JPH0567728A - Function trimming method for hybrid integrated circuit - Google Patents

Abstract

PURPOSE:To shorten a trimming time by making a cutting amount greater when the measuring value of characteristics is greatly deviated from a target value and making it increasingly smaller as the deviation becomes smaller. CONSTITUTION:When a characteristic value is adjusted by cutting the intermediate part of the electrodes 13 and 14 of the adjusting resistor 12 in the direction indicated by a line 15 for a hybrid integrated circuit 2, the characteristic value C is measured, the difference between the characteristic value C and a target value CG is obtained, and the product of such a difference multiplied by the rate of change DELTAC of the characteristic value is defined as the next cutting amount. In other words, if the difference between the target value CG and the measured value C is great, the cutting amount L is made larger. If the difference is small, the cutting amount is made smaller so that no over cutting will ensue. Therefore, compared to a case where a cutting is executed each by a cutting amount of DELTAL from the beginning so as not to create any over cutting, the number of cuttings and that of measurements are curtailed to shorten the time required for trimming.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a function trimming method in which the amplification characteristic of, for example, an amplifier formed as a hybrid integrated circuit is cut to a target by cutting off a part of its thick film or thin film resistance with a laser or the like. Regarding

[0002]

2. Description of the Related Art For example, an amplifier 11 as shown in FIG. 2A is constructed as a hybrid integrated circuit, and a thick film included in the amplifier 11 cuts and removes a part of an adjusting resistor 12 formed of a thin film. Therefore, the amplifier 11
Of the output waveform, for example, the rising and falling characteristics of the output waveform are adjusted.

For example, as shown in FIG. 2B, the relationship between the value of the rising characteristic of the amplifier 11 and the disconnection amount of the adjusting resistor 12 is influenced by the removal amount of the resistor when it is far from the target value, for example. The characteristics are small, and the characteristics greatly change with a slight removal amount as the target value is approached.

[0004]

A part of the adjusting resistor 12 is usually removed by irradiating a laser, and the cutting removal rate is usually about 0.5 to 20 mm / s. If the speed at which the characteristic of the amplifier 11 is measured is sufficiently high with respect to this cutting / removing speed, the characteristic is simultaneously measured while cutting / removing the resistor to determine whether or not the characteristic has reached the target value. Since a judgment can be made, high-speed continuous cutting trimming can be executed.

However, if it takes a relatively long time to measure the characteristic, for example, 0.2 to 0.5 seconds, if cutting and removing are performed at the same time as the measurement, an overcut, that is, an allowable value from the target characteristic value is obtained. There was a risk of passing through the above, and cutting and removal could not be performed while measuring. In this case,
Conventionally, step cutting trimming is performed in which the minimum cutting amount that does not cause overcut is determined and the process of "cutting only the minimum cutting amount-characteristic measurement-judgment of the measurement" is repeated. As a result, the number of measurements required to reach the target value increases, and there is a problem that trimming takes a long time.

[0006]

According to the present invention, in step cutting trimming, the difference between the target value and the measured value is obtained, and the next trimming amount (cutting removal amount) is reduced as the difference becomes smaller.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to FIG. Now, the adjustment resistor 12 of the mixed integrated circuit has the shape shown in FIG. 1A, and when the characteristic value is adjusted while cutting the intermediate portion of the electrodes 13 and 14 at both ends in the direction indicated by the line 15, It is assumed that the relationship between the cutting amount and the characteristic value is in the state shown in FIG. 1B. In the relationship between the cutting amount and the characteristic value, the cutting amount ΔL with respect to the allowable characteristic value amount ΔC at the target value C _G
Ratio, that is, the rate of change of the characteristic value near the target value Δ
S = ΔC / ΔL is experimentally obtained in advance.

In actual trimming, the characteristic value C is measured, the difference between the measured value C and the target value C _G is obtained, and the product of the difference and the characteristic value change rate ΔS is taken as the next cutting amount. For example, when the characteristic value change rate ΔS is 1.0, the target value C _G is 3.00, and the first measured value C is 2.72, the cutting amount L in the first step is L.
Is 0.28 mm. Hereinafter, the measured value C and the cut amount L for each cutting, measurement and determination are as follows, for example.

[0009] step number _{(C G - C) × ΔS} = L (mm) 1 3.00 - 2.72 × 1.0 = 0.28 2 3.00 - 2.75 × 1.0 = 0.25・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ N-1 3.00 − 2.82 × 1.0 = 0.18 N 3.00 − 2.92 × 1.0 = 0.08 In this numerical example The state of cutting at each step is shown in FIG. 1A with line 15 and step numbers.

As described above, according to the present invention, when the difference between the target value C _G and the measured value C is large, the cutting amount L is made large, and when the difference is small, the cutting amount L is made small to prevent overcutting. To Therefore, the number of times of cutting and the number of times of measurement are remarkably reduced, and the time required for trimming can be remarkably shortened, as compared with the case where the cutting amount is cut by ΔL from the beginning so that overcut does not occur.

The present invention is effective, for example, when the rising and falling edges of the output waveform in a high-speed pulse amplifier composed of a hybrid integrated circuit are measured with a digital oscilloscope and trimmed to obtain the desired characteristics. is there.

[0012]

As described above, according to the present invention, when the characteristic measured value is largely deviated from the target value, a large cutting amount is set, and the cutting amount is reduced as the deviation becomes smaller, so that the cutting In step cutting trimming, which requires a long time for the characteristic measurement and the determination with respect to the speed, the trimming time can be significantly shortened as compared with the conventional case.

[Brief description of drawings]

1A is a plan view showing an example of an adjustment resistance and a cutting amount for each trimming step, and FIG. 1B is a diagram showing an example of a relationship between a characteristic value, a cutting amount, and a cutting amount for each step.

FIG. 2A is an equivalent circuit diagram of an amplifier configured by a mixed integrated circuit, and B is a diagram showing a relationship between a characteristic value thereof and a cut amount of an adjustment resistor.

Claims (1)

[Claims] 1. A function trimming method for a hybrid integrated circuit, characterized in that a difference between a target value and a measured value is obtained, and the next trimming amount is reduced as the difference becomes smaller.