JP2018032670A - Chip component, mounting structure of chip component, and manufacturing method of chip resistor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chip component in which a protrusion is not formed at an end portion of a front electrode due to the formation of an end face electrode while preventing cracks due to heat shock. SOLUTION: The chip component (1) of the present invention has a rectangular body-shaped insulating substrate (2), a pair of front electrodes (3) arranged opposite to each other at a predetermined interval on the surface of the insulating substrate, and an insulating substrate. A pair of back electrodes (4) arranged so as to face each other at predetermined intervals on the back surface thereof, and a pair of end face electrodes (7) that bridge the front electrode and the back electrode are provided. The end face electrodes have a first end face electrode (8) formed on the end face of the insulating substrate so as to be connected to the front electrode, and an L-shaped cross section from the back surface to the end face of the insulating substrate so as to be connected to the first end face electrode and the back electrode. It has a second end face electrode (9) made of a conductive resin formed in a shape. [Selection diagram] Fig. 1

Description

  The present invention relates to a chip component used by being mounted on a circuit board, a mounting structure for the chip component, and a method for manufacturing a chip resistor.

  A chip resistor, which is an example of a chip component, has a rectangular parallelepiped insulating substrate, a pair of front electrodes disposed opposite to each other with a predetermined interval on the surface of the insulating substrate, and a predetermined interval on the back surface of the insulating substrate. It is mainly composed of a pair of back electrodes arranged opposite to each other, a resistor connected to the pair of front electrodes, and an end face electrode provided on the end face of the insulating substrate and bridging the corresponding front electrode and the back electrode. .

  In general, when manufacturing such a chip resistor, a large number of front electrodes, back electrodes, and resistors are formed on a large substrate having a first divided line and a second divided line extending in a lattice shape. After forming in a lump, this large-sized substrate is primarily divided along a first dividing line to form a strip-shaped substrate, and an end face electrode is formed on the end surface of the strip-shaped substrate. After that, a large number of chip resistors can be obtained in a lump by dividing the strip-shaped substrate into a secondary division along the second division line. The chip resistor formed in this way is used in a state of being mounted on a circuit board (not shown), and is mounted on the circuit board by soldering the end face electrode to the land (for example, Patent Document 1). .

JP 2008-084905 A

  By the way, as a method of forming the end face electrode, there are a method of forming a thin film by sputtering a conductive material such as Ni-Cr on the end face of the strip-shaped substrate, and a method of forming a thick film by applying a conductive resin such as silver paste. Are known. In general, when an end surface electrode is formed by applying a conductive resin, a conductive resin paste is applied in advance to the flat upper surface of a transfer table in a film shape, and a strip-shaped substrate is applied to the conductive resin paste. Touch the end face of. At this time, since the conductive resin in contact with the end surface of the strip-shaped substrate wraps around both the front surface and the back surface from the end surface of the strip-shaped substrate, the end surface electrode extends from the end surface of the strip-shaped substrate to the front and back surfaces, and is formed in a U shape Is done.

  In the chip resistor described in Patent Document 1, since the end electrode made of conductive resin is formed so as to cover the entire back electrode, the thermal environment changes with respect to the chip resistor mounted on the circuit board. It is possible to prevent the solder joint from being damaged and cracking due to repeated thermal shock (so-called heat shock). However, the conductive resin that wraps around the surface of the strip-shaped substrate during application of the conductive resin protrudes upward at the end of the front electrode, and the upper surface of the chip component is formed by the protrusion formed at the end of the front electrode. The entire side is sucker-like (concave). Then, when the upper surface side of the chip component formed in the suction cup shape is sucked by the suction pad and the chip component is mounted on the circuit board, there is a possibility that the chip component does not separate from the suction pad (so-called take-away phenomenon).

  The present invention has been made in view of the actual situation of the prior art, and a first object is to form a protrusion at the end of the front electrode by forming the end face electrode while preventing cracks due to heat shock. A second object is to provide a mounting structure for such a chip component. A third object of the present invention is to provide a method of manufacturing a chip resistor in which no protrusion is formed at the end of the front electrode by forming the end face electrode while preventing cracks due to heat shock.

