JPS59104101A - Chip resistor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a chip resistor, and particularly to a chip resistor using polycrystalline silicon as a resistor.

FIG. 1 shows a conventional chip resistor. This chip resistor has a resistor 4 made of a metal film formed by a method such as vapor deposition on the upper surface of a substrate 2 made of an insulator such as ceramic, and electrodes 6.8 are attached to both ends of the resistor 4 using metal. It is made of a board.

A semicircular notch 10 formed in a part of the resistor 4 is formed by trimming to adjust the resistance value.

(1) In general, this type of chip resistor requires expensive trimming equipment such as a laser I or reamer to set the resistance value, and in order to improve the setting accuracy, the trimming work is not necessary. This is a time-consuming process. Furthermore, since the resistor 4G is formed to include a notched portion by rimming, its surface area becomes large, resulting in an increase in size. Further, in such a resistor 4, if trimming fails, it is impossible to recover the resistance value.

An object of the present invention is to provide a chip resistor whose resistance value can be modified purely electrically by using polycrystalline silicon containing a high concentration of impurities for the resistor.

This invention forms an insulating film on two surfaces of a substrate made of a semiconductor or an insulator, forms a resistor with polycrystalline silicon containing high concentration of impurities on the upper surface of this insulating film, and forms a resistor on the upper surface of the insulating film. It is characterized by electrodes formed on both ends of the body.

Embodiments of the present invention will be described in detail with reference to the drawings.

2 and 3 show an embodiment of a chip resistor (2) according to the present invention, FIG. 2 shows its overall configuration, and FIG. 3 shows a cross section taken along the line mm in FIG. 2. .

In the figure, the substrate 12 is made of a semiconductor or an insulator,
C:1 insulation Il on the left side of the board 12! ! An oxide film 14 is formed as a film. On the upper surface of this oxide film 14, Z is formed from polycrystalline silicon containing a high concentration of impurities.
A resistor 1G is formed. The impurity contained in this resistor 16 is, for example, an element such as phosphorus P, arsenic AS, holon, etc., and its concentration is about IXIQ211
cm-, 3 or more -1-.

The oxide film 14 is formed on the negative side and side surfaces of the resistor 1G except for a part thereof, that is, the resistor 16
The peripheral surface portion of , except for a part of the -1- plane, is covered with the oxide film 14 . The IIEs are provided at both ends of the substrate 12.
Electrodes 18.20 are provided for electrical connection to both ends jH1ζ of the antibody IG, and the end surfaces G and r of the contacts 1 to 22.24 are protruded from the inner side of these electrodes 18.20.
, are electrically connected to the resistor 16. The electrodes 18 and 20 of this embodiment are formed from highly conductive metal plates, and (3) the resistor 16 is formed by utilizing the 31i1 strength of the material.
The electrodes 18,20 are electrically connected to the resistor 16 by pressing on two sides and by means of connection such as mechanical contact or welding.

With the above configuration, the chip resistor can be configured in the same form as a conventional chip resistor using a metal film as a resistor. Furthermore, since the resistor 16 is made of polycrystalline silicon that contains impurities to a high degree, the resistor 16 can be heated to a level higher than the dark value by applying electrical energy or thermal energy to the resistor 16. The resistance value decreases and maintains the value for the maximum applied current value or maximum temperature, and the value of the maximum current value or maximum temperature becomes the dark value, and no current or heat of -1- above the dark value is applied. as long as
It has the property of being stably maintained. Therefore, a chip resistor configured with such a resistor 16 is different from a conventional chip resistor in which a metal film is used as a resistor, and I/rimming of the resistance value is performed by applying current, voltage, pulse, etc. to the resistor. 16
This can be done purely electrically by giving . Therefore, the area of the resistor 16 can be reduced compared to the case of performing mechanical trimming as in the conventional method (4), so that the size of the chip resistor can be reduced. Regarding trimming work, 4) Since no expensive processing equipment such as a laser trimmer is required, the processing steps can be simplified and the amount of trimming work I. can be reduced. Furthermore, since the trimming is purely electrical, it can be trimmed while being incorporated into the circuit, and the electrical characteristics of the circuit b'/F can be adjusted to the optimum state.

In addition, the resistance value can be recovered by heating the resistor 16, and the value can be returned to almost the initial value, so it is possible to reset the resistance value or compensate for a failure in setting the resistance value. Yield can be improved.

