JP5433455B2 - Manufacturing method of thermal fuse with resistance - Google Patents

Description

  The present invention relates to a method of manufacturing a thermal fuse with resistance, which is a protective element of an electric / electronic device.

  As a conventional thermal fuse with a resistor, there is one using a ceramic substrate in which a membrane resistor and a lead conductor membrane electrode and a fuse element membrane electrode are arranged in an electrically connected state on both sides of the membrane resistor. The lead conductor film electrode is fixed in a state where the lead conductor is electrically connected, and a pair of lead conductors are respectively arranged on both sides of the fuse element film electrode. The pair of lead conductors and the fuse element film electrodes are provided in a state where the fuse elements are straddled, and the pair of lead conductors and the fuse element film electrodes are electrically connected. The entire ceramic substrate including this fuse element is applied and sealed with resin (see Patent Document 1).

JP 2007-87783 A

In the manufacturing process of the conventional thermal fuse with resistance, first, a pair of lead conductors are disposed on both sides of the fuse element film electrode of the ceramic substrate. Next, by disposing the fuse element across the pair of lead conductors, the fuse element is connected between the pair of lead conductors and the fuse element film electrode. Thereafter, the ceramic substrate is conveyed to the next step.
As the speed is increased during the conveyance, the lead conductor vibrates more strongly. This vibration is concentrated on the location where the lead conductor and the fuse element are connected, the location where the fuse element membrane electrode and the fuse element are connected, or the fuse element itself. May occur.
In addition, in the manufacturing process of this resistance thermal fuse, there is a process of coating and sealing the entire ceramic substrate with a resin. In this step, the ceramic substrate is also lifted by lifting the pair of lead conductors. In this lifted state, the entire ceramic substrate is coated with resin and sealed. However, the lead conductor vibrates more strongly as the speed is increased in the lifting. Therefore, even in this case, the vibration is concentratedly applied to the location where the lead conductor and the fuse element are connected, the location where the fuse element membrane electrode and the fuse element are connected, or the fuse element itself, and the location where the connection is made. There is a risk of cracking in the element itself.
When this crack occurs, the resistance value of the fuse element changes and the operating temperature of the temperature-equipped thermal fuse differs from the set temperature.

  The invention of the present application prevents cracks from being generated at the location where the lead conductor and the fuse element are connected, the location where the fuse element membrane electrode and the fuse element are connected, or the fuse element itself during transport to the next process or sealing process. It is an object of the present invention to provide a method for manufacturing a thermal fuse with resistance that can be used.

According to the first aspect of the present invention, the membrane resistance (1) and the membrane electrode for lead conductor (2) electrically connected to the membrane resistance (1) are disposed on one side, and the membrane resistance (1 The fuse element film electrode (3) to be electrically connected to the insulating substrate (4) disposed from the one surface to the other surface and the lead conductor film electrode (2). A lead conductor (5), a pair of lead conductors (6) disposed on both sides of the fuse element film electrode (3) existing on the other one surface, and a fuse element film existing on the other one surface A fuse element (7) disposed across the electrode (3) and the pair of lead conductors (6) and electrically connecting the fuse element film electrode (3) and the pair of lead conductors (6). Thermal fuse with resistance A manufacturing method,
One side of the insulating substrate (4) is fixed on the supporting substrate (8), and the pair of lead conductors (6) are fixed on the supporting substrate (8) in parallel with the insulating substrate (4). And a process of
The fuse element (3) straddling the fuse element film electrode (3) and the pair of lead conductors (6) present on the other surface of the insulating substrate (4) fixed on the support substrate (8). 7) disposing and electrically connecting the fuse element film electrode (3) and the pair of lead conductors (6);
Sealing the insulating substrate (4) on the support substrate (8) and the pair of lead conductors (6) on the support substrate (8) with an insulating sealing material (9). It is characterized by.

The invention according to claim 2 is provided with a pair of membrane electrodes (13) on the support substrate (8),
The lead conductor (6) electrically connected to the fuse element film electrode (3) is fixed to each film electrode (13) by soldering.

  The invention described in claim 3 is characterized in that the lead conductor (6) electrically connected to the fuse element film electrode (3) is fixed on the support substrate (8) with an adhesive.

