TW201621955A - Circuit element and method for manufacturing circuit element - Google Patents

Abstract

A circuit element (10) which, by holding a flux sealed in a highly dispersed state and for the purpose of stabilising the operation characteristics thereof, holds the flux (19A) at any location at which contact is made with a fusible conductor (13). The circuit element is characterised by: comprising at least one pair of electrodes (15A, 15B) provided on an insulating substrate (11), further comprising a connecting medium (18A, 18B) which is formed from a solder paste and connects the electrodes and the fusible conductor, and further comprising a plurality of gap sections (19) provided to the connecting medium; and the flux being held by being filled into at least one of the gap sections.

Description

Circuit component and circuit component manufacturing method

The present invention relates to a circuit element for holding a flux such as a protective element and a short-circuiting element of a circuit connected to a current path by a fuse current path, and a method of manufacturing the circuit element. The present application claims priority to Japanese Patent Application No. 2014-225240, filed on Jan.

Conventionally, a protective element mounted on a secondary battery device or the like has a function of preventing overcurrent and overvoltage prevention. The protective element laminates a fusible conductor composed of a heating element and a low melting point metal body on the substrate, and is formed to fuse the fusible conductor by an overcurrent, and can also generate a heating element in the protection element when an overvoltage occurs. When energized, the fusible conductor is blown by the heat of the heating element. When the fusible conductor is melted in the melting of the fusible conductor of the low melting point metal, the molten low melting point metal is pulled onto the electrode due to the wettability of the surface of the connected electrode, and as a result, the fusible conductor is broken. Turn on and interrupt the current.

On the other hand, with the miniaturization of electronic devices such as portable devices in recent years, the protective elements mounted on the protection circuit of the power source mounted on the electronic device are also required to be smaller and thinner, and are further required to operate. Stability and speed. In order to improve the stability and speed of the operation of the protective element, a fusible conductor of a low melting point metal body is placed on the insulating substrate, the fusible conductor is sealed with an insulating cover, and the flux is coated on the fusible conductor. In this way, by applying a flux to the fusible conductor, it is sought to prevent oxidation of the surface of the fusible conductor and to be fusible. When the conductor is heated, the melting is quickly and stably promoted to improve the melting characteristics.

Since the flux is rich in thermal fluidity, when the protective element is mounted on the circuit board, when exposed to a reflow oven or the like, the flux sometimes flows out of the surface of the fusible conductor and does not remain. However, the inability to perform its function becomes a cause of poor fusion of the fusible conductor. Patent Document 1 and Patent Document 2 disclose a protective element capable of ensuring rapid and correct melting of a fusible conductor in an abnormal state by holding a flux on a fusible conductor at a predetermined position by an insulating cover portion. . Further, Patent Document 3 discloses that a flux-impregnated multi-gap metal body is provided in proximity to a fusible conductor, and the molten alloy is sucked into a metal mesh or the like while sufficiently maintaining the action of the flux to achieve an operating speed. Rapidly alloyed temperature fuses.

Advanced technical literature

[Patent Document 1] Japanese Laid-Open Patent Publication No. 2010-170802

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2010-170803

[Patent Document 3] Japanese Patent No. 4015244

Since the flux also contains volatile components and the like, its characteristics are easily deteriorated when directly exposed to the atmosphere or moisture. Therefore, in order to prevent oxidation of the surface of the fusible conductor and to improve the fusing characteristics of the fusible conductor, it is expected that the protective element can be completely sealed with an insulating cover or the like. However, there is a problem that cracks occur in the outer casing such as the insulating cover during reflow soldering or when the fuse is blown. Therefore, it is not easy to form a circuit element such as a protective element into a sealed type. Moreover, in the case where the flux is disposed on the upper portion of the fusible conductor, the space for using the flux or the use is required. In order to maintain the organization, there will be problems that are not easy to reduce the height. Further, in order to prevent the oxidation of the surface of the fusible conductor by the flux or to improve the melting characteristics of the fusible conductor, it is preferable to uniformly disperse the flux to the fusible conductor.

