Chip Resistor and Method of Manufacturing the Same

Abstract

To provide a chip resistor capable of improving surge characteristics and finely adjusting a resistance value with high accuracy.SOLUTION: A chip resistor 1 includes a rectangular parallelepiped insulating substrate 2, a first front electrode 3 and a second front electrode 4 provided at both ends of the insulating substrate 2 in the longitudinal direction, and a resistor 5 connected to these first and second front electrodes 3 and 4, and the resistor 5 is formed in a meandering shape in which a first region 8 and a second region 9 are continuous via a connecting portion 10 between a pair of connecting portions 6 and 7. In the first region 8, a first trimming groove 11 for coarse adjustment is formed to lengthen a current path of the resistor 5, and in the second region 9, a second trimming groove 12 for fine adjustment is formed so as to extend in a direction inclined with respect to the straight line along the extending direction of the first trimming groove 11.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a chip resistor whose resistance value is adjusted by forming a trimming groove in a resistor provided on an insulating substrate, and a method for manufacturing such a chip resistor.

Background Art

[0002] A chip resistor mainly includes a rectangular parallelepiped insulating substrate, a pair of front electrodes oppositely arranged on the surface of the insulating substrate at a predetermined interval, a pair of back electrodes oppositely arranged on the back surface of the insulating substrate at a predetermined interval, an end face electrode bridging the front electrode and the back electrode, a resistor bridging the paired front electrodes, and a protective film covering the resistor.

[0003] Generally, when manufacturing such a chip resistor, after forming a large number of electrodes, resistors, protective coating layers, etc. on a large-sized substrate at once, the large-sized substrate is divided along grid-like dividing lines (for example, dividing grooves) to obtain a large number of chip resistors. In the manufacturing process of such a chip resistor, a large number of resistors are formed on one side of the large-sized substrate by printing and baking a resist paste. However, due to factors such as misalignment and bleeding during printing, or temperature unevenness in the firing furnace, it is inevitable that there will be some variations in the size and film thickness of each resistor. Therefore, a resistance value adjustment operation is performed to form a trimming groove in each resistor in the state of the large-sized substrate to set it to a desired resistance value.

[0004] In a chip resistor having such a configuration, when a surge voltage generated by static electricity, power supply noise, etc. is applied, the characteristics of the resistor will be affected by excessive electrical stress, and in the worst case, the resistor may be damaged. In order to improve the surge characteristics, it is known that if the resistor is formed in a meandering shape (a meander shape) to increase the total length, the potential drop becomes gentle and the surge characteristics can be improved.

[0005] As a prior art of this kind, as shown in FIG. 8, between a pair of front electrodes 101 provided at both ends of an insulating substrate 100, a meander-shaped resistor 105 in which a first meandering portion 103 and a second meandering portion 104 at both ends are continuous with a central adjustment portion 102 interposed therebetween is printed, and an I-cut-shaped first trimming groove 106 for lengthening the current path of the resistor 105 is formed in the adjustment portion 102. After roughly adjusting the resistance value of the resistor 105 to a value slightly lower than the target resistance value, a chip resistor has been proposed in which a second trimming groove 107 having an L-cut shape is formed in the second meandering portion 104 so as to finely adjust the resistance value of the resistor 105 until it matches the target resistance value (see Patent Document 1).

