JP4881557B2 - Manufacturing method of chip resistor - Google Patents

Description

The present invention relates to a method of manufacturing a chip resistor having a good outer shape and a good resistance value yield.

  As a conventional method for manufacturing a chip resistor, for example, one described in Japanese Patent Application Laid-Open No. 2001-118703 (Patent Document 1) can be cited. This is because, for example, in the process of manufacturing a small chip resistor having a size of 0.6 mm × 0.3 mm or less in plan view, a pair of mutually parallel guide walls is projected on the resistor arrangement surface after the electrode portion is formed. Alternatively, a guide wall having a substantially rectangular frame shape is projected on the resistor mounting surface, and the resistor paste is printed in the guide wall to prevent bleeding and sagging associated with the printing of the resistor paste. The purpose is to make the thickness of the fired resistive film uniform. And in the manufacturing method of patent document 1, the 1st break groove | channel and the 2nd break groove | channel are previously formed in the insulated substrate, and it divides | segments along these break grooves in a predetermined process, and forms a chip resistor.

  In a conventional chip resistor manufacturing process, a dicing saw having a disk-like blade having a thickness of about 40 μm and a diameter of about 50 mm is used to cut an insulating substrate vertically and horizontally. An insulating substrate made of alumina ceramic or the like has a relatively large hardness and poor machinability, so when it is cut with a dicing saw, it is not cut to the end in the thickness direction, leaving a burr on the cut surface. there were. This problem cannot be solved by the technique of Patent Document 1.

As what can solve this problem, the thing described in Unexamined-Japanese-Patent No. 2002-313612 (patent document 2) can be mentioned. In Patent Document 2, a plurality of resistors are formed on a collective substrate, a protective coating film of 20 to 50 μm made of a resin material is formed on the upper surface side of the resistors, and an adhesive sheet so that this protective coating film is on the bottom The collective substrate is installed on the top, and is cut with a blade from the back surface of the collective substrate. At the time of cutting, although the force to spread left and right across the blade acts on the collective substrate, even at the moment of substrate cutting, the protective coat film part is connected, so the cracking of the substrate during cutting is prevented, Moreover, since the protective coat film has better machinability than the substrate, the occurrence of burrs on the cut surface is prevented.
JP 2001-118703 A JP 2002-313612 A

With the miniaturization and high functionality of various electronic devices, the demand for ultra-small chip resistors is also increasing. For example, the planar external dimensions are 0.6 mm × 0.3 mm or 0.4 mm × 0. There is a demand for a chip resistor of 2 mm.
On the other hand, according to the chip resistor manufacturing method described in Patent Document 1, it is possible to prevent bleeding and sagging associated with printing of the resistive paste and to make the thickness of the fired resistive film uniform. Although it is possible, some problems remain as follows.
(1) Materials and processes increase with the formation of guide walls.
(2) Since the guide wall is formed by screen printing of glass paste, bleeding or sagging occurs in the area of the guide wall during printing, affecting the shape of the resistance film in the guide wall and causing variations in the resistance film. Cause it to occur.
(3) Since the protective coat is formed by printing on each minute area so as to cover each resistive film, the cross section of the protective coat becomes a bowl shape, increasing the adsorption mistake in the mounting machine.
(4) In the middle of the manufacturing process, the insulating substrate is divided along the first and second break grooves provided in advance on the insulating substrate. The insulating substrate warps due to repeated heating, and the division groove spacing becomes non-uniform due to thermal distortion, so that the divided shape after division is not stable, and the insulating substrate is easily damaged during the manufacturing process.

Also in Patent Document 2, the following problems remain regarding complication of man-hours, increase in man-hours, increase in material costs, and the like.
(1) Since the insulating substrate is cut vertically and horizontally by a blade, it takes a long time to cut.
(2) Waste is generated because an insulating substrate of a size that allows for the width of the blade to be cut is required.
(3) Strict quality control is required to ensure the flatness of the protective coating film surface, and the use of an insulating substrate bonded with materials with different hardness and machinability is unavoidable, leading to an increase in material costs. .
(4) Increase in material costs due to the pressure-sensitive adhesive sheet and a process for fixing to the pressure-sensitive adhesive sheet are required.

