JPH03255658A - Trimming method - Google Patents

Abstract

PURPOSE:To sharply lessen a functional trimming in time by a method wherein the deviation of a previously controlled physical quantity from a target value and the data of an index total length are obtained, a function to obtain the index length to cut to the deviation of the physical quantity is formed basing the deviation and the data concerned, and an index trimming is carried out basing on the value of the function concerned. CONSTITUTION:In a previous trimming, a function, IDT = f(DEV), can be approximately obtained from the deviation of a measured value from a target value in each step and a figure in which the index total length to the deviation is plotted, applying a Lagrange's interpolation formula or the like. At this point, IDT and DEV denote an index total length and a deviation respectively. The deviation of a measured value from a target value is obtained in each step, an index length to cut is obtained basing on the deviation concerned and a previously obtained function, an index length is cut as long as possible in each step, and an index trimming procedure is lessened in number of steps as a whole.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention performs index trimming using a laser trimming device for printing resistors on HIC substrates constituting electronic circuits to meet standards that define the characteristics of HIC substrates. Regarding the trimming method to adjust within.

[Conventional technology]

Conventionally, this type of trimming involves trimming the printed resistor 2 on the HIC board 1 as shown in FIG. 3(a), as shown in FIG. 3(b), to adjust the circuit characteristics within established standards. Therefore, a method was used in which measurements of physical quantities that should be included in the standard and trimming using a fixed index length were repeated until the target value was reached.

[Problem to be solved by the invention]

The above-described conventional index trimming method performs trimming at a constant index length, so the index length is determined by the rate of change in the vicinity of the target value and the standard of the target value. For example, in the case of trimming that takes the course shown in Fig. 2, the rate of change in the vicinity of the target value 18 is 0.06C%/μ.
m], and if the target value standard is ±1 [%], the index length must be about 5 [μm]. By this index trimming, 1600 [μm
], 320 steps are required. When trimming a laser beam by moving it using a beam positioner, more time is spent measuring the physical quantity than moving the beam. Therefore, in the case of normal element trimming where the physical quantity is resistance or DC voltage, tracking trimming is used in which a comparator is used and measurement and trimming are performed in parallel. The processing time for this tracking trimming is determined by the trimming speed. However, I started getting closer. In this functional trimming, the resistance is trimmed, but the physical quantity serving as the target value is a quantity other than the resistance or the DC voltage, such as two cycles of frequency or an AC voltage. Measuring instruments for these physical quantities are not available in normal trimming equipment, and external measuring instruments and GPIB
It is measured through an interface such as R8-232C or R8-232C.

Therefore, index trimming is usually the only method for functional trimming of such special physical quantities. For example, in the example shown in Figure 2, if tracking trimming is performed by 1600 [μm], the trimming will normally be 20 [mm/S].
] Trimming speed ±l[%]
Approximately o, o s [s] 0600 [μml/20 [
mm/S]) to complete the trimming. However,
Index trimming of a certain physical quantity to 1600 μm
] is performed in 320 steps, and the time for one measurement including GPIB communication is approximately 0.05 [S], the very long trimming time of 16 [S] (320XO, 05 [S]) It's time. Therefore, in order to shorten this time to some extent, a method of trimming by changing the index length into two stages is sometimes used.

For example, in the example in Figure 2, when the deviation from the target value is 15% or more, the index length is set to 200 [μm],
When it becomes smaller, index trimming is performed at 5 [μm]. When the index length is 200 [μm], the deviation becomes 10% in 7 steps, and the remaining trimming length becomes 200 [μm]. That is, the remaining 2
Trimming 00 [μm] with an index length of 5 [μm] results in 40 steps, so by adding the previous 7 steps, the improved method can trim in 47 steps.

If this is converted into time, it becomes 2.35 [S] (47 [steps] x O, 05 [S]).

However, in reality, due to variations in the initial values, the deviation of the index length may be as much as 15%. Then, since the remaining length is 300 [μm], it takes 60 steps with an index length of 5 [μm]. Therefore, it will take a maximum of 67 steps, and the trimming time will be 3.35 [S steps] x 0.05 [S steps].
becomes. That is, even with the improved method, the speed is 4.8 times faster than constant index trimming, but it still does not reach the tracking trimming time of 0.08 [S].

Conventional index trimming as described above has the drawback of being very time consuming.

[Means to solve the problem]

The trimming method of the present invention calculates the part to be cut with a given index length, the deviation between the measured value and the target value at that time, and the output part of the total trimming length, and the deviation from the output data of the deviation and the total length of the index. It also has a part that creates a function to find the index length for the index length.

The present invention calculates a deviation from the measured value and target value for each step, determines the index length to be cut from this deviation and a predetermined function, cuts the index length as large as possible for each step, and performs index trimming. It has the advantage of reducing the overall number of steps.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 2 is a diagram plotting the deviation between the measured value and the target value of each step and the total index length against the deviation from the output of the total index length in advance trimming. From this figure, this function IDT=f (DEV) can be approximately found by applying Lagranche's interpolation method or the like. Here, ■DT is the total index length, and DEV is the deviation. From now on, the method for determining the function for calculating the index length for deviation is to let IDX be the index length, k
If it is a number smaller than 1, the process will follow as shown in Table 1, and the standard will be reached at 10 steps.

shall be. However, when IDX is smaller than 5 [μm], IDX=5 [μm]. This 5 [μm] is a value obtained as follows from the rate of change in the vicinity of the target value 18 (0.06%/μm) and the standard of the target value (±1 [%]).

l [%co 10.06[%/pmco /3 [stepco #5[,umco] FIG. 1 is a flowchart outlining the trimming method of the present invention. In steps 8 to 13, a function is created to determine the index length for the deviation, and in steps 4 to 17, the function is used to perform index trimming.

For example, if we set the coefficient k to 0.5 in the function that calculates the index length from the deviation mentioned above, example 1 in Figure 2
Therefore, the trimming time is 0.5 [S], as in 0.05 [S] x 10 = 0.5 [S].

In reality, the number of steps will be approximately 1.5 times the maximum due to variations in the initial values, but the processing time will still be 0.7
It is within 5 [S], which is about 1/21 to 1/4.5 compared to conventional index trimming.

〔Effect of the invention〕

As explained above, when performing index trimming, the present invention obtains data on the deviation of the physical quantity to be adjusted from the target value and the total index length, and based on this data, the index length to be cut with respect to the deviation of the physical quantity is calculated. By creating the desired function and performing index trimming using this value, the time required for function trimming can be significantly reduced.

[Brief explanation of drawings]

Fig. 1 is a flowchart showing the index trimming method of the present invention, Fig. 2 is a diagram plotting the progress of trimming by the deviation from the target value and the total index length by preliminary index trimming, Fig. 3 (a), (b) )
1 is a plan view of an example of a HIC substrate to which the present invention is applied, and an enlarged view of a printed resistor.

Claims (1)

[Claims] Using a trimming device, print the resistor on the HIC board.
In the method of index trimming to bring a specified physical quantity within a specified standard, trimming is performed in advance at a certain index length, and at each step, the physical quantity is measured to determine the relationship between the trimming length and the physical quantity. Then, using this relational expression, find the length to achieve the target value from the measured value of the physical quantity at each step,
A trimming method characterized in that the length multiplied by a certain ratio is set as the index length.