JP2880819B2 - Laser trimming method for chip resistor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser trimming method for a chip resistor, which irradiates a laser to a resistor of a chip resistor to correct a resistance value by removing a part of the resistor.

[0002]

2. Description of the Related Art Generally, as shown in FIG.
Are formed in a grid shape in the vertical and horizontal directions, and two electrodes 5 and 2 are provided in the substrate surface surrounded by the separating line 3 for break.
5 and a resistor 7 straddling both electrodes 5 are formed by printing, and a plurality of chip resistor elements 1 adjacent to each other via a break separation line 3 are formed.

[0003] The resistance values of these multiple chip resistor elements are slightly different from each other due to the difference in printing width and printing film thickness due to the formation of a printing pattern. Therefore, the resistance value of each chip resistance element is corrected to be constant using a laser trimming device. In this resistance value correction process, a measurement probe pin is attached to both electrodes of one chip resistance element, a laser is irradiated to the resistance body while measuring the resistance value, a part of the resistance body is deleted, and the resistance value is removed. The laser irradiation is stopped when becomes constant.

[0004]

In the conventional laser trimming system, a large number of chip resistor elements are arranged one by one via a break separating line, and each of them is laser trimmed. In other words, for example, a laser trimming process is started from the chip resistor element located on the leftmost side of the ceramic substrate, and when the correction of the resistance value of the chip resistor element on the left end is completed, the process proceeds to a laser trimming process on the chip resistor element on the right. is there. In this method, the laser beam feed pitch in the trimming direction is set to be constant. For this reason, as shown in FIG. 6, for example, in the chip resistor elements A and B in which the element length and the width are misaligned, a deviation between the laser beam feeding pitch and the element length occurs, so-called a so-called middle cut. A chip characteristic referred to as (two or more current paths are formed in the resistor 7, "A" in the figure) or both ends (the resistor 7 is trimmed from both sides other than the electrode surface, "B" in the figure) (Noise characteristics, temperature characteristics, withstand voltage characteristics).

According to the present invention, the above-mentioned problems are solved, and two chip resistor elements are paired, and a break separating line located at the center is set as a starting point of laser trimming processing of each chip resistor element. It is another object of the present invention to provide a laser trimming method for a chip resistor, which makes it easy to align a laser irradiation position in a laser trimming device and completely eliminates the occurrence of a middle cut or a double cut due to a printing shift.

[0006]

According to the laser trimming method for a chip resistor of the present invention, a break-off separating line is formed in a grid pattern on a ceramic substrate in the vertical and horizontal directions.
A laser trimming device is used to irradiate a laser with a laser trimming device to a plurality of chip resistor elements each having two electrodes and a resistor straddling both electrodes in a substrate surface surrounded by the break separation line. The two chip resistance elements adjacent to each other with a break separation line in the direction along the extending direction of the two electrodes of the chip resistance element as one set, and this one set The laser trimming of the resistors in the two chip resistor elements is performed by starting laser irradiation starting from the break separation line in the direction along the extending direction of the two electrodes.

In such a laser trimming method for a chip resistor, two chip resistor elements adjacent to each other via a break separating line are paired, and each chip resistor element starts at a break separating line serving as a center line. To perform the laser trimming process. In other words, laser trimming of the chip resistor on the left side of the pair of two chip resistors starts laser irradiation from the break separation line, moves the irradiation in a direction away from the break separation line that is the starting point, and moves the laser for a certain distance. After the irradiation is advanced, the irradiation direction is changed (changed in the direction perpendicular to the downward direction), the movement is performed until the correction of the resistance value is completed, and the laser irradiation is stopped upon completion of the correction. Then, returning to the break separating line, the laser trimming of the chip resistor element on the right side is executed with the break separating line as a start point (irradiation overlapping point). Start laser irradiation from the break separation line, move the irradiation in the direction away from the break separation line, advance the irradiation to a certain distance, change the irradiation direction (change to the perpendicular direction downward), and correct the resistance value Until the correction is completed, and the laser irradiation is stopped when the correction is completed. Thereafter, the laser beam is moved to a break separation line interposed between a pair of adjacent two chip resistance elements, and the same laser trimming is performed.

Thus, since the laser trimming is repeated with two elements as one set, the trimming process can be executed easily and quickly. In addition, since the break separation line is used as the starting point, the alignment of the laser irradiation position is simple and accurate, and it is possible to eliminate the middle cut and both cuts due to the displacement of the resistance printing.