The present invention solves the above-described problems, and an object of the present invention is to realize a microchip resistor having a planar outer dimension of 0.6 mm × 0.3 mm or less and using a relatively thin insulating substrate. At the same time, it is possible to produce as many chip resistors as possible from an insulating substrate of a predetermined size, to prevent bleeding and sagging associated with the printing of the resistance paste, and to uniform the thickness of the fired resistive film made, the protective coating film dividing surface and the insulating substrate dividing accompanied dividing surface shape precision is good in the of the simplification and man-hour temporal compression of steps to provide a process for the preparation of possible chip resistor realized It is in.

  The above-described problems of the present invention are solved by the following means.

(1) Using an insulating substrate in which the division grooves are not engraved in advance, a large number of pairs of electrode films are formed in a predetermined region of the insulating substrate , and a resistive film is formed so as to overlap a part of each pair of electrode films. In the method of manufacturing a chip resistor, the electrode film is formed by printing and firing a large number , forming a trimming groove for adjusting a resistance value in the resistance film, and forming a protective coating film in a predetermined region of the resistance film including the trimming groove. Printing the resistive film superimposed on a part of the substrate in a strip shape in the primary direction of the insulating substrate and drying,
The unnecessary portion of the strip-shaped resistive film formed by drying in the process is removed by a laser beam, and then the resistive film is baked, and after trimming the resistive film, the resistive film is in the primary direction. a step that form a belt-shaped protective coating film, Engineering you engraved also split grooves at the same time the insulating substrate when cutting at predetermined intervals in the primary direction and the secondary direction by the laser beam the electrode film and-holding protection coat film A method for manufacturing a chip resistor, comprising:

(2) the unnecessary portion of the strip of resistive film, and removing by irradiating a laser beam having a region of the fundamental wave or UV wavelengths, the electrode layer and the protective coating layer, the primary direction and the secondary direction given the division Mizokoku set to the same time the insulating substrate when cutting at intervals, the manufacturing method of the chip resistor according to claim 1, characterized in that comprising a step of irradiating a laser beam having a UV wavelength region.

In the manufacturing method of the chip resistor described in (1) above, an insulating substrate in which a dividing groove is not engraved in advance is used, and the protective coating film and the electrode film are divided at a predetermined interval, and are simultaneously applied to the insulating substrate. Since the dividing groove is engraved, warpage of the insulating substrate and distortion of the dividing groove interval due to repeated firing accompanying the formation of the element film such as the electrode film and the resistance film are suppressed. For example, the thickness is 0.2 mm or less. The degree of freedom to use an extremely thin insulating substrate can be increased.
In the manufacturing method of (1) above, unnecessary portions of the strip-shaped resistive film are removed in a dried state before firing, so that the width of the resistive film can be freely set even when a thick resistive paste is used. In addition, the power consumption that can be loaded on the chip resistor can be set large.
In the manufacturing method (1), even when a thick film resistance paste is used, no sagging or bleeding occurs, and the film thickness of the resistance film can be finished substantially uniformly and well until it reaches both side edges. Thereby, the dispersion | variation in resistance value distribution after baking a resistance film can be suppressed.

The manufacturing method of the chip resistor described in the above (2) is different from the conventional manufacturing method in which the surface is raised in a bowl shape when the protective coating film is individually formed in a minute region. Since a plurality of films are formed in a strip shape and then divided by irradiation with a laser beam, the surface can be formed substantially flat. If the protective coating film is flat as described above, it is possible to reduce a suction error of the mounting machine.
In the manufacturing method of (2) above, the patterning of the resistance film, the division of the electrode film and the protective coating film, and the formation of the dividing groove on the insulating substrate are performed by laser beam irradiation. The number of chip resistors that can be produced from a single insulating substrate can be increased.
In the manufacturing method of (2) above, the electrode film and the protective coating film are divided by irradiating a laser beam having a UV wavelength region, so that scattered matter at the time of division due to the ablation effect can be significantly suppressed. Moreover, even if it is an ultra-thin insulating substrate having a thickness of 0.2 mm or less, a stable dividing groove can be formed without passing through the insulating substrate and cutting.
In the above (2) manufacturing method, the electrode film and the protective coating film are each divided at predetermined intervals by laser beam irradiation. At that time, the laser beam reaches the surface of the insulating substrate, and the dividing groove is also engraved on the insulating substrate. To do. Therefore, the divided section of the electrode film and the dividing surface of the insulating substrate are formed substantially flush with each other, and the dividing section of the protective coating film and the divided surface of the insulating substrate are also formed substantially flush with each other.

