KR101064534B1 - Low resistance chip resistor of resistance metal plate and its manufacturing method - Google Patents

Abstract

An object of the present invention is to provide a method for manufacturing a low resistance chip resistor having a high reliability of less than 1mΩ without a complicated process. Aggregate multilayer board body by soldering the copper plate 13 to the one or both surfaces of the resistance metal plate 11 by the brazing filler metal 12, and removing the oxide film from the surface, and forming a tin plating film 14 over the entire surface of the copper plate. (20) is formed, the aggregated laminates are cut into strips with a desired width to form strip-shaped laminates (22), and the center of the short-sided direction is approximately the center of one side or both sides on which a tin plated film of the strip-shaped laminates is formed. Is cut in a long side direction with a predetermined width, and at least the diffusion layer between the tin plated film, the copper plate, the brazing material, and the resistive metal plate and the brazing material is removed to form the concave portion 15 on one or both surfaces thereof. After the protective film 16 is formed, the strip-shaped multilayer body is cut into a desired width to produce a chip-shaped resistor 10.

Resistance metal plate, copper plate, oxide film, aggregated plate, tin plated film, lead material, diffusion layer, protective film, low resistance chip resistor

Description

RESISTANCE CHIP RESISTOR OF RESISTANCE METAL PLATE AND ITS MANUFACTURING METHOD

The present invention relates to a resistance metal plate low resistance chip resistor and a method of manufacturing the same.

In electronic components, such as a shunt resistor which detects the electric current when an electric current is supplied to the control circuit of a motor or a switching regulator, the metal plate chip resistor in which the electrode layer was formed in the both ends of the plate-shaped metal resistor made of alloy is conventionally used, The resistance value is It is set relatively low in the order of several mΩ-1Ω. With respect to such metal plate chip resistors, there is a desire to stabilize the resistance temperature coefficient and current characteristics, to reduce the inductance value, and to increase the current detection accuracy, and a method of manufacturing a chip resistor corresponding to this is disclosed in Japanese Patent Application. 2003-115401 (JP-2003-115401-A).

In other words, in JP-2003-115401-A, flakes of a highly conductive material such as copper are fixed to both ends of the metal resistor by crimping or fusion to form electrodes, and the side surfaces of the metal resistor are cut along the longitudinal direction, or The manufacturing method of the low resistor which cuts the upper and lower surfaces of a metal resistor in the thickness direction, adjusts a resistance value by adjusting the dimension of the shaping process, and provides a protective film in the exposed surface of a metal resistor is described.

In the method of manufacturing this low resistor, there is a problem that the process of adjusting the resistance value while cutting off the side or top and bottom surfaces of the metal resistor has a problem that productivity is reduced, and a thin piece of a highly conductive material such as copper is pressed onto the metal resistor. There is no description of a specific method for fusion, and it is difficult to introduce the method of JP-2003-115401-A into an actual production site.

In Japanese Patent Application Laid-Open No. 11-97203 (JP-11-97203-A), a sheet-shaped resistor made of a copper alloy such as manganine and constantan is laminated on the surface of the ceramic substrate, and a copper plate is laminated on the back surface. A shunt resistor element is integrally bonded by an activating metal method using silver lead or the like and provided with bonding electrode portions for current and voltage detection at both ends of the sheet-shaped resistor.

However, when joining a ceramic substrate and a sheet-shaped resistor (resistance metal plate) with the brazing material containing an active metal, there exists a subject that the brazing material is expensive and joining time is too long and productivity falls.

SUMMARY OF THE INVENTION The present invention solves the above problems, and its object is to provide a high reliability since the current value to be detected is relatively high, for example, when the resistance value is 5 A or more, a resistance metal plate low resistance chip resistor having a resistance value of less than 1 mΩ is required. It is to provide a method for manufacturing a low resistance chip resistor of less than 1mΩ without a complicated process.

