JP5255899B2 - Chip resistor manufacturing method and chip resistor - Google Patents

Description

  The present invention relates to a chip resistor and a manufacturing method thereof.

  Conventionally, when manufacturing a chip resistor, it is common to use a method in which a resistor or an electrode portion is formed on a substrate on which a primary slit and a secondary slit are formed in advance.

  That is, as a method of manufacturing the chip resistor B configured as shown in FIG. 7, a solid alumina substrate formed by the method shown in FIG. 8 and firstly formed with a primary slit and a secondary slit in advance on its upper surface. (This alumina substrate is a large one having at least the size of an insulating substrate of a plurality of chip resistors), and a bottom electrode is formed on the back surface of the alumina substrate (S111). Thereafter, an upper surface electrode is formed on the upper surface of the alumina substrate (S112), and a resistor is formed on the upper surface of the alumina substrate (S113). Thereafter, after the cover coat is formed (S114), the resistor is trimmed (S115), and a protective film is formed (S116). Then, after dividing the substrate along the primary slit (S117), side electrodes are formed (S118), divided along the secondary slit (S119), and then plated (S120). To manufacture.

  The chip resistor B manufactured by the above method includes the insulating substrate 10, the resistor 20, the upper electrode 30, the lower electrode 40, the side electrode 50, the plating 60, the cover coat 70, and the protective film 80. The plating 60 is formed of two layers of nickel plating 62 and tin plating 64.

  Recently, there has been an increasing demand for miniaturization of chip resistors, and with the miniaturization of chip resistors, it is required to increase the effective area of the resistor. For example, in the chip resistor described in Patent Document 1, the effective width of the resistor is made longer than that of a general case by setting the width of the resistor to about 70% of the width of the insulating substrate.

In addition, in Patent Document 2, when manufacturing a chip resistor, a resistor arrangement surface is provided to prevent bleeding and sagging in the resistor paste printed after screen printing of the resistor paste on an insulating substrate. The point that a pair of mutually parallel guide walls protrudes is disclosed.
JP 2004-23006 A JP 2001-118703 A

  However, an alumina substrate having slits formed in advance is obtained by pressing the blade mold against the upper surface side of the flat green sheet to form the primary slit and the secondary slit, and then firing the green sheet. Therefore, as shown in FIG. 9, distortion occurs in the primary slit S1 and the secondary slit S2. That is, the alumina substrate in which the slit is formed in advance generally has a distortion in the slit.

  When a resistor is formed on the upper surface of the alumina substrate, so long as the resistor is formed in the width direction (direction perpendicular to the direction between the electrodes), the resistor paste enters the secondary slit. In particular, when an alumina substrate having a slit in the slit as described above is used, the slit is likely to drop, and further, as the size of the chip resistor is reduced, the end of the resistor is reduced. Since the distance between the secondary slit and the secondary slit becomes short and the influence of the distortion of the slit is strong, the slit is easily dropped. In particular, if the resistor falls into the secondary slit, trimming cannot be performed accurately.

  In order to prevent the resistor from dropping into the secondary slit, a method of projecting a guide wall as in Patent Document 2 is also conceivable. However, a separate step of forming the guide wall is required, and the resistor If it is going to be formed long in the width direction, it is impossible to form the guide wall itself, and the guide wall itself may be slit off.

  Further, when the chip resistor is reduced in size, the length of the resistor is reduced accordingly, and there is a problem that good load characteristics, particularly surge resistance characteristics cannot be obtained sufficiently.

  Therefore, the present invention provides a chip resistor manufacturing method and a chip resistor capable of sufficiently obtaining good load characteristics, in particular, surge resistance characteristics, even when a small chip resistor is manufactured. It is an object of the present invention to provide a method of manufacturing a chip resistor that can prevent slit dropping and that does not require a separate process for preventing slit dropping.

The present invention was created to solve the above problems, and firstly, a chip resistor manufacturing method, which is a substrate body that is an element of an insulating substrate in a chip resistor, A laser scriber having a primary slit which is a slit for primary division and a secondary slit which is a slit for secondary division is provided on the upper surface of the substrate body which is at least as large as the plurality of insulating substrates. The substrate material melted by laser irradiation rises and re-sinters on both sides along the primary slit and the secondary slit on the upper surface of the substrate body by laser scribe. a slit forming step of forming a jetty portion protruding upward from, YAG lasers and laser method in laser scribing, the wavelength 1000～1100Nm, the output 7 9W, Q rate 40 to 60 kHz, and a slit forming step of forming a jetty portion of the height of 3~10μm by a machining speed 60 to 80 mm / s, the primary slit and secondary slits on the upper surface of the substrate body In the resistor forming step of forming a resistor in proximity to the resistor, the resistor forming step of forming a resistor by printing and drying the resistor paste, and drying and baking after printing the top electrode paste In the upper surface electrode forming step of forming the upper surface electrode connected by being laminated on the upper surface on both sides of the resistor, the interelectrode direction is the direction connecting the both sides to which the upper surface electrode is connected in the resistor. An upper surface electrode forming step of forming an upper surface electrode that crosses the primary slit between adjacent chip resistors and is connected to each resistor of the adjacent chip resistors in the inter-electrode direction; In the step of forming the resistor / upper surface electrode, the substrate element body is divided using the effective length of the resistor, which is the length between the electrodes in the region not connected to the upper surface electrode in the resistor, as a chip resistor, and The substrate body was divided by using the length in the width direction, which is a direction perpendicular to the direction between the electrodes in the resistor, as a chip resistor, which is 70% or more and 95% or less of the length between the electrodes of the insulating substrate. as the state became 95% more than 80% in the width direction of the length of the insulating substrate below, a resistor-upper electrode forming step of forming a resistor and a top electrode, the thermal shock during trimming resistor antibody In the cover coat forming process for forming a cover coat for relaxing Form a cover coat Thus, the length in the width direction, which is perpendicular to the direction between the electrodes of the cover coat in each chip resistor, is substantially the same as the length in the width direction of the insulating substrate in which the substrate body is divided using the chip resistor as a chip resistor. The cover coat forming process for forming the cover coat to be the same, the resistance value adjusting process for trimming the resistor to adjust the resistance value of the resistor, the cover coat region and the resistance after the resistance value adjusting process A region for a plurality of chip resistors in a direction perpendicular to the inter-electrode direction in a protective film forming step for forming a protective film that covers a region of the body that is not covered with the top electrode and the cover coat and a region inside the top electrode. By forming the protective film in a strip shape, the substrate element body is divided with the length in the width direction perpendicular to the inter-electrode direction of the protective film in each chip resistor as the chip resistor. A protective film forming step of forming a protective film so as to be substantially the same as the length in the width direction of the insulating substrate, a primary dividing step of dividing the substrate element along the primary slit, and dividing the substrate element In the side electrode forming step of forming the side electrode by printing and drying the side electrode paste on the side surface in the interelectrode direction of the strip-shaped substrate, the upper portion of the side electrode is the top electrode The region not covered by the protective film and the end region in the interelectrode direction of the protective film are covered so that the inner end of the upper part of the side electrode is located inside the inner end of the upper electrode. A side electrode forming step for forming side electrodes, a secondary division step for dividing the strip-shaped substrate along the secondary slit, and a plating step for plating the side electrodes .

