JP4134568B2 - Manufacturing method of fuse - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a fuse suitably used for preventing damage or the like of electronic equipment due to abnormal heating or overcurrent.
[0002]
[Prior art]
Conventional thermal fuses are equipped with terminals at both ends of the fuse element that blows when a certain temperature is reached, and by connecting the terminals to a circuit such as a power supply, the components (batteries, etc.) that make up the power supply abnormally generate heat. When this occurs, the fuse element operates at a high temperature due to the abnormal heat generation, shuts off the power circuit and the like, and does not damage internal components.
[0003]
As a typical structure of a conventional thermal fuse, as shown in FIGS. 17 and 18, a fuse element 25 is joined between a pair of lead terminals 2 and 3, and the fuse element 25 is accommodated in a case. The inside of the case is sealed airtight and the case and the lead terminals 2 and 3 are fixed.
[0004]
As shown in FIG. 17, the lead terminals 2 and 3 have intermediate layers 17 and 26 in the vicinity of the end portions including the end portions 17b and 26b between the lead terminals 2 and 3, and fuses are formed on the surfaces of the intermediate layers 17 and 26. Element 25 was connected. The fuse elements were connected by electric welding, laser welding, or soldering with a soldering iron.
[0005]
[Problems to be solved by the invention]
However, in the conventional configuration, as shown in FIG. 17, it is difficult to set welding conditions for partially heating the low melting point fuse element 25 and melting only the end portions 25a and 25b to connect to the intermediate layers 17 and 26. If the heating amount is too large, the fuse element 25 is melted too much and the shape becomes thicker or thinner. If the heating amount is too small, the fuse element 25 is not connected. Therefore, the resistance value varies and the yield is poor. It was.
[0006]
Further, since the end portions 25a and 25b of the fuse element are partially spheroidized by the surface tension of the fuse element and necessarily become thicker than the thickness of the fuse element 25, there is a limit to making the thickness of the thermal fuse thinner.
[0007]
In particular, in the case of a small and thin fuse having a distance between lead terminals of 3 mm or less, the above-mentioned problem is particularly noticeable.
[0008]
The present invention solves the above-mentioned conventional problems, and thins the connecting portion of the fuse element, ensures the insulation distance after the fuse operates even if the distance between the terminals is reduced, and reduces the size and thickness. An object of the present invention is to provide a method for manufacturing a fuse that can be realized.
[0009]
[Means for Solving the Problems]
  The present inventionA fuse element is arranged on the lead terminal, a heat conducting member is contacted avoiding both end portions of the fuse element, and the fuse element and the lead terminal are welded in a state where a transparent member is provided at both ends of the heat conducting member. The transparent member is provided to face both end portions of the fuse element, and the transparent member has a thermal conductivity smaller than that of the heat conductive member..
[0010]
DETAILED DESCRIPTION OF THE INVENTION
  The invention described in claim 1A fuse element is arranged on the lead terminal, a heat conducting member is contacted avoiding both end portions of the fuse element, and the fuse element and the lead terminal are welded in a state where a transparent member is provided at both ends of the heat conducting member. The transparent member is provided to face both end portions of the fuse element, and the transparent member has a lower thermal conductivity than the heat conductive member.By using the fuse manufacturing method characterized in that, heat generated when welding the fuse element and the lead terminal is absorbed by the heat conducting member, so that the heat during welding is transmitted to the center of the fuse element. Therefore, it is possible to prevent the fuse element from being formed thinner or thinner than the other parts at the center or in the vicinity of the fuse element, reduce variation in resistance, improve mechanical strength, and thin fuse elements. Can be used to achieve downsizing.Furthermore, the fuse element does not protrude at the joint between the fuse element and the lead terminal, and the fuse can be made thinner.
[0013]
  Claim2In the described invention, the transparent member is transparent to at least infrared rays or near infrared rays, and the infrared rays or near infrared rays are irradiated to at least one of the fuse element or the lead terminal via the transparent member, and the fuse element and the lead terminal are irradiated. Welding1With the described fuse manufacturing method, at least one of the fuse element and the lead terminal can be heated through the transparent member, so that it can be easily manufactured without projecting the joint portion of the fuse element, and the thickness can be reduced.
[0014]
  Claim3The invention described is characterized in that near infrared rays or infrared rays are used as laser light.2By using the described fuse manufacturing method, pinpoint welding is possible, and reliable welding can be performed.
