JPH11111513A - Manufacture of chip resistor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method by which a chip resistor such that they can sufficiently cope with reduced size, the resistor is superior in mass production, and does not allow decomposition of its resistor film. SOLUTION: (1) A large-sized ceramic substrate 10, in which a plurality of element regions which become chip resistors are arranged in at least the lateral direction is prepared. (2) Belt-like resistor films 20 which are continuously extended in the lateral direction and conductor films 30a and 30b, which become a pair of belt-like terminal electrodes electrically connected to the facing edges of the resistor films 20, are formed in the element regions. (3) Independent resistor films 2 and terminal electrodes 3a and 3b are formed by removing the resistor films 20 and conductor films 30a and 30b from the boundary sections of the element regions. (4) Glass protective films 4 which cover the independent resistor films 2 are formed continuously from the plurality of element regions. (5) The ceramic substrate 10 is cut along the boundary sections of the element regions.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a chip resistor.

[0002]

2. Description of the Related Art A chip resistor is formed with a pair of terminal electrodes extending over three surfaces of a rectangular insulating substrate, namely, a front surface, an end surface, and a rear surface, and a pair of terminal electrodes is formed on the insulating substrate. In this structure, a resistor film is formed so as to straddle the electrodes, and a glass protective film is formed on the surface of the insulating substrate so that the terminal electrodes are exposed.

[0003] Chip resistors range from type 3216 (insulating substrate shape of 3.2 mm x 1.6 mm), type 2012 (insulating substrate shape of 2.0 mm x 1.2 mm) to type 1608 (insulating substrate shape). (1.6 mm x 0.8 mm) 1005
Mold (insulating substrate shape is 1 mm x 0.5 mm), 0603
No. (the size of the insulating substrate was 0.6 mm × 0.3 mm), and miniaturization was demanded, and this was met.

The above-mentioned 3216 type, 2012 type, 1608
The following manufacturing method has been adopted for a chip resistor of type 1005 in consideration of mass productivity.

(1) A step of preparing a large ceramic substrate in which each element region serving as an insulating substrate of a chip resistor is partitioned by vertical and horizontal division grooves. (2) A division groove on a short side of each element region of the large ceramic substrate. (3) forming a resistor film in each element region of a large ceramic substrate so as to extend over the terminal electrodes on the front surface side; Step (4) Step of forming a glass protective film covering at least the resistor film so as to straddle the divided groove on the long side of each element region of the large ceramic substrate (5) Each element region of the large ceramic substrate (1) a step of forming a strip-shaped substrate by performing primary division along the dividing groove on the shorter side of (6). The end face for conducting between the terminal electrode on the front side and the terminal electrode on the back side on the divided surface of the strip-shaped substrate Step of forming terminal electrode (7) Short Along the dividing groove on the long side of the element regions of the substrate consisted secondary division to process.

In the above-mentioned steps, the step of adjusting the resistance value and the steps associated therewith and the step of surface treatment of the terminal electrodes are omitted.

However, the resistor film in the above process is
It is formed by a thick film technique of printing, drying, and baking with a resistor paste, and is formed in each element region on a large substrate. Therefore, when the size of the chip resistor is reduced (the size of the element region is reduced), it is difficult to form a resistor film having a predetermined shape in the element region. That is, this is because the precision of printing bleeding when printing the resistive paste cannot sufficiently cope with miniaturization of the element region.

For example, it is conceivable that the resistor film is formed by using a thin film technique, for example, a vapor deposition or photography technique, instead of the thick film technique, but the number of steps increases.
It will increase the cost.

Also, in consideration of the printing blur of the resistor film,
Using a strip-shaped ceramic substrate in which a plurality of element regions serving as chip resistors are joined at a long side, a strip-shaped terminal electrode is formed at a pair of ends of a long side of the strip-shaped substrate, and a strip-shaped terminal is formed. After forming a resistor film connected to a pair of strip-shaped terminals on the surface of the insulating substrate and forming a series of glass protective films covering the resistor film, the strip-shaped insulating substrate may be divided into element regions. Conceivable.

[0010]

However, in the case where the resistor film is formed over a plurality of element regions by using the above-described strip-shaped substrate, the resistor film is separated from the divided surface of the strip-shaped substrate. Cross section is exposed.

For this reason, the resistance film is deteriorated due to moisture or the like, and the predetermined characteristics cannot be obtained.

In the method of manufacturing a chip resistor, a step of correcting the resistance value is required. In the above-described manufacturing method, if the resistance value is not corrected after dividing the strip-shaped substrate into each element. The resistance value of a single resistor film in the element region cannot be measured, and the correction of the resistance value becomes very complicated.