Another object of the present invention is that the current value to be detected is relatively high, for example, when 5 A or more, a resistance metal plate low resistance chip resistor having a resistance value of less than 1 mΩ is required, and therefore, less than 1 mΩ that can be manufactured without a complicated process. It is to provide a low-resistance metal sheet chip resistor.

In this invention, the said subject is solved by the means of (1)-(5) described below.

(1) In the present invention, after the copper plate is soldered to one or both surfaces of the resistive metal plate and the oxide film is removed from the surface, an aggregated plate is formed by forming a tin plated film over the entire surface of the copper plate to form the aggregated laminate. Is cut into strips with a desired width to form a strip-shaped multilayer board, and from one or both surfaces on which the tin-plated film of the strip-shaped multilayer board is formed, approximately the center of the short-side direction is cut in a long side direction at a predetermined width, and tin The at least one diffusion layer between the plated film, the copper plate, the brazing material, and the resistive metal plate and the brazing material is removed to form recesses on one side or both sides, and a protective film is formed on the bottom surface of the recesses. A resistor metal plate low resistance chip low characterized by cutting a chip-shaped resistor The manufacturing method of the group is provided.

(2) In this invention, the manufacturing method of the resistance metal plate low resistance chip resistor as described in said (1) whose said resistance metal plate is an alloy containing 90 weight% or more of copper is provided.

(3) In this invention, the resistance metal plate and the said copper plate are soldered with the brazing material which consists of a copper-silver binary alloy, The manufacturing method of the resistance metal plate low resistance chip resistor as described in said (1) is provided. .

(4) In this invention, the protective film is formed in the bottom surface of the said recessed part with the material containing polyamideimide resin, The manufacturing method of the resistance metal plate low resistance chip resistor as described in said (1) is provided. .

(5) In the present invention, an aggregated multilayer plate is formed by soldering a copper plate to one or both surfaces of the resistance metal plate, removing an oxide film from the surface, and forming a tin plated film over the entire surface of the copper plate. Is cut into strips with a desired width, the center of the short-side direction is cut in the long side direction from the one surface or both surfaces on which the tin plated film of the strip-shaped multilayer plate body is formed in the long side direction, and the tin plated film, the copper plate, the brazing material, and A resistor formed by removing at least the diffusion layer between the resistive metal plate and the brazing material to form recesses on one or both surfaces, and forming a protective film on the bottom surface of the recesses, and then cutting the strip-shaped multilayer board into chips with a desired width. A metal plate low resistance chip resistor is provided.

Further, from the one side or both sides of the strip-shaped multilayer plate body in which the tin plated film is formed, the center of the short side direction is cut in the long side direction at a predetermined width, and the tin plated film, the copper plate, the brazing material, and the at least diffusion layer between the resistive metal plate and the brazing material are cut. In the step of removing and forming the recesses on one surface or both sides, the cutting depth of the recesses may be measured by, for example, using a microscope or the like to measure the cross-section of the sampled strip-shaped laminate plate with a naked eye. It is set to the depth which can remove reliably the diffusion layer with a brazing filler metal. Therefore, in this process, the thickness of the resistive metal plate is also cut in addition to the diffusion layer.

In this invention, about the strip-shaped multilayer board body formed by soldering a copper plate to the single side | surface or both surfaces of a resistance metal plate, and forming a tin plating film in the whole surface of a copper plate, the substantially center of a short side is predetermined from the single side | surface or both surfaces in which a tin plating film was formed. By cutting in the long side direction by the width, the tinned film, the copper plate, the brazing material, and the diffusion layer between the resistive metal plate and the brazing material are collectively removed from one or both sides to form a recess, and then a protective film is formed on the bottom surface of the recess. Since the chip-shaped resistor is manufactured by cutting the shape multilayer plate into a desired width, it is not necessary to perform the chipping process for the individual chip-shaped resistors, and it is possible to efficiently manufacture a low-resistance chip resistor of less than 1 mΩ with high reliability. It is possible to do

In the present invention, an alloy containing 90% by weight or more of copper is used as the resistive metal plate, so that a difference in expansion coefficient does not occur much between the copper plate to be soldered to one or both sides, and the high temperature treatment in the soldering step is performed. Warping does not occur even after that, and the fall of the processing precision by a warping can be prevented.