  According to the first aspect of the present invention, when the lead conductor vibrates in the transporting or sealing process to the next process by fixing the lead conductor connected to the fuse element on the support substrate, the lead The vibration of the conductor can be suppressed at the fixed portion between the lead conductor and the support substrate. For this reason, it is possible to prevent a load from concentrating on the location where the lead conductor and the fuse element are connected, the location where the fuse element membrane electrode and the fuse element are connected, or the fuse element itself due to vibration from the lead conductor. it can.

  According to the second aspect of the present invention, since the lead conductor is fixed to the membrane electrode of the support substrate by soldering, it is supported as in the case of welding the lead conductor to the membrane electrode of the support substrate by spot welding or the like. There is no risk of the substrate being deformed.

  According to the third aspect of the present invention, since the lead conductor is fixed to the support substrate with an adhesive, thermal stress is not applied to the support substrate as in the case of fixing by soldering or welding.

(A) is a partially cutaway plan view showing an example of a temperature fuse with resistance manufactured by the method of manufacturing a temperature fuse with resistance of the present invention, and (b) is a temperature with resistance shown in (a). It is side surface sectional drawing of a fuse. (A) is a top view of the insulated substrate of the thermal fuse with a resistance shown by FIG. 1, (b) is a back side top view of the insulated substrate of (a). It is a top view of the support substrate of the thermal fuse with a resistance shown by FIG. (A) It is a manufacturing method of the thermal fuse with a resistance which is 1st Embodiment of this invention, Comprising: It is a top view of the thermal fuse with a resistance before providing a fuse element, (b) was shown by (a). It is the figure which showed the temperature fuse with a resistance from a pair of lead conductor side, (c) is sectional drawing which showed typically the temperature fuse with a resistance shown by (a). (A) is the manufacturing method of the resistance temperature fuse which is 1st Embodiment of this invention, Comprising: It is a top view of the resistance temperature fuse after providing a fuse element, (b) is shown by (a). FIG. 3 is a view showing a thermal fuse with resistance from a pair of lead conductors. (A) is the manufacturing method of the thermal fuse with a resistance which is 1st Embodiment of this invention, Comprising: It is a top view of the thermal fuse with a resistance after flux-applying to the outer surface of the fuse element of FIG. 5, (b) It is the figure which showed the thermal fuse with a resistance shown by (a) from a pair of lead conductor side. FIG. 7A is a plan view of a thermal fuse with resistance according to the first embodiment of the present invention, which is a method for manufacturing a thermal fuse with resistance, after an insulating sealing material is provided on the thermal fuse with resistance of FIG. (B) is a back side plan view of the thermal fuse with resistance shown in (a), and (c) is a diagram showing the thermal fuse with resistance shown in (a) from a pair of lead conductors. (D) is a side view of the thermal fuse with resistance shown in (a), and (e) is a partial sectional view of the thermal fuse with resistance shown in (d). It is a top view which shows another example in the manufacturing method of the thermal fuse with a resistance of this invention.

  A preferred embodiment of a method for manufacturing a thermal fuse with resistance according to the present invention will be described below with reference to the drawings.

As shown in FIGS. 1A and 1B and FIGS. 2A and 2B, the thermal resistor with resistance manufactured by the method for manufacturing a thermal fuse with resistance according to the first embodiment of the present invention has a film resistance. 1 and a lead conductor membrane electrode electrically connected to one side of the membrane resistor 1 are disposed on one side (rear surface), and a fuse element membrane electrode 3 electrically connected to the other side of the membrane resistor 1 Is provided with an insulating substrate 4 disposed on the other side (front surface) from the back surface. A lead conductor 5 is electrically connected to the lead conductor membrane electrode 2 of the insulating substrate 4 via the membrane electrode 10, and a pair of lead conductors 6 are provided on both sides of the fuse element membrane electrode 3 existing on the surface of the insulating substrate 4. Are arranged respectively. The back surface of the insulating substrate 4 is fixed on the support substrate 8, juxtaposed with the insulating substrate 4, and electrically connected to the lead conductor 5 electrically connected to the lead conductor film electrode 2 and to the fuse element film electrode 3. A pair of lead conductors 6 are fixed on one side (surface) of the support substrate 8. A fuse element 7 is disposed across the fuse element film electrode 3 and the pair of lead conductors 6 existing on the surface of the insulating substrate 4 to electrically connect the fuse element film electrode 3 and the pair of lead conductors 6. doing. A flux 11 is applied to the fuse element 7. Further, on the support substrate 8, the insulating substrate 4, the lead conductors 5 and 6, the fuse element 7 and the flux 11 applied to the fuse element 7 are covered and sealed with an insulating sealing material 9.

