JP2017112326A - Method for manufacturing chip resistor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a chip resistor which is high in production efficiency and can cope with miniaturization.SOLUTION: A laser scribing method is used in which, after forming a front electrode 2, a resistor 3, and a protective film 4 on a surface of a large-sized substrate 10, when the large-sized substrate 10 is primarily divided and secondarily divided in mutually orthogonal directions, as at least one division method, through slits 13, 16 are formed in the large-sized substrate 10 by laser light irradiation.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a method of manufacturing a chip resistor in which a plurality of sets of electrodes, resistors, and the like are formed on a large substrate, and then the large substrate is divided into a lattice and separated into pieces.

  The chip resistor is a rectangular parallelepiped insulating substrate made of ceramics, a pair of front electrodes disposed opposite to each other on the surface of the insulating substrate with a predetermined interval, and disposed opposite to the back surface of the insulating substrate with a predetermined interval. A pair of back electrodes, an end face electrode that bridges the front electrode and the back electrode, a resistor that bridges the pair of front electrodes, and an insulating protective film that covers the resistor. Yes.

  In general, when manufacturing such a chip resistor, a large number of electrodes, resistors, protective films, and the like are collectively formed on a large substrate, and then the large substrate is extended in a lattice shape. By dividing (breaking) along the dividing groove and the secondary dividing groove, a large number of individual chips are taken. These primary division grooves and secondary division grooves are formed in advance on a large-sized substrate, and as a method for forming them, a mold having a V-shaped cross section is embossed on a large-sized substrate (green sheet) before baking. And a method (laser scribing method) in which a large-sized substrate after firing is irradiated with laser light are known.

  Further, instead of such a break method using the division grooves, as described in Patent Document 1, a large number of electrodes, resistors, and protective films are provided for a large substrate having no division grooves. Etc. are formed in a lump, and then the large substrate is fixed to a support base, and a large substrate is cut into a lattice using a dicing blade, thereby obtaining a large number of individual chips. Dicing methods are also known.

JP 2007-173281 A

  However, in the dividing method in which the dividing groove provided in advance on the large substrate is broken, a bending stress that opens the dividing groove having a V-shaped cross section is applied to the large substrate to cause a break. Ceramics existing between the two are not broken at right angles to the substrate surface, and the part is broken (deformed cracking) in a random oblique direction with respect to the substrate surface, and the external dimensions of the chip resistor vary accordingly. May occur. Such a variation is within a dimensional error range for a chip resistor having a large outer dimension, but cannot be ignored in the case of an ultra-small chip resistor such as 0402 mm size or 0201 mm size.

  On the other hand, in the dividing method by dicing disclosed in Patent Document 1 and the like, a large substrate is cut using a diamond blade or the like that rotates at high speed, so that the shape can be processed with high dimensional accuracy. However, one cutting line is formed by scanning a blade that rotates at high speed from one side of the large substrate to the opposite side, and it is necessary to perform such a cutting process a plurality of times for each of the primary division and the secondary division. Therefore, there is a problem that it takes a lot of tact time to finish all the cutting steps. In addition, the cutting allowance corresponding to the thickness of the blade is cut from the large substrate by dicing, and it is necessary to secure such a cutting allowance on the large substrate in accordance with the number of dicing of the primary division and the secondary division. There is also a problem that production efficiency is very poor.

  The present invention has been made in view of the actual situation of the prior art, and an object of the present invention is to provide a method of manufacturing a chip resistor that has high production efficiency and can cope with downsizing.

  In order to achieve the above object, a method for manufacturing a chip resistor according to the present invention includes forming electrodes and resistors in a plurality of chip forming regions on the surface of a large-sized substrate made of ceramics, and then covering the resistors. A chip resistor in which an insulating protective film is formed on the substrate and then the large substrate is divided into a primary division and a secondary division in directions orthogonal to each other to obtain a large number of individual chips. In the manufacturing method, at least one of the primary division and the secondary division is performed by irradiating the large substrate with laser light to form a through slit.