According to the chip resistor having the first configuration, the effective length of the resistor is 70 % to 95% of the length of the insulating substrate, and the effective width of the resistor is 80 % to 95% of the width of the insulating substrate. Therefore, it is possible to obtain sufficient surge resistance, and in particular, even if the effective length and width of the resistor are made long, a jetty is formed by forming a slit by laser scribe on the periphery of the upper surface of the insulating substrate. Therefore, it is possible to prevent the resistor from falling off the slit (in particular, from the secondary slit). In addition, since slits are formed in the fired substrate body, it is possible to prevent distortion of the slits, which also prevents the resistor from falling off the slit and prevents the resistor from falling off even if the chip resistor is downsized. it can. Further, since the jetty portion is simultaneously formed in the step of forming the slit, a separate step for preventing the drop of the slit is not required.

In addition, since the upper surface electrode is laminated and connected to the upper surface of the resistor, a sufficient area for contacting the resistance measurement probe (terminal) can be secured during trimming, and trimming can be performed accurately. In addition, since the inner edge of the upper part of the side electrode is formed to be inside the inner edge of the upper surface electrode, even if the resistor becomes longer in the inter-electrode direction, the adhesion of the side electrode is improved. Even when the printed circuit board is greatly bent when mounted on the printed circuit board, the electrode portion can be prevented from peeling off. Since the adhesion area between the side electrode and the protective film is large, it is difficult for the corrosive gas to enter from the interface between the side electrode and the protective film, and corrosion of the top electrode and the resistor can be prevented.

  Further, in the cover coat forming step, a band is formed in the cover coat forming direction, which is parallel to the primary slit direction, and the formation region having a plurality of chip resistors in the cover coat forming direction is covered at a time. A coat is preferably formed. Thus, by forming the cover coat in a strip shape, it is possible to reliably cover the resistor formed in the width direction larger than the conventional one in the width direction.

Also, in the record over Saas Clive, YAG lasers and laser method, 1000 to 1100 nm wavelength, 7～9W output, Q rate 40 to 60 kHz, by Les over Saas Clive by the machining speed is 60 to 80 mm / s, The jetty portion can be formed high, and the slit can be prevented from dropping.

Second, in the first configuration, in the cover coat forming step, a glass coat is printed and baked to form a cover coat, and in the protective film forming step, the resin paste is printed and then dried and cured. Thus, a protective film is formed .

  Further, in the protective film forming step, a band is formed in the protective film forming direction which is parallel to the primary slit direction, and protection is performed at once on a forming region having a plurality of chip resistors in the protective film forming direction. A film is preferably formed. In this way, by forming the protective film in a strip shape, it is possible to reliably cover the resistor formed in the width direction in the width direction.

Third , the chip resistor is a substantially rectangular parallelepiped-shaped insulating substrate, and has at least a size corresponding to a plurality of insulating substrates in the manufacturing process of the chip resistor along the periphery of the upper surface thereof. Then, a primary slit which is a slit for primary division and a secondary slit which is a slit for secondary division are formed by laser scribe on the upper surface of the baked substrate body, and the laser method in the laser scribe is YAG laser. Along the primary and secondary slits on the upper surface of the substrate body by laser scribing with a wavelength of 1000 to 1100 nm, an output of 7 to 9 W, a Q rate of 40 to 60 kHz, and a processing speed of 60 to 80 mm / s. On both sides of the insulating substrate, there is a jetty formed by rising and re-sintering the substrate material melted by laser irradiation. An insulating substrate having a jetty portion along a periphery has a height of projecting 3~10μm above the upper surface of the insulating substrate, is formed on the upper surface of the insulating substrate, the upper electrode in the resistance body side portion of the insulating substrate A resistor formed in the vicinity of the side in the inter-electrode direction, which is the direction connecting both sides to be connected, and the side in the direction perpendicular to the inter-electrode direction, by printing and drying and baking the resistor paste The formed resistor and the upper surface electrode that is stacked and connected to the upper surface on both sides of the resistor, and the end opposite to the side connected to the resistor is formed up to the end of the insulating substrate in the inter-electrode direction. The upper electrode formed by printing and drying and baking the upper electrode paste, and a cover coat to alleviate the thermal shock at the time of trimming the resistor, in the direction between the electrodes than the length of the resistor Formed short In the width direction perpendicular to the inter-electrode direction, the cover coat having a length substantially the same as the length in the width direction of the insulating substrate, and the cover coat region and the upper surface electrode and cover coat in the resistor are covered. A protective film that covers the non-covered area and the inner area of the upper surface electrode, and is formed on the side surface of the insulating substrate in the width direction and having a length substantially the same as the length in the width direction of the insulating substrate. Covering the region of the top electrode that is not covered by the protective film and the end region of the protective film between the electrodes, and the inner edge of the side electrode is located inside the inner edge of the upper electrode. a side electrode has, and dried printed side electrode paste has then the side electrode formed by curing or firing, a plating formed on the surface of the side surface electrode, resistor On the top electrode Continued effective length is the length resistor between electrodes direction of a region not is 95% or less 70% of the length of the inter-electrode direction of the insulating substrate, and the inter-electrode direction perpendicular to the direction of the resistor The length in the width direction is 80% or more and 95% or less of the length in the width direction of the insulating substrate.

