JP2012099744A - Metal plate low resistance chip resistor and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metal plate low resistance chip resistor which allows for manufacturing cost reduction by a step for setting an exact resistance value easily.SOLUTION: In the metal plate low resistance chip resistor, both end sides of a metal resistance plate formed in substantially rectangular shape serve as a pair of terminal electrodes, notches are formed in both sides between the pair of terminal electrodes and a concave step is formed on the lower surface side as a fixed resistance part, and a protective film insulating the fixed resistance part and an electrode film insulating the pair of terminal electrodes are provided. Consequently, the manufacturing process can be simplified sharply, and the manufacturing cost can be reduced by decreasing the number of components.

Description

  The present invention relates to a metal plate low resistance chip resistor capable of reducing the manufacturing cost by a simple process and a method for manufacturing the same.

  It is well known to use low resistors (shunt resistors) for the detection of large currents.

  Conventionally, as a low-current resistor for current detection, for example, as described in Patent Document 1, a central portion on the back surface of a plate-shaped metal resistor is cut to form a recess, and a pair of bonding is formed at both ends of the surface. There is a current detection low resistor in which electrode pads are formed and a pair of connection electrodes are formed at both ends of the back surface adjacent to the recess.

JP 2001-118701 A

  However, in Patent Document 1, there is a problem that the manufacturing process becomes complicated because the resistance value is adjusted by cutting the back center portion of the metal resistor and adjusting the cross-sectional area.

  In view of the above circumstances, the present invention provides a metal plate low-resistance chip resistor for current detection that has a simple manufacturing process and has a small number of parts and can reduce manufacturing costs, and is excellent in heat dissipation, and a method for manufacturing the same. It is.

The metal plate low resistance chip resistor in the first configuration of the present invention has a pair of terminal electrodes at both ends of the metal resistor plate formed in a substantially rectangular shape, and has notches formed on both sides between the pair of terminal electrodes. In addition, a concave step portion is formed on the lower surface side by press molding to form a fixed resistance portion, a protective film including the fixed resistance portion and insulatingly coated, and an electrode in which at least the lower surface side of the pair of terminal electrodes is conductively coated And a membrane.
The metal resistor is made by adding a metal having a resistance higher than that of the base metal to a base metal having a low resistance such as a copper / nickel alloy, a nickel / chromium alloy or an iron / chromium alloy. Made of alloy.
Insulation in the insulating coating used in the present invention means having electrical insulation, and examples of the protective film include thermosetting resins. Conductivity in the conductive coating means having electrical conductivity, and examples of the conductive coating include metal plating.
The electrode film may be conductively coated not only on the lower surface side but also on the upper surface side of the terminal electrode.

In the second configuration of the present invention, the fixed resistance portion in the first configuration is formed by notching both sides between the pair of terminal electrodes and forming a concave step portion on the lower surface side by press molding and a convex step on the upper surface side. A fixed resistance portion is formed by forming a portion.
Whether to form the convex step on the upper surface side of the metal resistor plate is selected depending on various conditions such as a required resistance value, a material and thickness of the metal resistor plate, and a pressing force of press molding.

  The manufacturing method of the metal plate low resistance chip resistor according to the third configuration of the present invention includes a plurality of lines arranged in a line at a predetermined interval at a substantially central portion in the short side direction of the strip metal resistor plate along the long side direction of the strip metal resistor plate. An opening step for forming a hole in the metal strip, and a molding step for forming a continuous concave step portion by press molding on the lower surface side of the substantially central portion in the short side direction of the strip metal resistor plate along the long side direction of the strip metal resistor plate A protective film forming step of forming a protective film including the concave step portion of the strip-shaped metal resistor plate and an upper surface side facing the concave step portion to insulate and covering both ends of the strip-shaped metal resistor plate in the short side direction; An electrode film forming step of forming an electrode film by conductively coating the lower surface side of the side, and a cutting step of cutting the strip-shaped metal resistance plate in a short side direction at a portion where the hole is provided, To do.