  Thus, after forming an electrode, a resistor, and a protective film on the surface of a large-sized substrate, the large-sized substrate is irradiated with laser light to form a through slit, thereby forming either or both of the primary division and the secondary division. If this is done, the part of the substrate cut with the laser beam can be divided with high dimensional accuracy, and the cutting allowance associated with the division of the part will not be generated. In addition, a suitable chip resistor can be provided.

  In the manufacturing method described above, if the through slit is formed by irradiating the laser beam from the back side of the large-sized substrate, it is possible to reduce the influence that the resistor and the protective film are damaged by the heat of the laser beam.

  In the above manufacturing method, the first auxiliary groove is formed by irradiating laser light from one side of the front and back sides of the large substrate, and then the laser beam is irradiated from the opposite side of the large substrate to reach the first auxiliary groove. By forming the second auxiliary groove, the first auxiliary groove and the second auxiliary groove communicate with each other to form a through slit. When the through slit is formed, the laser beam is irradiated only from one side of the large-sized substrate. Compared with the case of forming the substrate, not only can the resistance and the protective film be damaged by the heat of the laser light, but also the tilt directions of the first auxiliary groove and the second auxiliary groove are reversed according to the beam angle of the laser light. Therefore, the surface shape of the large-sized substrate by the through slit can be smoothed.

  In the above manufacturing method, one of the primary division and the secondary division is performed by irradiating a large substrate with laser light to form a through slit, and either one of the large division substrate is diced. If it is done by cutting with a blade, the cutting efficiency on the split side using dicing will be somewhat reduced, but the smoothness of the cut surface due to dicing will improve, so a chip resistor with higher dimensional accuracy will be produced. Can be provided.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the chip resistor which can respond to size reduction with good production efficiency can be provided.

It is a top view of the chip resistor concerning the example of a 1st embodiment of the present invention. It is sectional drawing which follows the II-II line of FIG. It is sectional drawing which follows the III-III line of FIG. It is a top view which shows the manufacturing process of this chip resistor. It is sectional drawing which shows the manufacturing process of this chip resistor. It is sectional drawing which shows the manufacturing process of this chip resistor. It is a top view of the chip resistor concerning the example of a 2nd embodiment of the present invention. It is sectional drawing which follows the VIII-VIII line of FIG. It is sectional drawing which follows the IX-IX line of FIG. It is a top view which shows the manufacturing process of this chip resistor. It is sectional drawing which shows the manufacturing process of this chip resistor. It is sectional drawing which shows the manufacturing process of this chip resistor. It is the top view and sectional drawing which show the modification of the laser scribing method.

  Embodiments of the invention will be described with reference to the drawings. As shown in FIGS. 1 to 3, the chip resistor according to the first embodiment of the present invention includes a rectangular parallelepiped insulating substrate 1 and a pair of tables provided at both ends in the longitudinal direction on the surface of the insulating substrate 1. An electrode 2, a rectangular resistor 3 provided so as to be connected to these surface electrodes 2, an insulating protective film 4 covering a part of both surface electrodes 2 and the entire surface of the resistor 3, and an insulating substrate 1 A pair of back electrodes 5 provided at both ends in the longitudinal direction on the back surface, a pair of end face electrodes 6 provided at both ends in the longitudinal direction of the insulating substrate 1, and the end face electrodes 6, the front electrode 2 and the back electrode 5 It is mainly composed of a pair of external electrodes 7 deposited on the surface.

  The insulating substrate 1 is an alumina substrate made of ceramics, and this insulating substrate 1 was cut by a laser scribing along a primary division prediction line and a secondary division prediction line extending in the horizontal and vertical directions, and a large number of substrates were taken. Is.

  The pair of front electrodes 2 and the pair of back electrodes 5 are obtained by screen-printing Ag-based paste and drying and firing. The resistor 3 is obtained by screen-printing resistance paste such as ruthenium oxide and drying and firing. It is. Both ends in the longitudinal direction of the resistor 3 overlap the surface electrode 2 and are not shown, but the resistor 3 is formed with trimming grooves for adjusting the resistance value.

  The protective film 4 has a two-layer structure of an undercoat layer and an overcoat layer, of which the undercoat layer is a screen paste of glass paste dried and fired, and the overcoat layer is a screen print of an epoxy resin paste. And heat-cured.

