JP2006299289A - Alloy type temperature-sensitive element material, and temperature fuse using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an alloy type temperature-sensitive element material free from lead and cadmium. <P>SOLUTION: The first of invention is an alloy type temperature-sensitive element material to which zinc of 1 to 6 pts.wt. is added to 100 pts.wt. of an alloy composed of indium of 52±5 wt.%, and the balance tin, and a temperature fuse using the same. The second of invention is an alloy type temperature-sensitive element material to which zinc of 1 to <5 pts.wt. and bismuth of 5 to <9 pts.wt. are added to 100 pts.wt. of an alloy composed of indium of 52±5 wt.%, and the balance tin, and a temperature fuse using the same. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an alloy-type thermosensitive element material used for electrical equipment, electronic equipment, and the like, and a thermal fuse using the same. Specifically, the present invention relates to an In—Sn—Zn alloy, an In—Sn—Zn—Bi alloy, and a thermal fuse using the same, which are used as a temperature sensitive element for a thermal fuse having an operating temperature of approximately 90 ° C. to 109 ° C. Is.

When electrical and electronic equipment (hereinafter referred to as equipment) becomes abnormal due to a failure, etc., the equipment may become hot in some cases and cause a fire. In order to prevent this, a temperature fuse is used that senses an abnormal temperature rise of the device and cuts off electricity (for example, Patent Document 1 below).
JP2001-243865

  This temperature fuse has a structure in which an alloy wire that melts at a predetermined temperature is used as a temperature sensing element, lead wires are connected to both ends thereof, flux is applied to the surface of the temperature sensing element, and then housed and sealed in a container. . In addition, the flux includes a rosin as a base, an activator for removing oxides on the alloy surface, and various resins, waxes and the like for adjusting the melting point. Examples of the activator include hydrohalides of various amines and various organic acids.

  The operating mechanism of the thermal fuse is as follows. When the device becomes abnormal due to failure or other conditions, the temperature sensing element melts and the oxide is removed by the action of the flux applied to the temperature sensing element, manifesting its own surface tension and wetting the lead wire. As a result, the melted temperature sensitive element is agglomerated and divided at the end portion of the lead wire, whereby the electric circuit is interrupted. The aggregation of the temperature sensitive elements is generally called spheroidization.

  In such a thermal fuse having the above-described operating mechanism, the operating temperature is substantially determined by the temperature at which the alloy is spheroidized by the action of the flux. On the other hand, the thermal analysis concept of the alloy has factors such as a liquid phase temperature and a solid phase temperature, which are not necessarily important from the viewpoint of the operating temperature of the thermal fuse. This is because spheroidization may occur at a temperature lower than the liquidus temperature depending on the composition of the alloy. Therefore, it can be said that the temperature at which the thermosensitive element spheroidizes due to the action of the flux is an important factor.

  In addition to the temperature at which spheroidization occurs, whether or not spheronization is performed smoothly is also an important factor. If the molten alloy has poor fluidity or a sherbet-like semi-molten state, the speed of spheroidization is slow and slow due to the action of the flux, causing variations in operating temperature on the product base, and lead wires. It takes a long time to reach the necessary separation distance between them, and an increase in the electric arc at the time of interruption may cause an electrical breakdown, sometimes causing the product body to burst. Therefore, eutectic alloys having the same solid phase temperature and liquid phase temperature have been preferentially used.

As an alloy-type thermosensitive element that operates at the 90 ° C level,
(1) A known eutectic alloy having a melting point of 96 ° C. composed of 32% by weight of lead, 16% by weight of tin and 52% by weight of bismuth, and (2) composed of 44% by weight of indium, 42% by weight of tin and 14% by weight of cadmium. There is a known eutectic alloy having a melting point of 93 ° C.

On the other hand, as an alloy type temperature sensing element operating at a temperature of 100 ° C.,
(3) Known eutectic alloy having a melting point of 100 ° C. composed of 20% by weight of lead, 34% by weight of tin, and 46% by weight of bismuth, and (4) composed of 26% by weight of tin, 54% by weight of bismuth, and 20% by weight of cadmium. There is a known eutectic alloy having a melting point of 103 ° C.

