JPS5850403B2 - Trimming method and device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for automatically trimming a thin film or thick film resistor according to the electrical functional characteristics of a circuit.

Conventionally, when trimming thin film or thick film resistors according to their electrical characteristics, the target characteristics are mainly DC characteristics such as resistance value, and AC characteristics are static characteristics such as AC effective voltage or frequency.

Therefore, for dynamic function trimming that is performed by measuring the level and time relationship of points on a complex waveform, it is necessary to develop a dedicated measurement and control system for each object depending on the target object, which requires a large amount of development man-hours. This has become a problem.

An object of the present invention is to eliminate the above-mentioned conventional drawbacks, improve trimming accuracy, and provide a trimming method and device that is highly flexible for changing product types.

That is, the present invention allows the supply test signal group and the input signal group from the test terminals of the thin film or thick film circuit to be made independent of each other, so that the selection within each group can be freely set independently of the others.

Furthermore, in order to measure and trim the characteristic values on the waveform of the test signal, a common waveform memory such as a method for sampling and storing the waveform is provided, and the contents of this memory are analyzed and determined by a small computer, and a predetermined amount of In this method, the trimming is repeated until the standard characteristic value is reached.

This makes it possible to easily deal with changes in the target characteristic items by changing the control data or characteristic standard values, or by changing the trimming procedure program as necessary.

Hereinafter, the present invention will be explained in more detail according to one embodiment.

FIG. 1 is an overall circuit diagram of a laser trimming device according to an embodiment of the present invention, FIG. 2 is a circuit example showing the inside of the waveform storage device shown in FIG. 1 in further detail, and FIG. 3 is an example of waveform measurement. FIG. 4 shows an example of software processing.

First, the overall configuration and operation will be explained with reference to FIG.

In Figure 1, 1 is the thick film module to be trimmed, 2 is 1
3 is a probe for transmitting and receiving signals with the test terminal in 1, and 4 is a probe stand for supporting the probe in 3.

Reference numeral 13 denotes a test signal group in which there are a necessary number of test signal generators 14 each having a synchronizing signal generating section 15.

Furthermore, 16 is a test signal selector that selects only the necessary test signal 28 for each trimming item from the test signal group 13, and 17 is a test signal selector that selects the test signal 28 to one of the plurality of supply signal lines 29. 18 is a sync signal selector that selects one sync signal 33 corresponding to each trimming item from among a plurality of sync signals 27; 19 is a sync signal selector that selects one sync signal 33 corresponding to each trimming item from among a plurality of sync signals 27; An input signal selector 20 selects an input signal 31 to be focused on from the input signal 3;
1 is a variable band type variable filter that filters in a predetermined band, 21 is a waveform memory that samples the input waveform 32 based on the synchronization signal 33, and stores each sampling value; 6 and 8 are The laser beam from the laser oscillator 5 is passed through 10 mirrors and positioned on the thick film module 1 in the X and Y directions by an X-axis galvanometer and a Y-axis galvanometer, respectively.
．． This is done by giving commands to the X galvanometer controller 12 and Y galvanometer controller 12 to drive the motors 7 and 9, respectively.

Reference numeral 22 represents an interface circuit for interfacing each of the above devices with the microcomputer 23, and 24 represents a console for inputting control data and operation commands to the microcomputer 23.

In the operation shown in FIG. 1, first, in order to supply a specified test signal 28 to the thick film module 1, the test signal selector 16 selects a specified test signal 28 from the test signal generator 14 of the test signal group 13.
Select.

A test signal selection command 37 instructing this selection is given from the microcomputer 23 to the test signal selector 16 through the interface circuit 22.

Since each control command is thus given to each device through the microcomputer 23 and the interface circuit 22, a description of how to give each control command will be omitted below.

Next, the selected test signal 28 is distributed to a predetermined location on the supply signal line 29 by the test signal distributor 17 according to the distribution command 39, and the predetermined test signal is supplied to a predetermined terminal of the thick film module 1 through the probe 3. It turns out.