In the chip resistor having the third configuration, the effective length of the resistor is 70 % to 95% of the length of the insulating substrate, and the effective width of the resistor is 80 % to 95% of the width of the insulating substrate. Therefore, satisfactory load characteristics, in particular, surge resistance characteristics can be sufficiently obtained.

  Therefore, since the upper surface electrode is laminated and connected to the upper surface of the resistor, a sufficient area for contacting the resistance measurement probe (terminal) can be secured during trimming, and the trimming can be performed accurately. . The protective film covers a region of the resistor that is not covered with the upper surface electrode and a region inside the upper surface electrode, and the side electrode is between the region of the upper surface electrode that is not covered with the protective film and the electrode of the protective film. Covers the end region in the direction, and the inner end of the side electrode is located on the inner side of the inner end of the upper surface electrode, so that the side electrode adheres even if the resistor becomes longer in the inter-electrode direction. The force can be increased, and even when the printed circuit board is largely bent when mounted on the printed circuit board, the electrode portion can be prevented from peeling off. Since the adhesion area between the side electrode and the protective film is large, it is difficult for the corrosive gas to enter from the interface between the side electrode and the protective film, and corrosion of the top electrode and the resistor can be prevented.

Fourth, in the third configuration, the cover coat is formed by printing and baking a glass paste, and the protective film is formed by drying and curing after printing the resin paste. It is characterized by that.

  According to the chip resistor manufacturing method and the chip resistor according to the present invention, the effective length of the resistor is 60% to 95% of the length of the insulating substrate, and the effective width of the resistor is 70% of the width of the insulating substrate. % Or more and 95% or less, sufficient surge resistance can be obtained. In particular, in the method of manufacturing a chip resistor, even if the effective length and effective width of the resistor are formed long, the pier portion is provided by forming a slit by laser scribing on the periphery of the upper surface of the insulating substrate. It is possible to prevent the resistor from falling off the slit (in particular, secondary slit dropping). In addition, since slits are formed in the fired substrate body, it is possible to prevent distortion of the slits, which also prevents the resistor from falling off the slit and prevents the resistor from falling off even if the chip resistor is downsized. it can. Further, since the jetty portion is simultaneously formed in the step of forming the slit, a separate step for preventing the drop of the slit is not required.

  In the present invention, even when a small chip resistor is manufactured, it is possible to increase the effective length of the resistor (especially, the effective length in the width direction), and to manufacture a chip resistor that can prevent slit dropping. The object of providing a method and a chip resistor was realized as follows.

  A chip resistor A according to the present invention is configured as shown in FIG. 1, and includes an insulating substrate 10, a resistor 20, an upper electrode 30, a lower electrode 40, a side electrode 50, a plating 60, a cover coat. 70 and a protective film 80. In the figure, the Y1-Y2 direction is a direction perpendicular to the X1-X2 direction, and the Z1-Z2 direction is a direction perpendicular to the X1-X2 direction and the Y1-Y2 direction.

  Here, the insulating substrate 10 is an insulator formed of alumina having a content rate of about 96%. The insulating substrate 10 has a substantially rectangular parallelepiped shape as a whole. In the example shown in FIG. 1, the insulating substrate 10 has a rectangular shape in plan view, but may have another shape, for example, a square shape. Note that the chip resistor A has a so-called 1608 type size, and the insulating substrate 10 has, for example, a long side (side in the direction between electrodes) of 1.49 mm to 1.51 mm (preferably in a plan view). 1.50 mm) and the short side is 0.78 mm to 0.80 mm (preferably 0.794 mm). The chip resistor A has a so-called 1005 type size, the long side of the insulating substrate 10 is 0.89 mm to 0.91 mm (preferably 0.90 mm), and the short side is 0.48 mm to 0.50 mm. (Preferably, it may be 0.49 mm). In addition, the size of the insulating substrate 10 is not limited to this, and may be other sizes, and the lengths of the long side and the short side of the insulating substrate 10 are not limited to the above lengths. May be the length.

  Further, a jetty portion 10a (see FIG. 2) is formed on the periphery of the upper surface of the insulating substrate 10. The jetty portion 10a is continuously formed along the peripheral edges of the four sides of the upper surface of the insulating substrate 10, and is formed so as to rise with respect to the upper surface of the insulating substrate 10 (that is, the upper surface other than the jetty portion 10a). The height T of the jetty portion 10a with respect to the upper surface of the insulating substrate 10 is 3 to 10 μm. The jetty portion 10a is formed when the primary slit and the secondary slit are formed on the alumina substrate by laser scribing in the manufacturing process of the chip resistor A. Details will be described later.

