WO2017094400A1

WO2017094400A1 - Ptc element

Info

Publication number: WO2017094400A1
Application number: PCT/JP2016/081626
Authority: WO
Inventors: 正明岩井; 剛滝澤
Original assignee: Ｌｉｔｔｅｌｆｕｓｅジャパン合同会社
Priority date: 2015-12-01
Filing date: 2016-10-25
Publication date: 2017-06-08
Also published as: TW201721670A; KR20180088785A; JPWO2017094400A1; JP6779228B2

Abstract

The present invention provides a PTC element which comprises: a PTC unit that is in the form of a layer and has a first main surface and a second main surface; a first electrode that is positioned on the first main surface of the PTC unit; and a second electrode that is positioned on the second main surface of the PTC unit. This PTC element is characterized in that: at least a part of the first main surface is exposed; and the planar shapes of the first electrode and the second electrode are not the same.

Description

PTC element

The present invention relates to a PTC element.

Protective element that cuts off the current that flows through the electronic or electrical equipment when an abnormality occurs in the electronic or electrical equipment, for example, when excessive current flows through such equipment or when such equipment becomes extremely hot. Various protective elements such as bimetal elements, thermal fuse elements, PTC (positive temperature coefficient) elements (Patent Document 1), and the like are used.

US Pat. No. 6,051,814

When incorporating a PTC element into a device to be protected, the PTC element is fixed by caulking, bolts, screws, or the like. When the PTC element is fixed in this way, a certain pressure is applied to the PTC element, the expansion of the PTC element is hindered, and a malfunction such as failure to perform the original function or damage may occur.

For the reasons described above, various measures have been taken to reduce the pressure acting on the PTC element. For example, the pressure acting on the PTC element is relieved by disposing a resin gasket between the PTC element and a fixing member such as a screw. Moreover, the pressure which acts on a PTC element is relieve | moderated by fixing a PTC element with elastic members, such as a spring (for example, patent document 1). However, although such a measure can relieve the pressure acting on the PTC element to some extent, it may not be sufficient to exhibit the original function of the PTC element. Specifically, a decrease in resistance value in an operating state, a decrease in rated voltage, a decrease in current interruption response, and the like may occur. For example, the resistance value of a normal PTC element is several hundred thousand times higher than that at room temperature at a high temperature (for example, 130 ° C.), but increases only several hundred times when the PTC element is pressurized.

Therefore, the present inventors have conducted research in order to provide a PTC element that can be incorporated in an electronic or electric device without impairing the original function of the PTC element. As a result, the present inventors have designed the PTC element so that no pressure is applied to the expansion region of the PTC element, that is, the region where current flows when the PTC element is fixed. The inventors have found that the original function of the PTC element can be obtained. For example, an electrode located on one main surface of the PTC element extends to a region where the PTC element does not exist and is fixed by the extension, or on at least one main surface of the PTC element, It was found that the original function of the PTC element can be obtained by providing a portion where no electrode is present and fixing the portion where the electrode is not present.

However, as a result of further research, the PTC element as described above is fixed to an electronic or electric device by pressing only a part of the PTC element. I noticed that it might not be able to adhere well. For example, when the PTC element is annular and is fixed to the device by pressing the inner edge thereof, the fixing edge does not act on the outer edge portion of the PTC element, and cannot be sufficiently adhered to the device, There is a case.

Accordingly, an object of the present invention is to provide a PTC element that can sufficiently adhere to a fixing portion of an electronic or electric device even when only a part of the PTC element is pressed and fixed to the electronic or electric device. is there.

As a result of intensive studies on the above problems, the present inventors have peeled off part of the electrodes of the PTC element to expose the PTC element, so that when the PTC element trips, the position and shape of the exposed part of the PTC element It was found that the PTC element is deformed according to the above. And by utilizing this deformation | transformation, when the PTC element was fixed to the electronic or electric equipment, it discovered that a PTC element and an electronic or electric equipment could be stuck more closely, and came to this invention.

