JP4730799B2 - Chip resistor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a chip resistor used in an electronic circuit of a small electronic device.
[0002]
[Prior art]
As electronic devices become smaller, chip resistors used in electronic circuits of the electronic devices are also required to be reduced in size. As such chip resistors, for example, those shown in FIGS. 5 to 7 have been proposed. Among these, the chip resistor shown in FIG. 5 is formed by printing and baking an electrode paste on both ends of the insulating substrate 21 to form a pair of electrode films 22, and a rectangular resistor film between the electrode films 22. After printing and baking 23, a trimming groove 24 is formed by laser, the width of the resistance film 23 divided by the trimming groove 24 is made equal, and the resistance film 23 is meandered for a plurality of turns.
[0003]
Further, the chip-type resistor shown in FIG. 6 has a resistance value adjustment pattern in which a central portion is a rectangular resistance value adjustment pattern in which a resistance paste is printed and baked between a pair of electrode films 22 similar to the above, and both ends are elongated resistance film patterns. The resistance film 23 is formed, and two trimming grooves 24 by laser are formed in a rectangular resistance value adjustment pattern from different directions, and the resistance film 23 is meandered for four turns. Further, in the chip resistor shown in FIG. 7, between the pair of electrode films 22 similar to the above, a thin and long resistive film 23 having the same film width is printed and baked between a plurality of turns. In this way, they are connected.
[0004]
[Problems to be solved by the invention]
However, in the chip type resistor shown in FIG. 5, although the resistance value convergence accuracy after the trimming groove is formed can be ensured, the variation of the resistance value of the rectangular resistance film 23 causes the termination of the termination in surpaint tinting. Since the length of the trimming groove 24 varies and the resistance film 23 is rectangular, a positional deviation occurs during printing of the resistance film, the trimming start point is not determined, and the trimming groove 24 is formed at a biased position. In such a case, there is a problem that the withstand voltage characteristic of the resistance film is lowered and the electric characteristic is deteriorated.
[0005]
In the chip-type resistor shown in FIG. 6, the current path can be lengthened by making the elongated resistance film pattern continuous at both ends of the rectangular resistance film 23, and thereby the resistance resistance of the resistance film between the electrode films 22 can be increased. Although the voltage performance can be improved, there is a problem in that a reduction in the withstand voltage of the resistance film and a deterioration in electrical characteristics due to the trimming groove 24 cannot be avoided as in the case shown in FIG. Further, in the chip type resistor shown in FIG. 7, the problem due to the trimming groove 24 can be avoided, but there is a problem that the resistance value convergence accuracy is poor and the yield of the resistor is lowered.
[0006]
Further, even if it can be confirmed that the remaining width of the resistance film 23 is substantially equal after the trimming groove is engraved by the laser, at the engraving termination point of the trimming groove 24, it is caused by thermal distortion or the like in the laser beam irradiation progress direction. The generation of microcracks is not negligible, and the microcracks cause the current flow in the remaining width of the resistance film 23 to be uneven, resulting in a decrease in the withstand voltage of the resistance film and a deterioration in electrical characteristics. there were.
[0007]
Further, when connecting each electrode film 22 of the metal glaze paste in combination with a metal glaze-based elongated resistance film pattern, there is a step, thermal expansion at these connection portions due to the film thickness peculiar to the metal glaze paste. There is a problem that the resistance film pattern is likely to be cut off due to shrinkage, printing defects during the manufacturing process, and printing fading, thereby impairing the reliability of electrical connection.
[0008]
The present invention has been made paying attention to such a conventional problem, and even when a trimming groove is engraved by a laser in a chip resistor to be miniaturized, the resistance value convergence accuracy is improved and the inter-electrode film is improved. An object of the present invention is to provide a chip resistor capable of improving the reliability and electrical characteristics of the electrical connection of the resistive film to the electrode film while improving the withstand voltage of the resistive film.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, a chip resistor according to the invention of claim 1 includes two electrode films formed on both ends of an insulating substrate and two or more electrode films connected between the electrode films. A resistance value adjustment pattern, a resistance film in which a long and narrow resistance film pattern is integrally connected between the resistance value adjustment patterns and the electrode film, and a plurality of the resistors adjacent to each other through the long and narrow resistance film pattern A chip-type resistor in which trimming grooves are provided in the same direction or different directions in each of the value adjustment patterns, and a trimming start position recognition pattern in which a substantially semicircular recess is formed in the center of the resistance value adjustment pattern to form the said respective corners of the resistance value adjustment pattern and elongated resistive film pattern is formed in an arc shape, before Shiruso remainder width of the resistance value adjustment pattern from the end of the trimming grooves of respectively a substantially Is set to Shii width a, and, and characterized in that the width b of the resistance adjustment patterns隔成into two parts by the trimming and the width a, said larger than the width c of each elongate resistive film pattern To do.