In the fourth configuration of the present invention, the molding step in the third configuration is formed by forming a concave step portion by press molding on the lower surface side of the substantially central portion in the short side direction of the strip-shaped metal resistor plate, and on the upper surface side of the strip-shaped metal resistor plate. The molding step is to form a convex step portion facing the concave step portion.
Whether or not to form a convex step on the upper surface side opposite to the concave step provided on the lower surface side of the metal resistance plate depends on the required resistance value, the material and thickness of the metal resistance plate, the pressing force of the press molding, etc. It is selected according to various conditions.

According to the present invention, the belt-shaped metal resistor plate is deformed by press molding to form a concave step portion on the back surface side, and if necessary, a convex step portion is formed on the upper surface side to form a fixed resistance portion. A metal plate low resistance chip resistor having both ends as a pair of connection electrodes can be obtained, and the manufacturing process can be greatly simplified and the manufacturing cost can be reduced by reducing the number of components.
Further, in the metal plate low resistance chip resistor of the present invention, a fixed resistor portion having a narrow width can be provided between the terminal electrodes by cutting in the short side direction at the hole position of the belt-like metal resistor plate, and a predetermined specified with high accuracy. It becomes possible to be within the resistance value range.
Furthermore, the fixed resistor portion is narrower by notches on both sides of the fixed resistor portion than the terminal electrode, and can be formed longer than the width, so that it can be formed like a conventional metal plate low resistance chip resistor. Unlike the prior art in which holes, grooves or slits are provided, the occurrence of hot spots can be prevented, and high reliability and a sufficient physical strength can be ensured.

It is a general-view figure (a) of the metal plate low resistance chip resistor of the present Example 1, and a metal resistance plate (b). It is the top view (a) of the metal plate low resistance chip resistor of the present Example 1, AA sectional view (b), BB sectional drawing (c). It is explanatory drawing (a) of a strip | belt-shaped metal resistance board in the manufacturing process of the metal plate low resistance chip resistor of the present Example 1, and CC sectional view (b). They are a general-view figure (a) of the metal plate low resistance chip resistor of the present Example 2, and a metal resistance plate (b). It is the top view (a) of the metal plate low resistance chip resistor of the present Example 2, AA sectional view (b), BB sectional drawing (c). It is explanatory drawing (a) of a strip | belt-shaped metal resistance board in the manufacturing process of the metal plate low resistance chip resistor of the present Example 2, and CC sectional view (b).

  Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited thereto.

  FIG. 1 is a schematic view (a) and a metal resistor plate (b) of the metal plate low resistance chip resistor of the first embodiment, and FIG. 2 is a plan view of the metal plate low resistance chip resistor of the first embodiment ( They are a), AA sectional view (b), BB sectional drawing (c).

  In the metal plate low resistance chip resistor 10 according to the first embodiment, both end sides of the metal resistor plate 10a formed in a substantially rectangular shape are used as a pair of terminal electrodes 11. Notches 12a are formed on both sides between the terminal electrodes 11, and a concave step portion 12b is formed on the lower surface side by press molding, and the thickness is defined by the upper surface side flat portion 12c facing the concave step portion 12b. The fixed resistance portion 12 has a length D1r, a length L1r, and a width W1r. The upper surface side of the metal plate low resistance chip resistor 10, and the notch 12 a and the recessed step portion 12 b of the fixed resistance portion 12 are covered with an insulating film 13. The upper surface of the protective film 13 is formed flat, and the fixed resistance portion 12 including the notch 12a, the concave step portion 12b, and the flat surface portion 12c is included in the protective film 13 having the same width as the metal resistance plate 10a. Yes. Further, the lower surface side of the terminal electrode 11 is conductively covered with an electrode film 14.

