JP2019201139A - Manufacturing method for chip resistor - Google Patents

Abstract

To provide a manufacturing method for a chip resistor, capable of establishing both of high reliability and high accuracy while securing conduction reliability between an electrode and an end face electrode.SOLUTION: A large-sized substrate 10 on which a primary division groove 11 and secondary division groove 12 extending lengthwise and crosswise are formed is prepared. On a front face of the large-sized substrate 10 are formed rectangular front electrodes 3 that are independent of each other in chip regions adjacent to each other via the secondary division groove 12 and are laid across the primary division groove 11; and a resistor 4 connected to front electrodes 3 opposite to each other in a chip region is formed. Then, an insulating resin 13 extending in a belt shape along the secondary division groove 12 before performing resistance value adjustment on the resistor 4 using laser trimming. After that, the insulating resin 13 is removed and a step of forming a protection coating layer 8 and a step of dividing the large-sized substrate 10 are performed sequentially.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a method of manufacturing a chip resistor obtained by dividing a large substrate along a lattice-shaped primary division groove and a secondary division groove.

  In general, a chip resistor includes an insulating substrate having a rectangular shape in plan view, a pair of electrodes provided on the insulating substrate at a predetermined interval, a resistor that bridges the paired electrodes, and a resistor And a trimming groove for adjusting the resistance value is formed in the resistor.

  Usually, when manufacturing such a chip resistor, a primary divided groove and a secondary divided groove extending in the form of a lattice are formed in advance on one side or both sides of a sheet-like large substrate, and one side of the large substrate is formed. After forming electrodes, resistors, protective coats, etc. on the substrate, the large substrate is primarily divided into strip-shaped substrates along the primary dividing grooves, and the end electrodes are formed on the strip-shaped substrate, and then the secondary substrate is formed. A large number of chip resistors separated into individual pieces are completed by secondary division along the dividing grooves.

  In the manufacturing process of such a chip resistor, a large number of resistors are formed on one side of a large substrate by printing and baking a resistor paste. Since it is unavoidable that the resistance value of each resistor varies due to unevenness and the like, it is difficult to avoid resistance value adjustment work by forming a trimming groove in each resistor in the state of a large substrate and setting it to a desired resistance value. Done.

  In this resistance value adjustment work, the resistance value is measured by irradiating the resistor with laser light while measuring the resistance value by bringing a measuring probe into contact with a pair of electrodes connected to the resistor, thereby forming a trimming groove. Is generally rounded up to the target resistance value. In this case, the pair of electrodes are separated from the adjacent electrodes via the secondary dividing groove, but when the electrode material is printed so as to straddle the primary dividing groove, the electrode material is formed along the primary dividing groove. In the worst case, there is a situation in which adjacent electrodes are brought into conduction through the secondary dividing groove, and the resistance value adjusting operation cannot be performed.

  Therefore, conventionally, as described in Patent Document 1, an electrode formed on a large-sized substrate is formed in an H shape having a concave portion in the center, and the concave portion is positioned on the primary dividing groove to obtain a secondary shape. A technique has been proposed in which the interval between adjacent electrodes is widened through a dividing groove. According to such a conventional technique, the distance between the electrodes adjacent to each other through the secondary dividing groove is partially expanded on the primary dividing groove by the concave portion, so that the electrode material flows somewhat along the primary dividing groove. Moreover, it can suppress that the separation distance of the electrode which adjoins via a secondary division groove becomes narrower than a desired space | interval.

JP 59-75607 A

  In the prior art described in Patent Document 1, even if the electrode material flows along the primary dividing groove, the separation distance between the adjacent electrodes through the secondary dividing groove is smaller than a desired interval. Although it can be suppressed, since the area of the electrode itself is reduced by forming the concave portion in the electrode, there is a problem that it is difficult to bring the probe into contact with the electrode when adjusting the resistance value. Further, when the large-sized substrate is divided into strip-shaped substrates along the primary dividing grooves, the portion of the electrode narrowed by the concave portion is exposed on the dividing surface of the strip-shaped substrate. There has also been a problem that the reliability of conduction of the end face electrodes formed on the divided surfaces with respect to the electrodes is lowered.