In the first aspect of the present invention,
A layered PTC element having a first main surface and a second main surface; a first electrode located on the first main surface of the PTC element; and a second electrode located on the second main surface of the PTC element. A PTC element comprising:
At least a portion of the first main surface is exposed;
A PTC element is provided in which the planar shapes of the first electrode and the second electrode are not the same.

In the second aspect of the present invention, there is provided an electronic or electric device comprising the PTC element described above.

According to the present invention, by exposing a part of the PTC element, even when only a part of the PTC element is pressurized and the PTC element is fixed, the PTC element can be brought into close contact with the fixing part of the electronic or electric device. A PTC element that can be provided can be provided.

FIG. 1 schematically shows a plan view of a PTC element 1a according to an embodiment of the present invention as viewed from the first electrode 8 side. FIG. 2 schematically shows a cross-sectional view in the thickness direction of the PTC element 1a along the line xx. FIG. 3 schematically shows a cross-sectional view after the PTC element 1a shown in FIG. FIG. 4 shows a state in which the PTC element 1a shown in FIG. 3 is fixed to an electric element. FIG. 5 schematically shows a cross-sectional view of the PTC element 1b in one embodiment of the present invention. FIG. 6 schematically shows a cross-sectional view of a PTC element 1c according to another embodiment of the present invention. FIG. 7 schematically shows a cross-sectional view of a PTC element 1d according to another embodiment of the present invention. FIG. 8 schematically shows a cross-sectional view of a PTC element 1e according to another embodiment of the present invention. FIG. 9 schematically shows a cross-sectional view of a PTC element 1f according to another embodiment of the present invention. FIG. 10 schematically shows a cross-sectional view of a PTC element 1g according to another embodiment of the present invention. FIG. 11 schematically shows a cross-sectional view of a PTC element 1h according to another embodiment of the present invention. FIG. 12 schematically shows a cross-sectional view of a PTC element 1i according to another embodiment of the present invention. FIG. 13 schematically shows a cross-sectional view of a PTC element 1j according to another embodiment of the present invention. FIG. 14 schematically shows a cross-sectional view of a PTC element 1k according to another embodiment of the present invention. FIG. 15 shows the measurement results of temperature-resistance characteristics at the time of temperature rise of the PTC element in the example. FIG. 16 shows measurement results of temperature-resistance characteristics when the temperature of the PTC element in the example is lowered.

The PTC element of the present invention will be described in detail with reference to the drawings.

As shown in FIGS. 1 and 2, a PTC element 1 a according to an embodiment of the present invention includes a layered PTC element 6 having a first main surface 2 and a second main surface 4, and a first PTC element 6. It has a first electrode 8 located on the main surface 2 and a second electrode 10 located on the second main surface 4 of the PTC element 6.

The PTC element used in the present invention is a polymer PTC element. The polymer PTC element can be a well-known one, and generally includes a polymer (for example, polyethylene, polyvinylidene fluoride, etc.) in which a conductive filler (for example, carbon black, nickel alloy, etc.) is dispersed. It is obtained by extruding a conductive composition comprising: In one embodiment, the PTC element may be a so-called polymer PTC element having a thin layered electrode (eg, a foil electrode) on at least one of its major surfaces. When the polymer PTC element expands in a high temperature state, the distance between the conductive fillers dispersed therein increases, and the resistance value increases.

The thickness of the PTC element is not particularly limited, but may be, for example, 0.01 mm to 5.0 mm, preferably 0.05 mm to 3.0 mm, more preferably 0.1 mm to 1.0 mm.

The materials constituting the first electrode and the second electrode used in the present invention may be the same or different. The material constituting the first electrode and the second electrode is not particularly limited as long as it is a conductive material. For example, a conductive metal material, specifically nickel, stainless steel, iron, copper, aluminum, tin, titanium, Or the alloy of those metals is mentioned. In the present invention, the first electrode and the second electrode may be composed of, for example, two or more conductive material layers, for example, a conductive metal layer.