In the present invention, the resistance metal plate and the copper plate are soldered by a brazing material composed of a copper-silver binary alloy, so that the ohmic contact (ohm contact or ohmic contact) can be performed.

In this invention, since the protective film is formed in the bottom surface of the recessed part by the material containing polyamideimide resin, the characteristic which considered the environmental resistance with a resistance metal plate can be ensured.

EMBODIMENT OF THE INVENTION Hereinafter, although embodiment of this invention is described with reference to drawings, this invention is not limited to this.

1 is a perspective view of a resistive metal plate low resistance chip resistor 10 of one embodiment, and FIG. 2 is a perspective view of a resistive metal plate low resistance chip resistor 30 of a different embodiment.

The resistive metal plate low resistance chip resistor 10 of FIG. 1 solders the copper plate 13 as an electrode to one surface of the resistive metal plate 11 by the brazing filler metal 12, and the tin-plated film 14 on the copper plate 13. ), The recess 15 is formed by removing the tinned layer 14, the copper plate 13, the brazing filler metal 12, and the diffusion layer between the brazing filler metal 12 and the resistive metal plate 11 from approximately the center portion. The protective film 16 is formed in the bottom surface of the recessed part 15.

In the resistive metal plate low resistance chip resistor 30 of FIG. 2, the copper plates 33 and 33 are soldered on both sides of the resistive metal plate 31 by the brazing filler materials 32 and 32, and on both copper plates 33 and 33. Tin plating films 34 and 34 are formed, and the tin plating films 34 and 34, the copper plates 33 and 33, the brazing materials 32 and 32, and the brazing materials 32 and 32 and the resistive metal plate are formed from approximately central portions on both sides. At least the diffusion layer with (31) is removed to form the recesses 35 and 35 on both sides, and the protective films 36 and 36 are formed on the bottom surfaces of both recesses 35 and 35.

Here, the resistive metal plates 11 and 31 may use a plate body of an alloy containing 90% by weight or more of copper, and as such an alloy, for example, an alloy containing Cu and Ni, Cu, Mn, and Sn. And alloys containing Cu, Mn, Sn, and Ge. The brazing materials 12 and 32 can be made of a brazing material made of a copper-silver binary eutectic alloy, for example, silver lead prescribed by BAg-8 in JIS.Z.3261. BAg-8 contains 72% Ag and 28% Cu, and the melting temperature is 780 ° C of silver lead in both the solidus and liquidus lines. The protective films 16 and 36 may be formed of polyamideimide, which is an inorganic-organic composite material containing a silicone coupling agent or silica.

Next, the manufacturing method of the resistive metal plate low resistance chip resistor 10 of FIG. 1 is demonstrated with reference to FIG.

For example, when manufacturing the resistive metal plate low resistance chip resistor 10 having a length of 13 mm and a width of 6.3 mm, the first surface of the resistive metal plate 11 made of an alloy plate containing 90% by weight or more of copper is used. The copper plate 13 is soldered to a peak temperature of 850 ° C. in a hydrogen atmosphere furnace using a brazing filler material 12 made of a silver binary eutectic alloy.

Here, the resistive metal plate 11 uses, for example, an alloy plate body having a thickness of 0.5 mm, the brazing filler material 12 uses, for example, BAg-8 having a thickness of 0.05 mm, and the copper plate 13 has a thickness of 0.2, for example. Oxygen-free copper plates of mm are used, and all of them are about 500 mm long and 200 mm wide.

