JPH0345882B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for trimming thick film or thin film resistor elements fabricated on ceramic substrates or the like.

BACKGROUND ART In recent years, as devices have become smaller, electronic components have also been mounted in higher density. One of the implementation methods
One of them is hybrid IC (hereinafter referred to as HIC).
The method for manufacturing the resistor used in this HIC is to form resistor electrodes and wiring patterns on a ceramic substrate, and then form the resistor by printing or vapor deposition. However, the resistance value of the fabricated resistor is
Variations occur depending on firing or vapor deposition conditions.
Therefore, in order to set the resistance value of the resistor to a desired value, the resistor is trimmed to increase the resistance value and obtain the desired resistance value. This resistance value adjustment involves element trimming, which trims the resistance value of a single resistor itself to a predetermined value, and the adjustment of the resistor to a predetermined value while operating the circuit and measuring its circuit characteristics (oscillation frequency, etc.). There are two types of trimming functions. In recent years, there has been a trend toward higher density mounting of resistors and miniaturization of resistors, and thus adjustment of resistance values by trimming is becoming increasingly important.

Hereinafter, a conventional method for trimming a resistor will be described with reference to the drawings. FIG. 5 is a block diagram for explaining the conventional method of trimming a resistor, in which 1 is the HIC board, 2 and 3 are the resistance values R _p1 ,
A printed resistor having R _p2 , 4, 5, 6, 7 are probes pressed into contact with the resistor electrodes, 8 is a resistor 2,
Initial resistance value measuring means 9 sequentially measures the resistance values of the resistors 3 and 9, the initial resistance value R _pi (i=1, 2) of the resistor obtained by the initial resistance value measuring means 8 and the resistors 2 and 3
Geometry and desired resistance value R _ti (i=1, 2)
10 is a trimming amount calculating means for calculating the trimming amount l _pi (i=1, 2) from the above, and 10 is a trimming means for moving the focal point 12 of the laser 11 on the resistors 2 and 3 by the trimming amount l _pi . be. Moreover, the broken line part A in FIG. 5 is a resistance value measurement positioning stage, and the broken line part B is a trimming positioning stage.

The operation will be explained below with reference to FIG. First, position the HIC board 1 on the resistance value measurement stage A, press the probes 4, 5, 6, and 7 to the resistor electrode parts, and set the initial resistance value R _pi of the resistors 2 and 3.
(i=1, 2) is measured by the initial resistance value measuring means 8. Next, after removing probes 4, 5, 6, and 7,
Move the HIC board 1 to the trimming stage B, position it, and trim the amount l _pi (i=1, 2).
is calculated by the trimming amount calculating means 9. The trimming means 10 trims the laser focal point 12 by the trimming amount l _p1 determined by the above calculation, and
The resistor 3 is moved by the trimming amount l _p2 , and the trimming is completed. FIG. 6 shows an external view after trimming. 13a and 13b are electrodes added to the resistor, and 14 is a trimming groove. Further, W represents the resistor width, and L represents the resistor length.

Problems to be Solved by the Invention However, with the method described above, it is necessary to precisely trim the resistor by the required trimming amount. Because it is necessary to use several types of printing ink and printing masks depending on the value, the positioning of the resistor will vary from HIC board to HIC board due to variations in the positioning of the printing masks. Therefore, it becomes impossible to accurately know the position of the resistor. Therefore, it has become impossible to trim the resistor with high accuracy and the amount of calculation required, resulting in a problem that the resistance value error becomes large.

An object of the present invention is to provide a method for trimming a resistor that eliminates the conventional problems.

Means for Solving the Problems In order to solve the above problems, the resistor trimming method of the present invention is a trimming method that obtains a desired resistance value by trimming the resistor multiple times. After trimming other than the first time, measure the resistance value of the resistor, calculate the amount of trimming actually performed on the resistor from the measured resistance value, initial resistance value, trimming end position, and shape value of the resistor, The edge position of the resistor is detected from the trimming amount, and the trimming start position is corrected based on the detected resistor position to perform the next trimming.

Function As described above, the present invention performs trimming on the resistor multiple times and detects the resistor position, so that trimming can be performed with high precision.

Embodiment A method for trimming a resistor according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram for explaining the method of trimming a resistor according to the present invention, in which 15 is a resistance value measuring means, and 16 is a width of the resistor which is the shape value of each of resistors 2 and 3. This is a trimming amount and resistor position calculation means (hereinafter referred to as calculation means) that calculates a trimming amount from W and length L, an initial resistance value, and a desired resistance value. FIG. 2 is an explanatory diagram of the method of trimming a resistor according to the present invention, and is 18
17a and 17b are resistors, 17a and 17b are electrodes, 19 is a first trimming groove, and 20 is a second trimming groove, and is an explanatory diagram for obtaining a desired resistance value by the second trimming.