[0006] In the prior art disclosed in Patent Document 1 above, by forming the first trimming groove 106 in the adjustment portion 102 of the resistor 105 printed and formed in a meander shape, after roughly adjusting the resistance value of the resistor 105 to approach the target resistance value, by forming the second trimming groove 107 having an L-cut shape in the second meandering portion 104, the resistance value of the resistor 105 is finely adjusted to match the target resistance value. Therefore, it is possible to adjust the resistance value with high precision while improving the surge characteristics.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] In the chip resistor described in Patent Document 1, the current passes through the second meandering portion 104 of the resistor 105 along the shortest path indicated by the virtual line E in FIG. 8. This shortest path E is the part where the most current flows. Since the second trimming groove 107 is formed in a region where the current distribution is small, if consideration is given so that the tip of the second trimming groove 107 does not exceed the shortest path E, the resistance value of the resistor 105 can be finely adjusted to match the target resistance value according to the cutting amount of the second trimming groove 107. However, there is variation in the initial resistance value of the printed resistor 105. If the initial resistance value of the resistor 105 is too low, even if the second trimming groove 107 is formed, the resistance value of the resistor 105 cannot be increased to the target resistance value range, which may lead to a decrease in yield.

[0009] The present invention has been made in view of such circumstances of the prior art. The first object is to provide a chip resistor capable of improving surge characteristics and finely adjusting the resistance value with high precision. The second object is to provide a manufacturing method for such a chip resistor.

Means for Solving the Problems

[0010] To achieve the above first object, the chip resistor according to the present invention includes a rectangular parallelepiped insulating substrate, a pair of electrodes oppositely arranged on the insulating substrate with a predetermined interval therebetween, and a resistor bridging between the pair of electrodes. In the chip resistor in which the resistance value is adjusted by forming a trimming groove extending linearly in the resistor, the resistor is a printed body having a connection portion connected to the pair of electrodes and a rectangular adjustment portion located between the two connection portions. At least one of the connection parts is a turn part extending in a meandering shape, In the adjustment portion, a first trimming groove for rough adjustment that lengthens the current path of the resistor and a second trimming groove for fine adjustment that adjusts the resistance value after rough adjustment by the first trimming groove are formed. The straight line along the extending direction of the second trimming groove is inclined with respect to the straight line along the extending direction of the first trimming groove.

[0011] In the chip resistor configured as described above, by forming a first trimming groove in the adjustment section to lengthen the current path of the resistor element, the resistance value increases as the cut amount of the first trimming groove increases. Thus, the surge characteristics can be improved and the resistance value can be roughly adjusted. Further, by forming a second trimming groove in a region with a low current distribution in the adjustment section, the resistance value can be finely adjusted with high precision. Also, since at least one of the connection parts of the resistor is a turn part extending in a meandering shape, the current path of the resistor becomes longer and the surge characteristics can be improved. Moreover, by inclining the straight line along the extending direction of the second trimming groove with respect to the straight line along the extending direction of the first trimming groove, the second trimming groove can be formed to be long along the shortest current path. As a result, adjustment failures of the resistance value can be reduced and the yield can be improved.

[0013] In the chip resistor having the above configuration, both the first trimming groove and the second trimming groove may be formed in one adjustment section. However, if the adjustment section has a first region and a second region that are continuous via a connecting section, and the first trimming groove is formed in the first region and the second trimming groove is formed in the second region, the regions for forming the rough adjustment trimming groove and the fine adjustment trimming groove are separated. This enables more precise adjustment of the resistance value and lengthens the current path of the resistor element, further improving the surge characteristics.

[0014] In this case, the number of the first trimming grooves formed in the first region is not particularly limited. However, it is preferable that a plurality of first trimming grooves having an I-cut shape with different length dimensions are formed in the first region, as the resistance value of the resistor element can be roughly adjusted with high precision.

[0015] Here, when two first trimming grooves are formed in the first region, the second first trimming groove may be formed parallel to the first first trimming groove, or one of the first trimming grooves may be inclined with respect to the other first trimming groove. Alternatively, the two first trimming grooves may be formed to extend in opposite directions with the opposing sides of the first region as the starting ends.