  Furthermore, in recent years, there has been an increasing demand for high reliability of electrical characteristics and high accuracy of resistance values. In high reliability of electrical characteristics, a large resistor area is secured and connected to a resistor. In order to make the electrode portion (the convex portion other than the primary dividing groove in Patent Document 1) as wide as possible, it is necessary to narrow the interval between the adjacent electrodes via the secondary dividing groove. On the other hand, in order to increase the accuracy of the resistance value, for example, in a resistance value adjusting operation in a high resistance chip resistor, in order to prevent a measurement current at the time of laser trimming from leaking to an adjacent electrode, a secondary divided groove It is necessary to widen the distance between adjacent electrodes via the electrode. As described above, from the viewpoint of high reliability of electrical characteristics and high accuracy of resistance value, the distances required between the electrodes adjacent to each other through the secondary dividing groove are opposite to each other. In the prior art described in No. 1, although the interval between the electrodes adjacent to each other through the secondary dividing groove can be narrowed in the concave portion on the primary dividing groove, it can be widened over the entire secondary dividing groove. Therefore, it is difficult to cope with both high reliability and high accuracy.

  The present invention has been made in view of the actual situation of the above-described conventional technology, and its purpose is to cope with both high reliability and high accuracy while ensuring conduction reliability between the electrode and the end face electrode. An object of the present invention is to provide a method for manufacturing a chip resistor.

  In order to achieve the above object, a chip resistor manufacturing method according to the present invention prepares a large substrate in which a chip region corresponding to one component is defined by a primary dividing groove and a secondary dividing groove extending in a lattice shape. Independently between the chip regions adjacent to each other through the secondary dividing groove on one side of the large-sized substrate, and electrodes straddling the primary dividing groove are opposed to each other at both ends of the chip region. An electrode forming step for forming, a resistor forming step for forming a resistor between the electrodes facing each other in the chip region, and a resin forming step for forming an insulating resin extending in a strip shape along the secondary dividing groove; A resistance value adjusting step for adjusting a resistance value by forming a trimming groove in the resistor after the resin forming step, and a protective coat layer forming for forming a protective coat layer for covering the resistor after the resistance value adjusting step. Process A primary dividing step of dividing the large substrate along the primary dividing groove after the protective coating layer forming step to obtain a strip-shaped substrate; and an end face electrode connected to the electrode on a dividing surface of the strip-shaped substrate And a secondary dividing step of dividing the strip substrate along the secondary dividing grooves to obtain a large number of single chips after the end electrode forming step. Yes.

  In the chip resistor manufactured by the process as described above, the insulating resin formed along the secondary division groove before adjusting the resistance value enhances the insulation between the adjacent electrodes through the secondary division groove. Therefore, when the resistance value is adjusted by laser trimming performed thereafter, the measurement current can be prevented from leaking to the adjacent electrode, and the resistance value can be measured and adjusted with high accuracy. In addition, since the space between adjacent electrodes can be narrowed via the secondary dividing groove, the effective area of the resistor can be increased to improve the electrical characteristics, and the measurement probe can be used when adjusting the resistance value. Can be easily brought into contact with the electrode, and conduction reliability between the electrode and the end face electrode can be ensured.

  In the above-described chip resistor manufacturing method, the insulating resin is made of a material that can be washed, and after the resistance adjustment step, the insulating resin is washed and removed, and then the protective coat layer is formed. Since primary division and secondary division can be performed in a state where no resin is present, good division can be performed. Further, it is possible to provide a chip resistor having the same configuration as a general chip resistor that does not have an insulating resin.

  According to the manufacturing method of the chip resistor according to the present invention, it is possible to cope with both high reliability and high accuracy while ensuring the conduction reliability between the electrode and the end face electrode.

It is a top view of the chip resistor concerning the embodiment of the present invention. It is sectional drawing which follows the II-II line of FIG. It is a flowchart which shows the manufacturing process of the said chip resistor. It is a top view which shows the manufacturing process of the said chip resistor. It is a top view which shows the manufacturing process of the said chip resistor.

  Hereinafter, embodiments of the invention will be described with reference to the drawings.