  Further, as shown in FIG. 1, the resistor 20 is provided on the upper surface of the insulating substrate 10 and is formed in a strip shape in the longitudinal direction (inter-electrode direction or energization direction), and is substantially rectangular in plan view. It is formed in a shape. The end of the resistor 20 in the interelectrode direction is not formed up to the end of the insulating substrate 10, and is between the end of the resistor 20 in the interelectrode direction and the end of the insulating substrate 10 in the interelectrode direction. Is formed with a predetermined interval. Further, the end of the resistor 20 in the width direction is not formed up to the end of the insulating substrate 10, and between the end of the resistor 20 in the width direction and the end of the insulating substrate 10 in the width direction. A predetermined interval is formed. Here, the length Wb in the width direction (Y1-Y2 direction) of the resistor 20 is 70% to 95% of the length Wa in the width direction of the insulating substrate 10. That is, the effective width of the resistor 20 is 70% or more and 95% or less of the width of the insulating substrate 10. The resistor 20 is formed of a ruthenium oxide metal glaze thick film. More preferably, the length Wb of the resistor 20 in the width direction is 80% or more and 95% or less of the length Wa of the insulating substrate 10 in the width direction.

  Further, a pair of upper surface electrodes 30 are formed at both end regions in the longitudinal direction (X1-X2 direction (see FIG. 1)) of the upper surface of the insulating substrate 10 and have a substantially rectangular shape in plan view. That is, one upper surface electrode 30 is formed to have a predetermined length from the end portion on the X1 side of the upper surface of the insulating substrate 10, and the other upper surface electrode 30 is an end portion on the X2 side of the upper surface of the insulating substrate 10. To a predetermined length. Further, the width in the width direction of the upper surface electrode 30 is formed substantially the same as the width in the width direction of the resistor 20, and a gap is formed between the upper surface electrode 30 and the end portion of the insulating substrate 10 in the width direction. ing. Specifically, the upper surface electrode 30 is formed of a silver-based thick film (silver-based metal glaze thick film).

  Further, the upper surface electrode 30 is formed by being stacked on the end region of the resistor 20. That is, the outer region (region on the end portion (end portion in the inter-electrode direction) side) of the upper surface electrode 30 is formed on the upper surface of the insulating substrate 10, but the inner region is the resistor 20. It is formed by laminating on the upper surface.

  Further, the length Lb in the interelectrode direction of the region not covered by the upper surface electrode 30 in the resistor 20 is formed to be 60% or more and 95% or less with respect to the length La in the interelectrode direction of the insulating substrate 10. Has been. That is, the effective length of the resistor 20 is formed to be 60% or more and 95% or less of the length of the insulating substrate 10. More preferably, the length Lb in the interelectrode direction of the region not covered by the upper electrode 30 in the resistor 20 is 80% or more and 95% or less with respect to the length La in the interelectrode direction of the insulating substrate 10. Length.

  Further, as shown in FIG. 1, a pair of lower surface electrodes 40 are formed in both end regions in the longitudinal direction (X1-X2 direction (see FIG. 1)) of the lower surface of the insulating substrate 10, and are substantially rectangular in bottom view. It has a shape. The length of the lower surface electrode 40 (the length in the X1-X2 direction) is substantially the same as that of the upper surface electrode 30, but the length of the lower surface electrode 40 may be arbitrary. Further, the length in the width direction (Y1-Y2 direction) of the lower surface electrode 40 is formed substantially the same as the length in the width direction of the insulating substrate 10. The lower surface electrode 40 is formed of a silver-based thick film (silver-based metal glaze thick film).

  Note that the configuration of the lower surface electrode 40 may be omitted, and the lower portion 50b of the side surface electrode 50 may be substituted for the lower surface electrode.

  Further, the side electrode 50 includes a part of the upper surface electrode 30, a part of the protective film 80, the entire lower surface electrode 40, and the side surface of the insulating substrate 10 (that is, the side surface on the X1 side and the side surface on the X2 side). It is formed in a layer shape with a substantially U-shaped cross section so as to cover. The side electrodes 50 are provided at the end on the X1 side and the end on the X2 side, respectively. The side electrode 50 is formed of a resin / silver-based thick film containing a resin (specifically, an epoxy resin) and silver powder. In addition, you may form this side electrode 50 with the metal thin film by a sputtering method.

  Further, as shown in FIG. 1, the side electrode 50 has a substantially U-shaped cross section, and the upper portion 50a of the side electrode 50 (that is, the portion of the side electrode 50 laminated on the upper electrode 30 and the protective film 80) is the upper surface. A part of the upper surface of the electrode 30 and a part of the upper surface of the protective film 80 are stacked. That is, the end portion of the protective film 80 is laminated on a part of the upper surface of the upper electrode 30, and the side electrode 50 covers a region of the upper electrode 30 that is not covered with the protective film 80, and the protective film 80. The end region at is covered. In addition, the length of the upper portion 50 a in the side electrode 50 in the inter-electrode direction is longer than the length of the upper electrode 30 in the inter-electrode direction, and the inner end of the upper portion 50 a is the inner side of the upper electrode 30. It is located on the inner side (that is, the center side) than the end portion of. That is, the length Lc between the inner ends of the upper portion 50 a of the side electrode 50 is formed to be smaller than the length Lb between the inner ends of the pair of upper surface electrodes 30. The length in the width direction (Y1-Y2 direction) of the side electrode 50 is formed substantially the same as the length in the width direction of the insulating substrate 10. Therefore, the upper portion 50a of the side electrode 50 is formed so as to include the entire planar region of the upper surface electrode 30 in plan view. Further, the lower portion 50 b of the side electrode 50 covers the entire surface of the lower electrode 40. An intermediate portion of the side electrode 50 excluding the upper portion 50a and the lower portion 50b is formed mainly in the vertical direction on the side surface of the insulating substrate 10.

  The plating 60 is composed of nickel plating (Ni plating) 62 and tin plating 64, and is provided in the end region on the X1 side and the end region on the X2 side, respectively. That is, the plating 60 is provided on the surface of the electrode portion for connecting the chip resistor, the inner layer is the nickel plating 62, and the outer layer is the tin plating 64.

  Here, the nickel plating 62 is formed on the surface of the side electrode 50 so as to cover the entire side electrode 50. The nickel plating 62 is formed with a substantially uniform film thickness by electroplating. The nickel plating 62 is made of nickel and is formed to prevent solder erosion of internal electrodes such as the upper surface electrode 30. In addition to nickel, this nickel plating may use copper plating.