[0016] Also, in order to achieve the above second object, a method for manufacturing a chip resistor according to the present invention includes an insulating substrate, a first electrode and a second electrode oppositely arranged on the insulating substrate with a predetermined interval therebetween, and a resistor bridging between the first electrode and the second electrode. In the method for manufacturing a chip resistor in which the resistance value is adjusted by forming a trimming groove linearly extending in the resistor, the resistor includes a turn portion extending in a meandering shape and connected to the first electrode, a rectangular first region connected to the turn portion, a rectangular second region connected to the second electrode, and a connecting portion connecting between the first region and the second region, and is formed of a printed body. After forming a first trimming groove for rough adjustment that lengthens the current path of the resistor in the first region, a second trimming groove extending in a direction inclined with respect to a straight line along the extending direction of the first trimming groove is formed in the second region, thereby finely adjusting the resistance value after rough adjustment by the first trimming groove to a target resistance value range.

[0017] In the method for manufacturing a chip resistor including such steps, after printing and forming a meander-shaped resistor in which the first region and the second region are continuous via a connecting portion, by forming a first trimming groove that lengthens the current path of the resistor in the first region, the resistance value increases with the cutting amount of the first trimming groove, so that the surge characteristics can be improved and the resistance value can be roughly adjusted. Then, after forming the first trimming groove, by forming a second trimming groove in the second region in a direction inclined with respect to the first trimming groove, the second trimming groove can be formed long along the shortest current path, so that the resistance value can be finely adjusted with high precision and the adjustment failure of the resistance value can be reduced to improve the yield.

Effects of the Invention

[0018] According to the present invention, it is possible to provide a chip resistor capable of improving surge characteristics and finely adjusting the resistance value with high precision.

Brief Description of the Drawings

[0019]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0020] Hereinafter, embodiments of the invention will be described with reference to the drawings. FIG. 1 is a plan view of a chip resistor according to the first embodiment of the present invention.

[0021] As shown in FIG. 1, the chip resistor 1 according to the first embodiment mainly includes a rectangular parallelepiped insulating substrate 2, a first front electrode 3 and a second front electrode 4 provided at both longitudinal ends of the surface of the insulating substrate 2, and a resistor body 5 provided on the surface of the insulating substrate 2 so as to be connected to the first and second front electrodes 3 and 4, and a protective coat layer (not shown) provided so as to cover the resistor body 5. Although not shown in the figure, a pair of back electrodes are provided on the back surface of the insulating substrate 2 so as to correspond to the first and second front electrodes 3 and 4, and end face electrodes that bridge the corresponding front electrodes and back electrodes, and external electrodes plated so as to cover the end face electrodes are provided at both end faces in the longitudinal direction of the insulating substrate 2. In the following description, the direction between the electrodes of the first and second front electrodes 3 and 4 is the X direction, and the direction orthogonal to this X direction is the Y direction.

[0022] The resistor 5 is formed in a meander shape in which a first region 8 and a second region 9 are continuous via a connecting portion 10 between a pair of connecting portions 6 and 7, and such a meander shape is defined by the printed shape of the resistor paste. The connecting portion 6 on the left side in the figure is a turn portion formed in a meandering shape, and this connecting portion 6 connects between the first front electrode 3 and the upper end portion of the first region 8. Further, the connecting portion 7 on the right side in the figure is a linear pattern, and this connecting portion 6 connects between the second front electrode 4 and the lower end portion of the second region 9. The first region 8 and the second region 9 are adjustment portions for adjusting the resistance value of the resistor 5, and both the first region 8 and the second region 9 are formed in a rectangular shape. The upper end portion of the first region 8 and the upper end portion of the second region 9 are connected via the connecting portion 10, and the pattern widths of this connecting portion 10 and both connecting portions 6 and 7 are set to be substantially the same.

[0023] In the first region 8, two first trimming grooves 11 having different length dimensions are formed, and the resistance value of the resistor 5 is roughly adjusted by these first trimming grooves 11 so as to approach the target resistance value. The longer first trimming groove 11 is an I-cut shaped slit extending in the Y direction from the upper side to the lower side of the first region 8. By forming such a first trimming groove 11 in the first region 8, the resistor 5 has a shape of meandering three turns and the current path becomes longer. The shorter second first trimming groove 11 is also an I-cut shaped slit extending in the Y direction from the upper side to the lower side of the first region 8, and the first first trimming groove 11 and the second first trimming groove 11 extend parallel to each other. However, the number of the first trimming grooves 11 formed in the first region 8 is not limited to two, and may be one or three or more.