  According to a first aspect of the present invention for achieving the first object, a rectangular parallelepiped insulating substrate, a pair of front electrodes disposed opposite to each other at a predetermined interval on the surface of the insulating substrate, and a back surface of the insulating substrate In a chip component comprising a pair of back electrodes opposed to each other at a predetermined interval, and a pair of end surface electrodes bridging the front electrode and the back electrode, the end surface electrode includes the front electrode and A first end face electrode formed on the end face of the insulating substrate so as to be connected, and a conductor formed in an L-shaped cross section from the back face to the end face of the insulating substrate so as to be connected to the first end face electrode and the back electrode. And a second end face electrode made of a conductive resin.

  In the first invention, the second end face electrode made of conductive resin is formed in an L-shaped cross section from the back surface to the end face of the insulating substrate so as to connect to the first end face electrode and the back electrode. It is possible to provide a chip component in which no protrusion is formed at the end of the surface electrode, and it is possible to prevent cracks due to heat shock.

  A second invention for achieving the first object described above includes a rectangular parallelepiped insulating substrate, a pair of front electrodes opposed to the surface of the insulating substrate at a predetermined interval, and a back surface of the insulating substrate. A chip component comprising: a pair of back electrodes disposed opposite to each other with a predetermined interval; and a pair of end surface electrodes bridging the front electrode and the back electrode on an end surface of the insulating substrate. Has a surface side electrode portion formed on the surface of the insulating substrate, and an end surface side electrode portion continuously extending from the surface side electrode portion to the end surface side of the insulating substrate. The conductive substrate is made of a conductive resin having an L-shaped cross section from the back surface to the end surface of the insulating substrate so as to be connected to the end surface side electrode portion and the back electrode.

  According to the second invention, the end surface electrode made of conductive resin is formed in a cross-sectional L shape from the back surface to the end surface of the insulating substrate, so that it is connected to the end surface side electrode portion and the back electrode of the front electrode and the surface of the front electrode Since it has a structure that does not reach the side electrode part, it is possible to provide a chip component in which no protrusion is formed at the end of the front electrode by forming the end face electrode, and it is possible to prevent cracking due to heat shock Become.

  In the invention for achieving the second object described above, the chip parts according to the first invention and the second invention are mounted on the lands provided on the circuit board with the back electrode facing each other. It is characterized by.

  In this case, the solder electrode formed between the back electrode and the end surface electrode and the land is damaged by the end surface electrode made of the conductive resin formed in an L-shaped cross section from the back surface to the end surface of the insulating substrate. It is possible to prevent cracks from occurring.

  The invention for achieving the above third object is a surface electrode forming step of forming a plurality of pairs of surface electrodes on the surface of a large-sized substrate in which a first divided line and a second divided line extending in a lattice shape are set, A back electrode forming step of forming a plurality of pairs of back electrodes at positions corresponding to the plurality of pairs of front electrodes on the back surface of the large substrate; and a resistor connected to the front electrodes paired with the surface of the large substrate. Forming a resistor, dividing the large substrate along the first dividing line to form a strip-shaped substrate, and forming the strip-shaped substrate with the surface electrodes corresponding to both end faces of the strip-shaped substrate; An end face electrode forming step of forming an end face electrode that bridges the back electrode, and a second dividing step of dividing the strip substrate along the second dividing line to form individual chip elements, In the end face electrode forming process, the surface electrode is connected. A first end face electrode forming step of forming a first end face electrode in a thin film on the end face of the strip substrate, and a second end face electrode made of a conductive resin in a L-shaped cross section from the back surface to the end face of the strip substrate. A second end face electrode forming step, wherein the second end face electrode is connected to the back electrode and the first end face electrode, respectively.

  In the present invention, since the first end face electrode connected to the front electrode is formed on the end face of the strip substrate in the first end face electrode forming step, a chip resistor is provided in which no protrusion is formed at the end of the front electrode. In addition, since the second end surface electrode having an L-shaped cross section is formed with a conductive resin from the back surface to the end surface of the strip-shaped substrate in the second end surface electrode forming step, cracks due to heat shock can be prevented. .

  In the above configuration, the second end face electrode forming step transfers the strip-shaped substrate so that both the end surface and the back surface of the strip-shaped substrate are inclined with respect to the surface of the transfer table to which the conductive resin paste is applied. In this state, either one of the strip-shaped substrate and the transfer table is relatively moved so that the corner portion where the end surface and the back surface of the strip-shaped substrate intersect is in contact with the conductive resin paste. By making the conductive resin paste wrap around the end surface and the back surface of the strip-shaped substrate from the corner portion, the corner portion is separated from the conductive resin paste. It is possible to reliably prevent the protrusion from forming around the surface of the surface electrode.

