JPS6040964A - Resistance value measuring probe for laser trimming - Google Patents

Abstract

PURPOSE:To reduce the beam path obstacle of laser beam, by providing such a structure that a contact pin for the electrical continuity with the electrode part of a resistor is erected on a transparent insulating base plate pervious to laser beam and wiring is performed to a transparent film conductor pervious to laser beam. CONSTITUTION:In trimming a film resistance base plate 13 having a resistor 11 and an electrode part 12 formed thereto, a transparent insulating base plate 14 easily transmitting laser beam is used and holes are provided to the base plate 14 at the positions corresponding to the electrode part 12 while contact pins 15 having springiness are planted to the holes in an upright state. In the next step, the pins and external connection terminals 16 are connected by transparent thin film conductors transmissive to laser beam, for example, a thin film pattern 17 formed of indium oxide to which about 5wt% of tin is added. By using thus constituted resistance value measuring probe, the resistor 11 can be trimmed and the beam path obstacle of laser beam can be reduced because laser beam 18 is transmitted even if the conductor 17 is present on the beam path of said beam 18.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a resistance value measuring probe for laser trimming that has fewer parts that obstruct the laser beam during laser trimming of a resistor.

[Technical background of the invention and its problems]

Recently, hybrid integrated circuits and resistance modules have come into widespread use to make electronic devices smaller and lighter.ζ Sets the resistance value of the resistor formed by printing or vapor deposition in hybrid integrated circuits and resistance modules. It is extremely difficult to manufacture products that match these values. For this purpose, it is customary to form a resistive element with a lower value than the set value, and then trim this resistor to the set point by sandblasting, laser beams or drilling. Using a laser beam for trimming allows for higher precision and faster trimming than methods that use sandblasting or a drill, making it suitable for mass production.

Laser trimming usually involves irradiating a laser beam onto the resistor to be trimmed, cutting part of the resistor while planning the resistance value of the resistor, and stopping cutting when the resistance value reaches the set value. This is done by

FIG. 1 shows a conventional resistance value measuring probe used for measuring the resistance value of a resistor in the laser trimming described above. That is, a resistance value measuring probe 5 fixed to a larger probe card 4 is attached to an insulating substrate 3 on which a resistor 1 made of a thick-film or thin-film resistor and its electrode part 2 are formed, and the resistance value measuring probe 5 fixed to a larger probe card 4 is attached. Connect the tip of the resistor to the electrode part 2
Spread diagonally until the end. In this way, a large number of probes 5 are set up on the electrode portion 2 of the resistor in one substrate 3, and the resistance value is measured while trimming is performed by irradiating the laser beam 6 from above. At this time, since the material of the globe 5 is generally a metal material such as neem copper or brass, the resistor l in the shadow of the globe 5 cannot be trimmed by the laser beam 6. Therefore, the recent high-density mounting of resistors requires an increase in the space occupied by the resistance measurement probes in laser trimming, but it is possible to install the resistance measurement probes all at once to ensure the optical path of the laser beam. Quantity will be limited. Therefore, when laser cutting and trimming resistors in a hybrid integrated circuit or a resistor module in which resistors are mounted at high density, it is necessary to use, for example, a plurality of probe cards and trim the resistors in multiple steps.

[Purpose of the invention]

The present invention has been made in order to solve the above-mentioned drawbacks, and an object of the present invention is to provide a resistance value measuring probe for laser trimming that has fewer parts that obstruct the optical path of the laser beam.

[Summary of the invention]

In the present invention, a contact pin having a spring property for making contact with an electrode part of a resistor is erected almost vertically on a transparent insulating substrate that is easily transparent to a laser beam, and the laser beam is transmitted between the contact pin and an external connection terminal. It is characterized by having a structure wired with a transparent thin conductor that is easy to pass through.