The protective elements of Patent Documents 1 and 2 are configured to be held at a predetermined position before the operation of the flux, thereby improving the fusing characteristics of the protective element, but by the lowering of the protective element and the flux There is still a problem in achieving high stability in the stabilization of the melting characteristics. Further, in Patent Document 3, it is disclosed that a flux-impregnated multi-gap metal body is provided in proximity to a fusible conductor to hold a flux to maintain a flux function, but the flux is highly dispersed to stabilize the fusing characteristics. It has not been mentioned.

The present invention has been made in view of the above problems, and an object of the invention is to provide a novel and improved circuit element and circuit element which can be hermetically held in a highly dispersed state and stabilized in operation characteristics. Production method.

A circuit component according to an aspect of the present invention is characterized in that a flux is held at any one of a portion abutting on a fusible conductor, and includes: at least one pair of electrodes provided on the insulating substrate; and a connection between the electrode and the fusible conductor a connection medium; and a plurality of void portions provided in the connection medium; and the flux is held in at least one of the gap portions.

According to an aspect of the present invention, since a gap portion in a highly dispersed state is provided in a connection medium connecting a fusible conductor and an electrode, the flux can be held in a high dispersion state by holding the flux in the gap portion, thereby It is possible to stabilize the operating characteristics of the flux.

In this case, in one aspect of the invention, the gap portion may have a ratio of a void diameter of 0.01 to 0.1 mm of 1 to 40% and a void diameter of 0.1 to 0.2 mm of 40 to 80%.

In this way, since the flux can be hermetically held in a highly dispersed state, it is possible to surely stabilize the flux operating characteristics.

Further, in one aspect of the invention, the connection medium includes a low melting point metal and a high melting point metal, and each of the gap portions may be formed by being surrounded by particles of the high melting point metal.

In this way, since the gap portion for holding the flux can be formed into a uniform size, the flux can be hermetically held in a more uniform and highly dispersed state, and the stability of the operation characteristics can be surely achieved.

Moreover, another aspect of the present invention is a method of manufacturing a circuit component for holding a flux at any portion of a portion abutting a fusible conductor, comprising: fabricating at least one pair of electrodes for forming a connection on the insulating substrate; a solder paste forming step of the solder paste connecting the medium and a solder paste melting step of melting the solder paste, in the solder paste forming step or the solder paste melting step, in the solder paste The connection medium formed is formed with a plurality of void portions, and the flux portion holds the flux.

According to another aspect of the present invention, in the process of forming a solder paste for connecting a fusible conductor and an electrode, the solder paste is intentionally formed into a void portion in a highly dispersed state, and a flux can be held in the void portion.

In this case, in another aspect of the present invention, after the low-melting-point metal and the high-melting-point metal are blended in a predetermined weight ratio in the solder paste forming step, the solder paste is melted by the solder paste melting step, thereby connecting the solder paste. The medium forms the gap portion at a ratio of a void diameter of 0.01 to 0.1 mm of 1 to 40% and a void diameter of 0.1 to 0.2 mm of 40 to 80%, and naturally the flux can be held in the void portion.

As a result, the flux can be more uniformly and tightly held in a highly dispersed state, so that the flux operating characteristics can be surely stabilized.

Further, in another aspect of the invention, in the solder paste producing step, the predetermined weight ratio of the low melting point metal to the high melting point metal may be adjusted from 10:90 to 90:10.

In this case, when the reflow soldering is heated, it is connected to the fusible conductor with respect to the melting of the low melting point metal, and since the high melting point metal is not melted, the metal particles constituting the high melting point metal are plurally aggregated, so that the metal particles are The surrounding void portion is formed in a highly dispersed state, and the flux can be held in the void portion.

Moreover, in another aspect of the present invention, the low melting point metal and the high melting point metal, which are raw materials of the solder paste, are each granular, and the particle diameter of the low melting point metal is larger than the particle diameter of the high melting point metal.

As a result, when the low melting point metal is melted in the reflow soldering, the high melting point metal is covered, and the void portion can be more easily formed by the particles of the high melting point metal.

Moreover, in another aspect of the present invention, the solder paste melting step includes a preheating step of heating to a predetermined temperature in advance, a solid heating step of heating the solder paste to perform soldering, and cooling after completion of the solid heating step. a cooling step of adjusting a temperature condition of any one of the preheating step, the actual heating step, or the cooling step in the solder paste melting step to change a melting condition of the solder paste, whereby the void portion is formed in the foregoing The medium is connected to the medium while maintaining the flux at least one or more of the gap portions.