[0015]
  Claim4The described inventionPlace the fuse element on the lead terminal,Apply liquid to the surface of the heat conduction member facing the fuse element,Welding the fuse element and the lead terminal in a state where the heat conducting member is in contact with avoiding both end portions of the fuse element;The liquid is present between the heat conducting member and the fuse element.RuhiBy making a manufacturing method ofThe heat conduction member absorbs the heat generated when welding the fuse element and the lead terminal, so that the heat during welding can be prevented from being transmitted to the center of the fuse element. In addition, it is possible to suppress the formation of a thinner or narrower part than other parts, reduce the variation in resistance value, improve the mechanical strength, and use a thin fuse element.By boiling or vaporizing the liquid, heat during welding can be reliably absorbed, and in addition to cooling due to boiling or vaporization, heat conduction between the heat conducting member and the fuse element is promoted, and the heat conducting member is connected to the fuse element. The contact surface can also be cleaned.
[0016]
  Claim5The described inventionA fuse element is disposed on the lead terminal, and the fuse element and the lead terminal are welded in a state in which a heat conducting member is brought into contact while avoiding both end portions of the fuse element,The heat conducting member includes a first part having good heat conduction and a second part having poor heat conduction.RuhiBy making a manufacturing method ofThe heat conduction member absorbs the heat generated when welding the fuse element and the lead terminal, so that the heat during welding can be prevented from being transmitted to the center of the fuse element. In addition, it is possible to suppress the formation of a thinner or narrower part than other parts, reduce the variation in resistance value, improve the mechanical strength, and use a thin fuse element.The wettability between the lead terminal and the fuse can be improved, and the protrusion height of the fuse element can be lowered.
[0017]
  Claim6In the described invention, the thermal conductivity of the first portion is 20 W · m.^-1K^-1The thermal conductivity of the second part is 20 W · m^-1K^-1Claims smaller than5By using the fuse manufacturing method described above, the wettability between the lead terminal and the fuse can be further improved, and the protruding height of the fuse element can be reduced.
[0018]
  Claim7The invention described in claim 1 is characterized in that second portions are provided at both ends of the first portion so as to sandwich the first portion.5By adopting the fuse manufacturing method described above, both ends of the fuse element are usually joined to the lead terminals, so that the productivity can be greatly improved.
[0019]
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings showing the manufacturing process and the configuration.
[0020]
First, as shown in FIG. 1, a substrate 1 is prepared. The substrate 1 is made of an insulator and may be plastic, glass, ceramic, or a metal that has been subjected to an insulating coating process. In the present embodiment, an alumina ceramic plate is used as the substrate 1. Further, in the present embodiment, the rectangular plate-like substrate 1 is used, but a disk-like, elliptical, triangular, or pentagonal or more polygonal plate-like body may be used.
[0021]
As shown in FIG. 2, lead terminals 2 and 3 are bonded on the substrate 1. The lead terminals 2 and 3 are electrically conductive materials, preferably metals, and specifically, at least one simple material selected from iron, nickel, copper, aluminum, gold, silver, and tin, or those metal materials Or at least one simple substance selected from the above-mentioned material group or a metal material in which an element other than the above-mentioned material group is contained can be used.
[0022]
As a material for bonding the lead terminals 2 and 3 on the substrate 1, plastic resin, glass, and a plastic film or a metal film containing glass can be used. When a metal film is used as an adhesive, the metal film is formed on the substrate 1 by printing or the like, the lead terminals 2 and 3 are placed on the metal film, and the substrate 1 is bonded to the substrate 1 using ultrasonic welding or the like. The lead terminals 2 and 3 are joined. When the material of the substrate 1 is a thermoplastic, the surface of the substrate 1 can be directly melted and bonded by rapid heating and rapid cooling after the lead terminals 2 and 3 are arranged on the substrate 1. In the present embodiment, a nickel plate tin-plated on the surface is used as the lead terminals 2 and 3, and an epoxy resin containing an alumina and silica filler is used as an adhesive.
[0023]
Next, as shown in FIG. 3, welding flux is applied to the end portions 4 and 5 of the lead terminals 2 and 3. The welding flux is an auxiliary agent for electrically connecting the lead terminals 2 and 3 and the fuse element 6 of FIG. 4. After confirming the compatibility of the material of the lead terminals 2 and 3 and the material of the fuse element 6. Can be selected. In the present embodiment, a rosin liquid flux is used as the welding flux.