As a result, the trimming groove engraving efficiency and the resistance adjustment efficiency can be improved.
Furthermore, the current flow becomes smooth, and the withstand voltage characteristics of the resistance film can be improved.
[0015]
The chip resistor according to the invention of claim 2 is continuous between the elongated resistance film pattern continuous between the electrode film and the plurality of resistance value adjustment patterns, and between the plurality of resistance value adjustment patterns. The length of the elongated resistive film pattern is set to be substantially equal.
As a result, it is possible to average the withstand voltage characteristics of the resistance films connected between the electrode films and to improve the electrical characteristics.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory view conceptually showing a chip resistor of the present invention and a manufacturing process of the chip resistor. In FIG. 1, 1 is a rectangular insulating substrate made of alumina porcelain. For the sake of convenience, the sheet-like insulating substrate in which divided slits are inserted in the vertical and horizontal directions is shown as being divided into chips by the divided slits.
[0017]
First, as shown in FIG. 1A, a back electrode film 2 having a predetermined width is formed on both the left and right ends of the back surface of the insulating substrate 1 so as to straddle the primary and secondary split slides. The back electrode film 2 is obtained by printing Ag or Ag · Pd metal glaze paste and baking at about 850 ° C.
[0018]
Further, the left and right ends of the surface of the insulating substrate 1 are printed with an Ag / Pd-based metal glaze paste so as to be separated from the primary and secondary split slides, and are baked at about 850 ° C. A surface electrode film lower layer 3 as a film as shown in FIG. 1B is formed. Further, the elongated resistance film pattern 4a integrally connected to both sides of the resistance value adjustment pattern 4b is superposed on a part of the width of the elongated resistance film pattern 4a. Connected. The resistance value adjustment pattern 4b and the elongated resistance film pattern 4a form the resistance film 4.
[0019]
The connection length (overlapping length) of the elongated resistance film pattern 4a to the surface electrode film lower layer 3 is approximately twice or more the width of the elongated resistance film pattern 4a as shown in FIG. The dimensions are close to the length equivalent. This resistance film 4 is obtained by printing a RuO ₂ -based metal glaze paste and baking at 850 ° C. In addition, a substantially semicircular recess 5 serving as a trimming start position recognition pattern is formed at the center of the resistance value adjustment pattern 4b in the resistance film 4. Providing this recess 5 makes it easy to recognize the trimming start point, enables to cut a trimming groove with high positional accuracy and resistance value adjustment accuracy, and realizes resistance value adjustment with a good resistance value yield. .
[0020]
Next, the surface electrode film upper layer 6 is formed thereon so as to cover the surface electrode film lower layer 3 across the elongated resistive film pattern 4a and the vertical division slits overlapping the surface electrode film lower layer 3. It is formed as shown in FIG. The surface electrode film upper layer 6 is obtained by printing an Ag · Pd-based metal glaze paste and baking at about 600 ° C.
[0021]
Further, an undercoat film 7 made of transparent or translucent green glass so as to cover the resistance value adjusting pattern 4b and the elongated resistive film pattern 4a and a part of the surface electrode film upper layer 6 is formed as shown in FIG. ). Here, glass coat printing is performed and baking is performed at about 600 ° C.
[0022]
Next, a trimming groove 8 by a laser method is formed on the resistance value adjustment pattern 4b from the undercoat film 7 with reference to the trimming start position recognition pattern 5 position. The trimming groove 8 is shown in FIG. Here, the distance (width) a from the end of the trimming groove 8 to the position where the extended line of the trimming groove 8 intersects the outer edge of the resistance value adjustment pattern 4b and the trimming groove 8 are separated into two parts. The width b of the resistance value adjustment pattern is made larger than the width c of the elongated resistive film pattern 4a. Thereby, disturbance of current density due to micro cracks generated near the trimming groove 8 and on the extension of the termination point due to thermal distortion caused by laser light irradiation can be alleviated, resistance value variation can be suppressed, and the withstand voltage characteristic of the resistance film 4 can be improved. Can be achieved.