The thicknesses of the first electrode and the second electrode are not particularly limited, but may be, for example, 0.01 to 1.0 mm, preferably 0.03 to 0.3 mm.

As shown in FIGS. 1 and 2, the first electrode 8 has two slits 12 along the diameter direction of the ring, and the first main surface 2 of the PTC element 6 is exposed from the slit portions. ing. That is, the first main surface 2 has an exposed portion 14. The second electrode 10 covers the entire second main surface 4 of the PTC element 6. The first electrode 8 and the second electrode 10 have different planar shapes, and the first electrode 8 is positioned so as to face a part of the second electrode 10 with the PTC element 6 therebetween. . In the present invention, the exposed portion 14 of the PTC element does not have to be covered with the first electrode 8 and may be covered with another material, for example, an insulating substance such as a protective coating.

By having the structure as described above, the PTC element 1a trips and generates heat, and when it returns to room temperature, the PTC element 1a is deformed due to the difference in coefficient of thermal expansion between the PTC element and the first electrode, and part or all of it Bend. That is, the PTC element of the present invention has a curved portion by tripping once. For example, as shown in FIG. 3, the PTC element 1a has a dish shape. By bending the PTC element 1a in this way, when the PTC element 1a is fixed to the installation location, the adhesion between the installation location and the first electrode of the PTC element 1a can be enhanced. For example, as shown in FIG. 4, the PTC element 1a deformed as shown in FIG. 3 is arranged so that the first electrode 8 is in contact with the electric element 16, and is fixed by pressing with a screw 18 from the second electrode 10 side. In this case, stress toward the electrical element (downward in the drawing) acts on the outer edge portion of the PTC element 1a. Since the outer edge portion of the PTC element 1a is pressed against the electric element 16 by this stress, the PTC element 1a and the electric element 16 can be in close contact with each other over the entire PTC element. It should be noted that the place and degree of bending can be adjusted by changing the thickness, shape, etc. of the PTC element, the first electrode, and the second electrode.

In the above, the PTC element 1a is first deformed and then fixed to the electric element 16. However, the PTC element 1a is first fixed to the electric element 16, and then the PTC element 1a is tripped and deformed. Also good. By deforming after fixing in this manner, the shape of the PTC element 1a can be made to correspond to the shape of the fixing portion of the electric element 16, and the adhesion can be further improved.

The present invention is not limited to the above-described embodiment, and various modifications can be made.

For example, in the above-described aspect, the PTC element, the first electrode (when there is no slit), and the second electrode are annular, but the PTC element, the first electrode, and the second electrode used in the present invention are circular. The shape is not limited to an annular shape, and may be any shape as long as the object of the present invention can be achieved. For example, in the above-described embodiment, the shape of the outer and inner contours (ie, openings) of the PTC element is circular, but these are other shapes such as polygons such as triangles, quadrangles, pentagons, ellipses, etc. Alternatively, the shape may be a combination of these. Moreover, the opening part of a PTC element does not necessarily need to exist in the center part of a PTC element, for example, may exist in the peripheral part of a PTC element. Moreover, the opening part does not need to exist. In addition, the first electrode and the second electrode need not be entirely present on the first and second major surfaces of the PTC element, respectively, and partially extend beyond the edge of the PTC element. It may be.

The shape of the slit (or notch) of the first electrode is not particularly limited, and can be various shapes depending on the purpose. That is, the shape of the exposed portion of the PTC element can be various shapes. The PTC element may have an exposed portion having a linear shape, a curved shape, a circular shape, an annular shape, a polygonal shape, or the like, or a combination thereof.

In one aspect, the PTC element may have one or more toroidal exposed portions. The size, width, position, number, and the like of the ring are not particularly limited, and can be appropriately selected according to the shape and size of the PTC element, the shape after deformation of the PTC element, and the like.