On the other hand, the test signal from the thick film module 1 is transmitted to the probe 3.
and is taken in through the input signal line 30.

There are as many input signal lines 30 as there are measurement points, and a predetermined input signal 31 is selected from among these by the input signal selector 19.
It is selected by the selection command of 0.

The selected input signal 31 is filtered by the variable filter 20 in accordance with a command 41 in order to remove noise components or extract signals outside a predetermined band.

The input signal 32 that has passed through the variable filter 20 is sent to the waveform memory 2
1 by a command 42 based on a predetermined synchronization signal 33 and stored.

This synchronization signal 33 is generated by each synchronization generation section 15 of the test signal group 13.
The synchronizing signal selector 18 selects one of the synchronizing signal outputs 27 from the synchronizing signal output 27 according to a selection command 28.

Now, the contents of a predetermined portion of the stored waveform are taken into the microcomputer 23 through the storage output 34 according to a command 42, and are analyzed and judged.

The judgment result is output as the amount of movement of the laser beam to the X and Y axis command data 36.35, and the motor 7.9 is driven through the X galvanometer controller 11 and the Y galvanometer controller 12 to perform the X axis galvanometer and Y axis galvanometer make. A predetermined resistance on the thick film module 1 is trimmed through the mirror 10 while positioning the laser beam 25 in a controlled manner.

The above is a series of operations, and this operation is repeated until the characteristic value falls within the required reference value.

The console 24 is used to input the aforementioned various command data and operation commands to the microcomputer 23.

Here, an example of the internal circuit of the waveform memory 21 in FIG. 1 will be explained in more detail with reference to FIG. 2.

In FIG. 2, 43 is a variable attenuator whose attenuation amount can be varied, 44 is a sample and hold circuit, and the output is digitized by an A/D converter 45.

47 and 48 are synchronization signal 33 and start command 55, respectively.
49 is an AND gate circuit that ANDs the output of the latch circuits 47 and 48 and a sample clock 65 obtained by dividing the sample clock generator 52 by a frequency dividing circuit 53; 51 is a counter that counts the sample period; 4
6 is the timing 69 from the sample timing circuit 50
This is a shift type memory in which the output 61 of the A/D converter 45 is sequentially shifted and stored, and the contents of the memory can be read by command 58 to read out the contents of any address to output 34.

To explain the operation of FIG. 2, the input signal 32 is attenuated by the variable attenuator 43 by a specified amount of attenuation 54 and leveled.

Thereafter, the sample is held at 44 and A/D converted at 45 according to each sampling timing command 67.degree.68.69 created by the sample timing circuit 50 from the sample clock 66, and the result 61 is sequentially stored at 46.

On the other hand, this sample clock 66 is generated by converting the output of the sample clock generator 52 into a clock 65 having a predetermined clock rate in the frequency dividing circuit 53 according to the command 57, and then generating the start command 55.
and the AND gate circuit 4 together with the outputs 63 and 62 of the latch circuits 48 and 47 indicating that the synchronization signal 33 has arrived, respectively.
9, and the sample clock 66 is generated after the start command 55 and synchronization signal 33 arrive.

In addition, the number of samples of the sample clock 66 can be decreased by decrementing the counter 51 preset by the command 56 using the suspension clock 66, and by resetting the latch circuit 47.48 with the output cuff 0 when it becomes zero. Can be specified externally.

With the above operation, the synchronization signal 33 is stored in the waveform memory 21.
The input signal 32 can be sampled by a specified number of samples at a specified clock rate and the sampled values can be stored, and the contents can be retrieved from 34 for flexible analysis.

The present invention has been described above using an example of a concrete circuit, but in order to further explain the effectiveness, an example of processing using software will be described.

FIG. 3 shows an example of a waveform to be measured, and FIG. 4 shows an example of a processing flow.

