JP4682978B2 - Surface mount type current fuse and manufacturing method thereof - Google Patents

Description

  The present invention relates to a surface-mount current fuse that melts and protects various electronic devices when an overcurrent flows, and a method of manufacturing the same.

  As shown in FIG. 7, this conventional surface mount type current fuse has a space 3 formed between a case 1 made of ceramic and a lid 2 made of ceramic, and an element is formed in the space 3. In addition to the arrangement of the part 4, external electrodes 5 connected to the element part 4 were provided at both ends of the case 1.

As prior art document information relating to the invention of this application, for example, Patent Document 1 is known.
JP-A-8-222117

  In the conventional surface mount type current fuse described above, since the case 1 and the lid body 2 have different shapes, a plurality of molds are required, thereby causing a problem that productivity is inferior.

  SUMMARY OF THE INVENTION The present invention solves the above-described conventional problems, and an object thereof is to provide a surface-mount current fuse that can improve productivity and a method for manufacturing the same.

  In order to achieve the above object, the present invention has the following configuration.

  The invention according to claim 1 of the present invention includes a first base having a recess and a shape in which the height of the other end is made lower than the height of the one end in the longitudinal direction, and the first base. And a second base having substantially the same shape, and a second base on the upper surface of the first base so that one end of the first base and the other end of the second base are in contact with each other. A rectangular main body is formed by joining the lower surface of the base, and an element portion is disposed in a space formed by the concave portion in the first base and the concave portion in the second base, and The boundary between the first base and the second base is configured to pass through the center of the side surface of the main body. According to this configuration, the first base and the second base Are configured in substantially the same shape, so only one mold is required for the base, thereby improving productivity. In addition, since the boundary line between the first base and the second base passes through the center of the side surface of the main body, the space between the first base and the second base There is no gap, and this can prevent the element portion from being deteriorated by the flux or solder at the time of solder dipping and the fusing characteristics from being deteriorated. In addition, since the first base and the second base have a shape in which the height of the other end is lower than the height of the one end in the longitudinal direction, the one end and the other end of the element portion are different planes. As a result, the length of the element part is inevitably increased, so that when the overcurrent flows, the heat capacity of the element part can be increased, resulting in a surface mount type current fuse with excellent inrush resistance. The effect of being obtained is obtained.

  In the invention according to claim 2 of the present invention, in particular, the first base and the second base each have a height on one end side higher than the center line in the longitudinal direction and a height on the other end side. According to this configuration, one end and the other end of the element portion can be easily positioned on different planes, so that the length of the element portion can be easily increased. The effect that it is possible to obtain is obtained.

  In the invention according to claim 3 of the present invention, in particular, the first base and the second base are configured such that their heights are linearly different from one end to the other end in the longitudinal direction. Therefore, according to this configuration, since the upper surface of the first base becomes a flat surface, it is possible to easily apply the adhesive, thereby obtaining the effect of increasing the productivity. It is.

  In the invention according to claim 4 of the present invention, in particular, a plurality of grooves are respectively formed at one end in the longitudinal direction of the first base and the second base, and one end of the first base is formed. The element portion is bridged between any one of the groove portions and any one of the groove portions at one end portion of the second base. According to this configuration, the groove portion on which the element portion is placed is selected. As a result, the operational effect that the length of the element portion can be easily finely adjusted can be obtained.

  According to a fifth aspect of the present invention, there is provided a first base and a first base having a concave portion and a height at the other end lower than a height at one end in the longitudinal direction, using the same mold. And a lower surface of the second base on the upper surface of the first base so that one end of the first base and the other end of the second base are in contact with each other. And a step of disposing an element portion in a space formed by the concave portion of the first base and the concave portion of the second base. However, according to this manufacturing method, since the first base and the second base are configured in substantially the same shape by the same mold, only one mold is required for the base. The effect that productivity can be improved is obtained.

  As described above, the surface mount type current fuse of the present invention has a first base having a recess and a shape in which the height of the other end is lower than the height of the one end in the longitudinal direction, and the first base. A second base having substantially the same shape as that of the base, and a first base on the upper surface of the first base so that one end of the first base and the other end of the second base are in contact with each other. The lower surface of the second base is joined to form a rectangular main body, and the element portion is disposed in a space formed by the recess in the first base and the recess in the second base. In addition, since the boundary line between the first base and the second base passes through the center of the side surface of the main body, only one mold is required. It has an excellent effect that productivity can be improved.

  Hereinafter, a surface-mount current fuse according to an embodiment of the present invention will be described with reference to the drawings.

  1 is a perspective view of a surface mount type current fuse according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line AA of FIG. 1, and FIG. 3 is a perspective top view of a main part of the surface mount type current fuse. is there.