[0024] In the second region 9, a second trimming groove 12 having an I-cut shape extending in an inclined direction with respect to the Y direction from its upper side to its lower side is formed, and the resistance value of the resistor 5 is finely adjusted by this second trimming groove 12 so as to approach the target resistance value. Here, the tip of the second trimming groove 12 is set at a position not exceeding an imaginary line E that connects the connecting portion 10 and the connecting portion 7 on the right side in the drawing at the shortest distance. Since the imaginary line E is the portion where the most current flows within the second region 9, the second trimming groove 12 is formed within a region where the current distribution in the second region 9 is small. Moreover, since the extending direction of the second trimming groove 12 is inclined with respect to the extending direction (Y direction) of the first trimming groove 11, the second trimming groove 12 can be formed long along the shortest current path (imaginary line E). Therefore, the amount of change in the resistance value associated with the cutting amount of the second trimming groove 12 becomes small, the resistance value of the resistor 5 can be finely adjusted with high precision, and adjustment failures of the resistance value can be reduced to improve the yield.

[0025] Next, the manufacturing process of the chip resistor 1 configured as described above will be described with reference to FIG. 2.

[0026] First, a large-sized substrate on which a large number of insulating substrates 2 are taken is prepared. On this large-sized substrate, primary division grooves and secondary division grooves extending vertically and horizontally are provided in a grid pattern, and each of the meshes separated by both division grooves becomes a chip region for one piece. Although a large-sized substrate 2A corresponding to a chip region for one piece is representatively shown in FIG. 2, actually, the following respective processes are collectively performed on the large-sized substrate corresponding to a large number of chip regions.

[0027] That is, as shown in FIG. 2(a), after Ag-based paste is screen-printed on the surface of this large-sized substrate 2A, it is dried and fired to form a pair of first surface electrodes 3 and second surface electrodes 4 (surface electrode forming step). Incidentally, simultaneously with or before and after this electrode forming step, after Ag-based paste is screen-printed on the back surface of the large-sized substrate 2A, it is dried and fired to form a back electrode (not shown) (back electrode forming step).

[0028] Next, as shown in FIG. 2(b), a resistor paste such as ruthenium oxide is screen-printed on the surface of the large substrate 2A and dried and fired to form a resistor 5 whose both longitudinal ends overlap with the first front electrode 3 and the second front electrode 4 (resistor forming step). This resistor 5 has a meandering connection part (turn part) 6 connected to the first front electrode 3, a connection part 7 connected to the second front electrode 4, and rectangular first region 8 and second region 9 connected to both these connection parts 6 and 7, and the first region 8 and the second region 9 are connected via a connecting part 10. Note that the order of the front electrode forming step and the resistor forming step may be reversed, and after forming the resistor 5, it is also possible to form the first front electrode 3 and the second front electrode 4 so as to overlap both ends of the resistor 5.

[0029] Here, in FIG. 2, if the extending direction of the secondary division groove is the X direction and the extending direction of the primary division groove is the Y direction, the connection part 6 on the left side in the figure has a lower horizontal part 6a extending in the X direction from the first front electrode 3, a vertical part 6b extending in the Y direction from the right end of the lower horizontal part 6a, and an upper horizontal part 6c extending in the X direction from the upper end of the vertical part 6b and connected to the upper end of the first region 8. Also, the connection part 7 on the right side in the figure extends in the X direction and connects between the lower end of the second region 9 and the second front electrode 4, and the connecting part 10 extends in the X direction and connects between the upper end of the first region 8 and the upper end of the second region 9.