[0024]
Next, as shown in FIG. 4, the fuse element 6 is mounted on the end portions 4 and 5 of the lead terminals. The fuse element 6 is a material that generates a fuse function. As a current fuse, gold, copper, silver, nickel, aluminum, tin, and a composite material or an alloy thereof can be used. As a temperature fuse, tin, bismuth, or indium is used. In addition, low melting point metals such as lead and cadmium can be used alone or as an alloy in which a plurality of them are mixed. In this embodiment, a fuse element of a thermal fuse that is a ternary alloy of tin, bismuth, and lead having a melting point of 96 ° C. is used as the fuse element 6.
[0025]
In the present embodiment, the outer shape of the fuse element 6 is a substantially rectangular parallelepiped, but a disk-shaped, cylindrical, or linear shape may be used.
[0026]
Next, as shown in FIG. 5, both end portions 6 a and 6 b of the fuse element 6 are melted and joined to the lead terminals 2 and 3. The connection method at this time will be described in detail with reference to FIGS. 6 and 10 which are sectional views thereof.
[0027]
As shown in FIG. 6, the fuse element 6 is placed on the lead terminals 2 and 3 coated with welding flux. Next, the cooling plate (heat conducting member) 11 is brought into contact with the portion of the fuse element 6 excluding the end portions 6a and 6b. At this time, the cooling plate 11 has the effect of mechanically fixing the fuse element 6 to the lead terminals 2 and 3 and the effect of cooling the fuse element 6.
[0028]
The material of the cooling plate 11 has a thermal conductivity of 20 W · m in order to obtain a cooling effect.^-1K^-1The above materials can be used. Specifically, aluminum, magnesium, copper, titanium, gold, silver nickel, iron, carbon (graphite), silicon single metal or alloys thereof, oxides, nitrides and composites thereof can be used. Can be used. Thermal conductivity 20W ・ m^-1K^-1In the following materials, for example, as shown in FIG. 15, the thermal conductivity is 1.1 W · m.^-1K^-1In the case of cooling by the glass 11b, which is a material of the above, there is an effect that the fuse element 6 is mechanically temporarily fixed to the lead terminals 2 and 3. However, when the fuse element 6 is welded, The element is spheroidized in the vicinity of the welded portions 10a and 10b, and the fuse element is thinned or disconnected at the positions of the thinned portions 10c and 10d between the fuse element central portion 10 and the welded portions 10a and 10b, and the welding heat is small. In some cases, welding is not performed, the welding condition width is narrow, and the yield is small when mass production is performed.
[0029]
Further, as shown in FIG. 16, the thermal conductivity is 15 W · m as in the stainless alloy 11c.^-1K^-1The material of FIG. 5 has the effect of mechanically fixing the fuse element 6 to the lead terminals 2 and 3, but after the fuse element 6 is welded, the heat of fusion of the welded portions 10 a and 10 b is transmitted to the center portion 10 of the fuse element 6. As a result, the cross-sectional shape of the fuse element 6 becomes thicker or thinner, the welding condition width is narrow, and the resistance value variation becomes large when mass-produced, resulting in poor yield.
[0030]
Further, as described above, when the central portion 10 or the narrow portions 10c and 10d of the fuse element 6 are thinned, when the impact is applied from the outside during the manufacturing, the thinned portion may be lost. If the electrical continuity cannot be obtained or the cross-sectional area of the fuse element 6 is not increased, the center portion 10 or the narrow portions 10c and 10d are thinned as described above, and thus disconnection or the like occurs. It is difficult to use a fuse element 6 having a small cross-sectional area, that is, a thin or thin fuse.
[0031]
In the present embodiment, FIG. 6 shows a case where the cooling effect is enhanced by using an aluminum single metal or an aluminum alloy containing 90% or more of aluminum as the cooling plate 11.
[0032]
Next, the end portions 6 a and 6 b of the fuse element 6 are heated and welded to the end portions of the lead terminals 2 and 3. As the heating method of the end portions 6a and 6b of the fuse element 6, the lead terminals 2 and 3 are heated by a heater, or electricity is passed through the lead terminal 2 alone to cause the lead terminal 2 itself to generate heat, or the lead terminal. It is possible to heat the lead terminal 3 itself by causing a current to flow by itself, or to directly heat the lead terminals 2 and 3 and the end portions 6a and 6b of the fuse element 6 with infrared rays. . In the present embodiment, since the end portions 6a and 6b of the fuse element 6 can be welded by heating on one side of the lead terminals 2 and 3, the near-infrared laser beam 8 from the directions of arrows A and B in FIG. 9 was used to heat.
