JPH0354803A - laser trimming device - 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 Field of the Invention The present invention relates to a laser trimming device for trimming thick film resistors.

Prior art In recent years, laser trimming equipment has been developed using thick film hybrid I
As C becomes more sophisticated, it is desired to improve trimming accuracy.

An example of the conventional laser trimming device mentioned above will be described below with reference to the drawings.

FIG. 3 shows a main configuration diagram of a conventional laser trimming device. In FIG. 3, 1 is a laser unit, 3 is a resistor, 6 is an amplification section for detecting resistance value, 8 is a comparison section for detecting resistance coincidence, and 9 is a D/A for setting target resistance value (
Digital/analog (hereinafter abbreviated as DA) converter section,
10 is a controller section that operates the entire device.

The operation of the laser trimming device configured as described above will be explained below. First, after the resistance value of the resistor 3 is amplified by the amplification section 6, the comparison section 8 compares it with the output of the D/A converter section 9 for setting a target resistance value. At that time, when the resistance value is lower than the target value, the controller section 10
Send a signal to laser unit 1, emit laser beam B, process the resistor, and adjust the resistance value to the target value.

Problems to be Solved by the Invention However, the above structure has a problem in that it is greatly affected by heat during laser pulse irradiation, leading to a decrease in trimming accuracy.

In view of the above problems, the present invention provides a laser trimming device capable of trimming with high precision without being affected by heat during laser pulse irradiation.

Means for Solving the Problems In order to solve the above problems, the laser trimming device of the present invention is provided with a sample hold section that operates in synchronization with one noser pulse after the resistance value detection amplifier section. It is something that

Function The present invention uses the above-described structure to continue holding the previous value by the sample hold while being affected by the heat during laser pulse irradiation, and when it becomes stable, triggers the sample hold part. Since the new values are multiplied and compared, there is no decrease in accuracy due to the effects of heat immediately after laser pulse irradiation.

Embodiment A laser trimming device according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a main configuration diagram of a laser trimming device in an embodiment of the present invention. In Figure 1,
1 is a laser unit, 2 is a laser beam emitted from the laser unit, 3 is an object to be trimmed, that is, a resistor, 4 is a part processed by the laser, 5 is a probe for measuring resistance value, and 6 is an amplification unit for detecting resistance value. , 7 is a sample and hold section, 8 is a comparison section for resistance value coincidence detection, 9 is a D/A converter section for setting a target resistance value, and 10 is a part of a controller for operating the entire apparatus.

The operation of the laser trimming device configured as described above will be explained below with reference to FIGS. 1 and 2.

First, Fig. 2 shows signal waveforms during trimming, where a is the output waveform of the resistance value detection amplification section, b is the output waveform of the sample and hold section, C is the output waveform of the sample and hold section, and d is the output waveform of the sample and hold section. The output waveform of the target resistance value setting section e is the trigger waveform of the laser oscillator Q switch. The operation begins with the D/A converter 9 depending on the target resistance value.
The value of is set by the controller 10. Resistor 3
The resistance value is amplified by the resistance value detection amplification section 6, and is transmitted to the resistance value coincidence detection comparison section via the sample and hold section 7. Then, the laser beam is irradiated while scanning in the direction of the arrow X until the set value, that is, the target value and the current resistance value match or exceed the value. At this time, when the controller outputs the trigger signal e to the laser, the laser light is emitted all at once and processes the resistor. At that time, the output waveform of the resistance value detection amplifier section is as shown in a, and a glitch occurs in response to the trigger pulse. Next, the signal passes through a sample-horved section 7 synchronized with the Q-switch pulse, and its output waveform becomes as shown in C.

As described above, according to this embodiment, the sample and hold section is provided between the resistance value detection amplifier section and the resistance value match detection comparison section, and is operated in synchronization with the Q switch pulse, so that the resistance value can be adjusted. The influence of unstable parts can be reduced.

Effects of the Invention As described above, the present invention can improve trimming accuracy by providing the sample hold section after the resistance value detection amplifier section.

[Brief explanation of drawings]

FIG. 1 is a main configuration diagram of a laser trimming device according to an embodiment of the present invention, FIG. 2 is a signal waveform diagram of each part, and FIG. 3 is a main configuration diagram of a conventional laser trimming device. ■... Laser unit, 3... Resistor, 4... Processing section, 6... Amplifying section for resistance value detection, 7...・Sample hold section, 8...
... Comparison section, 9... D/A converter section,
10... Controller section.

Claims (1)

[Claims] Comparing the values of a laser unit that can irradiate a laser to a resistive part, a measuring part that can measure the resistance value of a resistive part, a converter part that has set a target resistance value in advance, and a value of this converter part and a value of the measuring part, A laser trimming device comprising: a control section that sends a signal to operate the laser unit based on the comparison by the comparison section; and a sample hold section that operates in synchronization with laser pulses.