  Here, after extruding the above alloy into a wire with a diameter of 0.7 mm and cutting it to a length of about 5 mm, a tin-plated copper wire with a diameter of φ0.6 mm is welded to both ends, and a flux is applied to this alloy part IEC60691 defines that the ceramic case is inserted into a cylindrical ceramic case having an outer diameter of about 2.5 mm, an inner diameter of about 1.5 mm, and a length of about 10 mm, and the openings at both ends of the ceramic case are sealed with a thermosetting epoxy resin. It is known that when the operating temperature is measured by this method, it is 2 to 3 ° C. higher than the spheroidizing temperature of the alloy. Therefore, the spheroidizing temperature of the alloy + (2 to 3 ° C) can be expected as the operating temperature.

  Therefore, if the known eutectic alloy (1) is used, it is possible to provide one that operates at about 98 ° C., and using the known eutectic alloy (2) can provide one that operates at about 95 ° C. In addition, when the known eutectic alloy (3) is used, an alloy that operates at about 102 ° C. can be provided, and when the known eutectic alloy (4) is used, an alloy that operates at approximately 105 ° C. can be provided.

  In recent years, the movement to ban the use of harmful substances from the viewpoint of environmental conservation has become active, and in the EU (European Union) "Leader Hazardous Substances Regulation (RoHS Directive)" lead, mercury, cadmium, hexavalent Substances such as chromium are subject to regulation in principle, and there is a need to convert wiring materials, connection materials, and mounted parts used in equipment to those that do not contain the above substances.

  Lead and cadmium, which have been used as alloy type thermosensitive element materials until now, can no longer be used due to the above-mentioned substance restrictions, so an alloy type thermosensitive element material that does not contain them and a thermal fuse using the same are required. ing.

  The present invention has been made in view of such circumstances, and provides an alloy type thermosensitive element material that does not contain lead and cadmium, and a thermal fuse that operates on the order of 90 ° C. to 100 ° C. using the same. Is the purpose.

  In order to achieve the above object, the first alloy-type thermosensitive element material of the present invention has a zinc content of at least 6 parts by weight with respect to 100 parts by weight of an alloy composed of 52 ± 5% by weight of indium and the balance of tin. The gist is that the composition is added in an amount of not more than parts by weight.

  In order to achieve the above object, the second alloy type thermosensitive element material of the present invention is composed of 1 ± 1 part by weight of zinc with respect to 100 parts by weight of an alloy composed of 52 ± 5% by weight of indium and the balance of tin. The gist is that the composition is added in an amount of less than 5 parts by weight and bismuth in an amount of 5 parts by weight to less than 9 parts by weight.

  In order to achieve the above object, the first thermal fuse of the present invention is composed of 1 to 6 parts by weight of zinc with respect to 100 parts by weight of an alloy composed of 52 ± 5% by weight of indium and the balance of tin. The gist is that an alloy type thermosensitive element material having an added composition is used.

  In order to achieve the above object, the second thermal fuse of the present invention is composed of 1 to 5 parts by weight of zinc with respect to 100 parts by weight of an alloy composed of 52 ± 5% by weight of indium and the balance of tin. The main point is that an alloy type temperature sensitive element material having a composition in which bismuth is added in an amount of 5 parts by weight or more and less than 9 parts by weight is used.

  Among the problems described above, the present inventor has focused on an eutectic alloy having an indium-tin melting point of 117 ° C. to 119 ° C. as a means for providing a thermal fuse operating at a temperature of 100 ° C. In order to lower the operating temperature and make it spherical at a temperature of 100 ° C., various trials were repeated, and it was found that a temperature sensitive element that operates agilely can be obtained by adding zinc and bismuth.