  As shown in FIGS. 1 to 3, the surface-mount current fuse according to the embodiment of the present invention has a recess 11 and the height of the other end portion 12 b is lower than the height of the one end portion 12 a in the longitudinal direction. The first base 13 having the shape and the second base 14 having substantially the same shape as the first base 13, the one end 12 a of the first base 13 and the second base 14, the lower surface of the second base 14 is joined to the upper surface of the first base 13 so as to be in contact with the other end portion 12 b of the first base 13, thereby forming the rectangular main body 15, and the first base 13, an element portion 17 is disposed in a space portion 16 constituted by the recess 11 in the second base 14 and the recess 11 in the second base 14, and the boundary between the first base 13 and the second base 14. The wire is configured to pass through the center of the side surface of the main body 15.

  The first base 13 and the second base 14 are made of an insulating material made of ceramic or resin, and are formed of the same mold and have substantially the same shape. In addition, as shown in FIG. 4, both the shapes are configured such that the height on the one end 12 a side is higher than the center line L in the longitudinal direction of the main body portion 15 and the height on the other end 12 b side is lower. The height is in two stages. Moreover, as shown in FIG. 2, a plurality of groove portions 18 are respectively formed at one end portion 12a in the longitudinal direction of the first base 13 and the second base 14, and the groove portions 18 are Although there are three in FIG. 3, other numbers may be used. Further, the same number of grooves 18 formed in the first base 13 and the second base 14 are formed at the same location.

  The main body 15 includes a first base 13 and a second base 14, and one end 12 a of the first base 13 and the other end 12 b of the second base 14 And the other end 12b of the first base 13 and the one end 12a of the second base 14 are in contact, that is, the first base 14 is rotated 180 degrees. The lower surface of the second base 14 is joined to the upper surface of the base 13. Moreover, the main-body part 15 is square shape, and the external shape of the cross section is a square or a rectangle.

  The upper surface of the first base 13 and the lower surface of the second base 14 are bonded with an adhesive. In addition, a heat-shrinkable tube may be provided in the periphery in order to reliably prevent flux or solder at the time of solder dipping from entering the space portion 16 and deteriorating the element portion 17.

  When the upper surface of the first base 13 and the lower surface of the second base 14 are joined together, the space 16 opposes the concave portion 11 in the first base 13 and the concave portion 11 in the second base 14. It is constituted by making it. The element portion 17 is made of a metal having good conductivity, such as silver, copper, nickel, and aluminum. The element portion 17 is disposed inside the space portion 16 and melts at a high temperature when an overcurrent flows. It has a function to cut off power. One end portion of the element portion 17 is placed on the upper surface of the portion where the height of the first base 13 is high, and the other end portion is placed on the upper surface of the portion where the height of the first base 13 is low. Placed. That is, since the first base 13 and the second base 14 have the other end 12b lower in height than the one end 12a in the longitudinal direction, the one end and the other end of the element portion 17 are It can arrange | position in a different plane, Thereby, the length of the element part 17 can be lengthened easily.

  The element portion 17 is either one of the groove portions 18 provided in the one end portion 12a of the first base 13 or one of the groove portions 18 provided in the one end portion 12a of the second base 14. It is bridged between one. In FIG. 3, the element portion 17 is placed in the central groove portion 18 among the three groove portions 18. At this time, if the element portion 17 is placed in the left groove portion 18 and the right groove portion 18, the length of the element portion 17 can be maximized. Thus, by selecting the groove portion 18 on which the element portion 17 is placed, the length of the element portion 17 can be easily finely adjusted, thereby adjusting the fusing characteristics and adjusting the length of the element portion 17. By doing so, the resistance value of the element part 17 can also be finely adjusted.

  Furthermore, external electrodes 19 formed by a rectangular tube-shaped electrode cap having a function as a connection terminal between the element portion 17 and the outside are formed at both ends of the square-shaped main body portion 15, and this corner The cylindrical electrode cap is attached by press-fitting the cylindrical portion into both end portions of the rectangular main body portion 15. In addition, the bonding between the first base 13 and the second base 14 can be strengthened by the electrode cap.

  The height of the first base 13 on the one end 12a side and the other end 12b side is not two steps as shown in FIG. 4, but three steps or more as shown in FIG. Alternatively, the boundary line between the first base 13 and the second base 14 may be linear as shown in FIG. In this way, when the boundary line is linear, since the upper surface of the first base 13 is a flat surface, the adhesive can be easily applied with a roller or the like, thereby improving productivity. It is.

  At this time, as viewed from the side surface of the main body portion 15, the boundary line between the first base 13 and the second base 14 passes through the central portion of the side surface of the main body portion 15. The base 13 and the second base 14 can be joined without a gap. Accordingly, it is possible to prevent the flux or solder at the time of solder dipping from adhering to the element portion 17 and deteriorating the element portion 17, thereby preventing deterioration of the fusing characteristics.

  Next, a method for manufacturing a surface-mount current type fuse according to an embodiment of the present invention will be described.