  The pair of end face electrodes 6 are made by sputtering Ni—Cr or the like, dipped Ag paste, dried and fired, and these end face electrodes 6 are formed on the end face of the insulating substrate 1 to form the front electrode 2 and the back electrode. 5 is conducting.

  The pair of external electrodes 7 has a two-layer structure of a barrier layer and an external connection layer, of which the barrier layer is a Ni plating layer formed by electrolytic plating, and the external connection layer is a Sn plating layer formed by electrolytic plating. .

  Next, a manufacturing method of the chip resistor configured as described above will be described with reference to FIGS. 5 shows a cross-sectional view along the line XX in FIG. 4, and FIG. 6 shows a cross-sectional view along the line YY in FIG.

  First, a large-sized substrate 10 made of ceramic from which a large number of insulating substrates 1 are taken is prepared. Although the large-sized substrate 10 is not formed with a primary dividing groove or a secondary dividing groove, the large-sized substrate 10 has primary dividing lines extending in the vertical and horizontal directions in the subsequent processes shown in FIGS. 4 (e) and 4 (i). Laser scribing is performed along the secondary division lines, and each square section defined by the two division lines becomes a chip formation region for one piece.

  Then, by printing an Ag-based paste on the surface of the large-sized substrate 10 and drying and baking it, a predetermined interval exists on the surface of the large-sized substrate 10 as shown in FIGS. A plurality of front electrodes 2 are formed. Also, before and after this, an Ag-based paste is printed on the back surface of the large substrate 10 and dried and fired to form a plurality of back electrodes 5 with a predetermined interval on the back surface of the large substrate 10.

  Next, a resistor paste such as ruthenium oxide is screen-printed on the surface of the large-sized substrate 10 and then dried and fired, so that a pair of front electrodes 2 are formed as shown in FIGS. A plurality of resistor bodies 3 are formed to straddle. In addition, the formation order of the surface electrode 2 and the resistor 3 may be reverse to the above.

  Next, after reducing the damage to the resistor 3 at the time of trimming groove formation, after forming an undercoat layer (not shown) covering the resistor 3 by screen-printing glass paste, drying and firing, A trimming groove is formed in the resistor 3 from above the undercoat layer to adjust the resistance value. Thereafter, an epoxy resin paste is screen-printed from above the undercoat layer and heat-cured to arrange in the vertical direction (Y-Y direction) of the figure as shown in FIGS. A plurality of protective films 4 are formed to cover each resistor 3 formed in a strip shape.

  Next, as shown in FIGS. 4, 5, and 6 (d), the adhesive 11 is applied to the entire back surface of the large substrate 10, and the fixing base material 12 is attached to the large substrate 10 through the adhesive 11. Thereafter, the adhesive 11 is thermally cured. The adhesive 11 is preferably one that can be washed with a specific solvent. In the case of this embodiment, a shellac resin that is soluble in an alcohol solvent is used. Further, the fixed base 12 is preferably a hard material such as glass, and in the case of this embodiment, the same ceramic substrate as the material of the large substrate 10 is used.

  Next, by irradiating laser light from the surface side of the large-sized substrate 10 and scanning the laser light along a primary division predicted line passing through the center portion of the surface electrode 2 sandwiched between the pair of protective films 4, As shown in FIGS. 4, 5, 6 (e), a through slit 13 that penetrates the large substrate 10 and reaches the middle of the fixed base 12 is formed. Since the through slits 13 are formed by a laser scribing method of cutting with laser light, a large number of through slits 13 are formed with high accuracy in a short time at a predetermined position (primary division expected line) of the large substrate 0. can do.

  At this time, since the cross-sectional shape of the through slit 13 becomes a wedge shape following the beam angle of the irradiated laser light, the slit width of the through slit 13 is from the surface side of the large substrate 10 as shown in FIG. Along with this, the cut surface of the large-sized substrate 10 becomes an inclined surface that expands downward from above.

  After forming the through slits 13 for primary division on the large substrate 10 by laser scribing in this way, the adhesive (shellac resin) 11 is washed with an alcohol solvent to peel the fixed base 12 from the large substrate 10. Thus, as shown in FIGS. 4, 5, and 6 (f), a strip-shaped substrate 10 </ b> A having substantially the same width as the chip resistor is obtained from the large substrate 10.