  Further, the tin plating 64 is disposed with a substantially uniform film thickness so as to cover the surface of the nickel plating 62. Note that solder plating may be used in addition to tin plating.

  The upper surface electrode 30, the lower surface electrode 40, the side surface electrode 50, and the plating 60 form an electrode portion. That is, in the chip resistor A, the electrode portions are formed at the end portions in the inter-electrode direction.

  Further, the cover coat 70 is formed on the upper surface of the resistor 20 and is formed to alleviate the thermal shock during trimming of the resistor 20. The cover coat 70 is formed shorter in the inter-electrode direction than the length of the resistor 20, and the end region of the resistor 20 in the inter-electrode direction is exposed from the cover coat 70. The length in the width direction is formed substantially the same as the length in the width direction of the insulating substrate 10. The cover coat 70 is made of a glass-based material, specifically, a lead borosilicate glass thick film.

  The resistor 20 and the cover coat 70 are formed with trimming grooves 20T (see FIG. 1) by trimming.

  Further, as shown in FIG. 1, the protective film 80 includes a cover coat 70, a part of the resistor 20 (a region of the resistor 20 that is not covered with the cover coat 70 and the upper electrode 30), and the upper electrode 30. It is provided to cover a part. That is, the protective film 80 is formed so as to cover a region of the resistor that is not covered with the top electrode and a region inside the top electrode, and at least cover an exposed region of the resistor 20. That is, the formation position of the protective film 80 will be described in more detail. The protective film 80 is formed in the width direction substantially the same as the width of the insulating substrate 10, and is formed in the inter-electrode direction substantially the same as the length of the resistor 20. The end position of the protective film 80 in the interelectrode direction is substantially the same position in the horizontal direction as the end position of the resistor 20 in the interelectrode direction. The protective film 80 is formed of a resin, specifically, an epoxy / phenolic resin. As described above, the protective film 80 covers the region where the resistor 20 is exposed, and protects the resistor 20 so that the resistor 20 is not exposed to the outside.

  The manufacturing method of the chip resistor A having the above-described structure will be described with reference to FIGS. 3 and 4. First, a solid alumina substrate in which slits are not formed on both the upper surface and the back surface (this alumina substrate has a plurality of A large-sized chip resistor having at least the size of an insulating substrate of a chip resistor, which is obtained by firing a flat plate-like green sheet (a green sheet containing alumina with a content of about 96%) in advance (substrate body) Is prepared, and a lower surface electrode is formed on the back surface (that is, the bottom surface) of the alumina substrate (S11, lower surface electrode forming step). That is, a paste for the lower surface electrode (for example, a silver-based paste such as silver-based metal glaze) is printed, dried and fired. In forming the lower surface electrode, the lower surface electrode is simultaneously formed for adjacent chip resistors. Furthermore, in the direction perpendicular to the inter-electrode direction, a bottom electrode is formed continuously in a strip shape.

  A primary slit S1 and a secondary slit S2 are formed on the upper surface of the alumina substrate (S12, slit forming step). That is, as shown in FIG. 4A, the primary slit S1 is formed in the Y1-Y2 direction and the secondary slit S2 is formed in the X1-X2 direction. This primary slit is a slit for primary division, and forms a primary slit in the Y1-Y2 direction at the boundary position between the chip resistors adjacent in the X1-X2 direction. The secondary slit is a slit for secondary division, and a secondary slit is formed in the X1-X2 direction at the boundary position of the chip resistor adjacent in the Y1-Y2 direction.

  The primary slit S1 and the secondary slit S2 are formed by laser scribing. By forming the slits by laser scribing in this way, as shown in FIG. 5, the jetty portions 10a are formed on both sides of the slit along the slit. That is, the jetty portions 10a are formed on both sides of the primary slit S1 along the primary slit S1, and the jetty portions 10a are formed on both sides of the secondary slit S2 along the secondary slit S2. This is because re-sintering is performed in a state where the molten substrate material is raised by irradiating a laser with laser scribing, thereby forming a jetty portion 10a protruding above the upper surface of the substrate body.

The laser scribing conditions are as follows: the laser system is a YAG laser, the wavelength is 1000 to 1100 nm (preferably 1064 nm), the output is 7 to 9 W (preferably 8 W), and the Q rate is 40 to 60 kHz (preferably 50 kHz) and a processing speed of 60 to 80 mm / s (preferably 70 mm / s), a slit having a depth of 40 to 50 μm is formed, and the height of the jetty 10 a is 3 to 3 mm. It is formed to 10 μm. In particular, the laser system is a YAG laser, the wavelength is 1000 to 1100 nm (preferably 1064 nm), the output is 7 to 9 W (preferably 8 W), the Q rate is 40 to 60 kHz (preferably 50 kHz), processing When the speed is 60 to 80 mm / s (preferably 70 mm / s), the height of the formed jetty 10a can be increased. In addition, it is preferable that the depth of the primary slit is 50 μm and the depth of the secondary slit is 40 μm. In this case, the processing speed of the primary slit is slower than that of the secondary slit.

  Next, the resistor 20 is formed on the upper surface of the alumina substrate (S13, resistor forming step) (see FIG. 4B). That is, after the resistor paste of the resistor 20 is printed, the resistor is formed by drying and baking. The resistor paste is a ruthenium oxide paste (for example, ruthenium oxide metal glaze).