The present invention has been devised in view of the above-mentioned problems, and has as its object to sufficiently cope with the miniaturization of chip resistors, to be excellent in mass productivity, and to make the resistor film deteriorated. It is an object of the present invention to provide a method of manufacturing a chip resistor which does not occur.

[0014]

According to the present invention, a rectangular resistor film is disposed on the surface of a rectangular insulating substrate, and a terminal electrode connected to the resistor film is disposed at an end of the short side. In a method of manufacturing a chip resistor, a glass protective film is formed on the resistor film. (1) A method of manufacturing a chip resistor, the method including: (2) a step of preparing a large ceramic substrate having a plurality of element regions (2) a pair of band-shaped resistive films connected to a plurality of device regions and electrically connected to opposing ends of the band-shaped resistive film; (3) removing the resistive film and the pair of conductive films at the long-side boundary portions of the plurality of element regions to form independent resistive films and terminal electrodes. Step (4) Continuously and independently of a plurality of element regions Forming a glass protective film covering each resistor film (5) separating a large ceramic substrate at each boundary between the plurality of element regions.

[0015]

According to the present invention, a resistor film is formed over an adjacent device region, and a resistor film present at a boundary portion of a device region to be finally cut is removed by dicing. . Thereafter, a glass protective film is formed so as to extend over the adjacent element region, including the portion where the resistor film has been removed by dicing.

First, a strip-shaped resistor film is formed across the element region where the resistor film is adjacent. That is, since it is not necessary to form an independent resistor film in the element region in consideration of the size of the element region, it is possible to sufficiently cope with miniaturization of the element region.

Further, the resistor film deposited on the boundary portion of the element region is removed by dicing, and thereafter, the glass protective film is covered. That is, even if this boundary portion is finally cut, the resistor film does not appear from the cut surface, so that no alteration of the resistor film occurs.

Further, since the resistor film, the terminal electrode, and the glass protective film can be formed before the cutting of the above-mentioned large substrate, the manufacturing method is excellent in mass productivity.

Furthermore, if the strip-shaped resistor film and the conductor film serving as the terminal electrode are subjected to dicing processing, the resistor film and the terminal electrode become independent as the resistor film and the terminal electrode constituting the chip resistor. By adjusting the resistance film in the state of the large substrate before cutting, the resistance value can be adjusted efficiently.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for manufacturing a chip resistor according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is an external perspective view of a chip resistor according to the present invention, FIG. 2 is a sectional view taken along line XX, and FIG.
FIG. 4 is a sectional view taken along line -Y.

In FIG. 1, 1 is an insulating substrate, 2 is a resistor film, 3a and 3b are terminal electrodes, and 4 is a glass protective film.

The insulating substrate 1 is a rectangular ceramic substrate such as alumina and has a rectangular shape of, for example, 0.6 mm × 0.3 mm. Further, on the short side of the substrate 1, there are formed concave portions 11a and 12a which are cut into a substantially half circular shape having an adjustment of 0.2 mm so as to penetrate the thickness of the substrate. A resistor film 2 extending in the longitudinal direction is formed on the surface of the insulating substrate 1. This resistor film is formed, for example, by printing and baking a resistance paste such as ruthenium oxide. Further, terminal electrodes 3 are provided on both ends of the resistor film 2 in the longitudinal direction.
a, 3b are formed. These terminal electrodes 3a, 3b
Is formed on the surface of the insulating substrate 1 so as to overlap with the end of the resistor film 2 and around the semicircular recesses 11a and 12a. At the same time, the semicircular recess 11
It is formed around the inner wall surfaces of a and 12a and the semicircular recesses 11a and 12a on the back surface of the insulating substrate 1. The terminal electrodes 3a and 3b are formed by printing and printing a conductive paste containing Ag as a main component such as Ag-Pd. On the surface of the insulating substrate 1, at least the resistor film is completely covered, and a glass protective film 4 is formed over the entire width of the substrate 1. Although the glass protective film 4 has a single-layer structure in the drawing, it may have a multilayer structure of a primary glass protective layer and a secondary glass protective layer. That is, after forming a primary glass protective layer on the resistor film 2, while measuring the resistance value of the resistor film 2 using the terminal electrodes 3a and 3b connected to both ends of the resistor film 2, By scanning while irradiating the primary glass protective layer with a YAG laser or the like, a part of the resistor film 2 is burned off, and the resistance value of the resistor film 2 can be adjusted to a predetermined value.