In this way, by adjusting the melting conditions of the solder paste, the void portion for holding the flux can be formed in a highly dispersed state in the connection medium made of the solder paste.

According to the invention as described above, since the gap portion in the highly dispersed state is provided in the connection medium composed of the solder paste connecting the meltable conductor and the electrode, the flux is held in the gap portion, so that the operating characteristics of the flux can be stabilized. . Therefore, it is possible to prevent the oxidation of the surface of the fusible conductor and the melting characteristics of the fusible conductor with the flux.

10, 20‧‧‧Protection components (circuit components)

11, 21‧‧‧Insert substrate

12, 22‧‧‧ heating element

13, 23‧‧‧ fusible conductor

14, 14A, 14B, 15, 15A, 15B, 24, 24A, 24B‧‧‧ electrodes

16, 26‧‧‧Insulating components

17, 27‧‧‧ conductor layer

18, 18A, 18B, 18C, 28, 28A, 28B, 28C‧‧‧Connect media

18D‧‧‧low melting point metal

18E‧‧‧High melting point metal (metal particles)

19, 29 ‧ ‧ gap

19A, 29A‧‧‧ Flux

Fig. 1 is a plan view showing a protective element as an example of a circuit element according to an embodiment of the present invention.

Fig. 2 is a cross-sectional view taken along line A-A of the protective element of the circuit element example of the embodiment of the present invention shown in Fig. 1.

Fig. 3 is an enlarged view of a main part of a connection medium provided as a protection element of an example of a circuit element according to an embodiment of the present invention.

Fig. 4 is an enlarged view of a void portion formed in a connection medium provided in a protective element as an example of a circuit element according to an embodiment of the present invention.

Fig. 5 is a cross-sectional view showing a protective element as an example of a circuit element according to another embodiment of the present invention.

Fig. 6 is an enlarged view of a main part of a connection medium provided as a protective element of an example of a circuit element according to another embodiment of the present invention.

Fig. 7 is an explanatory view showing temperature conditions in a method of manufacturing a circuit component according to another embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail. Further, the present embodiment described below is not intended to limit the scope of the present invention described in the scope of the patent application. The constitutions described in the description are not necessarily all necessary as a means of solving the invention.

First, the configuration of the circuit element according to an embodiment of the present invention will be described using the drawings. Fig. 1 is a plan view showing a protective element as an example of a circuit element according to an embodiment of the present invention, and Fig. 2 is a cross-sectional view taken along line A-A of the protective element of the circuit element example of the embodiment of the present invention shown in Fig. 1.

As shown in FIG. 1, the protective element 10 of the embodiment of the present invention has a heat generating body 12 and a fusible conductor 13 on an insulating substrate 11, and has a fusible conductor 13 as a current path by heat generation of the heat generating body 12, Protects the function of the circuit connected to the current path. In the present embodiment, the protective element 10 has a pair of electrodes 14 (14A, 14B) formed at both ends of the upper surface of the insulating base substrate 11, and another pair of electrodes 15 is provided at the opposite edge portion orthogonal to the pair of electrodes 12. (15A, 15B).

A heating element 12 made of a resistor is connected between the electrodes 15A and 15B. The heating element 12 is passed through an insulating layer 16 disposed to cover the heating element 12, and a conductor layer 17 connected to one of the electrodes 15A is laminated. The conductor layer 17 is connected to a central portion of the fuse-meltable conductor 13 made of a low-melting-point metal of the pair of electrodes 14 (14A, 14B), and transmits a metal component having a good wettability to the molten fusible conductor 13. A connection medium 18 (18C) composed of a solder paste is connected to the conductor layer 17. Further, as shown in Fig. 2, the soluble conductor 13 and the electrodes 14 (14A, 14B) are connected by a connection medium 18 (18A, 18B) made of a solder paste. The details of the material of the solder paste 18 forming the connection medium will be described later.

