JP2007049071A - Chip resistor and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve soldering strength of a chip resistor having a pair of right and left terminal electrodes provided on one surface of a resistor made of a metal plate. <P>SOLUTION: A solder plating layer 6 is formed over both of the bottom surfaces of both terminal electrodes 3 in a chip resistor 1 and both right and left end surfaces 2a in a resistor 2. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a chip resistor configured to exhibit a low resistance value using a metal plate, and a method for manufacturing the chip resistor.

  In the chip resistor described in Patent Document 1 as a prior art, a resistor is formed in a chip shape with a metal material having a predetermined specific resistance value, and an upper surface insulating film is formed on the upper surface of the resistor. On the other hand, a pair of left and right terminal electrodes are formed on the lower surface of the resistor, and an insulating film is formed between the two terminal electrodes.

In addition, in Patent Document 1, a material metal plate is prepared by arranging a large number of the resistors in an integrated manner for the manufacturing method of the chip resistor having the above configuration, and an upper surface insulating film is formed on the upper surface of the material metal plate. On the lower surface of the material metal plate, an insulating film in each resistor is formed by thick film printing, and a pair of terminal electrodes in each resistor is formed by metal plating, It has proposed a method of cutting a material metal plate for each resistor.
JP 2004-63503 A

  By the way, in the chip resistor having the above-described configuration, it is necessary to form a solder plating layer on the surfaces of both terminal electrodes in order to surely and easily solder the terminal electrodes to the printed circuit board or the like.

  However, performing the solder plating process for forming the solder plating layer after the material metal plate is divided for each resistor, the portion of the surface of the resistor where the insulating film is not formed in advance, that is, Since the solder plating layers are also formed on the left and right side surfaces of the resistor, the total resistance value changes.

  Therefore, in the manufacturing method described in Patent Document 1, the solder plating process for forming the solder plating layer is performed following the metal plating process for forming the terminal electrode, and thereafter, The plate is cut for each resistor.

  Therefore, in this manufacturing method, solder plating layers cannot be formed on the left and right end faces of the resistor.

  For this reason, when the manufactured chip resistor is mounted by soldering to a printed circuit board or the like, the solder frets do not rise on the left and right end surfaces, so that not only the soldering strength is low but also the soldering quality is good. This cannot be confirmed by the rise of solder frets.

  An object of the present invention is to provide a chip resistor having high soldering strength and a method for manufacturing the chip resistor.

In order to achieve this technical problem, the chip resistor according to the present invention is, as described in claim 1, “While the upper surface insulating film is formed on the upper surface of the resistor made into a chip type with a metal material, the resistor In the chip resistor formed by forming a pair of left and right terminal electrodes on the lower surface of the substrate and forming an insulating film between the two terminal electrodes,
Solder plating layers were formed on both the lower surfaces of the terminal electrodes and the left and right end surfaces of the resistor. "
It is characterized by that.

Next, the manufacturing method of the present invention, as described in claim 2,
“Manufacturing a metal plate made by integrally arranging a plurality of resistors constituting one chip resistor in a plurality of rows in the vertical and horizontal directions;
Forming an upper surface insulating film on the upper surface of each resistor of the material metal plate;
Forming a lower surface insulating film on a portion of the lower surface of each resistor of the material metal plate excluding the left and right ends;
A step of forming a pair of terminal electrodes in each resistor in a portion of the lower surface of each resistor of the material metal plate where the lower surface insulating film is not formed by plating the material metal plate;
Cutting the material metal plate into a plurality of rod-shaped material metal plate pieces arranged in a line with a plurality of the resistors having the terminal electrodes at both ends thereof facing sideways;
Performing a solder plating process on each of the rod-shaped metal plate pieces;
A step of cutting each of the rod-shaped material metal plate pieces for each of the resistors; "
It is characterized by that.

Further, the manufacturing method of the present invention, as described in claim 3,
“In the description of claim 2, the cutting of the material metal plate into each bar-shaped material metal plate piece is a cutting that makes each of the bar-shaped material metal plate pieces integrally connected to each other at one end thereof.”
It is characterized by that.

  According to the first aspect of the present invention, when the solder plating layer is formed over both the lower surface of both terminal electrodes and both the left and right end surfaces of the resistor, the resistor is mounted on the printed circuit board by soldering. Since the solder frets swell on the left and right end surfaces of the solder, the soldering strength can be greatly improved, and the swell of the solder frets can easily and reliably determine the quality of the soldering. .