  An alloy type thermosensitive element material which does not contain lead and cadmium, and a thermal fuse operating at 90 ° C. to 110 ° C. using the same have been obtained.

  Next, embodiments of the present invention will be described in detail.

  FIG. 1 is a diagram showing a thermal fuse to which the present invention is applied. In the thermal fuse 1, a fuse element 3 is provided between a pair of lead conductors 2. The fuse element 3 is composed of a low melting point soluble alloy 4 which is an alloy type temperature sensitive element material, and a rosin flux 5 applied to the soluble alloy 4. This flux 5 is applied to prevent oxidation of the fusible alloy 4 and to promote spheroidization when the fusible alloy 4 is melted.

  The fuse element 3 is housed in a cylindrical insulating case 6 made of ceramics, an insulating resin molded product or the like, and the openings at both ends of the insulating case 6 are closed by a sealing resin 7 such as an epoxy resin, The pair of lead conductors 2 and the fuse element 3 are fixed by the sealing resin 7.

  First, an alloy type temperature sensitive element material made of an In—Sn—Zn alloy will be described.

  The present inventor paid attention to a binary eutectic alloy having a melting point of 117 ° C. to 119 ° C. and having a melting point of 117 ° C. to 119 ° C. in order to provide a thermal fuse operating at a temperature of 100 ° C. It has been found that by adding zinc with a ratio alloy as a base alloy, the melting point can be lowered and spheroidized at a temperature of 100 ° C.

  Then, with respect to 100 g of the alloy composed of 52% by weight of indium and 48% by weight of tin, the alloys in which the addition amount of zinc was sequentially increased from 1 g were adjusted to obtain samples shown in Table 1 below.

  Each of the above samples is processed into a linear shape, flux is applied, placed on a temperature-controllable plate, heated to melt and spheroidize, the temperature of the nearby plate surface is read, the spheroidizing temperature is measured, and the spherical shape is measured. When the smoothness of crystallization was observed, the results shown in Table 1 below were obtained.

  As can be seen from Table 1 above, if zinc (Zn) is added within a range of 1 to 6 g with respect to 100 g of an alloy composed of 52% by weight of indium (In) and 48% by weight of tin (Sn), 105 to 110 It can be seen that a thermal fuse that operates smoothly at 105 to 110 ° C. can be provided if it is spheroidized smoothly at ° C. and this alloy is used as a temperature sensitive element.

  Thus, conventionally, in solder used for printed wiring boards of electrical and electronic equipment, zinc was supposed to reduce fluidization and hinder solderability, but if it is an application of an alloy type temperature sensitive element It was found that it works smoothly without spheroidizing up to a certain amount.

  In addition, when the addition amount of zinc is less than 1 part by weight, the spheroidizing temperature does not decrease to 110 ° C. or lower, and the operating temperature when commercialized does not become 110 ° C. or lower. It becomes difficult to make it smooth.

  However, with the addition amount of zinc within a range not deteriorating the spheroidizing property, the performance as an alloy-type thermosensitive element used for a thermal fuse operating at 90 to 100 ° C. described later, that is, the spheroidizing temperature is 90 to 100 ° C. It could not be reduced.

  As described above, in the present invention, based on an alloy composed of 52% by weight of indium and 48% by weight of tin as a reference composition, 1 to 6 parts by weight of zinc is added to 100 parts by weight of this alloy. did.

  Here, the base alloy having the reference values of 52% by weight of indium and 48% by weight of tin can be used by changing the composition by a few thousand within a range in which the composition of the reference may be sandwiched. For example, even if 54% by weight of indium and 46% by weight of tin are used, the melting point hardly changes and the temperature range of the solid-liquid coexisting phase is narrow. Similarly, even when 50 wt% indium and 50 wt% tin are used, the melting point hardly changes and the temperature range of the solid-liquid coexisting phase is narrow.