[0023]
Next, a protective coating film 9 made of glass or resin as shown in FIG. 1G is formed on the undercoat film 7 so as to fill the trimming grooves 8, and then the insulating substrate 1 is formed in the vertical direction of the divided slides. Divide into strips along the split slit. Further, an end face electrode film 10 is formed on the end face of the insulating substrate 1 so as to partially overlap the front electrode film upper layer 6 and the back electrode film 2 shown in FIG. Form. Subsequently, the insulating substrate 1 is divided into chips along the horizontal dividing slits, and the plating film 11 is shown on the front electrode film upper layer 6, the back electrode film 2 and the end face electrode film 10 in FIG. Thus, a chip resistor is completed.
[0024]
In FIG. 1C, the connection length of the elongated resistive film pattern 4a to the surface electrode film lower layer 3 is described as being close to the length corresponding to the length of the surface electrode film lower layer 3, but FIG. As shown in FIG. 5, the connection length can be made substantially equal to the length d of the surface electrode film lower layer 3, or can be made to be a length d 'that is substantially twice or more the width c of the elongated resistance value pattern 4a. As a result, electrical and physical connection between the surface electrode film lower layer 3 and the elongated resistance value pattern 4a can be reliably performed with a minimum necessary connection length, and a sufficient withstand voltage at the connection portion can be ensured. That is, disconnection due to thermal expansion and contraction and thermal breakdown due to current concentration can be prevented in advance while eliminating the lack of printing of the resistance film due to the level difference at the connection site. Since the other steps are the same as those described with reference to FIG.
[0025]
When there are a plurality of resistance value adjustment patterns 4b as shown in FIGS. 3 and 4, trimming start position recognition patterns 5 are formed in the same direction or different directions with respect to the adjacent resistance value adjustment patterns 4b. can do. Also in this case, by making the distances a formed by the trimming grooves 7 equal, variations in the adjusted resistance value can be suppressed, and the withstand voltage characteristic of the resistance value is also improved.
[0026]
Further, by making the lengths of the elongated resistance film patterns 4a between the surface electrode film lower layer 3 or the surface electrode film upper layer 6 and the resistance value adjustment pattern 4b and between the adjacent resistance value adjustment patterns 4b substantially equal. In addition, the withstand voltage performance of the entire resistance film 3 is averaged, and thermal breakdown due to current concentration in a part of these can be avoided.
[0027]
The undercoat 7 functions to suppress the expansion of microcracks near or at the end of the trimming groove 8 due to thermal distortion caused by laser light irradiation as described above. This makes it possible to easily recognize the resistance value adjustment pattern and the trimming start position in image recognition and visual inspection. Further, it contributes to the efficiency of the engraving operation of the trimming groove 8 and the improvement of the engraving accuracy such as the engraving state of the trimming groove and the laser trimming groove.
[0028]
3 and 4 are plan views showing other forms of the chip resistor of the present invention, and show the chip resistor in the process corresponding to FIG. 1 (f). As an explanation on the drawing, a mode in which the formation of the protective coat 9 is omitted and a trimming groove is formed is shown. 3 and 4 show two or more resistance value adjustment patterns 4b of the resistance film 4, and a long and narrow resistance film pattern 4a is provided between these and the surface electrode film lower layer 3 respectively. . In FIG. 3, the positions and lengths of the trimming grooves 8 on the respective resistance value adjustment patterns 4b are made substantially equal. In FIG. 4, the positions of the trimming grooves 8 are alternately made opposite to each other, and the lengths are made almost equal. is there. Each trimming groove 8 is formed with reference to each of the recesses 5.
[0029]
For this reason, the remaining widths of the resistance value adjustment patterns 4b separated by the respective trimming grooves 8 become substantially equal, so that variations in resistance values can be suppressed, and as a result, the micro-processing at the end of the trimming groove 8 by laser processing can be suppressed. It is possible to improve the withstand voltage characteristics of the entire resistance film 4 while alleviating the disturbance of current density due to cracks.
