase the resistance value of the resistor. This device has a mechanism that measures the resistance value by applying a voltage and measuring the current flowing as a result, and has a structure that allows the resistance value of the resistor to be freely raised or lowered.

The method of using this device is to place a thick film resistor 2 on a substrate 1.
, 8 are fired to the target resistance value. At this time, due to errors in firing and variations in resistors, it is unlikely that all resistors will reach the target value. Therefore, using this device, the trimming laser 7 is used for the resistor 8 having a low resistance value, and the laser beam 4 for lowering the resistance value is used for the resistor 2 having a high resistance value for fine adjustment. This results in a resistor that does not require fine adjustment. Additionally, there are far fewer resistors to trim;
Even if you do this, you won't have to carve deeply, and defects will be less likely to occur.

The adjustment operation for lowering the resistance value will be specifically explained below. The resistance value of the resistor 2 is measured by applying a DC voltage to a conductor 3 such as silver valadinium connected to both ends of the thick film resistor 2 using a power source 5 and reading the current value using an ammeter 6.

Then, by irradiating the resistor 2 with a laser beam and heating it, silver in the silver-valadinium component, which is the conductor 3, is caused to diffuse within the resistor 2, and its resistance value is lowered to the target value. let

〔Effect of the invention〕

According to the present invention, the resistance value of a thick-film resistor that has been fired once can be lowered by heating the resistor with a current flowing through the resistor and a beam method without applying a shock to the resistor. It is possible to reach the target value. Therefore, since the area of the resistor can be fully utilized, power is consumed over the entire area, which makes it difficult for the resistor to burn out, which also makes it possible to increase the packaging density.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing one embodiment of the present invention, and FIG. 2 is a perspective view showing one embodiment of the present invention.
It is an A-AM sectional view in the figure. Description of symbols 1... Substrate, 2... Thick film resistor, 3... Conductor, 4... Laser beam, 5... Power supply, 6... Ammeter, 7... Trimming laser , 8... Thick film resistor.

Claims (1)

[Claims] While measuring the resistance value of the fired thick film resistor by the value of the current generated by applying a potential difference between conductors containing silver palladium etc. connected to both ends of the resistor, the entire surface or A method for adjusting the resistance value of a thick film resistor, characterized by lowering and adjusting the resistance value of the resistor by applying heat to a part of the resistor using a beam method.