  In the above configuration, after forming the first end face electrode in a thin film by sputtering Ni—Cr on the end face of the strip-shaped substrate in the first end face electrode forming step, the first end face electrode forming step is performed by the first end face electrode forming step. The conductive resin is applied so as to partially cover the end face electrode to form the second end face electrode in a thick film, and the end face electrode forming step is performed before the second end face electrode forming step. A first end face electrode protective film forming step of forming a first end face electrode protective film on the entire surface of the one end face electrode; and the first end face electrode protection exposed from the second end face electrode after the second end face electrode forming step. And a removing step of removing the film. According to this configuration, after forming the first end face electrode protective film as a thin film on the entire surface of the first end face electrode, the second end face electrode having an L-shaped cross section is formed as a thick film. Oxidation of the first end face electrode can be prevented by the heat treatment performed at the time. Then, in order to remove the first end face electrode protective film exposed from the second end face electrode after the second end face electrode forming step, the first end face electrode of the first end face electrode is subjected to electrolytic plating on the unoxidized first end face electrode. The surface can be covered with external electrodes.

  According to the present invention, it is possible to provide a chip component in which no protrusion is formed at the end portion of the surface electrode by forming the end face electrode while preventing cracks due to heat shock. It becomes possible to provide a structure. In addition, it is possible to provide a method for manufacturing a chip resistor in which no protrusion is formed at the end of the front electrode by forming the end face electrode while preventing cracks due to heat shock.

It is sectional drawing of the chip resistor which concerns on the example of 1st Embodiment of this invention. It is explanatory drawing which shows the manufacturing process of the said chip resistor. It is explanatory drawing which shows the manufacturing process of the said chip resistor. It is explanatory drawing which shows the end surface electrode formation process of the said chip resistor. It is a perspective view of a holder and a transfer table used when forming end face electrodes on a strip-shaped substrate. It is explanatory drawing which shows the 2nd end surface electrode formation process of the said chip resistor. It is sectional drawing which shows the mounting structure which mounts the said chip resistor in a circuit board. It is sectional drawing of the chip resistor which concerns on the example of 2nd Embodiment of this invention. It is sectional drawing of the chip resistor which concerns on the example of 3rd Embodiment of this invention.

  Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, a chip resistor 1 according to a first embodiment of the present invention includes a rectangular parallelepiped insulating substrate 2 and a pair of front and back surfaces arranged on the surface of the insulating substrate 2 at a predetermined interval. An electrode 3, a pair of back electrodes 4 opposed to each other on the back surface of the insulating substrate 2 at a predetermined interval, and a resistor 5 formed on the surface of the insulating substrate 2 so as to be connected to the pair of front electrodes 3 A protective layer 6 covering the resistor 5, a pair of end surface electrodes 7 provided on the end surface of the insulating substrate 2 to bridge the corresponding front electrode 3 and back electrode 4, and the front electrode 3, the back electrode 4 and the end surface electrode 7 and a pair of external electrodes 11 covering the respective surfaces of FIG. Although not shown, the protective layer 6 has a two-layer structure of an undercoat layer and an overcoat layer, and a trimming groove for adjusting a resistance value (not shown) is formed in the resistor 5 and the undercoat layer. Yes.

  The insulating substrate 2 is obtained by dividing a large substrate, which will be described later, along a first divided line and a second divided line in the form of a lattice, and a large number of large substrates are ceramics whose main component is alumina. It is a substrate. The main component of the front electrode 3 and the back electrode 4 is silver, and these electrodes 3 and 4 are obtained by screen-printing a conductive material paste on a large substrate, drying and firing. The resistor 5 is obtained by screen-printing a resistor paste such as ruthenium oxide on a large substrate so as to overlap the pair of front electrodes 3, drying and firing. The undercoat layer of the protective layer 6 is a glass paste screen-printed, dried and fired, and protects the resistor 5 from the heat of the laser when the trimming groove is formed. The overcoat layer of the protective layer 6 is obtained by screen-printing an epoxy-based resin paste, drying and baking, and is formed on the undercoat layer after the formation of the trimming groove to protect the resistor 5 from the external environment. Is.