Note that point a is the first trimming start point near the resistor, b is the first trimming end point, c is the resistor edge point determined by calculation, and d is the second trimming end point. Here, for the sake of simplicity, a method of obtaining a desired resistance value using only three resistors and trimming twice will be described. First, the HIC substrate 1 is positioned on the resistance value measurement stage A, and the probes 6 and 7 as electrical connection means are pressed against the electrodes of the resistor 3 to measure the initial resistance value R _p .

Next, the calculation means 16 calculates the first trimming amount l ₁ and positions the HIC substrate on the trimming stage B. For this l ₁ , the resistor width is W, the resistor length is L, and the desired resistance value is
If R _t and i=1, the following equation is calculated by solving the conformal mapping coordinate transformation method and the elliptic function, and the trimming amount l ₁ can be obtained.

l _i = W [1-2/πsin ^-1 exp {Lπ/4W (1-R _t・x/R _p )}] (1) However, π is pi, 0<x≦1, i is an integer In equation (1), x is usually a constant of about 0.9. In other words, since R _t is the desired resistance value,
This means that the first trimming is performed with the goal of making R _t ·X 90% of the desired resistance value. This is to prevent the resistance value from becoming higher than the sum of the desired resistance value and the allowable resistance value range due to the first trimming. Therefore, the value of X is determined by the variation in the manufactured resistance value before trimming, and if the variation is large and the allowable resistance value range is narrow, it is necessary to set the value of X small. Next, the HIC board is sent to the trimming stage B, and the trimming means 10 performs (1)
l ₁ determined by the formula is applied from a point a near the resistor in a direction perpendicular to the length of the resistor. The external view at that time is shown in (Figure 2a). Note that the trimming position is performed near the center of the electrodes 17a and 17b. Suppose now that trimming has finished at point b. Therefore, in order to know the resistor edge point c, it is sufficient to know the distance _l12 . Next, move the HIC substrate 1 to stage A, press the probes 6 _and 7 again to the electrodes of the resistor 3, and let the resistance value be R ₁ .
It is found as

l _i2 = W [1-2/πsin ^-1 exp {Lπ/4W (1-R _i /R _p )}] ......(2) However, π is pi and i is an integer. Therefore, ( Point c can be found from l ₁₂ found using equation 2) and the position of point b. As described above, the calculation means 16 calculates l ₁₂ from the position of point b and c
The point can be determined by calculation, which means that the resistor position (resistor edge point) has been detected.

Next, a method for obtaining a desired resistance value by the second trimming will be explained using FIG. 2b. FIG. 2b shows the appearance of the resistor after the second trimming. Now, the amount of trimming l ₂ to obtain R _t can be found using equation (1) with x=1 and i=2. The above l ₂ is calculated by the calculation means 16 and sent to the trimming means 10, and the HIC board is transferred to the trimming stage B.
is positioned. Next, trimming means 10
performs trimming from point c by _l2 amount. By continuing the steps above, the resistor position is detected, trimming is performed, and R _t can be obtained.
In addition, in FIG. 2, it is expressed that l ₁ and l ₂ are performed at the same position, but as shown in FIG. 3, l ₁ and l ₂ may be performed separately. Further, although l ₂ is performed from point c, it is clear that trimming by an amount of (l ₂ −l ₁₂ ) may be performed from point b. Also, when calculating l ₁ , we set x=0.9, but this means that x=
It is not limited to 0.9, and the obtained l ₁ is c
If it is inside the point, that is, if the constant is the amount of trimming that sufficiently trims the resistor, then 0<x
Any number may be used within the range of ≦1. Although the resistor 3 has been described above, the same applies to the resistor 2, and even if a large number of resistors are fabricated on the HIC substrate, they can be trimmed by the same procedure. The above also applies to the following description.