The insulating substrate 11 is formed of, for example, an insulating member such as alumina, glass ceramic, mullite or zirconia. In addition, materials for printed wiring boards such as glass epoxy substrates and phenol substrates may be used, but it is necessary to pay attention to the temperature selection material when the fuse is blown. Further, a cover member formed of a member having insulation properties may be placed on the insulating substrate 11 to protect the inside of the protective member 10.

The heating element 12 is a conductive material having a high electric resistance value and generating heat when energized, and is formed of, for example, W, Mo, Ru, or the like. The alloy or the composition, the powder of the compound, the resin binder, and the like are mixed to form a paste, and a pattern is formed on the insulating substrate 11 by a screen printing technique, and formed by firing or the like.

The fusible conductor 13 is made of a low-melting-point metal which is rapidly melted by the heat generated by the heating element 12. For example, it is very suitable to use a lead-free solder containing Sn as a main component. Further, the soluble conductor 13 may be a laminate of a low melting point metal and a high melting point metal such as Ag, Cu or an alloy containing the like as a main component.

The protective element 10 according to the embodiment of the present invention is constituted by a circuit in which the fusible conductor 13 connected in series through the conductor layer 17 and the heat generating body 12 which is electrically heated by the connection point through the soluble conductor 13 to melt the soluble conductor 13. As described above, the protective element 10, for example, the soluble conductor 13 is connected in series to the charge and discharge current path through the electrodes 14A, 14B, and the heat generating body 12 is connected to the current control element through the electrode 15B, for example. The protective element 10 formed by such a circuit structure can reliably fuse the fusible conductor 13 on the current path by the heat generated by the heating element 12.

Further, in the present embodiment, a plurality of void portions 19 are formed in a highly dispersed state in the connection medium 18 formed of a solder paste, and at least one or more of the void portions 19 are filled with a surface for preventing the meltable conductor 13 from being filled. Flux 19A used for oxidation and for improving the melting characteristics. That is, the protective element 10 of the present embodiment is connected to the connection medium 18A, 18B between the soluble conductor 13 as the fuse element and the electrodes 14A, 14B, and between the soluble conductor 13 and the conductor layer 17. The connecting medium 18C is formed by a hole, a void, a surface depression, etc. in a highly dispersed state. The plurality of void portions 19 are formed, and any one of the void portions 19 maintains the structure of the flux 19A. Further, as the flux 19A, a known flux such as a rosin-based flux can be used, and a halogen-free flux which does not have a halogen element such as bromine is preferable, and the viscosity is not limited.

As described above, in the present embodiment, the protective element 10 is formed in a highly dispersed state in any of the portions abutting on the soluble conductor 13, and at least one or more of the gap portions 19 are held. The composition of the flux 19A. Therefore, when the heat generating element 12 generates heat to melt the soluble conductor 13, the molten state at the position where the meltable conductor 13 is thermally coupled to the heat generating body 12 is made uniform, and the breakage of the soluble conductor 13 is promoted, so that Reduce the unevenness of the fusing characteristics. That is, the flux can be surely supplied more uniformly, and the stable melting behavior can be achieved. Further, since it is not necessary to separately provide a space for arranging the flux on the upper portion of the soluble conductor or a mechanism for holding it, it is possible to provide a structure in which the protective element 10 is made lower in height.

Next, the details of the material and the like of the connection medium provided in the protection element as an example of the circuit element in the embodiment of the present invention will be described with reference to the drawings. 3 is an enlarged view of a main part of a connection medium provided as a protection element as an example of a circuit element according to an embodiment of the present invention, and FIG. 4 is a protection element which is formed as an example of a circuit element in an embodiment of the present invention. An enlarged view of the gap portion of the connected medium.

In the present embodiment, the connection medium 18 is made porous by adjusting the metal composition, the particle diameter, and the mixing ratio of the connection medium 18 formed of the solder paste, so that a plurality of configurations of uniform size are used. The void portion 19 is formed in a highly dispersed state. As the material of the solder paste for forming the connection medium 18, it is preferable to use a metal component which has good wettability with respect to the molten fusible conductor 13, and which does not contain lead. Specifically, as a metal composition for forming a solder paste for forming the connection medium 18, a high melting point metal having a melting point higher than 300 ° C, such as silver Ag or copper Cu, and tin are mixed. A low melting point metal having a melting point of 300 ° C or less, such as Sn or bismuth Bi, is adjusted so that the weight ratio thereof is in the range of 10:90 to 90:10, whereby the connection medium 18 is made porous.