  In forming this resistor, the effective length of the resistor is 60% or more and 95% or less (preferably 80% or more and 95% or less) of the length of the insulating substrate 10, and the effective width of the resistor is 10% or less. The resistor is formed so as to be 70% to 95% (preferably 80% to 95%) of the width. That is, in the width direction, the distance between the secondary slits S2 (strictly speaking, the distance between the intermediate position in the width direction of a certain secondary slit S2 and the intermediate position in the width direction of the adjacent secondary slit S2 (that is, The distance is 70% or more and 95% or less (preferably 80% or more and 95% or less) of the width of the insulating substrate 10 when this distance becomes a chip resistor)). In the length direction (inter-electrode direction), the distance between the primary slits S1 (strictly speaking, the intermediate position in the width direction of a certain primary slit S1 and the intermediate position in the width direction of the adjacent primary slit S1 60% or more and 95% or less (preferably 80% or more and 95% or less) of the distance (that is, this distance becomes the length between the electrodes of the insulating substrate 10 when it becomes a chip resistor) The resistor is formed so that Since regions laminated with electrodes not included in the effective length, to form a long resistor than the desired effective length.

  When forming this resistor, the effective length of the resistor is 60% or more and 95% or less of the length of the insulating substrate 10 and the effective width of the resistor is 70% of the width of the insulating substrate 10 as described above. The resistor is formed so as to be 95% or less, and the end of the resistor is formed close to the slit as compared with the conventional chip resistor. Since the jetty portion 10a is provided along the secondary slit, the resistor paste does not fall into the slit by the jetty portion. Thereby, the secondary slit fall of a resistor paste can be prevented.

  Next, an upper surface electrode is formed on the upper surface of the alumina substrate (S14, upper surface electrode forming step) (see FIG. 4C). That is, the top electrode paste is printed so that a part thereof is laminated on the resistor, dried and fired. The upper surface electrode paste in this case is a silver-based paste (for example, a silver-based metal glaze paste). In addition, when it becomes a chip resistor, the upper surface electrode which adjoins mutually by the upper surface electrode of an adjacent chip resistor is formed in one printing area | region.

  The resistor forming process (S13) and the upper electrode forming process (S14) constitute a resistor / upper electrode forming process.

  Next, a cover coat is formed (S15, cover coat forming step). That is, a lead borosilicate glass-based glass paste is printed and fired on the upper surface of the region not covered by the upper electrode 30 and the upper surface of the region inside the upper electrode to form the cover coat 70. . In this case, the cover coat is formed in a band shape in the cover coat forming direction which is a direction perpendicular to the inter-electrode direction (in the example of FIG. 4, a direction parallel to the direction of the primary slit S1 (Y1-Y2 direction)). A cover coat is formed at a time on the formation region having a plurality of chip resistors in the cover coat forming direction, and a plurality of chip resistors are continuously formed in a strip shape. That is, a cover coat is continuously formed in a strip shape from one end to the other end of the resistor group arranged in the direction of the primary slit S1 among the plurality of resistors formed on the alumina substrate. Thus, by forming the cover coat in a strip shape, it is possible to reliably cover the resistor formed in the width direction larger than the conventional one in the width direction. Further, by forming the cover coat in a strip shape in this way, in the chip resistor A, the cover coat 70 is formed up to the end in the width direction of the insulating substrate 10 as shown in FIG. Become.

  Next, a resistance value is adjusted by forming a trimming groove in the resistor 20 and performing trimming (S16, resistor adjusting step). That is, a trimming groove is formed in the resistor 20 by laser trimming. In the connection region between the resistor and the upper surface electrode, the upper surface electrode is laminated on the upper surface of the resistor. Therefore, compared to the case where the resistor is laminated on the upper surface of the upper surface electrode, the resistance value measurement is performed at the time of trimming. A sufficient area for contacting the probe (terminal) can be ensured, and trimming can be performed accurately.

Next, a protective film is formed (S17, protective film forming step). That is, the protective film is formed so as to cover the entire region of the cover coat 70, the region not covered by the cover coat and the upper surface electrode of the resistor 20, and the region inside the upper surface electrode. That is, the resin paste was printed and dried and cured. After that, primary division is performed along the primary slit (S18, primary division step). In this case, the protective film is formed in a band shape in the protective film forming direction which is a direction perpendicular to the inter-electrode direction (in the example of FIG. 4, a direction parallel to the direction of the primary slit S1 (Y1-Y2 direction)) A protective film is formed at a time in a formation region having a plurality of chip resistors in the protective film forming direction. That is, the protective film is continuously formed in a strip shape from one end to the other end of the resistor group arranged in the direction of the primary slit S1 among the plurality of resistors formed on the alumina substrate. In this way, by forming the protective film in a strip shape, it is possible to reliably cover the resistor formed in the width direction in the width direction. Further, by forming the protective film in a strip shape in this way, in the chip resistor A, the protective film 80 is formed up to the end in the width direction of the insulating substrate 10 as shown in FIG. Become.

  Next, the side electrode 50 is formed with respect to the said strip-shaped board | substrate (S19, side electrode formation process). That is, the side electrode paste is printed, dried and cured. The side electrode paste may be printed, dried and fired, or the side electrode may be formed by forming a metal thin film by sputtering.

  In forming the side electrode, the inner end of the upper portion 50a of the side electrode is set to be inside the inner end of the upper surface electrode.

  Then, secondary division is performed along the secondary slit (S20, secondary division process). Next, plating is formed (S21, plating step). That is, nickel plating is formed, and then tin plating is formed. As described above, the chip resistor A is formed.

  The usage state of the chip resistor A will be described. The chip resistor A is used by being mounted on a wiring board (may be a printed board). In mounting on a wiring board, the chip resistor A is mounted on a land 102 formed on the wiring board 100 via a solder fillet 110 as shown in FIG. At that time, as shown in FIG. 6, the tin plating 64 is melted and diffused into the solder to be integrated with the solder fillet 110.

  As described above, according to the chip resistor of this embodiment and the manufacturing method thereof, the effective length of the resistor 20 is 60% to 95% of the length of the insulating substrate 10 (preferably 80% to 95%). The effective width of the resistor 20 is not less than 70% and not more than 95% (preferably not less than 80% and not more than 95%) of the width of the insulating substrate 10, so that sufficient surge resistance can be obtained. In particular, even if the effective length and effective width of the resistor 20 are long, the jetty portion 10a is formed on the periphery of the upper surface of the insulating substrate 10 by forming a slit by laser scribing. Slit dropping (especially secondary slit dropping) can be prevented.