[0033]
Next, the cooling plate 11 is removed from the welded fuse element 12. Since the welded fuse element 12 is melted only in the welded portions 12a and 12b, and the portion where the cooling plate 11 is in contact is hardly melted, the cross-sectional shape of the fuse element 6 is maintained. As a result, the welding condition width was wide, and when manufactured in large quantities, the resistance value variation was small and the yield was very good.
[0034]
In order to further enhance the cooling effect of the cooling plate 11, it is preferable to arrange a liquid having a boiling point near the melting point of the fuse element 6 between the cooling plate 11 and the fuse element 6. This is because the cooling effect is enhanced by cooling using the heat of vaporization of the liquid, and the heat conduction efficiency to the cooling plate 11 is improved by filling a slight gap between the cooling plate 11 and the fuse element 6 with the liquid. It is performed with the purpose of increasing and further the purpose of preventing foreign matter from adhering to the cooling plate 11 by washing away dirt due to repeated use of the cooling plate 11 with the liquid. Specifically, pure water, methyl alcohol, ethyl alcohol, propanol, butanol and the like can be used, and the solvent used for the liquid flux is preferable.
[0035]
7, 8, and 9 show graphs of welding conditions, resistance values, and disconnection failure rates when materials having various thermal conductivities are used as the cooling plate 11. The material used for the cooling plate 11 is copper (403 W · m^-1K^-1), Aluminum (236 W · m^-1K^-1), Brass (106 W · m^-1K^-1), Copper-nickel alloy (23 W · m^-1K^-1), Stainless alloy (15 W · m^-1K^-1), Glass (1.1 W · m^-1K^-1), Plastic (0.2W · m^-1K^-1) Was used. The terminals 2 and 3 were made of nickel as the base material and tin-plated on the surface, and the fuse element was made of a 1.2 × 0.2 × 3 mm low melting point soluble alloy. The distance between terminals was 1 mm, and the width of the cooling plate was 2 mm.
[0036]
The welding shown in FIG. 7 was performed by laser welding, the laser irradiation time and the atmospheric temperature were fixed, and the welding range was measured with the current value of the laser transmitter corresponding to the laser output. The resistance value data shown in FIG. 8 and the disconnection or unwelded data shown in FIG. 9 can measure the resistance value as a result of welding in the weldable region of the laser welding current shown in FIG. The resistance value data was measured for the thing, and the number of disconnection or unwelded was counted as the number of disconnection or unweld defects. The number of samples was 20 for each n = 20.
[0037]
7, 8, and 9, the thermal conductivity is 20 W · m^-1K^-1It can be seen that the larger the size is, the wider the weldable region becomes, and the cause of failure due to fluctuations in welding conditions is reduced.
[0038]
Next, an embodiment using another welding method will be described with reference to FIG. 6 differs from the welding method of FIG. 6 in that there is nothing on the side surface of the cooling plate 11 in FIG. 6, but in FIG. 10 transparent molding plates 13 and 14 are arranged on the side surface of the cooling plate 11. , 14 are arranged on the end portions 6a, 6b, which are portions to be welded, of the fuse element 6.
[0039]
With the addition of the transparent molded plates 13 and 14 which are side members of the cooling plate 11, the near-infrared laser beams 8 and 9 are transmitted through the transparent molded plates 13 and 14 from the directions of the arrows A and B as shown in FIG. Thus, the end portions 6a and 6b of the fuse element 6 are heated.
[0040]
With this configuration, in FIG. 6, square projections are generated in the welded portions 12 a and 12 b of the fuse element 12 after welding. However, in FIG. 10, the welded portions 7 a and 7 b of the fuse element 7 after welding are formed as transparent molded plates. According to the shape of 13,14, there is no square-shaped projection part and it is shape | molded thinly. This made it possible to design the product thinly.