That is, in the step of fabricating the connection medium 18 from the solder paste, by combining the low melting point metal and the high melting point metal at a predetermined weight ratio, a plurality of void portions 19 are intentionally formed in the connecting medium 18 in a uniform size, respectively. At least one or more of these void portions 19 hold the flux 19A. At this time, when the ratio of the high melting point metal is 90% or more, the connection medium 18 and the soluble conductor 13 cannot be connected. On the other hand, when the ratio of the low melting point metal is 90% or more, the void portion 19 is hardly formed in the connection medium 18.

Therefore, in the present embodiment, in the step of forming the connection medium 18 from the solder paste, the weight ratio of the low melting point metal to the high melting point metal is adjusted by 10:90 to 90:10 to form a plurality in the connection medium 18. The void portions 19 are formed in a highly dispersed state in a uniform size. Specifically, the formation condition of the void portion 19 is such that the ratio of the void diameter to the range of 0.01 to 0.1 mm is 1 to 40%, and the ratio of the void diameter is 0.1 to 0.2 mm is 40 to 80%. Part 19. Further, in the present specification, the "uniformity" described for the size of the void portion 19 includes those that are completely uniform to substantially uniform.

After the low melting point metal and the high melting point metal are tempered in this manner, when the heat of reflow soldering is applied in the step of melting the solder paste, as shown in FIG. 4, the low melting point metal 18D is melted and the fusible conductor 13 is melted. (Refer to Figure 2) Connect. On the other hand, since the high melting point metal is not melted, the plurality of metal particles 18E constituting the high melting point metal are aggregated, and as shown in FIG. 4, the void portion 19 surrounded by the metal particles 18E is formed in a highly dispersed state, and At least one or more of the void portions 19 naturally maintain the flux 19A at a high probability. According to this method, the flux 19A can be uniformly held in a highly dispersed state, so that the action characteristics of the flux 19A can be surely obtained. Standardized.

Further, in the embodiment, in the step of producing the solder paste for forming the connection medium 18, the low melting point metal and the high melting point metal which are the raw materials of the solder paste are respectively granular, and the particle diameter of the low melting point metal is Blending is carried out using a larger particle size of the higher melting point metal. Specifically, the particle diameter of the metal particles is 1 to 100 μm for the low melting point metal and 0.5 to 50 μm for the high melting point metal. By setting the low-melting-point metal and the high-melting-point metal of the connection medium 18 made of the solder paste to such a particle diameter, it is easier to cover the high-melting-point metal 18E when the low-melting-point metal 18D starts to be melted during reflow soldering. The void portion 19 is easily formed by the metal particles 18E constituting the high melting point metal. The particle diameter of the metal particles as a raw material referred to herein means the particle diameter of the low melting point metal and the high melting point metal before the reflow soldering (before melting).

Further, when the low-melting-point metal particles are smaller, it is difficult to cover the high-melting-point metal when the low-melting-point metal is melted, and the void portion 19 is not easily formed. Therefore, the surface of the low-melting-point metal has a higher melting point on the surface of the connection with the soluble conductor 13. The metal is much better. On the other hand, in order to increase the gap portion 19, the difference in particle diameter between the low melting point metal and the high melting point metal is preferably small. In other words, the particle diameters of the low melting point metal and the high melting point metal can be appropriately adjusted for various purposes such as the case where the reliability of the function of the protective element 10 is emphasized or the space saving of the protective element 10 is emphasized.

Further, in the present embodiment, in order to maintain the structure in which the flux 19A is held in the void portion 19, the amount of the flux 19A previously blended in the solder paste forming the connection medium 18 is also important. In order to reliably obtain the operational characteristics of the flux 19A, the content of the flux 19A is preferably as large as possible. However, when the flux 19A is excessive, the printability required for the solder paste forming the connection medium 18 and the shape retention after printing and the like are affected.