[0030] Next, a glass paste is screen-printed on the resistor 5 and dried and fired to form a precoat layer (not shown) covering the resistor 5, and then a laser beam is irradiated from above this precoat layer. As shown in FIG. 2(c), a first trimming groove 11 is formed in the first region 8. The first trimming groove 11 is an I-cut-shaped slit formed to extend in the Y direction from the upper side to the lower side of the first region 8, and this slit is formed along a straight line extending in the Y direction. And by forming such a first trimming groove 11 in the first region 8, the current path of the entire resistor 5 becomes longer, so that the resistor 5 formed in a printed shape having two meandering parts at this point becomes a meander shape with 3-turn meandering.

[0031] Subsequently, as shown in FIG. 2(d), a second first trimming groove 11 shorter than the first first trimming groove 11 is formed in the first region 8, and the resistance value of the resistor 5 is roughly adjusted to a value slightly lower than the target resistance value by these first and second first trimming grooves 11 (resistance value rough adjustment step). The second first trimming groove 11 is formed in a region with a low current distribution in the first region 8 after the first first trimming groove 11 is formed, and is an I-cut-shaped slit extending in the Y direction from the upper side to the lower side of the first region 8, similar to the first first trimming groove 11. Note that the number of the first trimming grooves 11 formed in the first region 8 is not limited to two, and may be one or three or more.

[0032] Next, as shown in FIG. 2(e), an I-cut-shaped second trimming groove 12 is formed in the second region 9, and the resistance value of the resistor 5 is finely adjusted to match the target resistance value by this second trimming groove 12 (resistance value fine adjustment step). The second trimming groove 12 is an I-cut-shaped slit extending from the upper side of the second region 9 at a predetermined inclination angle θ with respect to the Y direction, and consideration is given so that its tip does not exceed an imaginary line E connecting the connecting portion 10 and the connecting portion 7 on the right side in the drawing at the shortest distance.

[0033] Here, the part where the most current flows in the second region 9 is the virtual line E. The second trimming groove 12 is formed within a region where the current distribution in the second region 9 is small, and its extending direction is inclined with respect to the extending direction (Y direction) of the first trimming groove 11. Thereby, since the second trimming groove 12 can be formed long along the shortest current path (virtual line E), the change amount of the resistance value associated with the cutting amount of the second trimming groove 12 becomes small, and the resistance value of the resistor 5 can be finely adjusted with high precision. Note that the inclination angle θ of the second trimming groove 12 with respect to the Y direction, in other words, the inclination angle θ of the straight line along the extending direction of the second trimming groove 12 with respect to the straight line along the extending direction (Y direction) of the first trimming groove 11 is preferably within the range of 1° to 3° (1° ≤ θ ≤ 3°). When the inclination angle θ becomes larger than that, the change amount of the resistance value per unit length associated with the cutting amount of the second trimming groove 12 becomes too small, and the variation after the rough adjustment of the resistance value by the first trimming groove 11 may not be completely finely adjusted by the second trimming groove 12.

[0034] Next, an epoxy-based resin paste is screen-printed from above the first trimming groove 11 and the second trimming groove 12 and heat-cured to form a protective coat layer (not shown) that covers the entire resistor 5 (protective coat layer forming step).

[0035] Each of the steps up to this point is a batch process for the large-sized substrate 2A for mass production. In the next step, a strip-shaped substrate (not shown) provided with chip regions for a plurality of pieces is obtained by performing a primary break process of dividing the large-sized substrate 2A into strips along the primary dividing groove (primary dividing step). Next, by sputtering Ni / Cr on the dividing surface of the strip-shaped substrate, an end face electrode (not shown) that bridges the back electrodes corresponding to the first and second surface electrodes 3 and 4 is formed (end face electrode forming step).