  On the other hand, according to the manufacturing method of the present invention, the material metal plate is cut into a plurality of rod-shaped material metal plate pieces, and then each of the rod-shaped material metal plate pieces is subjected to solder plating treatment, so Solder plating layers can be formed on the left and right side surfaces in the longitudinal direction of the material metal plate pieces, that is, the left and right end surfaces of each resistor of the rod-shaped material metal plate pieces.

  Next, by cutting each rod-shaped material metal plate piece for each resistor, the chip resistor is formed on both left and right end surfaces and terminal electrodes without forming solder plating layers on the left and right side surfaces of the resistor. It is possible to manufacture in a form in which a solder plating layer is formed only on both of the lower surface of the substrate.

  In particular, according to the manufacturing method of the third aspect, the solder plating process for each bar-shaped metal plate piece can be performed in a state in which a plurality of bar-shaped metal plate pieces are integrated. Since the number of steps required can be reduced, the manufacturing cost can be reduced as compared with the case of solder plating for each bar-shaped metal plate piece.

  Embodiments of the present invention will be described below with reference to the drawings.

  1 and 2 show a chip resistor 1 manufactured according to the present invention.

  The chip resistor 1 includes a chip-shaped resistor 2, and terminal electrodes 3 are formed on the lower surface of the resistor 2 at both right and left ends, and a portion between the terminal electrodes 3 is heat resistant. The insulating lower surface insulating film 4 is formed, and the upper surface of the resistor 2 is also provided with a heat resistant upper surface insulating film 5. The resistor 2 has a length dimension in plan view. L is a rectangle with a width dimension W, and its thickness dimension is T.

  The chip resistor 1 has a structure in which solder plating layers 6 are formed on the lower surfaces of the terminal electrodes 3 and the left and right end faces 2a of the resistor 2, Does not form the solder plating layer 6.

  The chip resistor 1 having the above-described configuration is manufactured by the method described below.

  In this manufacturing method, first, as shown in FIG. 3, a plurality of resistors 2 constituting the one chip resistor 1 are arranged in a plurality of rows in the vertical direction and the horizontal direction, and are integrated with each other in this state. The material metal plate A is made of a metal material having a predetermined (appropriate) specific resistance to a plate thickness T.

  As will be described in detail later, the material metal plate A is divided for each resistor 2 by cutting along the vertical cutting line B1 and the horizontal cutting line B2.

  Next, as shown in FIG. 4, a heat resistant insulating film 4 is formed on the lower surface of the material metal plate A, while a heat resistant insulating film 5 is formed on the upper surface of the material metal plate A.

  Next, as shown in FIG. 5, the insulating film 4 on the lower surface of the material metal plate A is removed by removing a portion along the vertical cutting line B <b> 1 by a photolithography method or the like. The resistor 2 is formed by removing the left and right ends of the lower surface of each resistor 2.

  In this case, in another method, before forming the insulating film 4 on the lower surface of the material metal plate A, a tape is previously applied to a portion of the lower surface along the longitudinal cutting line B1, In this state, the insulating film 4 may be formed on the entire lower surface, and then the tape may be peeled off to form the insulating film 4 except for the left and right ends of the lower surface of each resistor 2. .

  Next, by performing a copper plating process on the entire material metal plate A, as shown in FIG. 6, a portion of the lower surface of the material metal plate A where the insulating film 4 is not formed, that is, each resistance Terminal electrodes 3 made of copper are formed on both ends of the body 2. The terminal electrode 3 may be made of a highly conductive metal other than copper.

  Next, by cutting the material metal plate A along the longitudinal cutting line B1, as shown in FIG. 7, a plurality of the resistors 2 are arranged in a row with the terminal electrodes 3 at both ends facing sideways. Are divided into a plurality of bar-shaped material metal plate pieces A1.

  This cutting is performed by cutting by dicing along the longitudinal cutting line B1, or by shearing by sharing.

  Next, a solder plating layer 6 is formed on the left and right end faces 2a of each resistor 2 and the lower surface of the terminal electrode 3 by performing a solder plating process on the whole of the rod-shaped metal plate pieces A1.

  Next, as shown in FIG. 8, each of the rod-shaped material metal plate pieces A1 is cut along a horizontal cutting line B2 and divided for each resistor 2 to obtain a plurality of chip resistors. Make 1 a finished product.