Figures 4-6 show an electrical trimming device. Trimming by current is performed by connecting a current source 28 to the chip resistor J: 126, supplying a constant current, and stopping the current supply when a predetermined resistance value is reached, as shown in FIG.

(5) For trimming by voltage, as shown in Fig. 5, voltage #30 is connected to the chip resistor 26, a constant voltage is applied to the chip resistor 26, and when the predetermined resistance value is reached, the voltage is Stop applying the voltage.

In addition, in pulse trimming, as shown in FIG. 6, a pulse source 32 is connected to the chip resistor 26, and pulses having a constant pulse width or different pulse widths are applied, and a predetermined pulse width is applied as in the trimming described above. When the resistance value is reached, the pulse application is stopped.

7 to 9 show the experimental results of 1-rimming. FIG. 7 shows the resistance value R that occurs when direct current is applied to the resistor 16 doped with boron.
The ratio of change (R/Ro) to the initial resistance value RO is shown. In this experimental result, curves a and b represent resistor 1
For curves c and d, the film thickness of resistor 16 is 0.29 μm, and for curves e and f, the film thickness is 0.48 μm.
Curves a, c, and e show those subjected to annealing treatment, and curves ., d, and f indicate those not subjected to annealing treatment. In addition, the arrow r)+ indicates that the current density (6) is 8. 'lX 105A/cth, arrow p2 indicates a current density of 8.8X+05A/cti, and arrow p3 indicates a current density of 8.3X 105A/crA. In this experimental result, when the current is increased, a constant current (1
It can be seen that when the value exceeds 7f, the resistance value shows a linear decreasing change.

FIG. 8 shows the ratio of change in the resistance value R to the initial resistance value Ro by 1 (R/R
o) is shown. In this experimental result, curve a,
, b4; 19 thickness of resistor 16 is set to 0.29 μm, curve No. 3, 1 sheet resistance R5-52Ω/hole, curve bc
Yoshi 111 (resistance Rs = 57Ω/mouth) is shown. Curves c and d show the film thickness of the resistor 16 of 0.4
8/fm, and curve C is sheet resistance R5-19Ω/
Mouth, curve number d,! Sea I-Resistance R3-18Ω/port is shown. Also, arrow p1 has a current density of 8.8X
105A/cJ, arrow p2 is current density 9.6X1
05A/cJ is shown. This experimental result shows that, as with the previous results, when the current value exceeds a certain value, the resistance value exhibits a substantially linear decreasing change.

(7) FIG. 9 shows the change ratio (R/ Ro) is shown. The period T of the pulse used in the experiment was 1.511S, and its voltage value was 6
It is 0V. In this experimental result, curves a and b represent the film thickness of the resistor 16 at 0.21/17 m, curves c and d represent the film thickness of the resistor 16 at 0°29 μm, and curves e and f represent the film thickness of the resistor 16 at 0.21/17 m. The film thickness was set to 0.48/7m. In addition, curves a, c, and e are curves that have been annealed,
d, , f are not subjected to annealing treatment. The results of this experiment show that at age 6, the resistance value shows a significant decrease as the number of pulses increases.

As is clear from the above experimental results, by applying pure electrical energy such as direct current or pulses, the resistance value can be reduced by 1
Rimming can be performed, and the resistance value decreases in proportion to the current value when the current value exceeds a certain value, and in proportion to the number of pulses in the case of pulse application, so it is easy to (8) A desired value can be set.

As explained above, according to the present invention, 1-
It can be rimmed, and 1-the rimming accuracy is high.
It eliminates the need for a conventional monovalent L trimming device, is more compact, and can be trimmed again by heating or other methods even after trimming fails.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing a conventional chip resistor, Fig. 2 is a perspective view showing an embodiment of the chip resistor of the present invention, and Fig. 3 is a cross-sectional view taken along line 1--2 in Fig. 2. , Figures 4 to 6
The figure is a circuit diagram showing a trimming circuit, and FIGS. 7 to 9 are explanatory diagrams showing experimental results of trimming. DESCRIPTION OF SYMBOLS 12... Substrate, 14... Oxide film as an insulating coating, 16... Resistor, 18.20... Electrode. (9) Figure 1 Figure 2 ■ 〆N υsu

Claims (1)

[Claims] An insulating film is formed on two sides of a substrate made of a semiconductor or an insulator, a resistor made of polycrystalline silicon containing a high concentration of impurities is formed on the upper surface of this insulating film, and both ends of this resistor are A chip resistor characterized by having electrodes formed on its parts.