[0030]
【The invention's effect】
As described above, according to the present invention, each electrode film formed on both ends of the insulating substrate and the resistance value adjustment pattern and both sides of the resistance value adjustment pattern are connected between the electrode films. A resistance film having a long and narrow resistance film pattern integrally connected thereto, and the length of the long and narrow resistance film pattern in a portion connected to the electrode film is approximately twice or more the width of the long and narrow resistance film pattern; Since the length of the electrode film lower layer 3 is substantially equal, the electrical and physical connection between the electrode film and the resistance film can be ensured, and thermal breakdown due to current concentration at these connection portions can be avoided.
[0031]
Also, by providing a trimming start position recognition pattern for recognizing the trimming start position in the resistance value adjustment pattern, the trimming position with respect to the resistance value adjustment pattern can be set with high accuracy, and resistance value adjustment with a good resistance value yield is achieved. Can be implemented. Further, a trimming groove is formed in the resistance value adjustment pattern, and the remaining width of the resistance value adjustment pattern is made larger than the width of the elongated resistance film pattern from the end of the trimming groove. The disturbance of current density due to cracks can be alleviated, and the withstand voltage characteristics of the resistance film can be improved.
[0032]
In addition, since the resistance film and a part of the electrode film are coated with transparent or translucent green glass, it is possible to suppress the expansion of microcracks near and at the end of the trimming portion due to thermal distortion of laser light irradiation. It is possible to facilitate the recognition of the resistance value adjustment pattern, the trimming start position, and the laser trimming groove engraved state in the image recognition and visual inspection during the value processing. Further, the trimming start position recognition pattern is provided at the same position in the same direction or in a different direction in each of the plurality of resistance value adjustment patterns adjacent via the elongated resistance film pattern. Efficiency and resistance adjustment work efficiency can be improved.
[0033]
In addition, since the remaining widths of the resistance value adjustment patterns from the end of the trimming groove are substantially equal to each other, a stable current density in each of the separated resistance value adjustment patterns can be secured, and as a result, the withstand voltage characteristics can be improved. . Further, since the length of the elongated resistance film pattern continuous between the electrode film and the resistance value adjustment pattern and the length of each elongated resistance film pattern continued between the resistance value adjustment patterns are substantially equal, It is possible to provide a small chip resistor in which the withstand voltage characteristics of the resistance films connected between the films are averaged and the electrical characteristics are improved thereby.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing a chip resistor and a manufacturing process thereof according to an embodiment of the present invention.
FIG. 2 is an explanatory diagram showing a modification of a part of the manufacturing process shown in FIG.
FIG. 3 is an explanatory view showing a part of a manufacturing process of a chip resistor according to another embodiment of the present invention.
FIG. 4 is an explanatory view showing a part of a manufacturing process of a chip resistor according to another embodiment of the present invention.
FIG. 5 is a plan view showing a conventional chip resistor.
FIG. 6 is a plan view showing another conventional chip resistor.
FIG. 7 is a plan view showing another conventional chip resistor.
[Explanation of symbols]
1 Insulating substrate 3 Surface electrode film lower layer (electrode film)
4 Resistance film 4a Elongated resistance film pattern 4b Resistance value adjustment pattern 5 Recessed portion (trimming start position recognition pattern)
6 Surface electrode film upper layer (electrode film)
7 Undercoat (glass)
8 Trimming groove 9 Protective coating film 10 End face electrode film 11 Plating film

Claims (2)

Each one electrode film formed on both ends of the insulating substrate, connected between these electrode films, two or more resistance value adjustment patterns, between these resistance value adjustment patterns, and between these and the electrode films A chip in which trimming grooves are provided in the same direction or in different directions in each of a resistance film in which elongated resistance film patterns are integrally connected to each other and a plurality of resistance value adjustment patterns adjacent to each other via the elongated resistance film pattern. A resistor,
While forming a trimming start position recognition pattern in which a substantially semicircular concave portion is formed in the center of the resistance value adjustment pattern, each corner of the resistance value adjustment pattern and the elongated resistance film pattern is formed in an arc shape,
Before Shiruso remainder width of the resistance value adjustment pattern from the end of the trimming grooves of respectively are set to be substantially equal to the width a, and the resistance adjustment patterns隔成into two parts by the trimming and the width a A chip resistor characterized in that a width b is made larger than a width c of each of the elongated resistive film patterns . The elongated resistance film pattern continuous between the electrode film and the plurality of resistance value adjustment patterns and the elongated resistance film pattern continuous between the plurality of resistance value adjustment patterns are set to be substantially equal. The chip resistor according to claim 1, wherein:

Images