Therefore, when manufacturing the protective element 10 of the present embodiment, the flux 19A is used. It is necessary to adjust the content in an appropriate range. Specifically, the amount of the flux to be blended is appropriately adjusted depending on the purpose, in such a manner that the ratio of the total weight of the low melting point metal to the high melting point metal to the weight of the flux is in the range of 80:20 to 99.5:0.5. In the solder paste in which the connection medium 18 is formed by the weight ratio, the flux 19A is previously mixed, that is, the flux 19A can be naturally held at least one or more of the void portions 19 formed in the connection medium 18 made of the solder paste.

As described above, in the present embodiment, the mixing ratio and the particle diameter of the low-melting-point metal and the high-melting-point metal constituting the solder paste for forming the connection medium 18 are adjusted, and the connection medium 18 is intentionally dispersed to form a uniform-sized void portion. 18 is made porous, and the flux portion 18 is held in the void portion 18. Therefore, the operational characteristics of the flux 19A can be stabilized, and the flux 19A can be prevented from oxidizing the surface of the soluble conductor 13 and the melting characteristics of the soluble conductor 13 can be improved.

In particular, the connection medium 18 made of a solder paste provided at a portion in contact with the soluble conductor 13 is intentionally formed in a highly dispersed state to hold the void portion 19 of the flux 19A while the flux 19A is held therein. Since at least one or more of the gap portions 19 are provided, the flux 19A can be supplied to the soluble conductor 13 more uniformly. According to this, since the fusing characteristic unevenness of the fusible conductor 13 disappears, the function of the protective element 10 as the stable fusing characteristic can be improved.

Next, the configuration of the circuit element according to another embodiment of the present invention will be described using the drawings. 5 is a cross-sectional view showing a protective element as an example of a circuit component according to another embodiment of the present invention, and FIG. 6 is an enlarged view of a main part of a connection medium provided as a protective element of an example of a circuit component according to another embodiment of the present invention. . Further, since the protective element 20 of the other embodiment of the present invention has substantially the same configuration as the protective element 10 of the above-described embodiment, the plan view is the same as that of FIG. 1, and FIG. 5 is another cross-sectional view corresponding to the AA line of FIG. Implementation form A cross-sectional view of the protective element of the state.

As shown in FIG. 5, the protective element 20 of the other embodiment of the present invention has a heat generating body 22 and a fusible conductor 23 on the insulating substrate 21, and the heat-generating body 22 heats the fusible conductor 23 as a current path. It has the function of protecting the circuit connected to the current path. In the present embodiment, the protective element 20 has a pair of electrodes 24 (24A, 24B) formed on both ends of the insulating base substrate 21, and is also provided at the opposite edge portion orthogonal to the electrodes 24A, 24B. Another pair of electrodes not shown. A heating element 22 made of a resistor is connected between the other pair of electrodes, and the heating element 22 is passed through an insulating layer 26 disposed to cover the heating element 22, and a layer is connected to one of the other pair of electrodes. Conductor layer 27.

A central portion of the fuse-satuable conductor 23 formed of a low-melting-point metal, which is connected to the pair of electrodes 24 (24A, 24B), is formed by a solder paste containing a metal component having a good wettability to the molten fusible conductor 23. The connection medium 28 (28C) is connected to the conductor layer 27. Further, the fusible conductor 23 and the electrodes 24 (24A, 24B) are connected by a connection medium 28 (28A, 28B) as shown in Fig. 5 . Further, the insulating substrate 21, the heating element 22, the soluble conductor 23, the electrode 24, the insulating layer 26, and the conductor layer 27 included in the protective element 20 of the present embodiment are the same as those of the protective element 10 of the above-described embodiment. Therefore, a detailed description thereof will be omitted.

The protective element 20 of the present embodiment is characterized in that, by adjusting the melting conditions of the solder paste forming the connection medium 28, a void 29 as a void portion is formed in a highly dispersed state in the connection medium 28, in which the void 29 is formed. At least one or more of the flux 29A is held. As the material of the solder paste forming the connection medium 28, it is preferable to use a metal component having a good wettability to the molten fusible conductor 23, and it is preferable to use a lead-free one. For example, tin (Sn) silver (Ag can be used. Copper (Cu) paste. Further, the specific molten strip of the connection medium 28 of the present embodiment Details of the adjustment of the pieces are reserved for later description.