  1 (a) and 1 (b), the operation mechanism of the thermal fuse with resistance is such that power is supplied to the electronic / electrical equipment through the lead conductor 6 and the fuse element 7, and an abnormality occurs in the electronic / electrical equipment. In this case, a current is passed through the membrane resistor 1 through the lead conductor 5 to cause the membrane resistor 1 to generate heat and the generated heat is blown to cut off the power supply. This fuse with a resistor can be used in various fields. For example, it is incorporated in a battery pack of a lithium ion secondary battery together with an IC control circuit for passing a current through the lead conductor 5 when an abnormality is detected. It can be used to stop charging and discharging during charging and overdischarge.

  1A and 1B has a structure in which the fuse element 7 and the pair of lead conductors 6 are directly connected to each other, so that the planar dimension of the insulating substrate 4 is reduced by the amount corresponding to the electrodes. In addition, the heat capacity of the insulating substrate 4 can be reduced. Accordingly, the energization heat generation rate of the membrane resistor 1 can be increased, the fusing of the fuse element 7 can be speeded up, and the operation speed can be increased.

  The insulating substrate 4 shown in FIGS. 2 (a) and 2 (b) is a good thermal conductive ceramic substrate having a thickness of 0.3 to 0.4 mm. A film resistor 1 and a lead conductor film electrode 2 are disposed on one surface (back surface) of the insulating substrate 4, and a fuse element film electrode 3 is disposed from the back surface to the other surface (front surface). ing. The film resistor 1 is disposed in the middle portion of the insulating substrate 4, the lead conductor film electrode 2 is disposed on one end side (the upper side of FIG. 2B), and the fuse element film electrode 3 is insulated. It is disposed on the other end side of the substrate 4 (the lower side in FIG. 2B). The membrane resistor 1 is electrically connected in a state where one end side thereof is superimposed and joined to the lead conductor membrane electrode 2, and the other end side is electrically connected in a state where the other end side is superimposed and joined to the fuse element membrane electrode 3. This film resistor 1 is provided by printing and baking of a resistance paste, for example, ruthenium oxide paste. The lead conductor film electrode 2 and the fuse element film electrode 3 are provided by printing and baking a conductive paste, for example, a silver paste. The fuse element film electrode 3 includes a fuse element connecting portion 3a bonded to the intermediate portion 7a of the fuse element 7 on the surface of the insulating substrate 4 by welding or the like, and a film overlappingly bonded to the film resistor 1 on the back surface of the insulating substrate 4. And a resistance connecting portion 3b. The fuse element connection portion 3a is formed so as to protrude from the membrane resistance connection portion 3b in the direction opposite to the membrane resistance 1. The fuse element connecting portion 3a is formed narrower than the membrane resistor 1 and the membrane resistor connecting portion 3b in order to increase the energization heat generation rate. A protective film 12 (for example, a glass baking film) for protecting the film resistance 1 is provided on the film resistance 1.

  The lead conductor 5 electrically connected to the lead conductor membrane electrode 2 via the membrane electrode 10 has a flat shape, for example, Sn plating on copper, iron having higher thermal resistance than copper, iron alloys such as iron alloys, nickel or the like Is used. The pair of lead conductors 6 electrically connected to the fuse element film electrode 3 via the fuse element 7 has a flat shape, and for example, Sn plated copper or the like is used. When the lead conductor 5 is made of iron such as iron or iron alloy having a high thermal resistance or nickel plated with Sn or the like, the generated heat to melt the fuse element 7 of the film resistance 1 is transmitted through the lead conductor 5. Therefore, the fuse element 7 can be blown out quickly.