[0041]
The material of the transparent molded plates 13 and 14 differs depending on the heating method used for welding, depending on the method of heating the lead terminals 2 and 3 with a heater, or the resistance of the lead terminals 2 and 3 by supplying electricity to the lead terminals 2 and 3. When using the method of heating by self-heating, the thermal conductivity is 20 W · m^-1K^-1A smaller material may be used, and in the case of using a method in which the lead terminals 2 and 3 and the end portions 6a and 6b of the fuse element 6 are directly heated by infrared rays, the thermal conductivity is 20 W · m.^-1K^-1It is a smaller material and needs to transmit infrared light.
[0042]
Here, thermal conductivity 20 W · m^-1K^-1Since the cooling effect similar to that of the cooling plate 11 begins to be exhibited, the end portions 6a and 6b, which are to be melted, are likely to be insufficiently melted, and the resistance value variation increases when produced in large quantities, resulting in a high yield. bad. Thermal conductivity is 20W ・ m^-1K^-1When a smaller material is used, the effect of keeping the end portions 6a and 6b, which are to be melted, to be melted works, and the molten state is sufficiently melted so that the welded state is stable. When mass production is performed, the resistance value variation is small and the yield is good. Specific examples of the material for the transparent molded plates 13 and 14 include a glass material transparent to infrared rays, a crystal material transparent to infrared rays, and a plastic material transparent to infrared rays. In the present embodiment, since near infrared laser beams 8 and 9 are used as the welding method, a glass plate that transmits near infrared rays is used. Thermal conductivity is 1.1 W · m^-1K^-1It is.
[0043]
In addition, by setting the shape of the transparent molding plates 13 and 14 freely, such as unevenness or an inclined plane, the shape of the welds 7a and 7b is not limited to a plane, and can be freely molded.
[0044]
In FIG. 10, the transparent molded plates 13 and 14 are disposed so as to cover the entire end portions 6 a and 6 b that are to be welded to the fuse element 6, but the end portions 6 a and 6 b are exposed as shown in FIG. 11. That is, the length of the transparent molded plates 13 and 14 may be shortened, and the molded plates 13a and 14a may be provided as opaque materials. Specifically, thermal conductivity 20 W · m on the side surface of the cooling plate 11.^-1K^-1Only by providing a thin plate or a thin film made of the following materials, it is possible to prevent the formation of angular projections such as the welded portions 12a and 12b in FIG. This is because, in the case of the embodiment shown in FIG. 6, the melted fuse element 7 is cooled on the side surface of the cooling plate 11 and solidified into a square-shaped protrusion, whereas the embodiment shown in FIG. 11. In this case, the thermal conductivity is 20 W · m on the side surface of the cooling plate 11.^-1K^-1When a smaller material is thinly arranged, the melted fuse element 7 is kept warm on the side surface of the cooling plate 11 and is therefore connected to the terminals 2 and 3 with better wettability, so that the fuse element 7 has a higher resistance than the embodiment shown in FIG. The protrusion becomes round and lower.
[0045]
In the embodiment shown in FIGS. 6, 10, and 11, the cooling plate 11 is used as a heat conducting member to be brought into contact with the fuse elements 7 and 12. However, the cooling plate 11 has a block shape, has good heat conduction, or has heat conduction. A plate or sheet having a high thermal conductivity may be pasted on a block-like body or a plate-like body having a poor heat resistance, or a thin film having a high thermal conductivity may be formed.
[0046]
In the embodiment shown in FIGS. 6, 10, and 11, the contact surface of the cooling plate 11 that is a heat conducting member with the fuse element 6 is flat, but it may be roughened or uneven. It is also good. If the contact surface of the cooling plate 11 with the fuse element 6 is made uneven, the fuse elements 7 and 12 after welding are likely to be uneven, but the heat at the time of welding is cooled by the cooling plate 11. 11, the fuse elements 7 and 12 are softened and the unevenness of the cooling plate 11 is not transferred.
[0047]
Further, in the present embodiment, the cooling plate 11 that is a heat conducting member is cooled by natural cooling when it is not in contact with the fuse element 6, but further, cooling means such as a Peltier element or a cooling fan is provided on the cooling plate 11. It is possible to cool the cooling plate 11 with a Peltier element or a cooling fan only when it is not in contact with the fuse element 6. Also good. In particular, when a cooling fan is used as the cooling means, the cooling plate 11 and the cooling fan are arranged apart from each other, and the cooling plate 11 is always used by the cooling fan when the cooling plate 11 is not in contact with or in contact with the fuse element 6. You may make it cool.
