JPS639643B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for manufacturing hybrid ICs using laser beams.
The present invention relates to a laser trimming device for trimming a resistor in a resistor module.

Resistance elements in hybrid integrated circuits and resistance modules are formed using vapor-deposited metal films such as nichrome or tantel in the case of thin-film circuits, and printed films such as ruthenium oxide in the case of thick-film circuits. It is extremely difficult to manufacture a device with a resistance value that perfectly matches the set value. For this reason, adjustment to the set value is usually performed by trimming after manufacture. When a laser beam is used for trimming, the processing diameter is smaller compared to conventional anodizing methods or sandblasting methods, and it is possible to trim with high precision and high speed against resistance of minute patterns, and it is easy to automate and integrate. It has many advantages, such as the ability to trim functions while maintaining the circuit in an operating state.

Laser trimming equipment usually uses a laser oscillator unit consisting of an Nd:YAG laser oscillator and an ultrasonic Q switch, moves the laser beam to the position of the resistor to be trimmed, and moves the laser beam over the resistor while irradiating it. It consists of a beam positioner section, a resistance measurement section that measures resistance values, a parts handler section that transports the trimming board, and a computer section that controls these by programming. Trimming is done by positioning the resistor to be trimmed so that the laser beam is irradiated at the cut position of the resistor, then generating a Q switch pulse and moving it over the resistor while measuring the resistance value to cut it until the resistance value reaches the set value. When this is reached, the Q-switch pulse and the movement of the laser beam are stopped. The substrate to be trimmed is transported by the parts handler section, including a step-and-repeat operation.

In the above-described laser trimming apparatus, as trimming substrates have become larger in recent years, the time required for beam positioning has become no longer negligible relative to the overall processing time. There are two methods: using a galvanometer-type optical scanner as a beam positioner, and moving the objective lens itself using an XY table driven by a DC motor or linear motor. The former is superior in terms of speed, but the maximum movement range is limited to 2 to 3 inches square, and the latter has a large movement range, but there is essentially a limit to how high the speed can be increased. Recent electronic circuits are becoming more complex, and the size of insulating substrates has begun to grow from 100mm to 300mm. As a beam positioner for trimming inside such large insulated substrates,
Although it is possible to use a method in which the objective lens is moved using an XY table, the longer positioning distance inevitably requires longer processing time.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a laser trimming device that can perform trimming without increasing the positioning processing time even if the size of the substrate increases.

According to this invention, in a laser trimming device that requires high-speed positioning for a large trimming board, the laser trimming device is mounted on a table movable in the x and y axes directions in accordance with the trimming start position of each resistor. an optical fiber guided from the objective lens and arranged in a line in the order of trimming, and an input optical system movable in one direction to sequentially make laser beams enter the optical fibers. Laser trimming can be obtained, which is characterized in that beam positioning is achieved by switching optical fibers and trimming is achieved by minute movement of an objective lens.

Next, the present invention will be explained with reference to the drawings. The figure shows a schematic configuration of a beam positioner section of a laser trimming device which is an embodiment of the present invention.

A resistor 12 formed by printing or vapor deposition on an insulating substrate 11 is connected to a resistor probe 13,
The resistance value is monitored by 13'. A plurality of objective lenses 15 mounted on a table 14 movable in x and y in accordance with the trimming start position of the resistor 12 are guided to an input optical system 17 by respective optical fibers 16 . Injection optical system 17
1 in the order of trimming the optical fiber 16
It is comprised of a fiber array 18 arranged in a row and a connecting optical system 20 that can be programmably controlled in one direction to make laser beams from a laser light source 19 enter the optical fibers 16 in sequence. In this embodiment, this connecting optical system has a reflecting mirror formed on the surface of a block 20 cut at an angle of 45 degrees. The drive source 23 moves the connecting optical system 20 in the direction of the arrow. Since the positioning of the laser beam corresponding to the trimming resistor is based on switching of optical fibers, it is possible to move the laser beam by a few hundred micrometers, and the distance between the resistors on the insulating substrate is significantly shortened, making it possible to achieve higher speeds. On the other hand, trimming is performed by minutely moving the x-y movable table 14 to which the objective lens 15 is fixed. 2
1 and 22 are the driving sources.

[Brief explanation of the drawing]

The figure is a perspective view mainly showing beam positioning of a laser trimming device which is an embodiment of the present invention. 11 is an insulating substrate, 12 is a resistor, 1
3 and 13' are resistance measurement probes, 14 is an xy table, 15 is an objective lens, 16 is an optical fiber, 17 is an input optical system, 18 is an optical fiber array, 19 is a laser light source, and 20 is a connection optical system. , 21 and 22 are driving sources of the xy table 14.

Claims (1)

[Claims] 1. In a laser trimming device that automatically adjusts a circuit or resistance value to a predetermined value by cutting a part of a plurality of resistors formed by printing or vapor deposition on an insulating substrate with a laser beam. , an objective lens group mounted on a table movable in x and y directions corresponding to the trimming start position of each resistor; an optical fiber array guided from the objective lens and arranged in a line in the trimming order; It includes a movable input optical system for sequentially injecting laser beams into optical fibers, and beam positioning is achieved by switching the optical fibers, and trimming is achieved by minute movements of the objective lens. Laser trimming equipment.