  Thereafter, Ni—Cr is sputtered on the end surface of the strip-shaped substrate 10A, or Ag paste is dip-coated on the end surface of the strip-shaped substrate 10A, followed by drying and firing, as shown in FIGS. Thus, the end surface electrode 6 which conducts the front electrode 2 and the back electrode 5 is formed on both end surfaces of the strip-shaped substrate 10A.

  Next, as shown in FIGS. 4, 5, 6 (h), an adhesive 14 is applied to the entire back surface of the strip-shaped substrate 10 </ b> A, and the fixing base material 15 is attached to the strip-shaped substrate 10 </ b> A via the adhesive 14. After the application, the adhesive 1 is thermally cured. The adhesive 14 and the fixing substrate 15 are the same as those used in the steps shown in FIGS.

  Next, a laser beam is irradiated from the surface side of the strip-shaped substrate 10A, and this laser beam is scanned along a secondary division prediction line so as to cross the protective film 4 existing between the respective resistors 3. As shown in 4, 5, 6 (i), a through slit 16 that penetrates the strip-shaped substrate 10A and reaches the middle of the fixed base material 15 is formed. Like the through slit 13 for primary division described above, this through slit 16 is also formed by a laser scribing method that cuts with laser light, so that a predetermined position (secondary division expected line) of the strip substrate 10A. A plurality of through slits 16 can be formed with high accuracy in a short time.

  Next, the adhesive 14 is washed with an alcohol-based solvent, and the fixing base 15 is peeled off from the strip substrate 10A, so that the chip resistor is removed from the strip substrate 10A as shown in FIGS. A large number of single chips 10B having the same size as the vessel are obtained.

  Finally, an external electrode (not shown) for covering the end face electrode 6, the front electrode 2, and the back electrode 5 is formed by performing electrolytic plating of Ni, Sn, etc. on the individual chip 10 </ b> B. A chip resistor as shown in FIG. 3 is completed.

  As described above, in the chip resistor manufacturing method according to this embodiment, after the surface electrode 2, the resistor 3 and the protective film 4 are formed on the surface of the large substrate 10, the large substrate 10 is orthogonal to each other. When dividing in the primary division direction and the secondary division direction, both the primary division and the secondary division are performed by using a laser scribing method in which the through slits 13 and 16 are formed by laser light irradiation. Chip resistors that can divide the substrate cut by the laser beam with high dimensional accuracy, eliminate almost no cutting allowance associated with the division of the portion, and have high production efficiency and support for downsizing Can be provided.

  Next, a chip resistor according to a second embodiment of the present invention will be described. As shown in FIGS. 7 to 9, the chip resistor according to the second embodiment includes a rectangular parallelepiped insulating substrate 1, and A pair of front electrodes 2 provided at both ends in the longitudinal direction on the surface of the insulating substrate 1, a rectangular resistor 3 provided so as to be connected to the front electrodes 2, and both the front electrodes 2 and the resistors 3 An insulating protective film 4 covering the entire surface, a pair of end surface electrodes 6 provided so as to go from the end surface of the insulating substrate 1 to the back surface and the upper surface of the protective film 4, and the surfaces of these end surface electrodes 6 were deposited It is mainly composed of a pair of external electrodes 7.

  The second embodiment is greatly different from the first embodiment described above in that the insulating substrate 1 does not have a back electrode on the back surface side, and the protective film 4 is formed of the front electrode 2 and the resistor 3. Since the entire surface is covered and the end face electrode is formed in a U-shaped cross section so as to go around to the upper surface of the protective film 4, the other configuration is basically the same. The description corresponding to that in FIG.

  Next, a manufacturing method of the chip resistor according to the second embodiment will be described with reference to FIGS. 11 shows a cross-sectional view along the line XX in FIG. 10, and FIG. 12 shows a cross-sectional view along the line YY in FIG.