In the present embodiment, the connection medium 28 adjusts the melting conditions such as temperature conditions of the general solder paste to form a plurality of pores 29 in a highly dispersed state, and at least one or more of the pores 29, that is, a part thereof. The aperture 29 holds the flux 29A. Therefore, in the pores 29, as shown in Fig. 6, in the pores 29 in which the flux 29A is held inside, the flux 29 is not mixed to some extent, and only the voids are formed. Further, since the size and arrangement of the apertures 29 are random, the balance between the connection stability and the flux retention is slightly inferior to that of the above-described embodiment.

However, in the present embodiment, the uneven particle diameter and shape of the pores 29 formed by the connection medium 28 made of the solder paste can reduce the conventional protective element such as the soldering condition of the solder paste which does not form the connection medium. The risk of flux flowing out of the internal metal caused by internal metal alloying without the formation of voids inside. That is, since the flux 29A is surely held in at least one of the apertures 29 as compared with the connection medium composed of a conventional solder paste which is hardly formed by the void, it is possible to prevent fusibility by the flux 29A. The surface of the conductor 23 is oxidized and the melting characteristics of the fusible conductor 23 are improved, which is a preferable state.

Next, the adjustment of the melting conditions in the method of manufacturing a circuit component according to another embodiment of the present invention will be described with reference to the drawings. Fig. 7 is an explanatory view showing temperature conditions in a method of manufacturing a circuit component according to another embodiment of the present invention.

In the present embodiment, in the melting step of forming the solder paste of the connection medium 28, a preheating step of heating to a predetermined temperature in advance, a solid heating step of performing solid heating on the solder paste forming the connection medium 28 to perform soldering, and A cooling step in which cooling is performed after the end of the solid heating step. And adjusting either the preheating step, the actual heating step, or adjusting the cooling step The temperature conditions change the melting conditions of the solder paste forming the connection medium 28, whereby the pores 29 as void portions are formed in a highly dispersed state in the connection medium 28, and the flux 29A is held in the pores 29.

Specifically, as shown in Fig. 7, the melting temperature of the solder paste forming the connection medium 28 in the actual heating step is adjusted to a level lower than the conventionally low 200 to 300 °C. At this time, when the duration of the actual heating step is set to about 30 seconds, and the peak temperature is about 255 ° C ± 5 ° C, and the duration of the peak temperature is 5 seconds, the connection can be made of solder paste. The medium 28 forms a plurality of pores 29 in a highly dispersed state while maintaining the flux 29A at the pores 29. Further, after the completion of the actual heating step, it is naturally placed at a normal temperature to be slowly cooled.

Further, as shown in Fig. 7, the melting temperature of the solder paste forming the connection medium 28 in the preheating step is adjusted to a level as low as 150 to 200 °C. At this time, when the duration of the preheating step is set to about 90 seconds ± 30 seconds, a plurality of pores 29 can be formed in the highly dispersed state in the connection medium 28, and at least one of the pores 29 can be kept flux. 29A.

Further, as shown in P1 of FIG. 7, the temperature gradient when moving from the preheating step to the real heating step is set to be steep, even if it is sharply increased, or as shown in P2 of FIG. The cooling step after the heating step is rapidly lowered, and a plurality of pores 29 can be formed in a highly dispersed state in the connecting medium 28 made of solder paste, and at least one or more of the pores 29 can be kept in the flux 29A. Further, the flux 29A can be maintained by increasing the joint area so that the pores 29 are not easily detached.

As described above, in the present embodiment, by adjusting the melting conditions of the solder paste forming the connection medium 28, the gap portion 29 for holding the flux 29A is intentionally formed in the high dispersion state by the connection medium 28, and At least one or more of the void portions 29 hold the flux 29A. Therefore, since the operating characteristics of the flux 29A can be maintained in a stabilized state, it is possible to prevent the surface of the soluble conductor 23 from being oxidized by the flux 29A and to improve the melting characteristics of the soluble conductor 23. That is, in contrast to the conventional case in which the soldering conditions of the solder paste forming the connection medium 28 are not adjusted, in the present embodiment, the melting condition of the solder paste forming the connection medium 28 can be adjusted to deliberately connect the medium 28 The void portion 29 is formed in a highly dispersed state, and at least one or more of the void portions 29 are held to some extent by the flux 29A. Therefore, compared with the conventional one, it is possible to prevent the surface of the soluble conductor 23 from being oxidized by the flux 29A and to improve the melting characteristics of the soluble conductor 23.