The chip resistor of the present invention prints a resistive film in a strip shape using a thick-film resistive paste made of metal glaze between electrode films formed on an insulating substrate made of alumina ceramic that is not previously engraved with a dividing groove, and then dried. Then, unnecessary portions of the resistance film are removed by laser beam irradiation, and the remaining resistance film is baked after the removal, and then the resistance film is trimmed to form a groove for adjusting the resistance value, and the trimming groove is formed. After covering a predetermined region of the resistive film with a protective coat film, the electrode film and at least the protective coat film are divided at predetermined intervals by irradiating a laser beam, and at this time, the laser beam is directed to the surface of the insulating substrate. Reach and also divide the dividing groove.
As a result, when manufacturing an ultra-small and thin chip resistor having a planar outer dimension of, for example, 0.6 mm × 0.3 mm or 0.4 mm × 0.2 mm, and an insulating substrate thickness of 0.2 mm or less, The guide wall as in Patent Document 1 is not necessary, and sagging and bleeding associated with the printing of the thick resistive paste are suppressed, and the film thickness becomes substantially uniform until both sides of the resistive film are formed. Variations in the resistance value distribution after firing can also be suppressed. Even if the insulating substrate has no split groove formed in advance and is a thin insulating substrate, there is no warping of the insulating substrate due to repeated heating in the manufacturing process, no parallelism distortion between the split grooves, and insulation in the manufacturing process Breakage of the substrate can be avoided, and the outer dimensional accuracy accompanying the division can be maintained well. Compared with the conventional method in which the protective coating film is formed in a narrow range for each chip resistor, sagging and bleeding do not occur on both sides of the protective coating film, and a broad and substantially flat protective coating film is obtained. It is possible to reduce the suction error of the mounting machine when mounting on the substrate.

Hereinafter, although an embodiment of the present invention is described in detail with reference to drawings, the present invention is not limited to the following embodiment.
FIG. 1 is a schematic view showing a process of manufacturing an ultra-small and thin chip resistor. In FIG. 1, the number of chip resistors obtained from a single insulating substrate is shown to be smaller than that in an actual manufacturing process. More than one chip resistor is manufactured.
In FIG. 1A, for the purpose of manufacturing an ultra-small chip resistor having a planar outer dimension of 0.6 × 0.3 mm or less, a thickness of 0.2 mm or less in which no divisional grooves are previously engraved. The alumina ceramic substrate 11 is used. First, the electrode film 12 is formed for each region of the alumina ceramic substrate using a metal paste or resin paste made of resinate.
When manufacturing a chip resistor intended for face-up mounting, an electrode film (not shown) is also formed on the back side of the substrate so as to correspond to the front side electrode film 12. The electrode film on the back side is formed in a strip shape for each individual region or for each predetermined region.

Next, as shown in FIG. 1B, a resistive film 13a is printed using a metal glaze thick resistive paste so as to overlap a part of the electrode film 12 to be a pair of front electrodes. Dry this .