  As shown in FIGS. 1 and 2, a chip resistor 1 according to an embodiment of the present invention includes a rectangular parallelepiped insulating substrate 2 and a pair of front electrodes 3 provided at both longitudinal ends of the surface of the insulating substrate 2. A resistor 4 that bridges between the front electrodes 3, a precoat layer 5 formed on the resistor 4, and a pair of back electrodes 6 provided at both longitudinal ends of the back surface of the insulating substrate 2. And a pair of end face electrodes 7 provided on both end faces in the longitudinal direction of the insulating substrate 2 and a protective coat layer 8 formed so as to cover the precoat layer 5.

  The insulating substrate 2 is obtained by dividing a large-sized substrate, which will be described later, along a primary dividing groove and a secondary dividing groove extending in a lattice shape in the vertical and horizontal directions. The ceramic substrate.

  The pair of front electrodes 3 is obtained by screen-printing silver paste containing silver as a main component, drying and firing, and the front electrodes 3 are arranged at both ends in the longitudinal direction of the insulating substrate 2 so as to face each other with a predetermined interval. The part is formed in a rectangular shape. The pair of back electrodes 6 is also obtained by screen-printing silver paste containing silver as a main component, drying and firing, and these back electrodes 6 are formed at positions corresponding to the front electrodes 3 on the surface side of the insulating substrate 2. ing.

  The resistor 4 is obtained by screen-printing a resistor paste such as ruthenium oxide, drying and firing, and the resistor 4 is formed in a rectangular shape so that both end portions thereof overlap the surface electrode 3. A trimming groove 9 is formed in the resistor 4, and the trimming groove 9 is adjusted so that the resistance value of the resistor 4 becomes a predetermined value. The trimming groove 9 is a cut (slit) that can be formed in the resistor 4 by irradiation with laser light. In this embodiment, the trimming groove 9 having an L-cut shape is formed to adjust the resistance value of the resistor 4. However, the number of the trimming grooves 9 is not limited to one, and the resistance value may be adjusted using a plurality of trimming grooves 9, and the shape of the trimming grooves 9 is not limited to the L-cut. A trim groove having a cut shape may be formed, or a trim groove having a combination of L cut and I cut may be formed.

  The precoat layer 5 is a glass paste screen-printed, dried and fired, and the trimming groove 9 is formed by irradiating laser light from above the precoat layer 5. The precoat layer 5 is protected from the heat of the laser.

  The end face electrode 7 is formed by sputtering Ni / Cr on the end face of the insulating substrate 2, and the corresponding front electrode 3 and back electrode 6 are bridged by the end face electrode 7. Although not shown, the surface of the end electrode 7, the back electrode 6, and the surface of the front electrode 3 exposed on the surface of the chip resistor 1 is covered with a plating layer.

  The protective coat layer 8 is obtained by screen-printing and curing a resin paste such as epoxy or polyimide, and the protective coat layer 8 protects the resistor 4 having the trimming groove 9 from the external environment such as humidity and corrosive gas. Is done.

  Next, the manufacturing process of this chip resistor 1 is demonstrated using the flowchart shown in FIG. 3, and the top view shown in FIG. 4A to 4H show the steps before the primary division of the large substrate used in this manufacturing process, and FIGS. 5A to 5C show the steps after the primary division of the large substrate. Is shown.

  First, in step S1 of FIG. 3, as shown in FIG. 4A, a large substrate 10 on which a large number of insulating substrates 2 are taken is prepared. The large-sized substrate 10 is provided with primary division grooves 11 and secondary division grooves 12 having a predetermined depth extending in the vertical and horizontal directions in a lattice shape, and each of the squares divided by the division grooves 11 and 12 is one by one. One is a chip region corresponding to one chip resistor 1. FIG. 4 representatively shows a large substrate 10 corresponding to nine chip regions. Actually, the following steps are collectively performed for the large substrate 10 corresponding to many chip regions. Done.