By using an alloy plate containing 90 wt% or more of copper as the resistance metal plate 11 and using an oxygen-free copper plate for the copper plate 13 as an electrode, these resistance metal plates 11 and the copper plate 13 have approximately the same coefficient of expansion. The warpage can be prevented from occurring when soldering. On the contrary, when an alloy containing less than 90% copper is used, for example, when a copper plate as an electrode is soldered to an alloy plate of manganine (Cu 85%, Mn 12%, Ni 2%, Fe 1%), the warpage becomes large. In this invention, it is preferable to use the alloy plate body whose copper content rate is 90% or more.

Moreover, since the brazing material 12 which consists of a copper-silver binary eutectic alloy was used, the resistance metal plate 11 and the copper plate 13 contact ohmicly, and the electrical resistance in the vicinity of the copper plate 13 as an electrode is suppressed very low. It becomes possible.

After soldering the copper plate 13 to one side of the resistive metal plate 11, alkali degreasing is performed with a solution containing sodium hydroxide and sodium silicate as a main component to remove the fat or oil adhering to the metal surface, and then an aqueous solution of dilute sulfuric acid. It is immersed in and removes an oxide film. After removal of the oxide film, a tin plated film 14 having a thickness of approximately 5 m is formed on the entire surface of the copper plate 13 by an electroplating method.

By performing the above process, as shown in FIG.3 (a), the copper plate 13 is joined by the brazing filler material 12 to the single side | surface of the resistance metal plate 11, and the tin plating film on this copper plate 13 is carried out. The aggregated multilayer plate body 20 in which 14 was formed is formed. The aggregated multilayer plate body 20 is formed in about 500 mm length, about 200 mm width, and about 1.0 mm thickness, for example.

Then, the aggregated multilayer plate body 20 is cut into strips with a predetermined width W1 as shown by the dotted line 21 in Fig. 3A to form a strip-shaped multilayer plate body 22. Since the cutting width W1 (length W1 of the short side) of the strip-shaped multilayer plate body 22 is a portion which becomes the length of the resistance metal plate low resistance chip resistor 10 to be manufactured, it is set here to 13 mm, and The length of the long side is, for example, about 500 mm.

Subsequently, the center of the short side direction of the strip-shaped multilayer plate body 22 is cut in the long side direction at a width W2, for example, 4 mm in width, as shown in Fig. 3C. In this shearing process, the tin plating film 14, the copper plate 13, the brazing filler metal 12, and the diffusion layer between the brazing filler metal 12 and the resistive metal plate 11 are removed from one surface on which the tin plating film 14 is formed. The recessed part 15 is formed.

Further, the diffusion layer 23 between the brazing filler material 12 and the resistance metal plate 11 is scraped off from the surface of the tin plating film 14 to a depth of approximately d1 = 0.3 mm, as shown in FIG. The resistive metal plate 11 in the concave portion 15 is set to a thickness of approximately d2 = 0.46 mm, and the diffusion layer 23 is reliably removed.

As shown in Fig. 3 (c), when the concave portion 15 extending in the long side direction is formed at one side of the strip-shaped multilayer body 22 and in substantially the center of the short side direction, the bottom surface of the concave portion 15 is formed. That is, the protective film 16 is formed in the surface which the resistive metal plate 11 is exposed as shown in FIG.3 (e). The protective film 16 is formed of polyamideimide, which is an inorganic-organic composite material containing a silicone coupling agent or silica. After the protective film 16 is formed, the strip-shaped multilayer plate body 22 is cut to a predetermined length (here 6.3 mm) as shown by the dashed-dotted line 24 in FIG. The resistor 10 is completed.

By performing the above process, the resistance metal plate low resistance chip resistor 10 which has a resistance value of less than 1.0 m (ohm) and high reliability becomes possible.

Next, the manufacturing method of the resistive metal plate low resistance chip resistor 30 is demonstrated with reference to FIG.

