JPS62169401A - Manufacture of thick film resistance element - Google Patents

Abstract

(57) [Summary] 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 relates to a method for manufacturing a thick film resistor, and particularly to a method for stabilizing the resistance value.

(Prior art and its problems) Thick films are easy to manufacture, inexpensive, and have high mechanical strength, so they are widely used in various devices.

For example, the W-model thermal head selectively applies electric pulses of a certain magnitude and power value (according to image information) to a heating resistor element made of a thick film resistor to generate heat to a desired temperature. This is what I did. This thick film resistor is
Generally, when the applied power is large, the resistance value gradually changes.

Therefore, the resistance value changes during use, and the applied density changes due to the change in the heat generating area, resulting in the inconvenience that it becomes impossible to record image information faithfully.

Therefore, a method has been proposed in which, prior to use, a pulse is applied to the thick film resistor for a certain period of time to stabilize the resistance value.

However, these methods require a long working time per substrate and cannot provide sufficient reliability.

This holds true not only for thick-film thermal heads but also for other devices using thick-film resistors.

The present invention was made in view of the above-mentioned circumstances, and an object of the present invention is to provide a thick film resistor whose resistance value is stable and shows little change over time even when energized for a long time or used at relatively high power. shall be.

[Means for Solving the Problems] Therefore, the present invention introduces a high-temperature leaving step of forming a thick film resistor by printing and baking and then leaving it at a high temperature for a predetermined period of time.

[Function] As a result of various experiments, the inventors of the present invention found that by leaving the thick film resistor under high temperature for a predetermined period of time after firing, the change in resistance value over time can be reduced.

The present invention has been made with this in mind, and by adding a high temperature leaving step at 200 to 400'C for 30 to 60 minutes after firing the thick film resistor, the resistance value can be stabilized. It was designed to measure the

(Example) Hereinafter, examples of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram showing an outline of a thick film type thermal head formed by the method of the embodiment of the present invention, and FIG. 2 is a sectional view taken along line AA in FIG. This thick-film thermal head has gold electrode patterns 12 arranged in a staggered manner on a ceramic substrate 11, and a resistor pattern 13 formed on the top layer of which the main components are ruthenium oxide and glass. It is equipped with a driving IC (not shown).

The manufacturing method will be described below.

First, after forming a gold electrode pattern 2 with an inter-electrode distance d=0.3x and a wiring pattern (not shown) on a braced ceramic substrate by screen printing and firing, further, on the gold electrode pattern 2, By performing screen printing and baking using a resistance paste mainly composed of ruthenium oxide and glass to form a resistor pattern 3 with a width W = 0.2a+, and further forming a wear-resistant layer (not shown) V4 layer. , forming a thick film resistor circuit. The firing temperatures for the gold electrode pattern and resistor pattern at this time were 900"C and 870"C, respectively (both peak temperatures).
The firing time was 60 minutes in both cases.

At this time, the resistance value of the thick film resistor between two adjacent electrodes is 2
．． It was 3Ω.

Subsequently, the ceramic substrate on which the thick film resistor circuit was formed as described above was left in an infrared furnace maintained at 300'C for 1 hour, and then taken out and a driving IC (not shown) was placed there.
etc. are mounted at predetermined positions on the ceramic substrate.

In this way, it is possible to obtain a stable thick-film type thermal head with a small change in resistance value over time.

A 5011z, 1m5ec rectangular wave is applied to this thick film thermal head every minute at 0. The third table shows the measurement results of the resistance change rate when performing an acceleration test while increasing the power by IW.
As shown in the figure. In Figure 3, the vertical axis is the resistance change rate (ΔR/R>
, the horizontal axis shows the applied voltage horn.

Incidentally, FIG. 4 shows the results of a similar test performed on a conventional thick film type thermal head that was formed without performing the above-mentioned 300'01 hour high temperature standing process.

From these comparisons, it can be seen that the method of the present invention significantly reduces resistance value changes, has excellent pulse resistance characteristics, has small changes in resistance value over time, and is highly reliable.

Further, FIG. 5 shows the relationship between the storage temperature in the high-temperature storage step and the pulse resistance characteristic as a rate of resistance change. In Figure 5, the vertical axis shows the resistance change rate, the horizontal axis shows the applied power, and curves a to g are measurement curves for thick-film thermal heads subjected to a high-temperature exposure process under the conditions shown in the table below. It is.

From this figure, the table shows that during the incubation process! 2!13! I! It can be seen that the humidity is preferably 200 to 400°C.

Further, the material of the resistor pattern is not limited to the examples, and it goes without saying that the method of the present invention is effective for all thick film resistor patterns.

Furthermore, this method is effective for all devices using thick film resistors, such as thick film thermal heads and hybrid ICs.

[Effects] As explained above, according to the method of the present invention, after the thick film resistor is stamped and fired, the thick film resistor is left at a high temperature for a predetermined period of time, so that the thick film resistor can last for a long time. A very stable resistance value can be maintained over time.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a thick film type thermal head formed by the method of the embodiment of the present invention, and FIG. 2 is an A-A diagram of FIG.
3 is a cross-sectional view showing the relationship between the resistance change rate and the applied power when a voltage is applied to the thick-film thermal head formed by the method of the embodiment of the present invention, and FIG. 4 is a diagram showing the relationship between the rate of resistance change and the applied power A diagram showing the relationship between the resistance change rate and applied power when voltage is applied to a thick film thermal head formed by the method,
FIG. 5 is a diagram showing the relationship between treatment temperature and resistance change rate in the high temperature leaving step. 1... Ceramic substrate, 2... Gold electrode pattern, 3
...Resistor pattern.

Claims (1)

[Claims] A method for manufacturing a thick film resistor formed by printing and firing, comprising a high temperature treatment step of leaving the resistor at a high temperature for a predetermined period of time after printing and firing. manufacturing method.