[0048]
Thus, by using the cooling plate 11 which is a heat conducting member, the fuse element 6 and the lead terminals 2 and 3 are welded, so that a thin portion due to heat at the time of welding is formed at the center of the fuse element 6. Therefore, it is possible to use a fuse element 6 having a small thickness or a thin thickness, so that a fuse having any characteristics can be manufactured. This is particularly effective for a small fuse having a space between the lead terminals 2 and 3, that is, W1 shown in FIG. That is, when W1 is larger than 3.0 mm, the heat at the time of welding hardly reaches the center of the fuse element 6, so that the conventional problem is hardly generated. In order to obtain sufficient fusing characteristics, W1 is preferably set to 0.1 mm or more.
[0049]
Moreover, it becomes effective structurally.
[0050]
That is, as in the prior art, heat is also transmitted to the central portion 10 of the fuse element 6 during welding, and a thin portion is prevented from being formed in the central portion 10 of the fuse element 7. That is, as a shape of the fuse element 7, a flat portion is formed after welding in the same manner as before the manufacture. By using the fuse element 7 provided with a flat portion in this way, the appearance of the fuse element 7 is less likely to vary.
[0051]
Next, as shown in FIG. 12, a solid flux 15 is disposed on the fuse element 7 and its welds 7a and 7b. The solid flux 15 may be powder or individual pieces. In the present embodiment, the melted solid flux 15 is applied to the surfaces of the fuse element 7 and the welded portions 7a and 7b. As the solid flux 15, a rosin-based material was used.
[0052]
Next, as shown in FIGS. 13 and 14, the substrate 1 and the case 16 are fixed. As a material for bonding the substrate 1 and the case 16, plastic resin, glass, and plastic resin can be used. When the material of the substrate 1 and the material of the case 16 are thermoplastics, frictional heat generated by ultrasonic welding is used. The substrate 1 and the case 16 can also be welded directly. In this embodiment in FIGS. 13 and 14, an alumina ceramic case is used as the material of the case 16, and an epoxy resin containing an alumina and silica filler is used as the adhesive. At this time, the gap between the substrate 1 and the case 16 is almost filled with the adhesive, and the space provided between the substrate 1 and the case 16 is blocked from the outside.
[0053]
In this embodiment, the case length L1 shown in FIG. 10 is 5 mm to 15 mm, the case width L2 is 2 mm to 8 mm, the case thickness L3 is 1 mm to 2 mm, and the thermal fuse total length L4 is 10 mm to 35 mm. No. 7 used an alloy having a melting point of 96 ° C., a rosin-based solid flux was used as the solid flux 15, and it was possible to reduce the thickness as a temperature fuse with a rated voltage of 50 Vdc and a rated current of 4 A. Further, as a result of the fusing test, fusing was performed at 98 ± 2 ° C.
[0054]
In the present embodiment, the solid flux 15 is attached to at least a part of the fuse element (soluble alloy) 7, but it may not be provided depending on the specifications, use environment, and the like.
[0055]
Further, in the present embodiment, the substrate 1 and the case 16 have different shapes, but the case may be a round tube, a square tube, or a shape in which two substrates are stacked, and the substrate and the case may be It is possible to use any shape that is formed by hardening plastic without using it.
[0056]
Furthermore, in this embodiment, the fuse element (soluble alloy) 7 is a plate having a square cross section, but it may be a circular cross section or an elliptical cross section.
[0057]
In the present embodiment, the lead terminals 2 and 3 are plate members having a square cross section. However, the cross section may be a circular shape or an elliptical cross section. It may be.
[0058]
In this embodiment, a pair of lead terminals 2 and 3 and a single fuse element (soluble alloy) 7 are provided, but a plurality of lead terminals and fuse elements may be provided.
[0059]
【The invention's effect】
  The present inventionA fuse element is arranged on the lead terminal, a heat conducting member is contacted avoiding both end portions of the fuse element, and the fuse element and the lead terminal are welded in a state where a transparent member is provided at both ends of the heat conducting member. The transparent member is provided to face both end portions of the fuse element, and the transparent member has a thermal conductivity smaller than that of the heat conductive member.Therefore, heat generated when welding the fuse element and the lead terminal is absorbed by the heat conduction member, so that it is possible to suppress the heat at the time of welding from being transmitted to the center of the fuse element. It is possible to suppress the formation of a thinner or thinner part in the vicinity thereof, to reduce variations in resistance value, to improve the mechanical strength, and to use a thin fuse element, thereby realizing a reduction in size. .