For example, when manufacturing the resistive metal plate low resistance chip resistor 30 of 13 mm in length and 6.3 mm in width, the copper-cured metal plate 31 which consists of an alloy plate body containing 90 weight% or more of copper first is used. By the brazing materials 32 and 32 made of a silver binary eutectic alloy, the copper plates 33 and 33 are soldered at a peak temperature of 850 ° C. in a hydrogen atmosphere furnace.

Here, the resistive metal plate 31 uses, for example, an alloy plate body having a thickness of 0.5 mm, the brazing filler material 32 uses, for example, BAg-8 having a thickness of 0.05 mm, and the copper plate 33 has a thickness of 0.2, for example. Oxygen-free copper plates of mm are used, and they can all be about 500 mm long and 200 mm wide.

Subsequently, alkali degreasing is performed with a solution containing sodium hydroxide and sodium silicate as a main component to remove the fat or oil adhering to the metal surface, and the oxide film is removed by dipping in an aqueous solution of dilute sulfuric acid. Thereafter, tin plating films 34 and 34 having a thickness of approximately 5 탆 are formed on the entire surfaces of the copper plates 33 and 33 fixed to both surfaces of the resistive metal plate 31 by electroplating.

Through the above steps, as shown in Fig. 4A, the copper plates 33 and 33 are joined to both surfaces of the resistance metal plate 31 by the brazing filler materials 32 and 32, and these copper plates 33 and 33 are bonded to each other. The aggregated multilayer plate body 40 in which the tin plating films 34 and 34 were formed on each is formed. This collective multilayer plate body 40 is formed in about 500 mm length, about 200 mm width, and about 1.0 mm thickness, for example.

Next, as shown by the dotted line 41 in Fig. 4A, the aggregated multilayer plate body 40 is cut into strips with a predetermined width W3 to form a strip-shaped multilayer plate body 42. Since the cutting width W3 (length W3 of the short side) of the strip-shaped multilayer plate body 42 is the portion that becomes the length of the resistance metal plate low resistance chip resistor 30 to be manufactured, it is set here to 13 mm. The length of the long side is, for example, about 500 mm.

Subsequently, roughly the center of the short side direction from both surfaces of the strip-shaped multilayer plate body 42 is shaved in the long side direction at the width W4, for example, 4 mm in width, as shown in Fig. 4C. In the both-side shaping process of this strip-shaped multilayer board body 42, tin plating films 34 and 34, copper plates 33 and 33, brazing filler materials 32 and 32 from both surfaces in which the tin plating films 34 and 34 were formed, And up to the diffusion layer 44 between the brazing materials 32 and 32 and the resistance metal plate 31 to form the recesses 35 and 35.

Further, the diffusion layer 43 between the brazing filler material 32 and the resistance metal plate 31 has a depth of approximately d3 = 0.3 mm from both surfaces of the tin plating films 34 and 34, as shown in FIG. It cuts out and makes the resistance metal plate 31 in the recessed parts 35 and 35 into thickness of about d4 = 0.4 mm, and removes the diffusion layer 44 reliably.

As shown in Fig. 4 (c), when the concave portions 35 and 35 extending in the long side direction are formed at approximately the center of the short side direction of both sides of the strip-shaped multilayer plate body 42, the concave portions 35 and 35. Protective films 36 and 36 are formed on the bottom surfaces of the substrates, that is, on both surfaces of which the resistance metal plate 31 is exposed, using polyamideimide or the like. After the protective film 36 is formed, the strip-shaped multilayer plate body 42 is cut to a predetermined length (here 6.3 mm) as shown by the two-dot chain line 45 of FIG. The resistor 30 is completed. Through the above processes, the resistance metal plate low resistance chip resistor 30 having a resistance value of less than 1.0 m? And having high reliability can be manufactured.