Although omitted in the figure, the terminal electrodes 3a, 3a
On the surface of b, a Ni plating layer or a solder plating layer is adhered so that reflow soldering can be easily performed on the printed wiring board.

In the chip resistor of the present invention, as can be seen from FIG. 3, the width of the resistor film 2 is completely the same as the width of the terminal electrode 3a (3b). This is because the resistor film 2 and the terminal electrodes 3a and 3b are formed over the entire width of the substrate 1 (actually formed so as to be continuous with the adjacent element region on the large substrate), and then the resistor film 2 and the terminal electrodes 3a and 3b are formed. This is because the widths of 3a and 3b are adjusted.

Next, referring to FIGS. 4 to 11, FIGS.
A method for manufacturing a resistor using the chip shown in FIG.

First, as shown in FIG. 4, a large ceramic substrate 10 from which a plurality of insulating substrates 1 of chip resistors can be extracted is prepared. It should be noted that in the drawing, an element region that will eventually become a chip resistor is surrounded by an alternate long and short dash line.

As the large-sized substrate 10, a substrate in which at least a plurality of element regions are arranged adjacently in the width direction with the long side (vertical direction) as a boundary is used. In the drawing, a part of the large-sized substrate 10 is shown, and four element regions are arranged in the horizontal direction and two element regions are arranged in the vertical direction.

In the large substrate 10, through holes 11, 11,..., 12, 12,... Having a diameter of 0.2 mm are formed at the center of a boundary portion which is a short side (lateral direction) of each element region. ing.

The through holes 11 and 12 are separated at a boundary portion which is a short side of each element region to form semicircular concave portions 11a and 12a shown in FIGS. Heretofore, division grooves on the front and back of a large substrate are conventionally formed using each element region as a partitioning means, but can be omitted in the large substrate of the present invention.

Next, as shown in FIG. 5, a strip-shaped resistor film 20 to be the resistor film 2 is formed.

The resistor film 20 is formed so as to commonly straddle the element regions arranged in the horizontal direction among the element regions of the large-sized substrate 10. Specifically, the resistor paste is selectively printed so as to form a strip, dried, and baked.

Here, since the strip-shaped resistor film 20 is formed over a plurality of element regions, even if the chip resistor is miniaturized, that is, even if the element regions are miniaturized, the resistance is independently set for each element region. Since there is no need to form a body film (there is a printing margin around the resistor film), it is possible to sufficiently cope with this.

Next, as shown in FIG. 6, the terminal electrodes 3a,
Conductive films 30a and 30b to be 3b are formed. The strip-shaped conductor films 30a and 30b straddle the element areas arranged in the horizontal direction and the element areas adjacent in the vertical direction among the element areas of the large-sized substrate 10, and overlap a part of the strip-shaped resistor film 20. It is formed as follows. Specifically, selective printing is performed so that an Ag-based conductive paste is continuous with the element regions arranged in the horizontal direction with the short side boundary portion of the element region as the center, dried, and baked.

Here, the strip-shaped conductor film 30a is printed so as to overlap one end of the through holes 11 and the strip-shaped resistor film 20 which are arranged in a plurality in the horizontal direction, and the conductor film 30b is formed in a plurality in the horizontal direction. The printing is performed so as to overlap the arranged through holes 12 and the other end of the strip-shaped resistor film 20. This allows
A conductive paste adheres to the inner walls of the through holes 11 and 12,
It becomes a terminal electrode on the inner wall surface of the through holes 11 and 12. Note that, in order to assist the adhesion of the conductive pastes 11 and 12 on the inner wall surface, it is preferable to perform printing while sucking gas from the side opposite to the printing surface through the through holes 11 and 12.

Although not shown in the figure, a conductor film serving as a terminal electrode is also formed on the back surface of the substrate. Preferably,
On the back surface of the substrate, a conductor film serving as a terminal electrode is formed only around the through hole. However, in order to share the print pattern, a conductor film having the same pattern as the substrate surface shown in FIG. 6 may be formed. The conductor films 30a and 30b on the front surface of the substrate and the conductor film on the rear surface of the substrate can be printed together after being selectively printed and dried.

Next, as shown in FIG. 7, the strip-shaped resistor film 2 and the strip-shaped conductor films 30a and 30b are formed. Specifically, the large-sized substrate 10 has a wide blade (for example, width = 0.3 mm) so as to remove the band-shaped resistor film 20 and the band-shaped conductor film around the boundary of the long side of the element region. Dicing processing is performed using a dicing disk. In this dicing, at least the resistance film 2 and the strip-shaped conductor film 30
It is important that a and 30b are separated from each other, and there is no problem even if a cut mark A is formed on a part of the surface of the substrate by dicing.

