JPH08316096A - Laser trimmable capacitor and its manufacturing method - Google Patents

Abstract

PURPOSE: To attain an easy and accurate adjustment of the capacitance by a simple step of process. CONSTITUTION: Electrodes 14 and 15 such as Cu foils are mutually oppositely disposed on the front and back faces of an insulative substrate 12 to form a capacity. Either electrode 14 or 15 to be trimmed is formed like a comb web and the width of the comb web part 14b of the electrode 14 decreases in the trimming direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser trimmable capacitor in which electrodes are formed on the front and back of an insulating substrate with copper foil or the like, and the capacitance value can be adjusted by trimming the electrodes with a laser beam, and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventional laser trimmable capacitors are
As shown in FIG. 3, solid electrodes 2 and 3 made of copper foil are formed on almost the entire surface of the insulating substrate 1. Then, when trimming this capacitor, the end portion of the electrode 2 is separated and cut by a laser beam scanned as a laser beam locus 4 shown by an arrow in FIG. 3 to reduce the capacitance. Trimming. When adjusting this capacitance value, the feed pitch of the laser beam is made fine to reduce the electrode area to be scraped off, and at the time of fine adjustment, finer capacitance adjustment is performed by the overlapping pitch that makes the laser beam reciprocate at almost the same position. ing.

[0003]

In the case of the above-mentioned conventional technique, when the capacitance value is finely adjusted, the feed pitch of the laser beam has to be made finer and further adjusted by the overlapping pitch, so that the trimming time tends to be long. It was a thing. Furthermore, if the variation in capacitance value due to the initial electrodes 2 and 3 is large, the trimming position for fine adjustment also varies, and in order to find that position, the feed pitch must be made fine and fine adjustment must be performed. However, the fine adjustment itself is difficult and time-consuming and costly.

The present invention has been made in view of the above-mentioned conventional technique, and an object thereof is to provide a laser trimmable capacitor capable of easily and accurately adjusting the capacitance in a simple process, and a manufacturing method thereof. .

[0005]

According to the present invention, electrodes such as copper foil for forming capacitors are provided on the front and back surfaces of an insulating substrate so as to face each other, and the electrodes to be trimmed are comb-shaped. The laser trimmable capacitor is formed so that the width of the comb blade portion of the electrode becomes narrower toward the trimming direction. Furthermore, the comb-blade-shaped electrode is formed in a shape having different widths toward the tip of the comb-blade.

Further, according to the present invention, electrodes such as copper foil for forming capacitance are provided on the front and back surfaces of the insulating substrate so as to face each other, and the trimmed side of the electrodes is formed in a comb-teeth shape. In the manufacturing method of the laser trimmable capacitor, the width of the comb blade of the electrode is narrower toward the other side, and the trimming is performed by moving the laser beam from the wide side of the comb blade toward the narrow side. is there. The width of the comb blade portion of the electrode is different toward the tip portion, while moving the laser beam from the wide side of the comb blade portion to the narrow side, the narrower position of the comb blade portion. This is a method of manufacturing a laser trimmable capacitor in which the trimming is performed by moving in a stepwise manner, obliquely, or in a curved shape toward.

[0007]

According to the laser trimmable capacitor and the method of manufacturing the same of the present invention, the capacitance value to be trimmed is moved along with the movement of the laser beam by moving the laser beam from the wide side of the comb-shaped electrode to the narrow side thereof. It becomes smaller, and fine adjustment can be performed gradually with the movement of the laser beam.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment of a laser trimmable capacitor of the present invention. A laser trimmable capacitor 10 of this embodiment has a front surface and a back surface of an insulating substrate 12 made of a dielectric material such as ceramics or high dielectric resin. Electrodes 14, 1
5 is formed. The electrode 14 has a comb blade portion 14b extending in a comb blade shape from the base end portion 14a thereof, and the width of the comb blade portion 14b is gradually reduced from one side surface portion to the other side surface portion. Formed on the blade. The back electrode 15 is
Corresponding to the electrode 14 on the surface, it is formed facing at least the comb blade portion 14b.

Next, a method of manufacturing the laser trimmable capacitor 10 of this embodiment will be described. The laser trimmable capacitor 10 of this embodiment is formed by etching the electrodes 14 and 15 of the insulating substrate 12 into a predetermined shape, and the comb blade portion 14b of the electrode 14 can also be accurately formed by etching. . When trimming is performed, the laser trimmable capacitor 10 causes the tip end of the comb blade portion 14b of the electrode 14 to move to the base end portion 14a by a laser beam scanned as a laser beam locus 16 shown by an arrow in FIG.
To a predetermined length, and reduce the area of the electrode 14,
Adjust while reducing the capacitance value and measuring the value. At this time, the laser beam moves the comb of the electrode 14 from the wide side of the portion 14b toward the narrow side. This reduces the adjusted volume as the laser beam travels,
Even if the moving speed of the laser beam is the same, the volume to be adjusted is small, and more accurate adjustment is possible.