Next, in the strip-shaped resistive film 13a dried after printing, the sacrificial portion of the resistive film wider than the unnecessary portion of the strip-shaped resistive film 13a in the lateral direction (primary direction) of the insulating substrate 11 or the electrode film serving as the surface electrode is formed. Unnecessary portions (not shown) that have become blurred areas are removed by laser beam irradiation. FIG. 1C shows the insulating substrate 11 from which unnecessary portions are removed. Thus, by removing unnecessary portions by laser beam irradiation, individual independent resistance films 13b are obtained, and the primary resistance film 13b from which unnecessary portions are removed by irradiating a laser beam in a dry state. The side edge portion in the direction exhibits an effect superior to the guide wall of Patent Document 1. Then, through the subsequent baking process of the resistance film, a substantially uniform film thickness that reaches the side edge of the resistance film without sagging or bleeding of the resistance paste can be formed, and a plurality of films are formed on the insulating substrate. The dispersion of the resistance value distribution between the resistance films is suppressed, the range in which the resistance films are formed, and the degree of freedom in arranging the adjacent spaces between them is increased, and the insulating substrate can be effectively used.
The laser beam for removing unnecessary portions of the resistive film is a fundamental wave (wavelength is approximately 1064 nm) oscillated from an oscillation device such as Nd: YAG, Nd: YLF, Nd: YVO ₄ , or a UV wavelength obtained by converting the wavelength of the fundamental wave. A laser having a region (wavelength of approximately 262 to 266 nm) can be used. In the case of the fundamental wave, the output is 0.5 W, the Q rate is 10 kHz, and the speed is 40 mm / second. In the case of a laser having a UV wavelength region, the output is 0.5 W, the Q rate is 30 kHz, and the speed is 40 mm / second. Note that the output, Q rate, speed, and the like of the laser beam are appropriately adjusted in consideration of work efficiency.
When unnecessary portions of the dried resistive film are removed by irradiation with a laser beam having a UV wavelength region, ablation unique to UV laser, that is, a non-heat generation effect is obtained, while having a wavelength region of the fundamental wave. When removed by irradiating with a laser beam, the dried resistive film is irradiated with the laser beam, so that microcracks due to thermal strain seen in the fired resistive film do not occur at the side edge of the resistive film.

  After the resistance film is baked, as shown in FIG. 1D, an undercoat film 14 is formed on the resistance film with a glass paste thick film, and the resistance value is obtained by irradiating the undercoat film 14 with a laser beam. A trimming groove 15 for adjustment is formed. Here, the groove wall and side edges of the trimming groove 15 reduce the thermal influence due to the laser beam irradiation, and the undercoat film 14 prevents the scattered matter accompanying the laser beam irradiation from adhering to the resistance film.

  Next, as shown in FIG. 1E, a protective coat film 16 is formed in a strip shape using glass paste or resin paste so as to fill the trimming groove 15 so as to cover the undercoat film 14.

After the protective coat film 16 is formed, when a laser beam having a UV wavelength region is irradiated so as to be orthogonal to the horizontal direction (primary direction) and the vertical direction (secondary direction) of the insulating substrate, FIG. 1 (f) and FIG. Divided grooves 17 a and 17 b as shown are formed in the insulating substrate 11. That is, the laser beam divides the surface electrode film 12 and the protective coating film 16 (including the belt-like undercoat film 14), and further reaches the insulating substrate 11 below to cut the dividing grooves 17a and 17b into the insulating substrate 11. Set up.
FIG. 2 is a partial cross-sectional view taken along line XX in FIG.
Here, the laser beam is a UV laser having a UV wavelength region obtained by converting the wavelength of a fundamental wave oscillated from a laser oscillation device such as Nd: YAG, Nd: YLF, Nd: YVO ₄ , for example, a wavelength region of approximately 266 nm to 266 nm. The one having approximately 355 nm, an output of 0.5 W, and a Q rate of 30 kHz can be used. The output and Q rate of the UV laser are appropriately adjusted according to the thickness of the insulating substrate and the depth of the dividing groove.
In this way, when the electrode film 12 and the protective coating film 16 are divided and engraved, by using a UV laser, it is possible in particular to suppress the scattered matter around the divided and engraved locations. The ablation effect accompanying beam irradiation can also be used effectively.

  After the dividing grooves 17a and 17b are formed in the insulating substrate, the insulating substrate is divided along the dividing groove 17a in the horizontal direction (primary direction) to form a strip-shaped substrate 18 as shown in FIG. Further, each strip-shaped substrate 18 is divided along the dividing grooves 17b in the vertical direction (secondary direction) to form individual chips as shown in FIG. Here, the chip resistor of FIG. 1 (h) is obtained by forming the plating film 19 on the exposed portion of the electrode film, and is used as an ultra-small chip resistor corresponding to face-down mounting.