[Brief description of the drawings]
FIG. 1 is a perspective view showing a manufacturing process of a fuse in an embodiment of the present invention.
FIG. 2 is a perspective view showing a manufacturing process of a fuse in an embodiment of the present invention.
FIG. 3 is a perspective view showing a manufacturing process of a fuse in an embodiment of the present invention.
FIG. 4 is a perspective view showing a manufacturing process of a fuse in an embodiment of the present invention.
FIG. 5 is a perspective view showing a manufacturing process of a fuse in an embodiment of the present invention.
FIG. 6 is a cross-sectional view showing a manufacturing process of a fuse in one embodiment of the present invention.
FIG. 7 is a graph showing welding conditions for a fuse in an embodiment of the present invention.
FIG. 8 is a graph showing resistance value data of a fuse in one embodiment of the present invention.
FIG. 9 is a graph showing a defect rate of a fuse in an embodiment of the present invention.
FIG. 10 is a cross-sectional view showing a manufacturing process of a fuse in an embodiment of the present invention.
FIG. 11 is a cross-sectional view showing a manufacturing process of a fuse in an embodiment of the present invention.
12 is a perspective view showing a manufacturing process of a fuse in an embodiment of the present invention. FIG.
13 is a perspective view showing a manufacturing process of a fuse in an embodiment of the present invention. FIG.
FIG. 14 is a perspective view showing a fuse according to an embodiment of the present invention.
FIG. 15 is a diagram showing a comparative example of fuses in an embodiment of the present invention.
FIG. 16 is a diagram showing a comparative example of fuses in an embodiment of the present invention.
FIG. 17 is a cross-sectional view showing a conventional fuse manufacturing process;
FIG. 18 is an exploded perspective view showing a conventional fuse.
[Explanation of symbols]
1 Substrate
2,3 Lead terminal
4,5 End of lead terminal
6 Fuse element (soluble alloy)
6a, 6b End of fuse element
7, 10, 12, 22, 25 Fuse element after welding (fusible alloy)
7a, 7b, 10a, 10b, 12a, 12b, 22a, 22b, 25a, 25b Welded portion of fuse element (fusible alloy) after welding
8,9 Laser light
10 Central part
11 Cooling plate
13,14 Transparent molded plate
13a, 14a Molded plate
15 Solid flux
16 cases

Claims (7)

A fuse element is arranged on the lead terminal, a heat conducting member is contacted avoiding both end portions of the fuse element, and the fuse element and the lead terminal are welded in a state where a transparent member is provided at both ends of the heat conducting member. and, the transparent member is provided so as to face the both end portions of the fuse element, wherein the transparent member includes characteristics and be Ruhi Yuzu manufacturing method of the thermal conductivity is smaller than the heat conducting member. The transparent member is transparent to at least infrared rays or near infrared rays, and the infrared rays or near infrared rays are irradiated to at least one of the fuse element or the lead terminal via the transparent member, and the fuse element and the lead terminal are welded. The method of manufacturing a fuse according to claim 1, wherein The method for manufacturing a fuse according to claim 2, wherein near infrared rays or infrared rays are used as laser light. A fuse element is disposed on the lead terminal , a liquid is applied to a surface of the heat conduction member facing the fuse element, and the heat conduction member is in contact with the heat conduction member while avoiding both end portions of the fuse element. the lead terminals by welding, features and be Ruhi Yuzu method of manufacturing said liquid in the presence of between the heat conducting member and the fuse element. A fuse element is disposed on the lead terminal, the fuse element and the lead terminal are welded in a state where the heat conducting member is in contact with avoiding both end portions of the fuse element, and the heat conducting member has good heat conduction. features and to Ruhi Yuzu method of manufacturing further comprising: a first portion and a bad second partial thermal conduction. The thermal conductivity of the first portion is at 20W · m ^-1 K ^-1 or higher, according to claim 5, wherein the thermal conductivity of the second portion is smaller than a less 20W · m ^-1 K ^-1 Method of manufacturing fuses. 6. The method of manufacturing a fuse according to claim 5 , wherein second portions are provided at both ends of the first portion so as to sandwich the first portion.

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