[0036] Subsequently, a secondary breaking process of dividing the strip-shaped substrate along the secondary dividing groove is performed to obtain a single chip having the same size as the chip resistor 1 (secondary dividing step). Finally, electrolytic plating (Ni plating and Sn plating) is applied to both longitudinal ends of the insulating substrate 2 of each individual chip, and external electrodes (not shown) that cover the end face electrodes, the back electrode, and the first and second surface electrodes 3 and 4 exposed from the protective coating layer are formed, whereby the chip resistor 1 as shown in FIG. 1 is obtained.

[0037] As described above, in the chip resistor 1 according to the first embodiment, after the resistor body 5 having the rectangular first region 8 and the second region 9 is printed and formed, the first trimming groove 11 is formed in the first region 8, thereby lengthening the current path of the resistor body 5 to improve the surge characteristics and coarsely adjusting the resistance value of the resistor body 5 so as to approach the target resistance value. After such coarse adjustment of the resistance value, a second trimming groove 12 is formed in a region where the current distribution in the second region 9 is small. At this time, by inclining the extending direction of the second trimming groove 12 with respect to the extending direction of the first trimming groove 11, the second trimming groove 12 can be formed long along the shortest current path (virtual line E). As a result, the change in the resistance value due to the cut of the second trimming groove 12 becomes gentle, the resistance value can be finely adjusted with high precision, and the adjustment failure of the resistance value is reduced, thereby improving the yield.

[0038] Further, in the chip resistor 1 according to the first embodiment, the first region 8 and the second region 9, which are the resistance value adjustment parts, are connected via the connecting part 10, and the regions for forming the first trimming groove 11 for coarse adjustment and the second trimming groove 12 for fine adjustment are separated. Therefore, high-precision resistance value adjustment is possible, and the current path of the resistor body 5 becomes long, thereby improving the surge characteristics. Also, the resistance value is coarsely adjusted by the two first trimming grooves 11 formed in the first region 8, and since the second first trimming groove 11 is set shorter than the first first trimming groove 11, a chip resistor 1 excellent in withstand voltage (surge resistance characteristics) can be realized.

[0039] FIG. 3 is a plan view of the chip resistor 20 according to the second embodiment of the present invention. Parts corresponding to those in FIG. 1 are denoted by the same reference numerals, and redundant descriptions are omitted as appropriate.

[0040] The difference between the second embodiment and the first embodiment is that the two first trimming grooves 11 formed in the first region 8 do not extend in parallel, and the second first trimming groove 11 is formed in a direction inclined with respect to the first first trimming groove 11. Other configurations are basically the same as those of the chip resistor 1 shown in FIG. 1.

[0041] That is, as shown in FIG. 3, the first first trimming groove 11 is formed to extend in the Y direction from the upper side to the lower side of the first region 8, and the second first trimming groove 11 is formed to extend in an inclined direction with respect to the Y direction from the upper side of the first region 8. The second trimming groove 12 formed in the second region 9 is inclined with respect to the extending direction of the first first trimming groove 11, and the second first trimming groove 11 and the second trimming groove 12 are inclined in opposite directions with respect to the extending direction of the first first trimming groove 11.

[0042] In the chip resistor 20 according to the second embodiment configured as described above, since the second first trimming groove 11 extends in a direction inclined with respect to the first first trimming groove 11, the change in the resistance value associated with the cut of the second first trimming groove 11 becomes gentle, and a more accurate rough adjustment of the resistance value becomes possible. Further, since the microcracks generated at the tip of the second first trimming groove 11 are directed toward the first first trimming groove 11, the extension of the microcracks generated in the second first trimming groove 11 can be absorbed by the first first trimming groove 11.

[0043] In the chip resistor 20 according to the second embodiment, the second first trimming groove 11 is inclined with respect to the first first trimming groove 11. However, as in the chip resistor 30 according to the third embodiment shown in FIG. 4, after the first first trimming groove 11 is formed so as to extend in the inclined direction with respect to the Y direction from the upper side of the first region 8, the second first trimming groove 11 may be formed so as to extend in the Y direction from the upper side to the lower side of the first region 8. In this case, by forming the second first trimming groove 11 longer than the first first trimming groove 11, the expansion of the microcrack generated at the tip of the first first trimming groove 11 is absorbed by the second first trimming groove 11.