Thus, although the element regions arranged in the vertical direction and the terminal electrode 30 are shared, each element region has:
At least one resistor film 2 and a pair of terminal electrodes 30, 30 that are electrically connected to both ends of the resistor film 2 are arranged.

Next, as shown in FIG.
A band-shaped primary glass protective layer 41 serving as a primary glass protective layer is formed. The primary glass protective layer 41 is formed so as to commonly straddle the element regions arranged in the horizontal direction among the element regions of the large-sized substrate 10. Thereby, the plurality of resistor films 2 are covered by at least the primary glass protective layer 41. Specifically, low-melting glass paste such as lead borosilicate is selectively printed so as to be strip-shaped, dried, and baked. The thickness is
It is about 10 μm.

Next, the resistor film 2 disposed in one element region
Adjust the resistance value of. That is, the probe of the resistance value measuring device is brought into contact with the pair of terminal electrodes 30 and 30 arranged in one element region, and the resistance value of the resistive film 2 between the pair of terminal electrodes 30 and 30 is measured. At the same time, an energy beam such as a YAG laser is applied to the resistor film 2 through the primary glass layer 41, and the energy beam is scanned according to a change in the measured resistance value. Thereby, the resistance film 2 can be adjusted to a predetermined resistance value. FIG. 9 is a plan view showing a state in which this adjustment is performed. That is, as a result of the irradiation and scanning of the energy beam, the adjustment marks 2 in which a part of the primary glass protective layer 41 and the resistor film 2 have been burned off are formed in each blocking area.
1 is shown.

Next, as shown in FIG. 10, a band-shaped secondary glass protective layer 42 serving as a secondary glass protective layer serving as the glass protective film 4 is formed. The secondary glass protective layer 42 is formed so as to commonly straddle the element regions arranged in the lateral direction among the element regions of the large-sized substrate 10. The secondary glass protective layer 42 repairs the adjustment marks 21 formed on the resistor film 2 and the primary glass protective layer 41 as a result of the resistance value adjustment.

More specifically, a low-melting glass paste such as lead borosilicate is selectively printed so as to form a strip, dried, and baked. Its thickness is about 20 μm. Next, as shown in FIG. 11, the large substrate 10 is separated into individual element regions. Specifically, a dicing process is performed with a narrow blade (for example, width = 0.2 mm) around a boundary portion of each element region indicated by a chain line in FIG.
The large substrate 1 is separated.

It is to be noted that the order of separation may be such that each element region is cut from the long side boundary B and the short side boundary C is cut, or conversely, the short side boundary C is cut off. Cut from C,
The boundary portion B on the long side may be cut.

In addition to the above-described cutting, a dividing groove is formed in advance at the boundary of each element region indicated by a dashed line in the state of the large substrate 10 shown in FIG. May be.

Further, for example, a dividing groove is formed only at the short side boundary portion, and the long side boundary portion is cut by dicing. Can be divided.

In particular, when the dividing groove is formed on the long side, the band-shaped resistor film 20 and the band-shaped conductor films 30a and 30a, which are applied to the boundary on the long side by dicing shown in FIG.
When b is removed by dicing, the surface of the substrate 10 is also removed, and the dividing groove may disappear. Therefore, it is preferable to cut the boundary portion on the long side by dicing.

As described above, in the structure, the resistor film 2 and the terminal electrodes 3a and 3b are formed in common in the element regions arranged in the lateral direction, and thereafter, the wide dicing is performed at the boundary between the element regions by wide dicing. Since the shape of the resistor film 2 and the terminal electrodes 3a and 3b in the width direction are formed, even if the chip resistor is downsized and the element region is downsized, the resistor film is independently formed in the element region. Can be formed.

As a result, as shown in FIG. 9, the resistance value of the resistor film 2 independently arranged in each element region can be adjusted.

The resistor film 2 is completely covered with the glass protective film 4.
As a result, the periphery or the cross section of the resistor film 2 is not exposed to the outside as a result of joining the substrates as in the related art, so that the resistor film having the adjusted resistance value is very stably maintained. it can.

Further, in the above-mentioned steps from the preparation of the large substrate to the separation of each element region, the resistor film, the terminal electrode, and the glass protective film can be formed and processed in common in a plurality of element regions. It becomes a manufacturing method with excellent mass productivity.