  Next, a manufacturing method of the metal plate low resistance chip resistor of the first embodiment will be described. FIG. 3 is an explanatory view of a strip-shaped metal resistor plate (a) and a CC line sectional view (b) in the manufacturing process of the metal plate low resistance chip resistor of the first embodiment. The metal plate low resistance chip resistor 10 is manufactured from an opening process, a molding process, a protective film forming process, an electrode film forming process, and a cutting process.

In the opening process, a plurality of holes 1 a arranged in a line at a predetermined interval are formed at a substantially central portion in the short-side direction X of the strip-shaped metal resistor plate 1 along the long-side direction Y of the strip-shaped metal resistor plate 1.
In the molding step, a continuous concave step portion 1b is formed by press molding on the lower surface side of the substantially central portion in the short side direction X of the strip metal resistance plate 1 along the long side direction Y of the strip metal resistance plate 1.
In the protective film forming step, the protective film 1d for insulatingly covering the concave step portion 1b of the belt-shaped metal resistance plate 1 and the flat surface portion 1c on the upper surface side facing the concave step portion 1b is formed.
In the electrode film forming step, the electrode film 1f is formed by conductively coating the lower surfaces of the terminal portions 1e on both ends in the short side direction X of the strip-shaped metal resistor plate 1.
In the cutting process, the strip-shaped metal resistance plate 1 is cut in the short side direction X with the cutting width W1 at the portion where the hole 1a is provided.
Through the above steps, the strip-shaped metal resistor plate 1 is fixed with the concave step portion 12b (1b) covered with the protective film 13 (1d) and the flat portion 12c (1c) on the upper surface side facing the concave step portion 12b (1b). A metal plate low-resistance chip resistor 10 having a terminal electrode 11 (1e) that is conductively covered with the electrode film 14 (1f) is formed as the resistor 12.

  4A and 4B are a schematic diagram (a) and a metal resistor plate (b) of the metal plate low resistance chip resistor of the first embodiment, and FIG. 5 is a plan view of the metal plate low resistance chip resistor of the first embodiment (FIG. They are a), AA sectional view (b), BB sectional drawing (c).

  In the metal plate low resistance chip resistor 20 of the second embodiment, both end sides of the metal resistor plate 20a formed in a substantially rectangular shape are used as a pair of terminal electrodes 21. Notches 22a are formed on both sides between the terminal electrodes 21, a concave step portion 22b is formed on the lower surface side by press molding, and a convex step portion 22c opposite to the concave step portion 22b is formed on the upper surface side. A fixed resistance portion 22 having a length D2r, a length L2r, and a width W2r is formed. The upper surface side of the metal plate low resistance chip resistor 20, and the notch 22 a and the recessed step portion 22 b of the fixed resistance portion 22 are covered with a protective film 23. The upper surface of the protective film 23 is formed flat, and the fixed resistance portion 22 including the notch 22a, the concave step portion 22b, and the convex step portion 22c is included in the protective film 23 having the same width as that of the metal resistance plate 20a. ing. The lower surface side of the terminal electrode 21 is conductively covered with an electrode film 24.

  Next, the manufacturing method of the metal plate low resistance chip resistor of the second embodiment will be described. 6A and 6B are an explanatory view (a) and a cross-sectional view (b) taken along the line CC of the strip-shaped metal resistor plate in the manufacturing process of the metal plate low resistance chip resistor of the second embodiment. The metal plate low resistance chip resistor 20 is manufactured from an opening process, a molding process, a protective film forming process, an electrode film forming process, and a cutting process.