  The end face electrode 7 includes a first end face electrode 8 formed as a thin film on the end face of the insulating substrate 2 so as to be connected to the front electrode 3 and the back electrode 4, and a first end face formed as a thin film under the surface of the first end face electrode 8. The electrode protective film 10 and the second end face electrode 9 having a thick L-shaped cross section from the back surface to the end face of the insulating substrate 2 so as to be connected to the first end face electrode 8 and the back electrode 4 are provided. .

  The first end face electrode 8 is made of a Ni—Cr thin film formed by sputtering, and is formed on the entire end face of the insulating substrate 2. The first end face electrode protective film 10 is made of a Cu thin film formed by sputtering, and is formed so as to cover the lower surface of the first end face electrode 8. The second end face electrode 9 is obtained by applying a conductive resin paste containing resin to silver and heat-curing, and is formed so as to cover a part of the back electrode 4 and the first end face electrode protective film 10. ing. As will be described in detail later, the first end face electrode protective film 10 is for preventing the first end face electrode 8 from being oxidized by the heat curing of the second end face electrode 9, and the first end face electrode protective film 10 is A thin film is formed on the entire surface of the first end face electrode 8 before the second end face electrode 9 is heat-cured (before the thick film is formed), and the second end face electrode 9 is formed after the second end face electrode 9 is heat-cured (after the thick film is formed). The first end face electrode protective film 10 exposed from is removed with sulfuric acid or the like.

  The external electrode 11 is formed by electrolytically plating Ni, Sn or the like on the surface of the end face electrode 7 or the like. When the chip resistor 1 is surface-mounted on the circuit board, the external electrode 11 is formed on the circuit board land. And soldered together.

  Next, a manufacturing method of the chip resistor 1 configured as described above will be described with reference to FIGS. 2A to 2E are plan views showing a large-sized substrate and a strip-shaped substrate, and FIGS. 3A to 3E are cross-sectional views taken along line AA in FIG. FIGS. 4A to 4D are cross-sectional views showing a process of forming the first end face electrode and the second end face electrode applied to the strip-shaped substrate, and FIG. 5 is used for the process of forming the second end face electrode. FIG. 6 is a perspective view of a holder and a transfer table, and FIG. 6 is a diagram illustrating a process of forming a second end face electrode.

  First, as shown in FIGS. 2 (a) and 3 (a), a large substrate 20 on which a large number of insulating substrates 2 are taken is prepared. The large substrate 20 is provided with a first dividing line 21 and a second dividing line 22 that extend in a lattice shape in advance, and each of the squares divided by both the dividing lines 21 and 22 corresponds to one chip. It becomes a formation area.

  Next, as shown in FIGS. 2 (b) and 3 (b), Ag-Pd paste is screened on the surface of the large substrate 20 so as to overlap the first dividing line 21 set on the surface of the large substrate 20. A plurality of unfired front electrodes 3 are formed by printing and drying. Similar to the formation of the front electrode, Ag paste is screen-printed on the back surface of the large-sized substrate 20 and dried to form a plurality of unfired back electrodes 4 at positions corresponding to the formation positions of the front electrode group. Thereafter, the front electrode 3 and the back electrode 4 are fired at a high temperature of about 850 ° C. Thereby, the surface electrode 3 and the back electrode 4 which were baked on the surface and the back surface of the large-sized substrate 20, respectively, are formed. In addition, it is also possible to reverse the formation order of the front electrode and the back electrode, and after forming a plurality of back electrodes on the back surface of the large-sized substrate 20, a method for forming a plurality of front electrodes on the surface of the large-sized substrate 20 It may be.

  Next, as shown in FIG. 2C and FIG. 3C, a resistor paste such as ruthenium oxide is screen-printed on the surface of the large-sized substrate 20 and dried. After the body 5 is formed, the resistor 5 is fired at a high temperature of about 850 ° C. Thereby, the resistor 5 connected to the surface electrode 3 which makes a pair on the surface of the large format substrate 20 is formed.

  Next, as shown in FIGS. 2D and 3D, after the glass paste is screen-printed on the region covering the resistor 5, the glass paste is fired at a high temperature of about 600 ° C. An undercoat layer of the protective layer 6 covering the body 5 is formed.

  Next, although illustration is omitted, the undercoat layer of the resistor 5 and the protective layer 6 is irradiated with laser light to form a trimming groove so as to have a target resistance value. In the next step, the undercoat layer and the trimming groove are formed. After an epoxy resin paste is screen-printed so as to cover the resin paste, the overcoat layer of the protective layer 6 is formed by heat curing the resin paste at a low temperature of about 200 ° C.