  The cutting along the horizontal cutting line B2 is performed by cutting by dicing, or by shearing by shredding, similarly to the cutting along the vertical cutting line B1.

  Thus, the bar-shaped metal plate A1 is cut into a plurality of bar-shaped metal plate pieces A1, and then each of the bar-shaped metal plate pieces A1 is subjected to a solder plating process, whereby the bar-shaped metal plate. The solder plating layer 6 can be formed on the left and right side surfaces in the longitudinal direction of the piece A1, that is, on the left and right end surfaces 2a of each resistor 2 of the rod-shaped material metal plate piece A1.

  Next, by cutting each of the rod-shaped material metal plate pieces A1 for each resistor 2, the chip resistor 1 is left and right without forming solder plating layers on the left and right side surfaces 2b of the resistor 2. It can be manufactured in a form in which the solder plating layer 6 is formed only on both the end faces 2 a and the lower surface of the terminal electrode 3.

  Next, FIG. 9 shows a second embodiment.

  In the second embodiment, when the material metal plate A is divided into a plurality of rod-shaped material metal plate pieces A1, the rod-shaped material metal plate pieces A1 are integrated in one side portion of the material metal plate A. In other words, the cutting along the cutting line B1 in the vertical direction is stopped in the vicinity of the terminal end.

  As a result, the solder plating process for each of the rod-shaped metal plate pieces A1 can be performed simultaneously with the bar-shaped metal plate pieces A1 being joined together, thereby improving the workability of the solder plating process and further reducing the cost. .

  The present invention is not limited to the formation of the pair of left and right terminal electrodes 3 on the lower surface of the resistor 2, and the pair of left and right terminal electrodes 3 are also formed on the upper surface of the resistor 2, as shown in FIG. In the same manner, the solder plating layer 6 is formed on the three terminals of the terminal electrode 3 on the lower surface of the resistor 2, the left and right end surfaces 2a of the resistor 2, and the terminal electrode 3 'on the upper surface. The chip resistor 1 'can be configured as described above.

  In this case, the upper surface insulating film 5 and the terminal electrode 3 ′ on the upper surface of the resistor 2 are formed by the same method as the lower surface insulating film 4 and the terminal electrode 3 in the first embodiment.

It is a perspective view of a chip resistor. It is the II-II sectional view taken on the line of FIG. It is a perspective view which shows a 1st manufacturing process. It is a perspective view which shows a 2nd manufacturing process. It is a perspective view which shows a 3rd manufacturing process. It is a perspective view which shows a 4th manufacturing process. It is a perspective view which shows a 5th manufacturing process. It is a perspective view which shows a 6th manufacturing process. It is a perspective view which shows another manufacturing process. It is a perspective view which shows another chip resistor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,1 'Chip resistor 2 Resistor 3, 3' Terminal electrode 4, 5 Insulating film 6 Solder plating layer A Material metal plate B1 Longitudinal cutting line B1 Lateral cutting line A1 Bar-shaped material metal plate piece

Claims (3)

A top insulating film is formed on the upper surface of the resistor made into a chip type with a metal material, and a pair of left and right terminal electrodes are formed on the lower surface of the resistor, and an insulating film is formed between the two terminal electrodes. In the chip resistor consisting of
A chip resistor, wherein a solder plating layer is formed on both the lower surface of both terminal electrodes and both left and right end surfaces of the resistor. A process for producing a metal plate made by integrally arranging a plurality of resistors constituting one chip resistor in a plurality of rows in the vertical and horizontal directions;
Forming an upper surface insulating film on the upper surface of each resistor of the material metal plate;
Forming a lower surface insulating film on a portion of the lower surface of each resistor of the material metal plate excluding the left and right ends;
A step of forming a pair of terminal electrodes in each resistor in a portion of the lower surface of each resistor of the material metal plate where the lower surface insulating film is not formed by plating the material metal plate;
Cutting the material metal plate into a plurality of rod-shaped material metal plate pieces arranged in a line with a plurality of the resistors having the terminal electrodes at both ends thereof facing sideways;
Performing a solder plating process on each of the rod-shaped metal plate pieces;
A method of manufacturing a chip resistor, comprising a step of cutting each of the rod-shaped material metal plate pieces for each of the resistors.   3. The method according to claim 2, wherein the cutting of the material metal plate into each of the rod-shaped material metal plate pieces is a cutting for making the rod-shaped material metal plate pieces integrally connected to each other at one end thereof. A manufacturing method of a chip resistor.

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