In the above-described embodiment, the terminal electrodes on the end surfaces of the chip resistors are provided with the substantially semicircular recesses 11a and 12b.
However, for example, the semi-circular concave portions 11a and 12b may be eliminated, and may be formed directly on the end face on the short side of the rectangular insulating substrate. In this case, in consideration of mass productivity, after forming the secondary glass protection element 41, first, cutting is performed at the boundary portion on the short side of the large substrate 10, and then, the end surface on the short side of the large substrate 10 is cut. The conductive paste is printed and baked so that the terminal electrodes on the front surface and the terminal electrodes on the rear surface are electrically connected.

In the case where dust removed by dicing shown in FIG. 6 interferes with the resistance value characteristics of the resistor film, first, a band-shaped resistor film, a band-shaped conductor film, and a band-shaped primary film are formed on a large substrate. Each film is formed in the order of formation of the glass protective layer, dicing for dividing the resistor film and the terminal electrode, adjustment of the resistance value, and formation of the band-shaped secondary glass protective layer. With this configuration, the resistor film and the conductor film generated by dicing,
Since the debris of the primary glass protective layer does not directly adhere to the resistor film, there is no influence on the characteristics of the resistance value.

Further, as a structure of a terminal electrode suitable for practical use, a plating layer for improving solder wettability and preventing solder erosion is formed on the surface of a conductor film formed by baking an Ag-based conductive paste. . In the present invention, if the plating layer is formed after forming the secondary glass protective layer 42,
It may be performed in any process.

Further, as an example of the shape of the large-sized substrate, the element regions are arranged in a matrix, but, for example, a strip-shaped large substrate in which a plurality of element regions are arranged in a horizontal direction may be used. In this case, the terminal electrodes on the end surfaces can be formed following the formation of the terminal electrodes on the front surface side and the terminal electrodes on the rear surface side, and the baking processing of these three surface terminal electrodes can be performed at a time. Thereby, the number of heat histories applied to the resistor film is reduced, and a stable resistance value characteristic can be obtained.

[0055]

According to the present invention, an independent resistor film having a predetermined shape can be formed in each element region constituting a large substrate even if the chip resistor is downsized. Thereby, the resistance value of the resistor film can be easily adjusted, and furthermore, the resistor film can be completely covered with the glass protective film, and the deterioration of the resistor film can be prevented.

Further, since each of the films constituting the chip resistor can be processed and formed on a large-sized substrate, the manufacturing method is extremely excellent in mass productivity.

[Brief description of the drawings]

FIG. 1 is an external perspective view of a chip resistor according to the present invention.

FIG. 2 is a sectional view taken along line XX of FIG.

FIG. 3 is a sectional view taken along line YY of FIG. 1;

FIG. 4 is a plan view for explaining the method for manufacturing the chip resistor of the present invention.

FIG. 5 is a plan view for explaining the method for manufacturing the chip resistor of the present invention.

FIG. 6 is a plan view for explaining the method for manufacturing the chip resistor of the present invention.

FIG. 7 is a plan view for explaining the method for manufacturing the chip resistor of the present invention.

FIG. 8 is a plan view for explaining the method for manufacturing the chip resistor of the present invention.

FIG. 9 is a plan view for explaining the method for manufacturing the chip resistor of the present invention.

FIG. 10 is a plan view for explaining the method for manufacturing the chip resistor of the present invention.

FIG. 11 is a plan view for explaining the method for manufacturing the chip resistor of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Insulating substrate 10 ... Large insulating substrate 2 ... Resistor film 20 ... Strip-shaped resistor film 3a, 3b ... Terminal electrode 30a, 30b ... Strip-shaped conductor film 4 ... -Glass protective film 41: Primary glass protective layer 42: Secondary glass protective layer

Claims (1)

[Claims] 1. A rectangular resistor film is disposed on a surface of a rectangular insulating substrate, and a terminal electrode connected to the resistor film is disposed at an end of the short side, and a glass protective film is formed on the resistor film. (1) preparing a large ceramic substrate having a plurality of element regions so as to border at least a long side of an element region to be an insulating substrate of the chip resistor; (2) Forming a strip-shaped resistor film continuously on a plurality of element regions and a pair of strip-shaped conductor films to be electrically connected to opposite ends of the strip-shaped resistor film. (3) removing the resistor film and the pair of conductor films at the long side boundary portions of the plurality of element regions to form independent resistor films and terminal electrodes; Continuous and independent glass coating on each resistor film The method of manufacturing a chip resistor and a step step of (5) ceramic large substrate is separated at the boundary portion of the plurality of element regions forming the Mamorumaku.