  Next, in step S2 of FIG. 3, an Ag-based paste is screen-printed on the surface of the large-sized substrate 10 and dried and fired to pass through the secondary divided grooves 12 as shown in FIG. A rectangular surface electrode 3 that is independent between adjacent chip regions and straddles the primary dividing groove 11 is formed (electrode formation step). At the same time or before and after this, an Ag-based paste is screen-printed on the back surface of the large-sized substrate 10 and then dried and fired to form back electrodes (not shown) corresponding to the pair of front electrodes 3. To do.

  Next, in step S3 of FIG. 3, a resistor paste such as ruthenium oxide is screen-printed on the surface of the large-sized substrate 10, dried and fired, thereby facing the chip region as shown in FIG. 4C. The resistor 4 is formed by superimposing both ends on the surface electrode 3 to be formed (resistor forming step).

  Next, in step S4 of FIG. 3, after the glass paste is screen-printed on the resistor 4, the glass paste is dried and fired, so that the entire resistor 4 is formed as shown in FIG. Is formed (precoat layer forming step).

  Next, in step S5 of FIG. 3, a masking paste wider than the secondary divided grooves 12 is printed so as to fill the secondary divided grooves 12, and then dried and cured, as shown in FIG. An insulating resin 13 extending in a strip shape along the secondary dividing groove 12 is formed (resin forming step). The masking paste is made of a material that can be washed away with water, an organic solvent, or the like, and the insulating resin 13 is set to a width dimension that completely covers the secondary dividing groove 12.

  Next, in step S6 of FIG. 3, a pair of front electrodes 3 are brought into contact with a measurement probe (not shown), and the resistance value is measured to irradiate laser light from above the precoat layer 5, whereby FIG. As shown in (f), the trimming groove 9 is formed in the resistor 4 and the resistance value is adjusted so as to reach the target resistance value (resistance value adjusting step). At the time of adjusting the resistance value, since the insulating resin 13 is filled in the secondary divided grooves 12 and extends in a band shape, it is assumed that there is a printing blur that brings the surface electrode 3 closer to the secondary divided grooves 12. Also, the insulation between the adjacent surface electrodes 3 through the secondary dividing grooves 12 is enhanced by the insulating resin 13. Therefore, the measurement current can be prevented from leaking and flowing into the adjacent surface electrode 3, and the resistance value of the resistor 4 can be measured and adjusted with high accuracy.

  Next, in step S7 of FIG. 3, the large substrate 10 is washed, and the insulating resin 13 is washed away with water, an organic solvent, or the like as shown in FIG. 4G (resin removal step).

  Next, in step S8 of FIG. 3, a resin paste such as epoxy or polyimide is screen-printed on a rectangular region that is spaced apart with the primary dividing groove 11 interposed therebetween, and this resin paste is heated and cured, whereby FIG. As shown in h), a protective coat layer 8 is formed to cover the entire precoat layer 5 and a part of the surface electrode 3 except for the primary dividing grooves 11 (protective coat layer forming step).

  The process so far is a batch process for the large substrate 10. Next, in step S9 of FIG. 3, the large substrate 10 is subjected to primary division (break) along the primary division grooves 11, so that FIG. As shown in a), a plurality of strip-shaped substrates 10A are obtained from the large substrate 10 (primary division step).

  Next, in step S10 of FIG. 3, after stacking the plurality of strip-shaped substrates 10A in the vertical direction, Ni / Cr is sputtered onto the divided surface of each strip-shaped substrate 10A in this state, whereby FIG. ), An end face electrode 7 that bridges the front electrode 3 and a back electrode (not shown) is formed.

  Next, in step S11 of FIG. 3, the strip-shaped substrate 10A is secondarily divided (broken) along the second divided grooves 12 to obtain the same as the chip resistor 1 as shown in FIG. A piece having a size (chip unit 10B) is obtained (secondary division step).

  Finally, in step S12 in FIG. 3, a part of the front electrode 3 exposed from the end face electrode 7 and the back electrode and the protective coating layer 8 is coated by performing electrolytic plating on the singulated chip 10B. A plated layer (not shown) is formed, and the chip resistor 1 shown in FIGS. 1 and 2 is completed.