FIG. 3 is an example of a waveform when determining the clip level ratio of the input waveform 32, which is determined by the ratio of the level VC between the peak level υ2 and 01 to the level VT between (vt vo).

The processing flow for determining this ratio is shown in FIG. 4A.

In FIG. 4A, Vo is first obtained by averaging each sampled level between 0 and to of the waveform 32, and vl is similarly obtained from the level between t3 and t4.

Next, VT is obtained from (vl-vo), and (V2-vl) is calculated from the maximum level v2 between t] and t2, VC is obtained, and VC/VT is calculated.

On the other hand, FIG. 4B shows an example of a processing flow for trimming using this measurement value calculation method.

In FIG. 4B, numeral 71 indicates various control data, which is stored in a certain memory area within the microcomputer 23, for example.

Below, FIG. 4B will be explained in association with this data and the processing flow.

First, in order to apply a predetermined test signal to the thick film module 1 as described above, a supply signal is selected from the signal source data and signal distribution data.

Next, the input signal 32 is selected by the input signal data, and the synchronization signal is selected by the synchronization signal data.

After selecting the signal system in this way, the waveform is stored based on the waveform capture data.

Thereafter, the measured value as shown in FIG. 4A is calculated and compared with the trimming reference value data to determine whether it is within the reference value.

If the results are within the standard values, the trimming process will end, but
If it is outside the standard value, calculate the amount of trimming from the result,
The resistor corresponding to the trimming position data is trimmed by the specified amount.

After trimming, since the input signal changes, the waveform is captured and measured again, and this operation is repeated thereafter to automatically perform trimming work.

Note that in the cited embodiment, waveform storage is performed for one channel, but by storing this for two or more channels, it is possible to perform trimming using the correlation value between multiple waveforms, making the trimming device even more flexible. It can also be done.

As described above, according to the present invention, it is possible to store the entire waveform once and then analyze and judge it using a small computer to calculate the amount of trimming, as well as to control test signals, input signals, etc. independently of each other. A trimming device that is highly flexible and capable of waveform processing can be obtained that can cope with model changes using all data such as control data and trimming reference values.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram showing an embodiment of a trimming device according to the present invention, FIG. 2 is a diagram showing an internal circuit of the waveform memory shown in FIG. 1, FIG. 3 is a diagram showing measured waveforms, and FIG. The figure is the first
FIG. 3 is a diagram showing a processing flow within the small computer shown in the figure. Explanation of symbols, 1... Thick film module, 2...
...Trial slope, 3...Prologue, 5...
・Laser oscillator, 6...X-axis galvanometer,
8...Y-axis galvanometer, 11...
X galvanometer controller, 12... Y galvanometer make controller, 14... test signal generator, 16... test signal selector, 17...
... Test signal distributor, 18 ... Synchronous signal selector, 21 ... Waveform memory, 22 ... Interface circuit, 23 ... Micro Computer, 24...console.

Claims (1)

[Claims] 1. Selecting and applying a predetermined test signal to the object to be trimmed;
The characteristic waveform obtained from the object to be trimmed is measured and stored in the storage means, the stored content is analyzed by the calculation means to calculate the measured value, and the amount of trimming is calculated from the calculated measured value. A trimming method characterized by controlling a trimming means based on the calculated trimming amount and repeating trimming until the characteristics of the object to be trimmed fall within a predetermined reference value. 2. A test signal generator that supplies a plurality of test signals to the object to be trimmed, means for arbitrarily selecting each predetermined signal from among the test signals supplied from the test signal generator, and a plurality of test signals from the object to be trimmed. means for selecting and capturing a signal to be measured and storing the waveform of the signal at a specified synchronization signal and a specified clock rate; and analyzing the contents of the waveform storage means;
It is equipped with a means for calculating each measured value and a trimming amount from each measured value and outputting it to the outside, and a means for performing trimming by a specified amount using the outputted trimming amount. A trimming device that performs trimming to fall within a reference value.