5 is a graph of the resistance metal plate low resistance chip resistor 10 according to the present invention and the resistance temperature coefficient (TCR) at each temperature of the comparative example, and the resistance value written in the legend of FIG. 5 is 25 ° C at room temperature. The resistance value at.

Here, Sample A is a resistive metal plate low resistance chip resistor formed of BCuP-3 as a brazing filler material with a thickness of d2 = 0.39 mm, and exhibited 0.61 mΩ at room temperature of 25 ° C. BCuP-3 is a brazing material specified in JIS.Z. 3264, containing 6% phosphorus (P), 5% silver (Ag), and 89% copper (Cu).

Sample B was a resistive metal plate low resistance chip resistor formed of a thickness of d2 = 0.41mm using BAg-8 as the brazing filler material, and exhibited 0.56 mΩ at room temperature 25 ° C. BAg-8 is a brazing material specified in JIS.Z.3261, containing 72% silver (Ag) and 28% copper (Cu).

Sample C is a resistance metal sheet low resistance chip resistor formed of a thickness of d2 = 0.39mm using a P-Cu system as a brazing filler material, and exhibited 0.68 mΩ at a room temperature of 25 ° C. P-Cu-based brazing materials mainly contain only phosphorus (P) and copper (Cu).

Samples A and C are d2 = 0.39 mm and sample B is d2 = 0.41 mm, and their thicknesses are approximately the same. Therefore, if the TCR and resistance values of these samples A, B and C are compared as they are, copper-silver as a brazing material It turns out that the resistance value of sample B using BAg-8 which consists of binary alloys is the lowest at room temperature 25 degreeC, and TCR is also generally small.

1 is a perspective view of one embodiment of the present invention.

FIG. 2 is a perspective view of an embodiment different from FIG. 1. FIG.

3 is a diagram illustrating each process of manufacturing the resistive metal plate low resistance chip resistor of FIG. 1.

FIG. 4 is a diagram illustrating each process of manufacturing the resistive metal plate low resistance chip resistor of FIG. 2.

Fig. 5 is a graph of the resistance temperature coefficient at each temperature of the resistance metal sheet low resistance chip resistor according to the present invention, and the resistance value written in the legend is a resistance value at room temperature of 25 ° C.

<Description of the code>

10... Resistor metal sheet low resistance chip resistor 11... Resistance metal plate

12... Lead material 13. Copper plate

14... Tin plated film 15. Recess

16... Protective film 20. Assembly lamellar body

22 ... Strip-shaped multilayer plate body 23... Diffusion layer

30 ... Resistor metal sheet low resistance chip resistor 31... Resistance metal plate

32... Lead material 33. Copper plate

34... Tin plated film 35. Recess

36.. Protective film 40. Assembly lamellar body

42... Strip-shaped multilayer plate 43. Diffusion layer

Claims (5)

On one side or both sides of the resistance metal plate which consists of an alloy containing 90 weight% or more of copper, the copper plate as an electrode is soldered in a hydrogen atmosphere furnace at the peak temperature of 850 degreeC by the brazing material which consists of a copper-silver binary alloy, After removing the oxide film from the surface, an aggregated multilayer plate body is formed by forming a tin plating film over the entire surface of the copper plate, The aggregated laminate is cut into strips with a desired width to form a strip-shaped laminate. The center of the short side direction is cut in the long side direction by the predetermined width from one surface or both surfaces in which the tin plating film of the said strip-shaped multilayer board body was formed, and at least the diffusion layer of a tin plating film, a copper plate, a solder material, and a resistance metal plate and a solder material is removed. The recessed portion is formed on one surface or both sides, and a protective film is formed on the bottom surface of the recessed portion, and then the strip-shaped multilayer board is cut to a desired width to produce a chip-shaped resistor. Method of manufacturing a chip resistor. delete delete The method of manufacturing a resistive metal plate low resistance chip resistor according to claim 1, wherein a protective film is formed on the bottom surface of the concave portion by a material containing a polyamideimide resin. delete

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