[0009]

1 to 5 are specific process diagrams showing a laser trimming process of a chip resistor according to the present invention. The laser trimming process of the chip resistor performs a resistance correction of a large number of chip resistor elements 1 and 1a printed and formed on the ceramic substrate 4 through the break separating line 3 by a laser trimming device. The two chip resistor elements 1 and 1a adjacent to each other via the break separation line 3 are set as one set, and each chip resistor element 1
A probe pin 6 is connected to a pair of electrodes 5
6 and a set of two chip resistor elements 1, 1a
Is characterized in that laser irradiation is started from the break separation line 3 as a starting point. 2 to 4, the probe pins 6, 6 are not shown, but the probe pins 6, 6 are connected as in FIG.

First, as shown in FIG. 2, a pair of two chip resistor elements 1 and 1a is set as one set, and laser trimming of the left chip resistor element 1 is executed. Using a laser trimming device, probe pins 6 for resistance value measurement are attached to both electrodes 5. Then, laser irradiation is started from the break separating line 3, the irradiation is moved in a direction away from the break separating line 3, which is the starting point, the irradiation is advanced to a certain distance, and a part of the resistor 7 is deleted (( Then, as shown in Fig. 3, the irradiation direction of the laser is changed (changed in the downward perpendicular direction), and the laser beam is moved until the correction of the resistance value is completed. The irradiation is stopped (the part b where the resistor 7 has been deleted by the laser), and the process returns to the break separating line 3. Further, the break separating line 3 is set as a start point (irradiation overlapping point).
The laser trimming of the right chip resistance element 1a is performed. As shown in FIG. 4, the laser irradiation is started again from the break separating line 3, the irradiation is moved in a direction away from the break separating line 3 (in the direction opposite to the element 1), and the irradiation is advanced to a certain distance to make the resistor 7. Is deleted (deleted part c). After that, as shown in FIG. 1, the irradiation direction is changed (changed in the downward perpendicular direction), the movement is performed until the correction of the resistance value is completed, and the laser irradiation is stopped when the correction is completed. 7 deleted part d). Thereafter, as shown in FIG. 5, the laser beam is moved to a break separating line 3 interposed between a pair of adjacent chip resistor elements 2 and 2a, and the same laser trimming processing is executed.

Thus, since the laser trimming is repeated with two elements as one set, the trimming process can be executed easily and quickly. In addition, since the break separation line is used as the starting point, the alignment of the laser irradiation position is simple and accurate, and it is possible to eliminate the middle cut and both cuts due to the displacement of the resistance printing.

[0012]

According to the present invention, as described above, two chip resistor elements adjacent to each other with a break separating line interposed therebetween are connected by one.
As a set, the laser trimming processing of the resistors in the pair of two chip resistor elements is performed by starting the laser irradiation from the break separation line as a starting point, respectively. Therefore, the following effects are obtained. . (1) By setting the break separation line as the start point, the laser irradiation position can be easily and accurately adjusted, and the middle cut and both cuts due to the deviation of the resistance printing can be eliminated. (2) By repeating laser trimming with two elements as one set, the trimming process can be performed easily and quickly.

[Brief description of the drawings]

FIG. 1 is a process chart showing a fourth step of laser trimming processing of an example chip resistor.

FIG. 2 is a process chart showing a first step of a laser trimming process of the chip resistor of the embodiment.

FIG. 3 is a process diagram showing a second process of the laser trimming process of the chip resistor according to the embodiment.

FIG. 4 is a process diagram showing a third process of the laser trimming process of the chip resistor in the example.

FIG. 5 is an explanatory diagram showing a specific example of a laser trimming process of the chip resistor according to the embodiment.

FIG. 6 is an explanatory diagram showing laser trimming processing of a conventional chip resistor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Chip resistance element 1a Chip resistance element 3 Break-off line 4 Ceramic substrate 5 Electrode 7 Resistor

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01C 17/242 H01C 7/00

Claims (1)

(57) [Claims] 1. A ceramic substrate having grids arranged vertically and horizontally in a grid pattern.
A break line is formed for the rake and the break line
Two electrodes and two electrodes respectively on the substrate surface surrounded by the lines
A large number to form a straddling resistor chips resistive element
Laser is irradiated to the resistor by laser trimming device.
In the laser trimming method of the chip resistor to perform a resistance value correction Te, the direction of the probe along the direction of extension of the electrodes of the chip resistor element
Two chip resistors elements adjacent across the separation line for Lake and one set, put in the set of two chips resistive element
That the laser trimming of the resistor, each of the two conductive
A laser trimming method for a chip resistor, which is performed by starting laser irradiation from a break separation line in a direction along a pole extending direction as a starting point.