  First, a large-sized substrate 20 made of a ceramic from which a large number of insulating substrates 1 are taken is prepared, and an Ag-based paste is printed on the surface of the large-sized substrate 20 and dried and fired, whereby FIGS. ), A plurality of front electrodes 2 are formed on the surface of the large substrate 20 with a predetermined interval.

  Next, a resistor paste such as ruthenium oxide is screen-printed on the surface of the large-sized substrate 20 and then dried and fired, so that a pair of front electrodes 2 are formed as shown in FIGS. A plurality of resistor bodies 3 are formed to straddle. In addition, the formation order of the surface electrode 2 and the resistor 3 may be reverse to the above.

  Next, as a means for reducing damage to the resistor 3 when the trimming groove is formed, a glass paste is screen-printed, dried and fired to form an undercoat layer (not shown) that covers the surface electrode 2 and the resistor 3. After the formation, a trimming groove is formed in the resistor 3 from above the undercoat layer to adjust the resistance value. Thereafter, an epoxy resin paste is screen-printed from above the undercoat layer and heated and cured, so that all the surface electrodes 2 located in the chip formation region are shown in FIGS. And a protective film 4 covering the resistor 3 is formed.

  Next, as shown in FIGS. 10, 11, and 12 (d), an adhesive 21 is applied so as to cover the protective film 4 from the surface side of the large-sized substrate 20, and the fixing base material 22 is attached via the adhesive 21. After being attached to the large substrate 20, the adhesive 21 is thermally cured. The adhesive 21 and the fixing substrate 22 are the same as those used in the first embodiment.

  Next, by irradiating a laser beam from the back side of the large-sized substrate 20 and scanning the laser beam along a primary division predicted line passing through the center portion of each surface electrode 2 arranged in the YY direction, As shown in FIGS. 10, 11, and 12 (e), a through slit 23 that penetrates the large substrate 20 and reaches the middle of the fixed base material 22 is formed. Since the through slits 23 are formed by a laser scribing method of cutting with a laser beam, a large number of through slits 23 are formed with high precision in a short time at a predetermined position (primary division expected line) of the large-sized substrate 20. can do.

  In this way, after the through slit 23 for primary division is formed on the large substrate 20 by laser scribing, it is cut with a dicing blade along the predicted secondary division line extending in the XX direction from the back side of the large substrate 20. Thus, as shown in FIGS. 10, 11, and 12 (f), a large number of divided grooves 24 reaching the fixed base material 22 are formed at positions sandwiching the resistors 3 arranged in the YY direction. The secondary division process by dicing and the primary division process by laser scribing may be reversed. These primary division prediction lines and secondary division prediction lines are virtual lines set for the large format board 20, and each division prediction line is formed on the large format board 20 as in the first embodiment. It has not been done.

  Thereafter, the adhesive 21 is washed with an alcohol-based solvent and the fixing base 22 is peeled off from the large-sized substrate 20, so that the size is equal to that of a chip resistor as shown in FIGS. A large number of single chips 20B are obtained.

  Next, an Ag paste made of a resin is dip-applied to the end surface of the chip unit 20B and heated and cured, so that as shown in FIGS. Then, an end face electrode 6 is formed to wrap around to the upper surface of the protective film 4. Finally, an external electrode 7 that covers the end face electrode 6 is formed by subjecting each chip 20B to electrolytic plating such as Ni, Sn, etc., and a chip resistor as shown in FIGS. 7 to 9 is completed. To do.

  As described above, in the chip resistor manufacturing method according to the second embodiment, the through slit 23 is formed in the large substrate 20 by laser scribing to perform primary division, and the secondary division is performed with a dicing blade. Since the substrate 20 is cut, the tact time is increased or the production efficiency is reduced by the amount of the secondary division performed by dicing compared to the case where both the primary division and the secondary division are performed by laser scribing. However, since the smoothness of the cut surface by dicing is improved, a chip resistor with higher dimensional accuracy can be provided.

  In the chip resistor manufacturing method according to the second embodiment, in the laser scribing process shown in FIGS. 10, 11, and 12 (e), the through slit 23 is formed by irradiating laser light from the back side of the large substrate 20. Since they are formed, the influence of the resistor 3 and the protective film 4 being damaged by the heat of the laser beam can be reduced.