  As shown in FIGS. 2A and 5, the fuse element 7 has an intermediate portion 7a joined to the fuse element connection portion 3a of the fuse element film electrode 3 by welding or the like, and both end portions 7b are paired with each other. The lead conductor 6 is joined by welding or the like. The fuse element 7 is preferably a fusible alloy having a high bending rigidity composition. The flux 11 of FIG. 6 applied to the outer surface of the fuse element 7 is composed mainly of rosin, and the flux 11 has a melting point lower than that of the fuse element 7. The flux 11 can be applied by heating and melting the flux 11 and applying and solidifying the molten flux.

  The support substrate 8 shown in FIGS. 1, 3, 4, and 5 to 7 is a glass epoxy substrate having a thickness of around 0.1 mm and higher thermal resistance than the ceramic insulating substrate 4. By making the thermal resistance of the support substrate 8 higher than the thermal resistance of the insulating substrate 4, the generated heat to melt the fuse element 7 of the film resistance 1 of the insulating substrate 4 is prevented from leaking along the support substrate 8. Therefore, the fuse element 7 can be blown quickly.

  As for the surface of the support substrate 8, the membrane electrode 10 is provided by etching copper foil on one end side (upper side in FIG. 3), and the pair of membrane electrodes 13 is etched on the other end side (lower side in FIG. 3). Is provided. The pair of membrane electrodes 13 are provided with a predetermined gap between the membrane electrodes 13 where the fuse element membrane electrode 3 of the insulating substrate 4 can be arranged.

  As shown in FIG. 7, the insulating sealing material 9 is supported so as to surround the insulating substrate 4 and the protective sheet 9 a (for example, a ceramic sheet or a glass cloth sheet) disposed in contact with the flux 11 on the supporting substrate 8. A curable resin (epoxy resin) 9 b is disposed on the periphery of the substrate 8 and seals the gap between the protective sheet 9 a and the support substrate 8. As the curable resin 9b, a room temperature curable resin that is cured at a temperature lower than the melting point of the fuse element 7 is used.

  Next, a method of manufacturing the resistance-equipped thermal fuse shown in FIG. 1, which is the first embodiment of the present invention, will be described with reference to FIGS. 4, 5, 6, and 7. FIG.

  FIG. 4A shows a plan view of a thermal fuse with resistance in the process of fixing the insulating substrate 4 and the lead conductors 5 and 6 on the support substrate 8 in a juxtaposed state, and FIG. It is the figure which showed the thermal fuse with a resistance shown by a) from a pair of lead conductor 6 side, and FIG.4 (c) is sectional drawing which showed typically the AA cross section of Fig.4 (a). . First, the back surface of the insulating substrate 4 is fixed on the support substrate 8. Specifically, the lead conductor film electrode 2 existing on the back surface of the insulating substrate 4 is fixed to the film electrode 10 on the support substrate 8 by soldering or welding. Along with the fixing of the insulating substrate 4, the tip end portion of the lead conductor 5 electrically connected to the lead conductor membrane electrode 2 is fixed to the membrane electrode 10 on one end side of the support substrate 8 by soldering or welding. On the other hand, the tip ends of the pair of lead conductors 6 are fixed to each of the membrane electrodes 13 positioned on both sides of the fuse element membrane electrode 3 of the insulating substrate 4 on the other end side of the support substrate 8 by soldering or welding. However, if the tip portions of the lead conductors 5 and 6 are welded to the membrane electrodes 10 and 13 of the support substrate 8 by spot welding or the like, the support substrate 8 may be deformed. It is preferable to perform bonding with the soldering.

  FIG. 5A shows a fuse element film electrode 3 and a pair of lead conductors arranged across the fuse element film electrode 3 and the pair of lead conductors 6 existing on the surface of the insulating substrate 4. 6 is a plan view of a thermal fuse with resistance in a process of electrically connecting to FIG. FIG. 5B is a view showing the thermal fuse with resistance shown in FIG. 5A from the pair of lead conductors 6 side. Specifically, the intermediate portion 7 a of the fuse element 7 is joined to the fuse element connection portion 3 a of the fuse element film electrode 3 existing on the surface of the insulating substrate 4 by welding or the like. Along with this joining, both end portions 7b of the fuse element 7 are joined to respective tip portions of the lead conductor 6 by welding or the like.