  The process up to this point is a batch process for the large-sized substrate 20 for taking a large number of pieces. In the next step, a primary break process is performed in which the large-sized substrate 20 is divided into strips along the first dividing line 21. As a result, as shown in FIGS. 2E and 3E, a strip-shaped substrate 23 provided with a plurality of chip regions is obtained.

  Then, the formation process of the end surface electrode given to a strip-shaped board | substrate is demonstrated using FIGS. First, as shown in FIG. 4A, the first end face electrode 8 bridging the front electrode 3 and the back electrode 4 is thinned by sputtering Ni—Cr on the end face (divided face) of the strip-shaped substrate 23. Form (first end face electrode forming step).

  Next, as shown in FIG. 4B, the first end face electrode protective film 10 is formed into a thin film by sputtering Cu on the entire surface of the first end face electrode 8 (protective film forming step). In the present embodiment, the protective film forming step is performed before the second end surface electrode forming step for forming the second end surface electrode 9, and one of the first end surface electrode protective films 10 formed into a thin film in this protective film forming step. The portion is removed after the second end face electrode forming step.

  Next, as shown in FIG.4 (c), the 2nd end surface electrode 9 is formed into a thick film from the back surface to the end surface of the strip-shaped board | substrate 23 in cross-sectional L shape (2nd end surface electrode formation process). The second end face electrode forming step will be described with reference to FIGS.

  In the second end face electrode forming step according to this embodiment, the second end face electrode 9 is formed on the strip-shaped substrate 23 using the holder 30 and the transfer table 40 as shown in FIG. On the upper surface of the transfer table 40, a conductive resin paste 41, which is a material of the second end face electrode 9, is applied in a film shape.

  The holder 30 has plate-like portions facing each other in parallel, and the transfer table 40 is disposed between these plate-like portions so as to be movable in the vertical direction (the direction of arrows Z1-Z2 in FIG. 5). The holder 30 is provided with a plurality of groove portions 30a whose upper ends are opened at regular intervals along the direction of arrows X1-X2 in FIG. The groove portion 30 a is inclined with respect to the surface of the transfer table 40, and the groove width W of the groove portion 30 a is set wider than the plate thickness t of the strip-shaped substrate 23. Both ends in the longitudinal direction of the strip-shaped substrate 23 are inserted and held so that the surface of the strip-shaped substrate 23 faces the X1 direction in the opposed groove portions 30a.

  FIG. 5 shows a state in which one strip-shaped substrate 23 is inserted into the groove 30a, but in actuality, by inserting both longitudinal ends of the plurality of strip-shaped substrates 23 into the groove 30a, respectively. A plurality of strip-shaped substrates 23 are held by the holder 30 at regular intervals.

  As shown in FIG. 6A, when both ends in the longitudinal direction of the strip-shaped substrate 23 are held in the groove portion 30a, the end surface of the strip-shaped substrate 23 is held on the bottom surface of the groove portion 30a and the strip-shaped substrate 23. Is held by the right side of the groove 30a in the figure. As a result, both the end surface and the back surface of the strip-shaped substrate 23 are inclined with respect to the surface of the transfer table 40. At this time, the transfer table 40 is stopped at the lowered position in the direction of the arrow Z2 in FIG. 5, and the corner 23a where the end surface and the back surface of the strip substrate 23 intersect each other is from the conductive resin paste 41 on the transfer table 40 to the arrow Z1. It is separated in the direction.

  When the transfer table 40 is driven in the Z1 direction and moved to the raised position while the corner 23a of the strip-shaped substrate 23 is separated from the conductive resin paste 41, as shown in FIG. 23 a contacts the conductive resin paste 41. At this time, the conductive resin paste 41 wraps around the end surface and the back surface of the strip-shaped substrate 23 from the corner portion 23a. Thereafter, the corner 23a is separated from the conductive resin paste 41 by returning the transfer table 40 to the lowered position. Then, the strip-shaped substrate 23 is extracted from the groove 30 a of the holder 30 and turned upside down, and the conductive resin paste 41 is brought into contact with the corner 23 a on the opposite side of the strip-shaped substrate 23 in the same procedure. And although illustration is abbreviate | omitted, after drying the conductive resin paste 41 apply | coated to the cross-section L-shape from the back surface to the end surface of the strip-shaped board | substrate 23, it heat-hardens at about 200 degreeC. As a result, the second end face electrode 9 having an L-shaped cross section is formed in a thick film on the strip-shaped substrate 23. The surface of the first end face electrode protective film 10 is oxidized by the heating at this time.