  In the chip resistor manufacturing method according to the first and second embodiments described above, the through slit is formed by irradiating laser light from either the front surface side or the back surface side of the large substrate. However, as shown in FIG. 13, a through slit may be formed by irradiating laser light from both the front and back sides of a large substrate.

  That is, as shown in FIG. 13A, after the surface electrode 2, the resistor 3 and the protective film 4 are formed on the surface of the large substrate 30, the laser beam is directed from above the protective film 4 toward the surface of the large substrate 30. And a plurality of first auxiliary grooves 31a and 32a reaching from the surface of the large substrate 30 to the middle are formed by scanning the laser beam along the predicted primary division line and the secondary division expected line. In FIG. 13A, the upper left side is a plan view of the large substrate 30 as viewed from directly above, the lower side is a cross-sectional view along the line XX, and the right side is a cross-sectional view along the line YY. The same applies to FIGS. 13B and 13C described below.

  Next, as shown in FIG. 13B, an adhesive 33 is applied so as to cover the protective film 4 from the surface side of the large substrate 30, and the fixing base material 34 is applied to the large substrate 30 via the adhesive 33. After pasting, the adhesive 33 is thermally cured. The adhesive 33 and the fixing substrate 34 are the same as those used in the first and second embodiments.

  Thereafter, as shown in FIG. 13 (c), laser light is irradiated from the back side of the large substrate 30, and this laser light is scanned along the primary division prediction line and the secondary division prediction line. A plurality of second auxiliary grooves 31b and 32b extending from the back surface of the substrate 30 to the middle are formed. As a result, the front end portions of the first auxiliary groove 31a and the second auxiliary groove 31b communicate with each other to form the through slit 31 for primary division, and the front end portions of the first auxiliary groove 32a and the second auxiliary groove 32b. The through slits 32 for secondary division are formed by communicating with each other.

  When the through slits 31 and 32 are formed by irradiating laser light from both the front and back surfaces of the large substrate 30 as described above, the through slits are formed by irradiating the laser beam only from one side of the large substrate 30. In comparison, not only can the effect of the resistor 3 and the protective film 4 being damaged by the heat of the laser beam, but also the inclination of the first auxiliary grooves 31a and 32a and the second auxiliary grooves 31b and 32b according to the beam angle of the laser beam. Since the direction is reversed, the cut surface shape of the large substrate 30 by the through slits 31 and 32 can be smoothed.

DESCRIPTION OF SYMBOLS 1 Insulating substrate 2 Front electrode 3 Resistor 4 Protective film 5 Back electrode 6 End surface electrode 7 External electrode 10, 20, 30 Large-sized substrate 10A Strip-shaped substrate 10B, 20B Chip unit 11, 14, 21, 33 Adhesive 12, 15, 22, 34 Fixed base material 13, 16, 23, 31, 32 Through slit 24 Divided groove 31a, 32a First auxiliary groove 31b, 32b Second auxiliary groove

Claims (4)

An electrode and a resistor are respectively formed on a plurality of chip formation regions on the surface of a ceramic large-sized substrate, and then an insulating protective film is formed so as to cover the resistor, and then the large-sized substrate is orthogonal to each other. In a method of manufacturing a chip resistor in which a large number of single chips are obtained by dividing into a primary division and a secondary division in a direction,
A method of manufacturing a chip resistor, wherein at least one of the primary division and the secondary division is performed by irradiating the large substrate with a laser beam to form a through slit.   2. The method of manufacturing a chip resistor according to claim 1, wherein the through slit is formed by irradiating a laser beam from the back side of the large substrate.   2. The first auxiliary groove according to claim 1, wherein the first auxiliary groove is formed by irradiating laser light from one side of the front and back surfaces of the large substrate to form the first auxiliary groove, and then irradiating laser light from the opposite side of the large substrate. Forming the second auxiliary groove, the first auxiliary groove and the second auxiliary groove communicate with each other to form the through slit.   4. The method according to claim 1, wherein one of the primary division and the secondary division is performed by irradiating the large substrate with laser light to form the through slit. A method of manufacturing a chip resistor, wherein either one is performed by cutting the large substrate with a dicing blade.