  If the alloy of the base is an alloy composed of 52 ± 5% by weight of indium and the balance of tin, the spheroidization can be used without any problem. By adding 1 to 6 parts by weight of zinc to 100 parts by weight of this base alloy, 44.3 to 56.5% by weight of indium, 40.57 to 52.5% by weight of tin, 0.99 of zinc It was possible to obtain an alloy type temperature sensitive element material of the present invention having a composition range of 5.7% by weight and the balance consisting of inevitable impurities.

  Next, an alloy type temperature sensitive element material made of an In—Sn—Zn—Bi alloy will be described.

  The present inventor tried to add bismuth (Bi) as a means for providing a thermal fuse operating at 90 to 100 ° C. among the above-mentioned problems in order to make it spherical at 90 to 100 ° C. With respect to 100 g of the base alloy composed of 52% by weight of indium and 48% by weight of tin, an alloy in which the addition amount of bismuth was sequentially increased from 1 g was prepared, and samples shown in Table 2 below were obtained.

  Each of the above samples is processed into a linear shape, flux is applied, placed on a temperature-controllable plate, heated to melt and spheroidize, the temperature of the nearby plate surface is read, the spheroidizing temperature is measured, and the spherical shape is measured. When the smoothness of crystallization was observed, the results shown in Table 2 below were obtained.

  As shown in Table 2 above, when the added amount of bismuth is up to about 7 g, it is smoothly spheroidized at 105 to 115 ° C., and feels like an alloy for operating at 105 to 115 ° C. as with the addition of zinc. Although it was possible to provide a temperature element material, the spheroidizing temperature did not fall below 100 ° C. even when the amount of bismuth added was increased to 10 g, and the spheroidization was slow, which was unsuitable for use. With the addition of 15 g, the spheroidizing temperature finally reached 98 ° C. and in the 90 ° C. range, but this spheroidization was slow and it was unsuitable for use as an alloy type thermosensitive element for operation at the 90 ° C. level. It was.

  As a result of further intensive studies, the present inventor has found that it is effective to add both bismuth and zinc to the base alloy.

  Then, an alloy in which 0.5 to 5 g of zinc and 0.1 to 10 g of bismuth are further added to 100 g of a base alloy composed of 52 wt% indium and 48 wt% tin is prepared as shown in the following table. 3 and the samples shown in Table 4 were obtained.

  Each of the above samples is processed into a linear shape, flux is applied, placed on a temperature-controllable plate, heated to melt and spheroidize, the temperature of the nearby plate surface is read, the spheroidizing temperature is measured, and the spherical shape is measured. As a result, the results shown in Tables 3 and 4 below were obtained.

  Thus, in the present invention, zinc is added in an amount of 1 to 5 parts by weight and bismuth is 5 parts by weight or more to 100 parts by weight of a base alloy composed of 52% by weight of indium and 48% by weight of tin. Less than 9 parts by weight were added. With this alloy type thermosensitive element material, a spheroidizing temperature was controlled at 90 to 105 ° C., and a thermal fuse operating in this temperature range was obtained.

  In addition, if the addition amount of zinc is less than 1 part by weight, the spheroidization temperature does not decrease to 100 ° C. or less, and conversely if it is 5 parts by weight or more, spheroidization is difficult to occur. On the other hand, if the amount of bismuth added is less than 5 parts by weight, the spheroidization temperature does not decrease to 100 ° C. or less, whereas if it is 9 parts by weight or more, spheroidization does not occur smoothly.

  Also in this example, the alloy having the reference values of 52% by weight of indium and 48% by weight of tin should be used with the composition varied by a few thousand within a range that may cause spheroidization with the composition of the reference in between. Can do. For example, even if 54% by weight of indium and 46% by weight of tin are used, the melting point hardly changes and the temperature range of the solid-liquid coexisting phase is narrow. Similarly, even when 50 wt% indium and 50 wt% tin are used, the melting point hardly changes and the temperature range of the solid-liquid coexisting phase is narrow.