  Returning to FIG. 4, when the first end face electrode protective film 10 exposed from the second end face electrode 9 is acid-treated with sulfuric acid having a concentration of about 5% after the second end face electrode forming step (oxide film removing step). As shown in FIG. 4D, the first end face electrode protective film 10 is interposed between the first end face electrode 8 and the second end face electrode 9. 4D shows a state in which all of the first end face electrode protective film 10 exposed from the second end face electrode 9 has been removed. In the external electrode forming step described later, On the premise that the external electrode 11 can be formed by electrolytic plating performed on the surface, if the oxide film of the first end face electrode protective film 10 formed during the heat curing of the second end face electrode 9 is removed The first end face electrode protective film 10 exposed from the second end face electrode 9 may not be completely removed in the oxide film removing process.

  Then, the front electrode 3, the back electrode 4, and the end face electrode 7 are electrolytically plated with Ni, Sn, etc. to form a pair of external electrodes 11, and then the strip-shaped substrate 23 is divided along the second dividing line 22. By performing next break machining, the chip resistor 1 shown in FIG. 1 is completed.

  As shown in FIG. 7, the chip resistor 1 manufactured as described above is mounted on a land 51 provided on the circuit board 50 by adsorbing the upper surface of the chip resistor 1 with a suction pad (not shown) and soldering. Surface mounted by attaching. Specifically, after the solder paste is formed on the land 51, the chip resistor 1 is mounted on the solder paste with the back electrode 4 facing the land 51. Then, the circuit board 50 on which the chip resistor 1 is mounted is carried into a reflow furnace, and the solder paste is melted and solidified, whereby the solder 52 is formed between the back electrode 4 and the land 51, and the end face electrode A fillet-like solder 52 is formed between 7 and the land 51.

  As described above, in the present embodiment example, since the first end face electrode 8 is formed as a thin film on the end face of the insulating substrate 2 so as to be connected to the front electrode 3, the end face electrode is formed to protrude from the end of the front electrode. A chip resistor in which no part is formed can be provided. Thereby, when the chip resistor is mounted on the circuit board by adsorbing the upper surface side of the chip resistor with the suction pad, the problem that the chip resistor is not separated from the suction pad can be solved.

  In this embodiment, the second end face electrode 9 is formed of a conductive resin in a L-shaped cross section from the back surface to the end face of the insulating substrate 2 so as to be connected to the first end face electrode 8 and the back electrode 4. Therefore, it is possible to prevent the solder joint from being damaged and cracking due to the heat shock to the chip resistor mounted on the circuit board.

  The end face electrode forming step according to the present embodiment includes a first end face electrode forming step in which the first end face electrode 8 is formed as a thin film on the end face of the strip substrate 23 so as to be connected to the surface electrode 3, and the strip substrate 23. A second end face electrode forming step of forming a second end face electrode 9 made of a conductive resin in a L-shaped cross section from the back face to the end face. The second end face electrode 9 includes the back electrode 4 and the first end face. Since it is connected to the electrode 8 respectively, it is possible to provide a chip resistor manufacturing method in which no protrusion is formed at the end of the front electrode by forming the end face electrode, and to prevent the occurrence of cracks due to heat shock. it can.

  Further, in the second end face electrode forming process, the strip-shaped substrate 23 is transferred to the transfer table 40 so that both the end surface and the back surface of the strip-shaped substrate 23 are inclined with respect to the surface of the transfer table 40 to which the conductive resin paste 41 is applied. In this state, the transfer table 40 is moved so that the corner 23a where the end surface and the back surface of the strip-shaped substrate 23 intersect with the conductive resin paste 41 is brought into contact with the conductive resin paste 41. 23a, the conductive resin wraps around the surface of the front electrode 3 to reach the end of the front electrode 3 in order to separate the corner 23a from the conductive resin paste 41. It is possible to reliably prevent the protrusions from being formed.