Next, a method for obtaining R _t by trimming three times will be explained with reference to FIGS. 1 and 4. FIG. 4 is an explanatory diagram of obtaining R _t by trimming three times, 21 is the third trimming groove, and c' is the resistor edge point determined by calculation after the second trimming. The following explanation will also be limited to the resistor 3. First, position the resistance value measurement stage on the HIC board 1, and
is pressed against the electrode of the resistor 3, and the initial resistance value R _p is measured. Next, the calculation means 16 calculates the first trimming amount l ₁ and positions the HIC substrate on the trimming stage B. this l ₁
is determined by equation (1) with i=1 and x=0.9. Next (1)
l ₁ found by the formula from the point a near the resistor 3,
Apply in the direction perpendicular to the length of the resistor. The external view at that time is shown in [Fig. 4a]. Now, it is assumed that trimming is performed by the trimming means 10 and the trimming is completed at point b. Therefore, in order to know the edge point c, it is sufficient to know the distance _l12 . Next, HIC board 1
is moved to stage A, the probes 6 and 7 are again pressed into contact with the electrodes of the resistor 3, and the resistance value is _R1 , then _l12 can be found by setting i=1 in equation (2). Therefore, point c can be determined from l ₁₂ determined by equation (2) and the position of point b. Next, using Fig. 4b, correct the point c by a second trimming, and furthermore, correct the point c as the edge point of the resistor.
The method for finding point c′ will be explained. FIG. 4b shows the appearance of the resistor after the second trimming. The second trimming amount l ₂ can be determined using equation (1) with x=0.95 and i=2. The above l ₁₂ , l ₂ and the position of point c are determined by the calculation means 16 and sent to the trimming means 10, and the HIC substrate is positioned on the trimming stage B. Next, the trimming means 10 performs l ₂
Trimming is performed from point c by the amount. next,
The HIC board is placed on the resistance value measurement stage A, and the probes 6 and 7 are pressed against the electrodes again to measure the resistance value. Now let the resistance value be R ₂ . Next, use equation (2) to find l ₂₂ with i = 2, find point c' from point d and l ₂₂ , and use equation (1) to obtain the desired resistance value with x = 1.0 and i = 3. l ₃ is determined by the calculation means 16, and the HIC substrate is positioned on the trimming stage B. Next, the trimming means performs trimming by an amount of l ₃ from point c′, and the trimming is completed. As described above, by finding point c, then trimming from point c, and finding point c', it is possible to detect the resistor edge point more accurately, and therefore perform trimming with high precision. be able to. In the above explanation, the first
When calculating l ₁ , we set x = 0.9 (this x is x ₁ ), and when calculating the second l ₂ , we set x = 0.95 (this x is x ₂ ), but this constant is not enough. l ₁ is a value that sufficiently trims the resistor, and 0
Any number may be used as long as the relationship satisfies <x ₁ <x ₂ ≦1.

Effects of the Invention As is clear from the above description, this is a trimming method for obtaining a desired resistance value by trimming a resistor multiple times, and the amount of trimming is as follows:
Calculate from the shape value, initial resistance value, and desired resistance value of the resistor, measure the resistance value of the resistor after trimming other than the final time, and calculate the measured resistance value, initial resistance value, trimming end position, and resistance value of the resistor. This is a resistor trimming method that detects the edge position of the resistor by calculating the amount of trimming actually performed on the resistor from the shape value, and performs the next trimming from the detected resistor position. The positioning of the board can be done with low precision, and since the position of the resistor varies from board to board, there is no problem of errors in the amount of trimming applied to the resistor, which makes it possible to perform trimming with high precision and improve production. It has a great effect on sexuality.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the trimming method of a resistor of the present invention, FIGS. 2 and 4 are diagrams showing the trimming method, and FIG. 3 is an external view of the resistor when the trimming method of the present invention is applied to the resistor. FIG. 5 is a diagram showing a conventional trimming method for a resistor, and FIG. 6 is an external view of a resistor after the conventional trimming method is applied. 1... HIC board, 2, 3... Resistor, 4, 5,
6, 7... Probe, 8... Initial resistance value measuring means, 9... Trimming amount calculation means, 10... Trimming means, 11... Laser light, 12... Laser focusing point, 13a, 13b... Electrode , 14...trimming groove, 15...resistance value measuring means, 16...trimming amount and resistor position calculating means, 17a,
17b... Electrode, 18... Resistor, 19... First
2nd trimming groove, 20...2nd trimming groove, 21...3rd trimming groove.

Claims (1)

[Claims] 1. A trimming method for obtaining a desired resistance value by trimming a resistor multiple times, the first step being to press an electrical connection means to an electrode part of the resistor and measure the initial resistance value of the resistor. , a first trimming amount was calculated from the shape value of the resistor, the measured initial resistance value, and a first target resistance value smaller than the desired resistance value, and the electrical connection means was removed from the resistor electrode part. a second step of applying the first trimming amount to the resistor in the state; and after the first trimming, press the electrical connection means to the resistor electrode to measure the resistance value of the resistor; The third step is to detect the edge position of the resistor by calculating the trimming amount applied to the resistor from the initial resistance value, the trimming end position, and the shape value of the resistor, and the shape value of the resistor. and a fourth step of calculating a second trimming amount from the initial resistance value and the desired resistance value or a second target resistance value larger than the first target resistance value, and connecting the electrical connection means from the resistor electrode part. A method for trimming a resistor comprising a fifth step of applying the second trimming amount to the resistor from the detected edge position of the resistor in a detached state.