  The resistance thermal fuse shown in FIGS. 5A and 5B proceeds to the next step with the surface of the support substrate 8 to which the insulating substrate 4 and the lead conductors 5 and 6 are fixed facing upward. Be transported. In this case, since the lead conductor 6 connected to the fuse element 7 is fixed on the support substrate 8, when the lead conductor 6 vibrates during conveyance to the next process, the vibration of the lead conductor 6 is reduced. And the support substrate 8 can be suppressed. For this reason, when vibration is transmitted from the lead conductor 6, a load concentrates on the portion where the lead conductor 6 and the fuse element 7 are connected, the portion where the fuse element membrane electrode 3 and the fuse element 7 are connected, or the fuse element 7 itself, and cracks. Can be prevented from occurring.

  FIG. 6A shows a plan view of a resistance temperature fuse in the step of applying a flux 11 to the fuse element 7 disposed across the fuse element film electrode 3 and the pair of lead conductors 6. FIG. 7B is a diagram showing the resistance temperature fuse shown in FIG. 6A from the pair of lead conductors 6 side. The flux 11 is applied so as to cover the fuse element 7 as shown in FIGS. 6A and 6B and not to reach the support substrate 8.

  In the thermal fuse with resistance shown in FIGS. 6A and 6B, after the flux 11 is applied, the surface of the support substrate 8 to which the insulating substrate 4 and the lead conductors 5 and 6 are fixed is directed upward. It is conveyed to the next process in the state. Since the lead conductor 6 connected to the fuse element 7 is fixed on the support substrate 8 in this temperature-provided fuse, when the lead conductor 6 vibrates during conveyance to the next process, the vibration of the lead conductor 6 occurs. Can be suppressed by the fixing portion between the lead conductor 6 and the support substrate 8. For this reason, when vibration is transmitted from the lead conductor 6, a load concentrates on the portion where the lead conductor 6 and the fuse element 7 are connected, the portion where the fuse element membrane electrode 3 and the fuse element 7 are connected, or the fuse element 7 itself, and cracks. Can be prevented from occurring.

FIG. 7A shows a process of sealing the insulating substrate 4 on the support substrate 8 and the pair of lead conductors 6 on the support substrate 8 with an insulating sealing material 9 after applying the flux 11 to the fuse element 7. The top view of the thermal fuse with a resistance in is shown. 7B is a plan view of the back side of the thermal fuse with resistance shown in FIG. 7A, and FIG. 7C is a pair of lead conductors with the thermal fuse with resistance shown in FIG. 7A. It is the figure shown from the 6th side. FIG. 7 (d) is a side view of the thermal fuse with resistance shown in FIG. 7 (a), and FIG. 7 (e) is a partial perspective view of FIG. 7 (d). Here, the insulating sealing material 9 includes a protective sheet 9a (for example, a ceramic sheet or a glass cloth sheet) and a curable resin (epoxy resin) 9b. First, a curable resin 9b is dropped onto the periphery of the surface of the support substrate 8, and the curable resin 9b surrounds the insulating substrate 4 on the support substrate 8 and the lead conductors 5 and 6 on the support substrate 8. To do. The dropping application of the curable resin 9b is continued until the length of the curable resin 9b in the thickness direction becomes larger than the distance from the surface of the support substrate 8 to the surface of the flux 11. Next, the protective sheet 9a is placed on the upper end surface of the curable resin 9b, and the protective sheet 9a is pressed toward the support substrate 8 until the back surface contacts the surface of the flux 11, and the protective sheet 9a and the support substrate 8 are pressed. The gap is closed with a curable resin 9b and sealed.
In this sealing step, only one side of the support substrate 8 (the surface to which the insulating substrate 4 and the lead conductors 5 and 6 are fixed) is sealed with the insulating sealing material 9, so that the substrate can be sealed as in the prior art. The lead conductor 6 does not vibrate strongly as compared with a sealing process in which the entire substrate is applied with resin and sealed. Even when the lead conductor 6 vibrates in the sealing process, the lead conductor 6 connected to the fuse element 7 is fixed on the support substrate 8, so that the vibration of the lead conductor 6 is detected by the lead conductor 6 and the support substrate 8. It can be suppressed at the fixed part. For this reason, it is possible to prevent a load from concentrating on the place where the lead conductor 6 and the fuse element 7 are connected, the place where the fuse element film electrode 3 and the fuse element 7 are connected, or the fuse element 7 itself and cracking.