  Next, a chip resistor according to a second embodiment of the present invention will be described with reference to FIG. Compared with the chip resistor 1 according to the first embodiment, the chip resistor 61 according to the second embodiment is an insulating substrate so that the end surface electrode 67 is connected to the surface electrode 63 as shown in FIG. A first end face electrode 68 formed in a thin film on the end face of 62, and a conductive resin formed in a thick L-shaped section from the back face to the end face of the insulating substrate 62 so as to be connected to the first end face electrode 68 and the back electrode 64 The second end face electrode 69 is common, and the second end face electrode 69 is connected to the back electrode 64 and the first end face electrode 68, respectively. The difference is that a thin film is formed on the surface of the second end face electrode 69 and that the first end face electrode protective film is not formed on the first end face electrode 68.

  Specifically, in the end face electrode forming step, first, the conductive resin paste is brought into contact with the corners of the strip-shaped substrate by using the holder 30 and the transfer table 40 and is cured by heating, whereby the end surface of the strip-shaped substrate is obtained. After forming the second end face electrode 69 thickly in a L-shaped cross section on a part of the back electrode 64 and a part of the back electrode 64, Ni—Cr is applied to the entire end face of the strip-shaped substrate so as to cover the side face of the second end face electrode 69. A first end face electrode 68 is formed into a thin film by sputtering. In this case, since the first end face electrode 68 is not formed when the second end face electrode 69 is heat-cured, the first end face electrode 68 is not oxidized. For this reason, in the second embodiment, it is not necessary to form the first end face electrode protective film 10 as in the first embodiment, and as a result, the end face electrodes are formed with fewer steps than in the first embodiment. can do. Note that the chip resistor 61 according to the second embodiment example has the effect of the chip resistor according to the first embodiment example, that is, the end portion of the surface electrode is formed by forming the end face electrode while preventing cracks due to heat shock. Needless to say, there is an effect that no protrusion is formed.

  Next, a chip resistor according to a third embodiment of the present invention will be described with reference to FIG. As shown in FIG. 9, the chip resistor 81 according to the third embodiment is tapered at the boundary between the surface and the end surface of the insulating substrate 82, as compared with the chip resistor according to the first and second embodiments. The surface electrode 83 is formed on the surface of the insulating substrate 82. The surface electrode 83a is formed on the surface of the insulating substrate 82, and the surface electrode 83a continuously extends from the surface electrode portion 83a to the end surface of the insulating substrate 82. An end surface side electrode portion 83b formed so as to cover 82a, and the end surface electrode 87 formed of a conductive resin is connected to the end surface side electrode portion 83b and the back electrode 84 so as to be connected to the insulating substrate 82. Is different in that a thick film is formed in an L-shaped cross section from the back surface to the end surface.

  Specifically, a wedge-shaped primary dividing groove is provided in advance as a first dividing line on the surface of the large substrate, and when a plurality of pairs of surface electrodes are formed so as to overlap the primary dividing groove, the surface electrodes are formed in a large format. It flows into the primary dividing groove from the surface of the substrate. Then, when the large substrate is divided into strip-shaped substrates along the primary dividing grooves, the primary dividing grooves are divided into two, and a tapered specific surface 82a is formed on the upper end surface of the strip-shaped substrate. As a result, the surface electrode that has flowed into the primary dividing groove is divided into two, and the surface-side electrode portion 83a that covers the surface of the strip-shaped substrate, and continuously extends from the surface-side electrode portion 83a to the end surface side of the strip-shaped substrate. A front electrode 83 including the end face side electrode portion 83b is formed. Thereafter, as in the first and second embodiments, the conductive resin paste is brought into contact with the corner portion where the end surface and the back surface of the strip-shaped substrate intersect, thereby connecting to the end surface side electrode portion 83b and the surface side electrode. An end face electrode 87 having an L-shaped cross section that does not reach the portion 83a is formed. Then, by dividing the strip-shaped substrate along the second dividing line, the surface side electrode portion 83a covers the surface of the insulating substrate 82, and the end surface side electrode portion 83b covers the specific surface 82a. In this case, unlike the first and second embodiments, it is not necessary to form a first end face electrode thin film by sputtering Ni—Cr on the end face of the strip-like substrate. Therefore, the chip resistor according to the third embodiment has an effect that no protrusion is formed at the end of the surface electrode by forming the end face electrode while preventing cracks due to heat shock, and the end face electrode forming step The effect that can be simplified can also be produced.