[Embodiment 11 of the Invention] Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 2 is a schematic diagram showing an embodiment of a resistance value measuring glove for laser trimming according to the present invention. That is, a film resistance substrate 13 on which a resistor 11 and its electrode portion 12 are formed.
When performing laser trimming, a transparent insulating substrate 14, such as a glass plate or a transparent acrylic resin plate, through which laser beams can easily pass, is used to remove the insulating substrate 1 at a position corresponding to the electrode part 12.
4, and a contact pin 151FI having spring properties is planted in the hole, and a pin made of beryllium copper or brass plated with gold or rhodium plating is planted in the hole. Next, between the contact pin 15 and the external connection terminal 16, a transparent thin film conductor that transmits the laser beam is formed using a vapor deposition method, a vapor phase synthesis method, etc., such as indium oxide with tin added or tin oxide with antimony added. Thin 11 formed with! Connect with Hataan 17. The thin film pattern 17 may be formed into a required pattern shape, or the entire surface of the insulating substrate 14 may be colored in advance and formed into a required pattern shape by an etching method or the like. Further, the connection is more reliable if the contact pin 75 and the i-film pattern 17 are adhered with a conductive paint or the like (not shown). Resistance value for laser trimming according to the present invention as described above...1] In the structure of the constant probe, the transparent f
For example, when indium oxide is used as the material for the thin film pattern Z7 made of an Ig-film conductor, indium oxide conductors have high resistance, but by adding an appropriate amount of tin, the resistance becomes low and at the same time the laser beam transmission characteristics are also improved. Change. For example, when using a YAG laser oscillator, it is preferable to add about 5% tin to indium oxide.
As the film resistance decreases, it becomes most transparent to YA ( ) laser light with a wavelength of 1.06 μm.

Generally, the resistance of indium oxide decreases due to the addition of tin because tin enters the indium oxide structure as an impurity here and there and becomes tin ions, which contribute to electrical conduction as electron scoops. In addition, it is natural that the sheet resistance of the transparent 1 (J film 2) body will further decrease as the skin thickness increases.

Next, a specific implementation of the present invention: 651J will be explained.

For example, approximately 3,000 ml of indium oxide with 5 weight tin of tin is applied to the entire surface of a 3 mm thick glass plate (transparent insulating substrate).
This glass plate is then vapor-deposited, holes are drilled at predetermined positions on this glass plate using an ultrasonic processing machine, a pattern is drawn with ultraviolet curing resist, and after it is cured, it is etched with hydrochloric acid, the resist is washed off, and then it is placed in the predetermined position. A contact bottle made of gold-plated beryllium copper was placed in the hole, fixed with conductive adhesive, and electrically connected to the thin film pattern using silver paste that dried at room temperature.

If a resistance value measuring glove with the above structure is used, even if the transparent thin film conductor 17 is present on the optical path of the laser beam 18, the lower resistor 12 can be trimmed because the laser beam 18 will pass through. The only part through which the laser beam 18 cannot pass is the part where the conductor bottle 15 stands, and there are very few parts that will obstruct the optical path of the laser beam 18.

〔Effect of the invention〕

As described above, according to the present invention, the number of parts that obstruct the optical path of the laser beam is extremely small, and therefore, when laser trimming a resistor on a board on which resistors are densely mounted, many resistance values can be processed at once. The number of resistors that can be laser trimmed with -1 probe installations is significantly increased. That is, even on a board on which resistors are mounted at a very high density, the number of probe installation turns can be reduced to 11 times, and the trimming time can be shortened.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a row of conventional resistance value measuring gloves for laser trimming, and FIG.
It is a perspective view showing fc. II...Resistor, 12...Electrode portion, 13...Membrane resistance substrate, 14...Transparent insulating substrate, I5...Contact bottle, 16...External connection terminal, 17...Thin film Pattern, 18...Laser beam. Applicant's agent Patent attorney Takehiko Suzue Figure 1 38 Figure 2

Claims (2)

[Claims] (1) When laser trimming a resistor, in the laser trimming resistance measuring glove that measures the resistance value of the resistor, the transparent insulating substrate that transmits the laser beam must be electrically connected to the electrode part of the resistor. A resistance value measuring probe for laser trimming, characterized in that the probe has a structure in which contact pins are erected, and wiring is formed between the contact pins and external connection terminals on the transparent substrate using a transparent thin film conductor that transmits laser beams. (2) The resistance value measuring probe for laser trimming according to claim 1, characterized in that indicium oxide doped with about 5% tin by weight is used as the transparent thin film conductor.