  If the alloy of the base is an alloy composed of 52 ± 5% by weight of indium and the balance of tin, the spheroidization can be used without any problem. By adding 1 to 5 parts by weight of zinc to 100 parts by weight of this base alloy, and further adding 5 to 9 parts by weight of bismuth, 41.2 to 53.8% by weight of indium, tin Alloy type thermosensitive element material of the present invention having a composition range of 37.7 to 50% by weight, zinc 0.9 to 4.3% by weight, bismuth 4.7 to 7.8% by weight, and the balance consisting of inevitable impurities was gotten.

  An alloy (In: 47.27 wt% -Sn: 43.64 wt% -Zn) with an addition of 30 g of zinc and 70 g of bismuth to 1000 g of an alloy composed of 52 wt% indium and 48 wt% tin. : 2.73 wt%-Bi: 6.36 wt%) was extruded into a wire with a diameter of φ0.8 mm, and a tin-plated copper wire with a diameter of φ0.6 mm was welded to both ends of the cut piece. After applying flux to the part, it was inserted into a cylindrical ceramic case having an outer diameter of 3 mm, an inner diameter of 2 mm, and a length of 10 mm, and the openings at both ends of the ceramic case were sealed with a thermosetting epoxy resin as defined in IEC60691 The operating temperature was measured by the method. Table 5 below shows the results. As can be seen from Table 5, it can be seen that the device operates within a range of 98 to 99 ° C. with an operating temperature of 98.5 ° C. as the center.

  Next, the effect was confirmed by changing the composition of indium and tin in the base alloy having 52% by weight of indium and 48% by weight of tin as reference compositions.

  First, a base alloy in which the indium blending ratio was changed between 47 wt% and 57 wt% to make the balance tin was prepared, and a sample in which 3 wt parts of zinc was added to 100 wt parts of each base alloy was obtained. .

  Each of the above samples is processed into a linear shape, flux is applied, placed on a temperature-controllable plate, heated to melt and spheroidize, the temperature of the nearby plate surface is read, the spheroidizing temperature is measured, and the spherical shape is measured. When the smoothness of crystallization was observed, the results shown in Table 6 below were obtained.

  Next, the base alloy with tin as the balance is adjusted by changing the indium blending ratio between 47 wt% and 57 wt%, and 1 wt part of zinc and 6 wt% of bismuth with respect to 100 wt parts of each base alloy. A partially added sample was obtained.

  Each of the above samples is processed into a linear shape, flux is applied, placed on a temperature-controllable plate, heated to melt and spheroidize, the temperature of the nearby plate surface is read, the spheroidizing temperature is measured, and the spherical shape is measured. When the smoothness of crystallization was observed, the results shown in Table 7 below were obtained.

  From these results, it was found that if the base alloy composition is In52 ± 5 wt% and the remaining Sn is the base alloy, it can be used without any problem.

It is sectional drawing which shows the thermal fuse to which this invention is applied.

Explanation of symbols

1: thermal fuse 2: lead conductor 3: fuse element 4: fusible alloy 5: flux 6: insulating case 7: sealing resin

Claims (4)

  Alloy-type thermosensitive element material characterized in that zinc is added in an amount of 1 to 6 parts by weight with respect to 100 parts by weight of an alloy composed of 52 ± 5% by weight of indium and the balance of tin. .   It is a composition in which zinc is added in an amount of 1 to 5 parts by weight and bismuth to 5 to 9 parts by weight with respect to 100 parts by weight of an alloy composed of 52 ± 5% by weight of indium and the balance of tin. Alloy-type thermosensitive element material characterized by   An alloy-type thermosensitive element material having a composition in which zinc is added in an amount of 1 to 6 parts by weight with respect to 100 parts by weight of an alloy composed of 52 ± 5% by weight of indium and the balance of tin is used. Thermal fuse characterized by. An alloy having a composition in which zinc is added by 1 to 5 parts by weight and bismuth by 5 to 9 parts by weight with respect to 100 parts by weight of an alloy composed of 52 ± 5% by weight of indium and the balance of tin. A thermal fuse characterized by using a type thermosensitive material.

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