  In the first to third embodiments, the transfer table coated with the conductive resin paste moves in the vertical direction (arrow Z1-Z2 direction in FIG. 5), so that the corners of the strip-shaped substrate are made conductive. Although it is configured to come into contact with the resin paste, the present invention is not limited to this configuration, and the corners of the strip-shaped substrate can be obtained by moving the holder that holds the strip-shaped substrate in the vertical direction (the direction of arrows Z1-Z2 in FIG. 5). The part may be in contact with the conductive resin paste.

  In the first to third embodiments, the present invention is applied to the chip resistor. However, the present invention is not limited to this, and a fuse element such as an alloy is used instead of the resistor connected to the pair of front electrodes. It is possible to adapt the invention to the fuse resistors used.

1, 61, 81 Chip resistor 2, 62, 82 Insulating substrate 3, 63, 83 Front electrode 4, 64, 84 Back electrode 5, 65, 85 Resistor 6, 66, 86 Protective layer 7, 67, 87 End face electrode 8, 68 First end face electrode 9, 69 Second end face electrode 10 First end face electrode protective film 11, 70, 90 External electrode 20 Large-sized substrate 21 First divided line 22 Second divided line 23 Strip-shaped substrate 30 Holder 40 Transfer Table 83a Surface side electrode part 83b End face side electrode part

Claims (5)

A rectangular parallelepiped insulating substrate, a pair of front electrodes arranged opposite to each other on the surface of the insulating substrate with a predetermined interval, and a pair of back electrodes arranged opposite to each other on the back surface of the insulating substrate with a predetermined interval In a chip component comprising a pair of end face electrodes that bridge the front electrode and the back electrode,
The end face electrode extends from the back surface to the end face of the insulating substrate so as to connect to the first end face electrode formed on the end face of the insulating substrate so as to be connected to the front electrode, and to the first end face electrode and the back electrode. And a second end face electrode made of a conductive resin having an L-shaped cross section. A rectangular parallelepiped insulating substrate, a pair of front electrodes arranged opposite to each other on the surface of the insulating substrate with a predetermined interval, and a pair of back electrodes arranged opposite to each other on the back surface of the insulating substrate with a predetermined interval In a chip component comprising a pair of end surface electrodes that bridge the front electrode and the back electrode on the end surface of the insulating substrate,
The front electrode has a surface side electrode part formed on the surface of the insulating substrate, and an end surface side electrode part continuously extending from the surface side electrode part to the end surface side of the insulating substrate,
The chip part according to claim 1, wherein the end face electrode is made of a conductive resin having an L-shaped cross section from the back surface to the end face of the insulating substrate so as to be connected to the end face side electrode portion and the back electrode.   3. A chip component mounting structure, wherein the chip component according to claim 1 or 2 is mounted on a land provided on a circuit board in a state where the back electrode is opposed. A surface electrode forming step of forming a plurality of pairs of surface electrodes on the surface of the large substrate on which the first division line and the second division line extending in a lattice shape are set;
A back electrode forming step of forming a plurality of pairs of back electrodes at positions corresponding to the plurality of pairs of front electrodes on the back surface of the large format substrate;
Forming a resistor connected to the surface electrode paired with the surface of the large substrate; and
A first dividing step of dividing the large substrate along the first dividing line to form a strip-shaped substrate;
An end face electrode forming step of forming an end face electrode that bridges the front electrode and the back electrode corresponding to both end faces of the strip substrate;
Dividing the strip-shaped substrate along the second dividing line to form individual chip elements, and
The end face electrode forming step includes a first end face electrode forming step of forming a first end face electrode in a thin film on the end face of the strip-like substrate so as to be connected to the front electrode, and an L-shaped cross section from the back side to the end face of the strip-like substrate. A second end face electrode forming step of forming a second end face electrode made of a conductive resin in a thick film, wherein the second end face electrode is connected to the back electrode and the first end face electrode, respectively. A manufacturing method of a chip resistor characterized by the above. In the description of claim 4,
In the second end surface electrode forming step, the strip substrate is placed above the transfer table so that both the end surface and the back surface of the strip substrate are inclined with respect to the surface of the transfer table to which the conductive resin paste is applied. In this state, by moving either one of the strip-shaped substrate and the transfer table relative to each other and bringing the corner portion where the end surface and the back surface of the strip-shaped substrate intersect with the conductive resin paste, A method of manufacturing a chip resistor, characterized in that the conductive resin paste is made to wrap around the end surface and the back surface of the strip-shaped substrate from the corner portion, and then the corner portion is separated from the conductive resin paste. .