  Also, in the chip resistor manufacturing process, slits are formed in the once-baked alumina substrate, so that distortion of the slits can be prevented, which can also prevent the slits of the resistor from falling off, and the chip resistors can be downsized. However, the slit of the resistor can be prevented.

  Further, since the jetty portion 10a is formed at the same time in the process of forming the slit, there is no need for a separate process for preventing the slit from dropping as in Patent Document 2.

  Further, since the inner end portion of the upper portion 50a of the side electrode 50 is formed to be inside the inner end portion of the upper surface electrode 30, the side electrode is formed even if the resistor 20 becomes longer in the inter-electrode direction. 50 can be increased, and even when the printed circuit board is greatly bent when mounted on the printed circuit board, the electrode portion can be prevented from peeling off. That is, when the inner end of the upper portion of the side electrode 50 laminated on the upper surface of the upper surface electrode 30 is set as the position of the end of the protective film 80 as in the conventional chip resistor (see FIG. 7). If the length of the resistor 20 in the inter-electrode direction is increased to secure a long effective length, the protective film 80 is increased and the upper surface electrode 30 is shortened accordingly. The length will be shortened. Then, when mounted on a printed circuit board, the electrode portion may be peeled off due to the stress of the solder fillet. In the present embodiment, the protective film 80 is covered with the upper surface electrode 30 of the resistor 20. The side electrode 50 covers the region of the top electrode 30 that is not covered with the protective film 80 and the end region of the protective film 80 in the inter-electrode direction, and covers the side surface. Since the inner end portion of the electrode 50 is located inside the inner end portion of the upper surface electrode 30 and the upper portion 50a of the side electrode 50 is formed longer, there is no such fear. Further, since the adhesion area between the side electrode 50 and the protective film 80 is large, the corrosive gas hardly enters from the interface between the side electrode 50 and the protective film 80, and corrosion of the top electrode 30 and the resistor 20 can be prevented.

  In the above description, the end of the resistor 20 in the inter-electrode direction is not formed up to the end of the insulating substrate 10. However, the end of the resistor 20 in the inter-electrode direction is the insulating substrate 10. It is also possible that all the regions of the upper surface electrode 30 are formed on the upper surface of the resistor 20. In this case, in the resistor forming step, the resistor is formed in a strip shape in the resistor forming direction which is the direction between the electrodes (the direction parallel to the direction of the secondary slit), and the chip resistor is formed in the resistor forming direction. Resistors are formed at a time in a formation region having a plurality of resistors, and resistors for a plurality of chip resistors are continuously formed in a strip shape. That is, the resistors are continuously formed in a strip shape from one end to the other end of the resistor group arranged in the direction of the secondary slit S2 among the plurality of resistors formed on the alumina substrate.

  In the above description, in the connection region between the resistor and the upper surface electrode, the upper surface electrode is laminated on the upper surface of the end portion of the resistor, but the resistor is formed on the upper surface of the end portion of the upper surface electrode. You may laminate and form.

  In the above description, both the effective length and effective width of the resistor are limited to a length and width larger than usual. However, the present invention is not limited to this, and only one of the effective length and effective width of the resistor is used. Even if limited, surge resistance is improved.

  In the above description, the lower portion 50b of the side electrode 50 covers the entire surface of the lower electrode 40, but covers only a part of the surface (outer region) of the lower electrode 40, The inner region of the lower electrode 40 may be exposed from the side electrode 50, and in this case, the plating 60 is also formed on the surface of the region exposed from the side electrode 50 of the lower electrode 40. .

It is a figure which shows the structure of the chip resistor based on the Example of this invention, (a) is sectional drawing, (b) is a top view. It is principal part sectional drawing which shows the structure of the chip resistor based on the Example of this invention, and is principal part sectional drawing of the cross section fractured | ruptured by the PP line | wire of FIG. 5 is a flowchart illustrating a method for manufacturing a chip resistor according to an embodiment of the present invention. It is a principal part top view which shows the manufacturing method of the chip resistor based on the Example of this invention. It is principal part sectional drawing of the board | substrate base body at the time of forming a slit by laser scribing It is sectional drawing which shows the use condition of the chip resistor based on the Example of this invention. It is sectional drawing which shows the structure of the conventional chip resistor. It is a flowchart which shows the manufacturing method of the chip resistor in the past. It is a principal part top view which shows the problem of the alumina substrate which baked the green sheet in which the slit was formed.

Explanation of symbols

A, B Chip resistor 10 Insulating substrate 20 Resistor 30 Upper surface electrode 40 Lower surface electrode 50 Side electrode 50a Upper part 50b Lower part 60 Plating 70 Cover coat 80 Protective film

Claims (4)