In a preferred embodiment, the width of the ring at the exposed portion may be 0.5 to 5.0 mm, more preferably 1.0 to 4.0 mm, and even more preferably 1.5 to 3.0 mm. When the PTC element has an annular shape, it may be 5 to 50%, more preferably 10 to 40%, and further preferably 15 to 35% with respect to the width of the ring of the PTC element. In addition, the width | variety of a ring may be constant over a perimeter, or may differ. Preferably, the width of the annulus is constant.

In one aspect, the PTC element may have one or more linear exposed portions. The size, width, position, number, and the like of the straight line are not particularly limited, and can be appropriately selected according to the shape and size of the PTC element, the shape after deformation of the PTC element, and the like.

In a preferred embodiment, the width of the straight line of the exposed portion may be 0.3 to 3.0 mm, more preferably 0.5 to 2.0 mm, and still more preferably 0.8 to 1.5 mm. Note that the width of the straight line may be constant or different. For example, the straight line may have a gradually widened shape. Preferably, the width of the straight line is constant.

In a preferred embodiment, the straight line length of the exposed portion is a length that completely crosses the first electrode in the direction from the center of the PTC element toward the outer periphery.

In one aspect, the PTC element may have one or more linear exposed portions and one or more annular exposed portions. The size, width, position, number, and the like of the ring and the straight line are not particularly limited, and can be appropriately selected according to the shape and size of the PTC element, the shape after deformation of the PTC element, and the like.

When the first electrode is divided into a plurality of parts as in the PTC element 1a, it is preferable that they have the same shape and are evenly arranged with respect to the central part of the PTC element. By being arranged uniformly in this way, the current flowing through the PTC element can be made uniform, and the operation of the PTC element can be further stabilized.

The shape of the second electrode is not particularly limited as long as it is not the same as the shape of the first electrode, and the installation position is not limited. The second electrode may completely cover the second main surface of the PTC element, or may cover only a part.

As described above, since the shapes of the first electrode and the second electrode are not the same in the PTC element of the present invention, the PTC element has a portion that is not sandwiched between the first electrode and the second electrode. That is, there is a portion where at least one of the first main surface and the second main surface is exposed. In such a portion of the PTC element, substantially no current flows. Therefore, when the PTC element of the present invention is fixed to a device, the portion where at least one of the first main surface and the second main surface is exposed is fixed by, for example, caulking or fixing with a screw. be able to. At the fixed location, pressure acts so as to compress the PTC element in the thickness direction, but such a pressure is not applied to a portion sandwiched between the first electrode and the second electrode of the PTC element, that is, a portion where current flows. . Therefore, when the PTC element trips, the expansion of the PTC element is not hindered, and the PTC element can exhibit its original function.

The portion where at least one of the first main surface and the second main surface is exposed preferably exists along the inner edge of the PTC element when the PTC element is annular.

Accordingly, the present invention, in one aspect,
An annular and layered PTC element having a first main surface and a second main surface, a first electrode located on the first main surface of the PTC element, and a second electrode located on the second main surface of the PTC element A PTC element comprising:
At least a portion of the first main surface is exposed;
The shape of the first electrode and the second electrode is not the same,
A PTC element is provided in which at least one of the first main surface and the second main surface has an annular exposed portion along the inner edge of the PTC element.

In another embodiment, the first electrode or the second electrode may extend beyond the edge of the PTC element. In this way, by extending one electrode beyond the edge of the PTC element, it is possible to fix the PTC element with a screw or caulking or the like without applying pressure to the PTC element by using the extended portion. It becomes possible. Therefore, when the PTC element trips, the PTC element can exhibit its original function without being hindered from expanding.

Accordingly, the present invention, in one aspect,
A layered PTC element having a first main surface and a second main surface; a first electrode located on the first main surface of the PTC element; and a second electrode located on the second main surface of the PTC element. A PTC element comprising:
At least a portion of the first main surface is exposed;
The shape of the first electrode and the second electrode is not the same,
The PTC element, the first electrode and the second electrode are annular, and are arranged so that their centers coincide;
The inner diameter of the first electrode is smaller than the inner diameter of the PTC element and the inner diameter of the second electrode is the same as or larger than the inner diameter of the PTC element, or the inner diameter of the first electrode is the same as or larger than the inner diameter of the PTC element. Bigger,
A PTC element is provided in which the inner diameter of the second electrode is smaller than the inner diameter of the PTC element.