  FIG. 8 shows another embodiment of the method for manufacturing a thermal resistor with resistance according to the present invention, which is manufactured in the process of fixing the insulating substrate 4 and the lead conductors 5 and 6 on the support substrate 8 in a juxtaposed manner. An example plan view is shown. The thermal fuse with resistance of FIG. 8 differs from the thermal fuse with resistance of FIG. 4A in the arrangement configuration of the insulating substrate 4 and the lead conductors 5 and 6 on the support substrate 8. As shown in FIG. 8, the insulating substrate 4 is supported on the support substrate 8 in a state where the fuse element connecting portion 3 a of the fuse element film electrode 3 is directed to one side in the width direction of the support substrate 8 (left and right direction in FIG. 8). Stick on top. Along with the fixing of the insulating substrate 4, a pair of lead conductors 6 are disposed and fixed on one end side and the other end side of the support substrate 8, respectively, and the lead conductor 6 disposed on the other end side of the support substrate 8 In parallel, the lead conductor 5 is disposed and fixed to the other end side of the support substrate 8.

  In the method of manufacturing a thermal fuse with resistance of the above-described embodiment, the pair of lead conductors 6 are fixed to the membrane electrode 13 of the support substrate 8 by soldering or welding, but the present invention is not limited to this. Alternatively, the pair of lead conductors 6 may be directly fixed on the support substrate 8 with an adhesive. In this case, thermal stress is not applied to the support substrate 8 unlike the case where the pair of lead conductors 6 are fixed by soldering or welding.

  Moreover, although the insulation sealing thing 9 used for the manufacturing method of the thermal fuse with a resistance of the above-mentioned embodiment is the structure provided with the protection sheet 9a and curable resin (epoxy resin) 9b, this invention is to this. It is not limited. The insulating sealing material of the present invention may be anything that protects the insulating substrate on the supporting substrate and the lead conductor portion on the supporting substrate. For example, the insulating sealing material is dimensioned to cover the insulating substrate and the lead conductor portion. An insulating case may be used.

DESCRIPTION OF SYMBOLS 1 Membrane resistance 2 Membrane electrode for lead conductor 3 Membrane electrode for fuse element 4 Insulating substrate 5 Lead conductor 6 Lead conductor 7 Fuse element 8 Support substrate 9 Insulating sealing material 13 Membrane electrode

Claims (3)

A membrane resistor (1) and a lead conductor membrane electrode (2) electrically connected to the membrane resistor (1) are arranged on one side and for a fuse element electrically connected to the membrane resistor (1). An insulating substrate (4) in which the membrane electrode (3) is disposed from the one side to the other side opposite to the one side, and a lead conductor electrically connected to the lead conductor membrane electrode (2) (5), a pair of lead conductors (6) disposed on both sides of the fuse element film electrode (3) existing on the other side, and a fuse element film electrode ( 3) and a fuse element (7) disposed between the pair of lead conductors (6) and electrically connecting the fuse element film electrode (3) and the pair of lead conductors (6). Resistive thermal fuse A manufacturing method,
One side of the insulating substrate (4) is fixed on the supporting substrate (8), and the pair of lead conductors (6) are fixed on the supporting substrate (8) in parallel with the insulating substrate (4). And a process of
The fuse element (3) straddling the fuse element film electrode (3) and the pair of lead conductors (6) present on the other surface of the insulating substrate (4) fixed on the support substrate (8). 7) disposing and electrically connecting the fuse element film electrode (3) and the pair of lead conductors (6);
Sealing the insulating substrate (4) on the support substrate (8) and the pair of lead conductors (6) on the support substrate (8) with an insulating sealing material (9). A method of manufacturing a thermal fuse with a resistance. A pair of membrane electrodes (13) is provided on the support substrate (8),
The resistance thermal fuse according to claim 1, wherein the lead conductor (6) electrically connected to the fuse element film electrode (3) is fixed to the film electrode (13) by soldering. Production method.   The resistance thermal fuse according to claim 1, wherein the lead conductor (6) electrically connected to the fuse element film electrode (3) is fixed on the support substrate (8) with an adhesive. Manufacturing method.

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