  In FIG. 1 to FIG. 3, first, a first base 13 having a concave portion 11 and having a shape in which the height of the other end portion 12 b is lower than the height of the one end portion 12 a in the longitudinal direction, using the same mold. A second base 14 is formed. The first base 13 and the second base 14 are each formed with a plurality of groove portions 18 at the same location.

  Next, the element portion 17 is bridged between any one of the plurality of groove portions 18 formed on the first base 13 and any one of the plurality of groove portions 18 formed on the second base 14. In this state, the second base is applied while applying an adhesive to the upper surface of the first base 13 so that the one end 12a of the first base 13 and the other end 12b of the second base 14 are in contact with each other. A rectangular main body 15 is formed by joining the lower surface of the base 14. At this time, the space portion 16 is formed by making the concave portion 11 in the first base 13 and the concave portion 11 in the second base 14 face each other, and the element portion 17 is disposed inside the space portion 16. . Finally, external electrodes 19 are formed on both ends of the main body 15.

  In the above-described embodiment of the present invention, the first base 13 and the second base 14 are configured to have substantially the same shape, so that the bases 13 and 14 have only one mold. Thereby, the effect that productivity can be improved is acquired. In addition, since the boundary line between the first base 13 and the second base 14 passes through the center of the side surface of the main body 15, the first base 13 and the second base There is no gap between the base 14 and this can prevent the element portion 17 from being deteriorated by flux, solder or the like at the time of solder dipping and deteriorating the fusing characteristics.

  Further, in the surface mount type current fuse, if the length of the element portion 17 is increased in the space portion 16, heat is radiated from the both end portions of the element portion 17 to the external electrode 19 when an overcurrent flows at the time of abnormality. In addition, since the resistance value of the element portion 17 can be increased, the central portion of the element portion 17 can be heated to a higher temperature, thereby obtaining an excellent quick disconnection property. That is, it can be quickly blown when an abnormality occurs. In addition, since it can be melted quickly, it can be melted even if the diameter of the element part 17 is increased, and the heat capacity of the entire element part 17 can be increased by increasing the length of the element part 17, A surface mount type current fuse excellent in inrush resistance can be obtained.

  On the other hand, in the above-described embodiment of the present invention, the first base 13 and the second base 14 have a shape in which the height of the other end 12b is lower than the height of the one end 12a in the longitudinal direction. Therefore, one end portion and the other end portion of the element portion 17 can be formed on different planes, whereby the length of the element portion 17 can be increased, and further, by selecting the groove portion 18 on which the element portion 17 is placed, Since the length of the element portion 17 can be increased, excellent quick disconnection and inrush resistance can be obtained.

  Therefore, in the surface mount type current fuse according to the embodiment of the present invention, the productivity can be improved by using a single mold, and the length of the element portion 17 can be improved. High fastness and inrush resistance can be obtained.

  The surface mount type current fuse and the manufacturing method thereof according to the present invention have an effect that productivity can be improved, and in particular, a surface mount type current that melts and protects various electronic devices when an overcurrent flows. This is useful in fuses and the like.

The perspective view of the surface mount type current fuse in one embodiment of the present invention AA line sectional view of FIG. Perspective top view of the main part of the same surface mount type current fuse Side view of the same surface mount type current fuse Side view showing another example of the same surface mount type current fuse Side view showing another example of the same surface mount type current fuse Cross section of a conventional current fuse

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Recessed part 12a One end part 12b Other end part 13 1st base 14 2nd base 15 Main part 16 Space part 17 Element part 18 Groove part

Claims (5)

A first base having a recess and a shape in which the height of the other end is made lower than the height of the one end in the longitudinal direction, and a second base having the same shape as the first base A rectangular main body by joining the lower surface of the second base to the upper surface of the first base so that one end of the first base and the other end of the second base are in contact with each other And an element portion is disposed in a space portion formed by the concave portion in the first base and the concave portion in the second base, and further, the first base and the second base Surface mount type current fuse that is configured so that the boundary line with the center part of the side of the body part passes through. 2. The surface according to claim 1, wherein the first base and the second base are each configured such that the height on one end side is higher than the center line in the longitudinal direction and the height on the other end side is lower. Mounting type current fuse. 2. The surface mount type current fuse according to claim 1, wherein the first base and the second base are configured such that their heights are linearly different from one end to the other end in the longitudinal direction. A plurality of grooves are formed at one end in the longitudinal direction of the first base and the second base, respectively, and one of the grooves at one end of the first base and one end of the second base 2. The surface mount type current fuse according to claim 1, wherein the element portion is bridged between any one of the groove portions. Forming a first base and a second base having a recess and having a height at the other end lower than the height at the one end in the longitudinal direction, using the same mold; A rectangular main body is configured by joining the lower surface of the second base to the upper surface of the first base so that one end of the first base and the other end of the second base are in contact with each other. A method of manufacturing a surface mount type current fuse, comprising: a step; and a step of disposing an element portion in a space portion constituted by a concave portion in the first base and a concave portion in the second base.

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