In addition, in this specification, when the 1st electrode and the 2nd electrode are annular, when it is assumed that they do not have a slit or a notch, they are also said to be annular. For example, the first electrode 8 in the PTC element 1a of the above-described embodiment has an annular shape.

Examples of embodiments of the PTC element of the present invention other than the above-described PTC element 1a include the following PTC elements. Although the second electrode is not shown, it is preferable that the second electrode exists so as to cover the entire PTC element.

Aspect 2 (FIG. 5): An annular PTC element, in which the PTC element 6 has one linear exposed portion 22 along the diameter direction of the ring.
Aspect 3 (FIG. 6): An annular PTC element, in which the PTC element 6 has four linear exposed portions 22 along the diameter of the ring. The four exposed portions exist at an equal angle with respect to the center of the ring.
Aspect 4 (FIG. 7): An annular PTC element, in which the PTC element 6 has one annular exposed portion 24 along the inner edge.
Aspect 5 (FIG. 8): An annular PTC element in which the PTC element 6 has an annular exposed portion 24 along the inner edge thereof, and a linear exposed portion 22 along the annular diameter direction. 1 PTC element 1e.
Aspect 6 (FIG. 9): An annular PTC element in which the PTC element 6 has an annular exposed portion 24 along the inner edge thereof, and a linear exposed portion 22 along the annular diameter direction. PTC element If having two. The two linear exposed portions 22 are equiangular with respect to the center of the ring.
Aspect 7 (FIG. 10): An annular PTC element in which the PTC element 6 has an annular exposed portion 24 along the inner edge thereof, and a linear exposed portion 22 along the annular diameter direction. 1g of PTC element having four. The four linear exposed portions 22 are equiangular with respect to the center of the ring.
Aspect 8 (FIG. 11): An annular PTC element having an annular first electrode 20 along the inner edge on the PTC element 6 and an annular exposed portion 24 on the outside thereof. And a PTC element 1h having an annular first electrode 21 on the outer side.
Aspect 9 (FIG. 12): A PTC element 1i in which the inner first electrode 20 and the outer first electrode 21 of the PTC element of aspect 8 are partially connected.
Aspect 10 (FIG. 13): A PTC element 1j in which the outer first electrode 21 of the PTC element according to aspect 9 is divided by four exposed portions 22 that are linear along the annular diameter direction.
Aspect 11 (FIG. 14): A PTC element 1 k in which the inner first electrode 20 of the PTC element of Aspect 10 extends inward beyond the inner edge of the PTC element 6. The dotted line indicates the inner edge of the PTC element.

The PTC element of the present invention can be manufactured by separately manufacturing the PTC element, the first electrode and the second electrode, and bonding them together. Alternatively, an element in which both main surfaces of the PTC element are completely covered with the first electrode and the second electrode is obtained, and the electrode corresponding to the exposed portion is cut off by etching, sandblasting, cutter, or the like. Can be manufactured.

Even when the PTC element of the present invention is attached to an electronic or electric device by pressing only a part of the PTC element with a screw, caulking, etc., the entire PTC element is brought into close contact with the electronic or electric device. Is easy. Further, the electrode located on one main surface of the PTC element is extended to a region where the PTC element does not exist and is fixed by the extending portion, or the electrode is provided on at least one main surface of the PTC element. Since a portion where no electrode is present can be provided and fixed at a portion where the electrode does not exist, expansion of the PTC element is not inhibited, and the original function of the PTC element can be exhibited. Therefore, the PTC element of the present invention can be suitably used as a protective element for various electronic or electric devices such as cigarette lighter sockets, secondary batteries, secondary battery cells, vacuum cleaners, refrigerators, and automobile parts.