[0044] FIG. 5 is a plan view of a chip resistor 40 according to a fourth embodiment of the present invention. Parts corresponding to those in FIG. 1 are denoted by the same reference numerals, and redundant descriptions are appropriately omitted.

[0045] The difference between the fourth embodiment and the first embodiment is that the two first trimming grooves 11 are formed in opposite directions starting from the upper and lower sides of the first region 8, and the two second trimming grooves 12 are formed in opposite directions starting from the upper and lower sides of the second region 9. Other configurations are basically the same as those of the chip resistor 1 shown in FIG. 1.

[0046] That is, as shown in FIG. 5, the first first trimming groove 11 is formed so as to extend in the Y direction from the upper side to the lower side of the first region 8, and the second first trimming groove 11 is formed so as to extend in the Y direction from the lower side to the upper side of the first region 8. By forming the two first trimming grooves 11 in opposite directions from the upper and lower sides of the first region 8 in this way, the routing path of the first region 8 can be lengthened to improve the surge characteristics.

[0047] Regarding the fine adjustment of the resistance value, after forming the first second trimming groove 12 so as to be inclined with respect to the Y direction from the upper side to the lower side of the second region 9, the second trimming groove 12 is formed so as to be inclined with respect to the Y direction from the lower side to the upper side of the second region 9. Here, since the portion where the second second trimming groove 12 is formed is within a region where the current distribution in the second region 9 is extremely small, extremely high-precision fine adjustment becomes possible by forming the second second trimming groove 12. Note that the second second trimming groove 12 is also set at a position not exceeding the virtual line E, and both the first and second second trimming grooves 12 are formed along the shortest current path (virtual line E).

[0048] FIG. 6 is a plan view of a chip resistor 50 according to a fifth embodiment of the present invention. Parts corresponding to those in FIG. 1 are denoted by the same reference numerals, and redundant descriptions are omitted as appropriate.

[0049] The difference between the fifth embodiment shown in FIG. 6 and the first embodiment is that both of the pair of connection portions 6 and 7 are formed as linear patterns, and the other configurations are basically the same as those of the chip resistor 1 shown in FIG. 1. That is, the connection portion 6 on the left side in the figure is a linear pattern connecting between the first surface electrode 3 and the upper end portion of the first region 8, and the connection portion 6 on the right side in the figure is a linear pattern connecting between the second surface electrode 4 and the lower end portion of the second region 9. Even for a resistor 5 having such a shape, after forming the first trimming groove 11 for rough adjustment in the first region 8, by forming the second trimming groove 12 for fine adjustment extending in the inclined direction with respect to the first trimming groove 11 in the second region 9, it is possible to improve the surge characteristics and finely adjust the resistance value with high precision.

[0050] FIG. 7 is a plan view of a chip resistor 60 according to a sixth embodiment of the present invention. Parts corresponding to those in FIG. 1 are denoted by the same reference numerals, and redundant descriptions are omitted as appropriate.

[0051] The difference between the sixth embodiment shown in FIG. 7 and the first embodiment lies in that the first trimming groove 11 and the second trimming groove 12 are formed in one adjusting portion 51, and the other configurations are basically the same as those of the chip resistor 1 shown in FIG. 1. That is, the resistor body 5 has a connecting portion 6 on the left side in the figure that extends in a meandering shape, a connecting portion 7 on the right side in the figure that extends linearly, and a rectangular adjusting portion 51 formed between these two connecting portions 6 and 7. A first trimming groove 11 for rough adjustment and a second trimming groove 12 for fine adjustment are formed in this adjusting portion 51. Even for a resistor body 5 having such a shape, after forming the first trimming groove 11 so as to extend in the Y direction from the upper side to the lower side of the adjusting portion 51, and then forming the second trimming groove 12 so as to be inclined with respect to the Y direction from the upper side to the lower side of the adjusting portion 51, it is possible to improve the surge characteristics and finely adjust the resistance value with high accuracy.