In the opening process, a plurality of holes 2 a arranged in a line at a predetermined interval are formed at a substantially central portion in the short-side direction X of the strip-shaped metal resistor plate 2 along the long-side direction Y of the strip-shaped metal resistor plate 2.
In the molding step, a continuous concave step portion 2b is formed by press molding on the lower surface side of the substantially central portion in the short side direction X of the strip-shaped metal resistor plate 2 along the long-side direction Y of the strip-shaped metal resistor plate 2, and A convex step portion 2c facing the step portion 2b is formed on the upper surface side.
In the protective film forming step, a protective film 2d that insulates the concave step 2b and the convex step 2c of the strip-shaped metal resistance plate 2 is formed.
In the electrode film forming step, the electrode film 2f is formed by conductively coating the lower surface sides of the terminal portions 2e on both ends in the short side direction X of the strip-shaped metal resistor plate 2.
In the cutting step, the strip-shaped metal resistance plate 2 is cut in the short side direction X with the cutting width W2 at the portion where the hole 2a is provided.
Through the above process, the band-shaped metal resistor plate 2 is formed into the fixed resistance portion 22 in which the concave step portion 22b (2b) and the convex step portion 22c (2c) are insulated with the protective film 23 (2d), and the electrode film 24 (2f). A metal plate low resistance chip resistor 20 having a terminal electrode 21 (2e) coated with a conductive material is formed.

1 Strip metal resistance plate (Example 1)
DESCRIPTION OF SYMBOLS 1a Hole 1b Concave step part 1c Plane part 1d Protective film 1e Terminal part 1f Electrode film 2 Strip | belt-shaped metal resistance board (Example 2)
2a hole 2b concave step 2c convex step 2d protective film 2e terminal 2f electrode film 10 metal plate low resistance chip resistor (Example 1)
10a Metal resistance plate 11 Terminal electrode 12 Fixed resistance portion 12a Notch 12b Concave step portion 12c Planar portion 13 Protective film 14 Electrode film D1r Thickness (fixed resistance portion)
L1r length (fixed resistance part)
W1r width (fixed resistance part)
W1 Cutting width (metal resistance plate)
20 Metal plate low resistance chip resistor (Example 2)
20a Metal resistance plate 21 Terminal electrode 22 Fixed resistance part 22a Notch 22b Concave step part 22c Convex step part 23 Protective film 24 Electrode film D2r Thickness (fixed resistance part)
L2r length (fixed resistor)
W2r width (fixed resistance part)
W2 Cutting width (metal resistance plate)

Claims (4)

  Both ends of the metal resistor plate formed in a substantially rectangular shape are used as a pair of terminal electrodes, notches are formed on both sides between the pair of terminal electrodes, and a concave step is formed on the lower surface side by press molding. A metal plate low-resistance chip resistor comprising a fixed resistance portion, a protective film including the fixed resistance portion and insulatingly coated, and an electrode film conductively coated on at least the lower surfaces of the pair of terminal electrodes vessel.   The fixed resistance portion is formed by notching both sides between the pair of terminal electrodes, forming a concave step portion on the lower surface side by press molding, and facing the concave step portion on the upper surface side of the strip-shaped metal resistance plate. 2. The metal plate low resistance chip resistor according to claim 1, wherein the fixed resistance portion is formed with a protruding step portion. An opening step of forming a plurality of holes arranged in a line at a predetermined interval in a substantially central portion in the short side direction of the strip-shaped metal resistor plate along the long side direction of the strip-shaped metal resistor plate;
A molding step of forming a concave step portion by press molding on the lower surface side of the substantially central portion in the short side direction of the strip-shaped metal resistance plate;
A protective film forming step of forming a protective film including the concave step portion of the strip-shaped metal resistance plate and an upper surface side facing the concave step portion to insulate and cover;
An electrode film forming step of forming an electrode film by conductively coating the lower surfaces of both ends in the short side direction of the strip-shaped metal resistor plate;
And a cutting step of cutting the strip-shaped metal resistor plate in the short side direction at the portion where the hole is provided.   In the molding step, a concave step portion is formed by press molding on the lower surface side of a substantially central portion in the short side direction of the strip-shaped metal resistor plate, and a convex step portion facing the concave step portion on the upper surface side of the strip-shaped metal resistor plate 4. The method of manufacturing a metal plate low resistance chip resistor according to claim 3, wherein the forming step is a forming step.

Images