JPH06112006A - Chip resistor and manufacturing method thereof - Google Patents

Abstract

(57) [Summary] [Purpose] The fine adjustment part and the coarse adjustment part that avoid abrupt resistance value changes are formed in the same chip resistor, and the position detection is performed on the electrode part of the chip-shaped substrate. Also, by providing a marker for recognizing the resistor shape,
The resistor position on the chip is detected, the time required for trimming is shortened, and highly accurate trimming is possible. [Structure] At least one electrode part, or both electrode parts have markers for position detection and resistor shape recognition, and a trapezoidal, diamond-shaped, or drum-shaped resistor is provided on a substrate,
The fine adjustment portion and the rough adjustment portion for avoiding abrupt resistance value change are formed in the same chip resistor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chip resistor mounted on a circuit board for use in current adjustment and voltage adjustment, and a trimming method.

[0002]

2. Description of the Related Art Conventionally, a potentiometer has been used for current adjustment and voltage adjustment of electronic circuits, but in recent years, the resistance value of chip resistors has been adjusted by cutting with a laser or the like. . Further, when a resistor formed on an alumina substrate such as a hybrid IC is trimmed using a laser, the amount of change in resistance value becomes steeper the closer to the end of the resistor in the trimming in the direction perpendicular to the resistor. Since the trimming speed and the amount of change in the resistance value are not constant, adjustment is difficult, and a method called "L-cut" is used in which the trimming direction is trimmed so as to be parallel to the length direction of the resistor in the middle.

[0003]

However, the conventional trimming chip resistor has a "length: width" ratio of "2: 1".
Since the electrodes are formed at both ends in the length direction, the effective trimming resistor amount is small, and it is difficult to use the L-cut, and the trimming has a problem that the trimming in the vertical direction must be used. Had. Also,
Similarly, in the functional trimming in which the trimming is performed while detecting the output signal, the final fine adjustment is difficult because the amount of change in the trimming resistance value in the vertical direction of the resistor is steep.

The present invention has been made in view of the above problems, and an object of the present invention is to detect the position and shape of a resistor on a chip, shorten the time required for trimming, and perform highly accurate trimming. Is possible.

[0005]

In order to solve the above-mentioned problems, the present invention has at least one electrode portion, or both electrode portions having markers for position detection and resistor shape recognition, and is mounted on a substrate. A resistor having a shape, a rhombus shape, or an hourglass shape is provided, and a fine adjustment portion for avoiding a steep resistance value change and a rough adjustment portion are formed in the same chip resistor.

[0006]

According to the above-mentioned method of the present invention, the rough adjustment portion and the fine adjustment portion having different widths of the resistor are provided in the same chip resistor, and the position detecting and resistor shape recognizing markers are provided as electrodes. Since it is included in the part, trimming with high adjustment accuracy can be performed in a short time.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A chip resistor according to an embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a perspective view showing an embodiment of the chip resistor of the present invention. Reference numeral 1 is an end face electrode, 2 is a substrate, 3 is a rhombic resistor provided on the substrate 1, and 4 is a marker provided on the electrode 2 for position detection and low antibody shape confirmation.

Next, a method of manufacturing the trimming chip resistor will be described. The method of manufacturing the trimming chip resistor is the same as that of the conventional one, and alumina 9 is used as the substrate.
A 6% substrate is used, silver-palladium is printed on the electrode, ruthenium oxide is printed on the resistor, and baked at 850 ° C. for 10 minutes, and the marker 4 is formed by printing and baking the resistor simultaneously with ruthenium oxide.

Next, as a trimming method, a chip resistor is mounted by a chip mounter on an electrode on a printed wiring board on which a solder paste is printed, and the solder is melted in a reflow process to be mounted on the printed wiring board.

Next, the marker 4 on the trimming chip resistor is recognized by the image recognition device added to the trimming device, the mounting position is detected, and the shape of the resistor on the trimming chip resistor is recognized from the shape of the marker. Then, the narrowed portion of the resistor on the resistor rhombus is irradiated with a laser in a direction indicated by 5a to perform rough adjustment trimming, and finally, a laser is irradiated in a direction indicated by 5b to perform fine adjustment trimming to obtain a desired adjustment. Get a chip resistor with a resistance value.

The chip resistor trimmed in this way was able to be trimmed in 0.7 seconds, where it took 1.8 seconds conventionally to round up the value to ± 0.3% of the desired trimming target value. Further, the functional trimming, which performs the trimming while detecting the output signal, could be performed in about half the time of the conventional method.

In the above embodiment, the diamond shape is used as the resistor shape, but the shape of the resistor may be any one having a different width, and a trapezoidal shape, a drum shape and the like can be used. Of course, in that case, the positions of coarse adjustment and fine adjustment are different, and rough adjustment is performed in the narrow resistor width portion and fine adjustment is performed in the wide resistor width portion, enabling high-precision trimming in a short time. Becomes

Further, in the above embodiment, the square shape is used as the marker, but it is sufficient if the shape can be recognized, and a round shape or a triangle shape is also possible. Furthermore, the shape of the resistor can be recognized by the shape of this marker, and the shape of the resistor on the chip can be recognized at the same time, and high-precision trimming is also possible by instructing the trimming device about the cutting position, direction and speed Is.

[0015]

As described above, according to the trimming chip resistor of the present invention, the rough adjusting portion and the fine adjusting portion having different widths of the resistor are provided in the same chip resistor, and Since the electrode portion has the marker for recognizing the position and the resistor shape, the trimming with high adjustment accuracy can be performed in a short time.

[Brief description of drawings]

FIG. 1 is a perspective view showing a first embodiment of the present invention.

[Explanation of symbols]

 1 substrate 2 electrode 3 resistor 4 marker 5a coarse adjustment trimming direction 5b fine adjustment trimming direction

Claims (6)

[Claims] 1. A substrate, a trapezoid low antibody on the substrate, an electrode on an end surface of the substrate, and a marker for position detection and resistor shape recognition at at least one position of the electrode. Chip resistor. 2. The chip resistor according to claim 1, wherein the resistor on the substrate has a rhombus shape. 3. The chip resistor according to claim 1, wherein the resistor on the substrate has a drum shape. 4. The drum-shaped resistor has two or three constrictions.
The chip resistor according to claim 3, wherein the chip resistor has one piece. 5. A method of manufacturing a resistor, wherein the same composition as that of the resistor for forming the marker on the substrate is used, and the marker is printed and formed at the same time. 6. A step of detecting a position of the trimming chip resistor and recognizing a resistor shape by using an image recognition device for a marker on the trimming chip resistor, and narrowing the width of the trimming chip resistor. A method of manufacturing a chip resistor, comprising a rough adjusting step of trimming a portion and a fine adjusting step of trimming a wide portion of the trimming chip resistor.