[0052] Note that the present invention is not limited to the above-described embodiments, and various modifications are possible without departing from the technical gist thereof. For example, the first trimming groove 11 for rough adjustment is not limited to an I-cut shape, and may be an L-cut shape or a J-cut shape in which the tip of the straight portion turns as long as it has a straight portion.

[0053] Also, when the chip resistor has a resistor body with a meandering connecting portion as in the first to fourth embodiments, as the chip resistor is miniaturized, the distance between the resistor body and the front electrode becomes narrow, and the influence due to bleeding during printing of the resistor body becomes large. In such a case, the front electrode may be arranged so as to be biased toward the connecting portion side with the resistor body to widen (separate) the distance between the resistor body and the front electrode.

Explanation of Reference Numerals

[0054] 1, 20, 30, 40, 50, 60 Chip Resistors 2 Insulating Substrate 2A Large-Size Substrate 3 First Front Electrode 4 Second Front Electrode 5 Resistor Body 6, 7 Connecting Portions 8 First Region 9 Second Region 10 Connecting Part 11 First Trimming Groove 12 Second Trimming Groove 51 Adjusting Part

Claims

1. A chip resistor comprising a rectangular parallelepiped insulating substrate, a pair of electrodes oppositely disposed on the insulating substrate with a predetermined interval therebetween, and a resistor bridging between the pair of electrodes, wherein the resistance value is adjusted by forming a trimming groove extending linearly in the resistor. In the chip resistor, the resistor is a printed formed body having a connection portion connected to the pair of electrodes and a rectangular adjustment portion located between both connection portions, at least one of the connection portions is a turn portion extending in a meandering shape, a first trimming groove for rough adjustment to lengthen the current path of the resistor and a second trimming groove for fine adjustment to adjust the resistance value after rough adjustment by the first trimming groove are formed in the adjustment portion, a chip resistor, characterized in that a straight line along the extending direction of the second trimming groove is inclined with respect to a straight line along the extending direction of the first trimming groove.

2. The adjustment portion has a first region and a second region that are continuous via a connecting portion, the first trimming groove is formed in the first region, and the second trimming groove is formed in the second region. The chip resistor according to claim 1, characterized in that

3. The chip resistor according to claim 2, characterized in that a plurality of the first trimming grooves having an I-cut shape with different length dimensions are formed in the first region.

4. The chip resistor according to claim 3, characterized in that two first trimming grooves are formed in the first region, and one of the first trimming grooves is inclined with respect to the other first trimming groove.

5. The chip resistor according to claim 2, characterized in that two first trimming grooves are formed in the first region, and the two first trimming grooves extend in opposite directions starting from opposite side edges of the first region.

6. In a method for manufacturing a chip resistor comprising an insulating substrate, a first electrode and a second electrode oppositely disposed on the insulating substrate with a predetermined interval therebetween, and a resistor bridging between the first electrode and the second electrode, wherein the resistance value is adjusted by forming a trimming groove extending linearly in the resistor. In the method, the resistor is composed of a printed formed body having a turn portion connected to the first electrode and extending in a meandering shape, a rectangular first region connected to the turn portion, a rectangular second region connected to the second electrode, and a connecting portion connecting between the first region and the second region. After forming a first trimming groove for coarse adjustment that lengthens the current path of the resistor in the first region, a second trimming groove that extends in a direction inclined with respect to a straight line along the extending direction of the first trimming groove is formed in the second region, thereby finely adjusting the resistance value after coarse adjustment by the first trimming groove to a target resistance value range. A method for manufacturing a chip resistor is characterized by this.

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