Next, FIG. 3A is a plan view of a strip-shaped substrate 20 different from that in FIG. 1G, which is formed by forming electrode films at corresponding positions on the front and back of the insulating substrate, and forming the insulating substrate into a strip-like shape. Each strip-shaped substrate 20 is formed with an end face electrode film 21 for connecting the front and back electrode films. The end face electrode film 21 is formed of a material corresponding to the protective coat film 16. That is, when the protective coat film 16 is formed from a glass paste, the end face electrode film 21 is formed using a metal glaze conductive paste, while the protective coat film 16 is formed from a resin paste. For this, the end face electrode film 21 is formed using a conductive resin paste. The end face electrode film can be formed by stacking strip-shaped insulating substrates and using a vapor deposition method or a sputtering method.
After the end face electrode film 21 is formed on the strip-shaped substrate 20, it is divided along the dividing grooves 17b in the vertical direction (secondary direction), and individual chip resistors 22 as shown in FIG. 3B are manufactured. The
The chip resistor 22 can be mounted on both sides of the face-down or face-up mainly for solder fillet joining between an electrode land (not shown) on the circuit board and mainly an end face electrode of the chip resistor.

Next, FIGS. 4A and 4B are plan views showing some steps in a method of manufacturing a chip resistor different from that shown in FIG.
In this manufacturing method, an alumina ceramic substrate 30 similar to that shown in FIG. 1 is used. As shown in FIG. 4A, first, a plurality of strip-like resistive films 31 are printed on the substrate 30 and dried. Then, after the resistance film 31 is dried, a plurality of electrode films 32 are formed in a strip shape so as to overlap a part of each resistance film 31 as shown in FIG. That is, the resistance film 31 and the electrode film 32 are formed in the reverse order to that shown in FIG. 1, and thereafter, the chip resistor is formed by performing the same steps as those shown in FIGS. Can be manufactured.

(A)-(h) is a top view which shows each process in the manufacturing method of this invention. FIG. 2 is a partial cross-sectional view taken along line XX in FIG. (A) and (b) are the top views of the strip-shaped board | substrate and chip resistor different from FIG. It is a top view which shows the one part process in the manufacturing method different from FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Chip resistor 11 Insulating substrate 12 Electrode film 13a Resistive film 13b Resistive film 16 Protective coating film 17a Dividing groove (primary direction)
17b Dividing groove (secondary direction)
19 Electrode film 22 Chip resistor 31 Resistive film 32 Electrode film

Claims (2)

Using an insulating substrate that has not been previously engraved with a dividing groove, a large number of pairs of electrode films are formed in a predetermined region of the insulating substrate , and a large number of resistance films are printed so as to overlap a part of each pair of electrode films. In the manufacturing method of the chip resistor, the trimming groove for adjusting the resistance value is formed in the resistance film, and the protective coat film is formed in a predetermined region of the resistance film including the trimming groove.
Printing a resistive film overlapping a part of the electrode film, printing in a strip shape in the primary direction of the insulating substrate and drying;
Removing unnecessary portions of the strip-shaped resistive film formed by drying in the process by laser beam, and then firing the resistive film;
After trimming to the resistor film, a step that form a belt-shaped protective coating layer on the primary direction of the resistance film,-holding protection coating film and the electrode film with a laser beam by a predetermined primary direction and the secondary direction method of manufacturing a chip resistor which comprises a degree Engineering when divided to simultaneously insulating substrate you engraved dividing grooves at intervals. Unnecessary portions of the strip-shaped resistance film, a step of removing by irradiating a laser beam having a region of the fundamental wave or UV wavelengths,
Division Mizokoku setting of the electrode film and the protective coating layer, the same time the insulating substrate when cutting at predetermined intervals in the primary direction and the secondary direction, be comprised of a step of irradiating a laser beam having a UV wavelength region A method of manufacturing a chip resistor according to claim 1.

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