Therefore, in the second aspect, the present invention provides an electronic or electric device comprising the above-described PTC element of the present invention.

Although the present invention has been described with reference to the drawings, the present invention is not limited to this, and various modifications are possible.

Example 1
An annular PTC element having an outer diameter of 21 mm and an inner diameter of 8.3 mm, having a first electrode and a second electrode, was prepared on the entire first main surface and second main surface of the PTC element, respectively. A part of the first electrode of the PTC element is cut out with a cutter, the inner diameter of the first electrode is 14 mm, and two slits having a width of 1 mm are formed at an equal angle (target) with respect to the center of the ring. A PTC element as described in (1) was obtained (not curved).

The above PTC element was fixed by tightening with a screw (screw head outer diameter: 8.0 mm) and a bolt with the first electrode facing the socket and the first electrode facing the socket (tightening torque: 1 kgf). Screws and sockets are insulated. In this state, the PTC element was tripped three times, and the temperature-resistance characteristics between the socket and the second electrode at the time of temperature increase and temperature decrease were measured. FIG. 15 shows the results when the temperature was raised, and FIG. 16 shows the results when the temperature was lowered.

As shown in FIGS. 15 and 16, the resistance value exceeded 10 ⁸ at the first temperature increase. This is considered because the outer edge portion of the first electrode of the PTC element and the socket are not sufficiently in contact. The resistance value suddenly decreased at the first temperature drop. This is presumably because the PTC element was bent toward the socket and the first electrode was in close contact with the socket surface. In the second and third times, good PTC characteristics were confirmed both when the temperature was raised and when the temperature was lowered.

The PTC element of the present invention can be used as a protective element for a wide variety of electronic or electrical equipment.

1a to 1k ... PTC element, 2 ... first main surface, 4 ... second main surface,
6 ... PTC element, 8 ... 1st electrode, 10 ... 2nd electrode, 12 ... Slit,
14 ... exposed portion, 16 ... electric element, 18 ... screw, 20 ... first electrode,
21 ... first electrode, 22 ... exposed portion, 24 ... exposed portion

Claims

A layered PTC element having a first main surface and a second main surface; a first electrode located on the first main surface of the PTC element; and a second electrode located on the second main surface of the PTC element. A PTC element comprising:
At least a portion of the first main surface is exposed;
A PTC element, wherein the planar shape of the first electrode and the second electrode is not the same.
The PTC element according to claim 1, wherein the entire second main surface is covered with the second electrode.
The PTC element according to claim 1 or 2, wherein the PTC element, the first electrode, and the second electrode have openings.
The PTC element according to any one of claims 1 to 3, wherein the PTC element, the first electrode, and the second electrode have an annular shape and are arranged so that their centers coincide with each other. .
The PTC element according to any one of claims 1 to 4, wherein the first main surface has an annular exposed portion.
The PTC element according to any one of claims 1 to 5, wherein the first main surface has one or more linear exposed portions.
The first main surface has a plurality of linear exposed portions along the diameter direction of the ring, and the plurality of linear exposed portions exist at an equal angle with respect to the center of the ring, The PTC element according to any one of claims 4 to 6.
The first main surface has 2 to 4 linear exposed portions at an equal angle with respect to the center of the ring along the diameter direction of the ring. A PTC element according to 1.
Either of the first electrode or the second electrode extends from the main surface of the PTC element beyond its edge and into the opening. The PTC element according to any one of the above.
The PTC element, the first electrode and the second electrode are annular, and are arranged so that their centers coincide;
The inner diameter of the first electrode is smaller than the inner diameter of the PTC element;
The PTC element according to claim 9, wherein the inner diameter of the second electrode is equal to or larger than the inner diameter of the PTC element.
The PTC element according to any one of claims 1 to 10, which has a curved portion.
An electronic or electrical device comprising the PTC element according to any one of claims 1 to 11.