Further, in the above-described one embodiment and another embodiment, the case where the circuit element is applied to the protection element has been described, but the present invention can also be applied to, for example, a short-circuit element, a switching element, a current fuse, etc. The circuit component of the flux is held anywhere in the portion where the fuse conductor abuts. In other words, the circuit element of the present embodiment can be applied to a circuit element having a structure in which the fuse of the fuse-meltable conductor can be assisted and the flux used for the change of the year and the heat history can be effectively functioned.

As described above, by applying the embodiments of the present invention to the protection element device and the circuit element using the SCP, the current fuse, the short-circuit element, and the switching element of the fusible conductor, it is possible to reliably maintain the flux. The stability of the achieved operational characteristics, the amount of flux retained on the fusible conductor, and the reduction of the holding mechanism are reduced.

It is to be understood that the various embodiments of the present invention are described in detail hereinabove, and those skilled in the art can readily understand that various modifications can be made without departing from the spirit and scope of the invention. Accordingly, such modifications are all included within the scope of the invention.

For example, in the specification or the drawings, at least one term described together in a broader or synonymous term may be different at any position in the specification or the drawings. Replace the term. Further, the configuration and operation of the circuit elements are not limited to those described in the respective embodiments of the present invention, and various modifications can be made.

10‧‧‧Protection components (circuit components)

11‧‧‧Insert substrate

12‧‧‧heating body

13‧‧‧Solid conductor

14, 14A, 14B‧‧‧ electrodes

16‧‧‧Insulating components

17‧‧‧Conductor layer

18, 18A, 18B, 18C‧‧‧Connect media

19‧‧‧Voids

19A‧‧‧ Flux

Claims (8)

A circuit element for holding a flux at any of a portion abutting a fusible conductor, comprising: at least one pair of electrodes disposed on the insulating substrate; a connection medium connecting the electrode and the fusible conductor; and The plurality of void portions are connected to the medium; and the flux is held in such a manner as to fill at least one of the void portions. The circuit component according to claim 1, wherein the void portion has a ratio of a void diameter of 0.01 to 0.1 mm of 1 to 40% and a void diameter of 0.1 to 0.2 mm of 40 to 80%. The circuit component of claim 1 or 2, wherein the connection medium comprises a low melting point metal and a high melting point metal, each of the void portions being formed by being surrounded by particles of the high melting point metal. A method of manufacturing a circuit component that maintains a flux at any one of abutting portions with a fusible conductor: a solder paste forming step of forming at least one pair for connecting to an insulating substrate a solder paste connecting the electrode to the soluble conductor; and a solder paste melting step of melting the solder paste; and forming the solder paste in the solder paste forming step or the solder paste melting step The connection medium forms a plurality of void portions, and at least one or more of the void portions hold the flux. A method of manufacturing a circuit component according to claim 4, wherein the solder paste is In the production step, after the low-melting-point metal and the high-melting-point metal are blended in a predetermined weight ratio, the solder paste is melted in the solder paste melting step, so that the connection medium has a void diameter of 0.01 to 0.1 mm and a void ratio of 1 to 40%. The ratio of the diameter of 0.1 to 0.2 mm is 40 to 80% to form the void portion, and the flux is naturally held at the void portion. The method of manufacturing a circuit component according to claim 5, wherein the predetermined weight ratio of the low melting point metal to the high melting point metal in the solder paste forming step is adjusted at 10:90 to 90:10. . The method of manufacturing a circuit component according to claim 5, wherein the low melting point metal and the high melting point metal are respectively granular, and the low melting point metal has a particle diameter larger than the high melting point. The particle size of the metal. The method of manufacturing a circuit component according to the fourth aspect of the invention, wherein the solder paste melting step comprises: a preheating step of heating to a predetermined temperature in advance; and a solid heating step of performing real heating on the solder paste; a cooling step of cooling after the completion of the solid heating step; adjusting the temperature condition of any one of the preheating step, the solid heating step or the cooling step to change the melting condition of the solder paste in the solder paste melting step, The flux is held in the connection medium, and the flux is held in at least one of the gap portions.