According to the laser trimmable capacitor of this embodiment and the method of manufacturing the same, fine adjustment of the capacitance value can be easily performed at the time of trimming.
No adjustment by the overlapping pitch is required, the moving operation of the laser beam is simplified, and the trimming speed can be improved. In particular, even if there is a large variation in capacitance value before trimming, it is not necessary to perform many laser beam scans, and the capacitance value can be adjusted accurately with a small number of movements.

Next, a second embodiment of the laser trimmable capacitor and the manufacturing method thereof according to the present invention will be described with reference to FIG. Here, the same members as those in the above-described embodiment are designated by the same reference numerals, and the description thereof will be omitted. In the laser trimmable capacitor 10 of this embodiment, the comb blade portion 14 of the electrode 14 becomes narrower from one side to the other side surface as in the above-described embodiment, and the width thereof becomes closer to the tip. It is thin.

When trimming the laser trimmable condenser 10 of this embodiment, a laser beam is applied to the comb blade portion 14.
The wider side of b, the comb blade portion 14b from the tip side
Alternatively, the moving position of the laser beam 16 may be moved to the base end portion 14a side while measuring the capacitance value.
Further, the laser beam may be moved stepwise from the side of the base 14a having the wider width of the electrode 14 toward the tip of the comb blade 14b. As a result, as the laser beam moves, the electrode area to be adjusted becomes smaller and the fine adjustment becomes easier.

According to this embodiment, the capacitance value adjusted with the movement of the laser beam 16 becomes smaller and more precise adjustment is possible.

In the laser trimmable capacitor and the manufacturing method thereof according to the present invention, the shape of the comb blade of the electrode may be changed as appropriate, and the width thereof is gradually reduced in the moving direction of the laser beam. If it is good. Therefore, the width of the comb blade portion may be changed from one side surface to the other side surface and may be widened toward the tip portion,
It may have a curved width. Further, the moving path of the laser beam may be linear, stepwise or curved, and may be a right angle with respect to the comb blade portion or an obliquely traversing path. Further, the material of the insulating substrate may be any material as long as it is a dielectric, and can be appropriately selected.

[0015]

The laser trimmable capacitor according to the present invention enables laser trimming to be performed easily and accurately, and further, trimming time can be greatly shortened to perform efficient trimming.

[Brief description of drawings]

FIG. 1 is a schematic front view showing a laser trimmable capacitor according to a first embodiment of the present invention.

FIG. 2 is a schematic front view showing a laser trimmable capacitor according to a second embodiment of the present invention.

FIG. 3 is a schematic front view of a conventional laser trimmable capacitor.

[Explanation of symbols]

 10 Laser Trimmable Capacitor 12 Insulating Substrate 14, 15 Electrode 14b Comb Blade 16 Laser Beam Trajectory

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Hiroyuki Kurokawa 3158 Shimookubo, Osawano-cho, Kamishinagawa-gun, Toyama Prefecture Hokuriku Electric Industry Co., Ltd.

Claims (4)

[Claims] 1. An electrode for forming a capacitance is provided on the front and back surfaces of an insulating substrate so as to face each other, and a comb blade-shaped comb blade portion is formed on a trimmed side of this electrode. A laser trimmable capacitor formed such that the width of the comb blade portion gradually decreases from one side to the other side. 2. The comb blade portion of the electrode is such that the width of the comb blade portion is gradually narrowed from one side of the electrode toward the other side of the electrode, and the comb blade portion is formed toward the tip of the comb blade portion. The laser trimmable capacitor according to claim 1, wherein each of the laser trimmable capacitors is formed in a shape in which the width is changed. 3. An insulating substrate is provided with electrodes facing each other to form a capacitance on the front and back surfaces thereof, and a comb blade-shaped comb blade portion is formed on a trimmed side of the electrode. A method of manufacturing a laser trimmable capacitor, wherein the width of the comb blade portion is narrower toward the other side, and the laser beam is moved from the wide side of the comb blade portion toward the narrow side during trimming. 4. The width of the comb-teeth-shaped electrode is different toward the tip of the electrode, and the laser beam is moved from the wider side of the comb-shaped portion of the electrode toward the narrower side thereof. The method of manufacturing a laser trimmable capacitor according to claim 3, wherein the trimming is performed by moving the laser beam stepwise or obliquely toward the narrow width of the comb blade portion.