  As described above, in the manufacturing method of the chip resistor 1 according to the present embodiment, the insulating resin 13 is formed in a strip shape along the secondary dividing groove 12 before the resistance value adjusting step, thereby performing the secondary division. Since the insulation between the adjacent surface electrodes 3 through the groove 12 is enhanced, the probe measurement current may leak to the adjacent surface electrode 3 during the subsequent adjustment of the resistance value by laser trimming. The resistance value of the resistor 4 can be measured and adjusted with high accuracy. Even if the surface electrode 3 is rectangular and the area is increased, the insulation between the adjacent surface electrodes 3 through the secondary dividing grooves 12 is enhanced by the insulating resin 13. The probe can be easily brought into contact with the surface electrode 3, and further, the effective area of the resistor can be formed wide, and the reliability of the electrical characteristics can be improved. Moreover, when the large substrate 10 is broken along the primary dividing groove 11 to the strip-shaped substrate 10A, the rectangular surface electrode 3 is divided and exposed to the dividing surface of the strip-shaped substrate 10A. The end surface electrode 7 formed on the dividing surface of the strip-shaped substrate 10A can be reliably connected to the front electrode 3, and the conduction reliability of the chip resistor 1 can be improved.

  Moreover, in the manufacturing method of the chip resistor 1 according to the present embodiment, the insulating resin 13 is made of a masking paste that can be cleaned with water, an organic solvent, or the like, and the insulating resin 13 is cleaned and removed after the resistance value adjusting step. Then, since the protective coat layer 8 is formed, primary division and secondary division can be performed without the insulating resin 13, and good division can be performed. Moreover, the chip resistor 1 having the same configuration as that of a general chip resistor that does not have the insulating resin 13 can be manufactured.

  In the manufacturing method of the chip resistor 1 according to the above-described embodiment, the protective coating layer 8 is formed after the insulating resin 13 is washed and removed, but the insulating resin 13 is the same as the protective coating layer 8. It is also possible to form the protective coat layer 8 without removing the insulating resin 13 after the resistance value adjusting step. That is, the resin removing process in step S7 shown in FIG. 3 may be omitted, and the process may proceed from the resistance value adjusting process in step S6 to the protective coat layer forming process in step S8.

  In the above embodiment, the insulating resin 13 is formed after the precoat layer 5 covering the resistor 4 is formed, and then laser trimming is performed from above the precoat layer 5, but the precoat layer 5 is omitted. The trimming groove 9 may be formed by irradiating laser light on the resistor 4.

DESCRIPTION OF SYMBOLS 1 Chip resistor 2 Insulating substrate 3 Front electrode 4 Resistor 5 Precoat layer 6 Back electrode 7 End surface electrode 8 Protective coat layer 9 Trimming groove 10 Large format substrate 10A Strip-shaped substrate 10B Single chip 11 Primary division groove 12 Secondary division groove 13 Insulating resin

Claims (2)

A substrate preparing step of preparing a large substrate in which a chip region corresponding to one component is partitioned by a primary dividing groove and a secondary dividing groove extending in a lattice shape;
An electrode forming step of forming electrodes on one side of the large substrate independent of the chip regions adjacent to each other through the secondary division grooves and straddling the primary division grooves so as to face each other at both ends of the chip region When,
Forming a resistor between the electrodes facing each other in the chip region; and
A resin forming step of forming an insulating resin extending in a strip shape along the secondary dividing groove;
A resistance value adjusting step of adjusting a resistance value by forming a trimming groove in the resistor after the resin forming step;
A protective coat layer forming step of forming a protective coat layer covering the resistor after the resistance value adjusting step;
A primary dividing step of dividing the large substrate along the primary dividing groove after the protective coating layer forming step to obtain a strip-shaped substrate;
An end face electrode forming step of forming an end face electrode connected to the electrode on the split surface of the strip substrate;
A secondary dividing step of dividing the strip-shaped substrate along the secondary dividing grooves after the end face electrode forming step to obtain a large number of single chips;
A method of manufacturing a chip resistor, comprising: In the manufacturing method of the chip resistor according to claim 1,
A method of manufacturing a chip resistor, wherein the insulating resin is made of a washable material, and the protective coating layer is formed after the insulating resin is cleaned and removed after the resistance value adjusting step.

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