A method of manufacturing a chip resistor,
A substrate element which is an element of an insulating substrate in a chip resistor, and has at least a size corresponding to a plurality of the insulating substrates, and a primary slit which is a slit for primary division on the upper surface of the fired substrate element And a secondary slit which is a slit for secondary division were formed by laser scribing, and by laser scribing, both sides along the primary slit and the secondary slit on the upper surface of the substrate body were melted by laser irradiation. In the slit forming process of forming a jetty protruding above the upper surface of the substrate body by raising and re-sintering the substrate material , the laser method in laser scribing is YAG laser, the wavelength is 1000 to 1100 nm, the output is 7 ~9W, Q rate 40 to 60 kHz, processing speed by a 60 to 80 mm / s of the height of 3~10μm A slit forming step for forming a bank portion,
A resistor forming step of forming a resistor on the upper surface of the substrate body in the vicinity of the primary slit and the secondary slit, and forming the resistor by drying and baking after printing the resistor paste; and In the upper surface electrode forming step of forming the upper surface electrode that is laminated and connected to the upper surface on both sides of the resistor by printing and drying and baking the upper surface electrode paste, both sides of the resistor to which the upper surface electrode is connected are connected. In the inter-electrode direction, the upper surface electrode is formed so as to straddle the primary slit between the chip resistors adjacent in the inter-electrode direction and connect to each resistor of the chip resistor adjacent in the inter-electrode direction in the resistor-upper electrode formation step and a step, the effective length of the length a is the resistance of the inter-electrode direction of a region that is not connected to the upper electrode in the resistor body as a chip resistor Substrate element is 95% or less 70% of the length of the inter-electrode direction of the insulating substrate in a state of being divided, and the inter-electrode direction and a length in the width direction which is perpendicular in the resistor chip resistor A resistor / upper surface electrode forming step of forming the resistor and the upper surface electrode so as to be 80% to 95% of the length in the width direction of the insulating substrate in a state where the substrate body is divided as a container; ,
Cover-coating step of forming a cover coat for reducing the thermal shock at the time of trimming resistor antibody, together with the inter-electrode direction is formed shorter than the length of the resistor, a plurality of the inter-electrode direction perpendicular to the direction the chip A state in which the substrate body is divided by forming a cover coat in a strip shape in the area of the resistor, with the length in the width direction perpendicular to the direction between the electrodes of the cover coat in each chip resistor as the chip resistor A cover coat forming step of forming a cover coat so as to be substantially the same as the length of the insulating substrate in the width direction ;
A resistance value adjusting step of adjusting the resistance value of the resistor by trimming the resistor;
After the resistance value adjusting step, in the protective film forming step of forming a protective film covering the region of the cover coat, the upper surface electrode in the resistor, the region not covered by the cover coat, and the inner region of the upper surface electrode, By forming a protective film in a band shape in a region corresponding to a plurality of chip resistors in a direction perpendicular to the direction, the length in the width direction perpendicular to the direction between the electrodes of the protective film in each chip resistor is used as the chip resistor. A protective film forming step of forming a protective film so as to be substantially the same as the length in the width direction of the insulating substrate in which the substrate body is divided;
A primary division step of dividing the substrate body along the primary slit;
In the side electrode forming step of forming the side electrode by printing the side electrode paste on the side surface in the inter-electrode direction of the strip-shaped substrate obtained by dividing the substrate body and drying, and then curing or firing, the side electrode is formed. The upper portion of the upper surface electrode covers the region of the upper surface electrode that is not covered with the protective film and the end region of the protective film between the electrodes, and the inner end portion of the upper portion of the side electrode is the inner end portion of the upper surface electrode. A side electrode forming step of forming a side electrode so as to be at an inner position,
A secondary dividing step of dividing the strip substrate along the secondary slit;
A plating process for plating the side electrodes;
A method of manufacturing a chip resistor, comprising: The cover coat is formed by printing and baking a glass paste in the cover coat forming step, and the protective film is formed by drying and curing after printing the resin paste in the protective film forming step. The manufacturing method of the chip resistor of claim | item 1. A chip resistor,
A substantially rectangular parallelepiped-shaped insulating substrate, which has at least the size of a plurality of insulating substrates in the chip resistor manufacturing process along the periphery of the upper surface thereof, and is primarily divided on the upper surface of the fired substrate body A primary slit, which is a slit for use, and a secondary slit, which is a slit for secondary division, are formed by laser scribing. The laser system in the laser scribing is YAG laser, the wavelength is 1000 to 1100 nm, the output is 7 to 9 W, Q By performing laser scribing at a rate of 40 to 60 kHz and a processing speed of 60 to 80 mm / s, the substrate material melted by laser irradiation rises on both sides along the primary slit and the secondary slit on the upper surface of the substrate body. A jetty formed by re-sintering, above the upper surface of the insulating substrate along the periphery of the upper surface of the insulating substrate An insulating substrate having a jetty portion having a height protruding 3~10μm to,
It is formed on the upper surface of the insulating substrate and is close to the side portion between the electrodes and the side portion in the direction perpendicular to the inter-electrode direction, which is the direction connecting the two sides where the upper surface electrode is connected to the resistor at the side portion of the insulating substrate. A resistor formed by printing a resistor paste and then drying and firing after the resistor is formed ;
A top electrode paste is printed on the top electrode, which is stacked and connected on the upper surface of both sides of the resistor, and the end opposite to the side connected to the resistor is formed up to the end of the insulating substrate in the inter-electrode direction. An upper surface electrode formed by drying and firing , and
Cover coat to mitigate thermal shock during trimming of resistor. It is formed shorter than the length of the resistor in the inter-electrode direction, and the width of the insulating substrate in the width direction perpendicular to the inter-electrode direction. A cover coat having a length substantially the same as the length in the direction;
A protective film that covers the area of the cover coat, the upper surface electrode of the resistor, the area not covered by the cover coat, and the inner area of the upper surface electrode. In the width direction, the length is approximately the same as the length in the width direction of the insulating substrate. A protective film having a thickness;
It is formed on the side surface of the insulating substrate, and covers the region not covered by the protective film on the upper surface electrode and the end region in the direction between the electrodes of the protective film, and the inner end portion of the side surface electrode is inside the upper surface electrode. Side electrodes that are formed by printing the side electrode paste and drying, then curing or firing, with the side electrodes located inside the end of
A plating formed on the surface of the side surface electrode,
The effective length of the resistor, which is the length in the inter-electrode direction of the region not connected to the upper surface electrode in the resistor, is 70% to 95% of the length in the inter-electrode direction of the insulating substrate, and in the resistor A chip resistor characterized in that the length in the width direction perpendicular to the interelectrode direction is not less than 80% and not more than 95% of the length in the width direction of the insulating substrate. 4. The chip resistor according to claim 3 , wherein the cover coat is formed by printing and baking a glass paste, and the protective film is formed by drying and curing after printing the resin paste . .

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