JP2019174133A - Temperature sensor - Google Patents

Abstract

To provide a temperature sensor which is easy in mounting on a measurement object and can ensure insulation between a lead frame and a crimping terminal.SOLUTION: A temperature sensor includes: a heat sensitive element part 2; a pair of lead frames 3 connected to the heat sensitive element part; and a crimping terminal 6 having a screw mounting part 4 capable of being fixed to the measurement object on the tip side and also having an element mounting part 5, to which the heat sensitive element part is attached, on the rear end side. The heat sensitive element part includes: an insulating film; a thermistor element; a pair of pattern wiring; and a sealing resin part covering the thermistor element. The element mounting part includes: a bottom surface portion 5a to which the insulating film is adhered; and a pair of wall surface parts 5b standing on both sides of the bottom surface part. A pair of notches 5d is formed in a rear end part of a pair of wall surface parts and a portion close to the bottom surface part.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a temperature sensor that can be easily attached to a measurement object.

Conventionally, as a temperature sensor, a lead wire is attached to a chip-like or flake-like thermistor element, the thermistor element is resin-molded together with the lead wire connecting portion, and this portion is attached to a crimp terminal by crimping or bonding. (For example, see Patent Documents 1 and 2).
In this temperature sensor, an annular portion that can be screwed and attached to a crimp terminal, which is a so-called R terminal, is provided, so that the screw is inserted into this portion and is screwed onto a female screw portion or the like of an object to be measured. By doing so, the temperature sensor can be easily screwed to the measurement object.

In the temperature sensor described in Patent Document 1, the periphery of the thermistor element sealed with glass is further covered with a sealing resin. In the structure in which the glass-sealed thermistor element is sealed with a resin, the position of the element is not stable in manufacturing, and there is a disadvantage that the responsiveness varies.
On the other hand, in the temperature sensor described in Patent Document 2, the heat-sensitive element portion is connected to the insulating film attached to the crimp terminal, the thin film thermistor portion formed on the insulating film, and the thin film thermistor portion. And a pattern electrode formed on the film. That is, this temperature sensor can receive higher heat responsiveness stably by directly receiving the heat from the crimp terminal with the insulating film without passing through the glass or the sealing resin.

JP 2012-141164 A Japanese Patent Application Laid-Open No. 2006-161434

The following problems remain in the conventional technology.
That is, in the conventional structure in which the thermistor element is provided on the insulating film and mounted on the crimp terminal, when the lead frame is connected to the pattern electrode formed on the insulating film, if the lead frame and the crimp terminal are reduced in size, There is an inconvenience that it becomes difficult to secure insulation as the distance becomes shorter. In particular, when the lead frame is displaced, the distance between the lead frame and the crimp terminal is closer, and the lead frame protruding from the sealing resin portion may be too close to or in contact with the crimp terminal.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a temperature sensor that can be easily attached to an object to be measured and can ensure insulation between a lead frame and a crimp terminal. .

  The present invention employs the following configuration in order to solve the above problems. That is, the temperature sensor according to the first aspect of the present invention includes a thermal element portion, a pair of lead frames connected to the thermal element portion, and a screw attachment portion that can be fixed to a measurement object with a screw on the distal end side and a rear side. A crimp terminal having an element attachment portion to which the thermal element portion is attached on the end side, and the thermal element portion is provided on the surface of the insulating film and an insulating film bonded to the crimp terminal. A thermistor element, and a pair of pattern wirings formed on the surface of the insulating film and having one end connected to the thermistor element and the other end connected to the pair of lead frames, and the element mounting portion, A bottom surface portion to which the insulating film is bonded; and a pair of wall surface portions standing on both sides of the bottom surface portion; the rear end portions of the pair of wall surface portions and the proximity to the bottom surface portion A portion that, wherein a pair of notches are formed.

  In this temperature sensor, the element mounting portion includes a bottom surface portion to which the insulating film is bonded and a pair of wall surface portions erected on both sides of the bottom surface portion, and a rear end portion and a bottom surface portion of the pair of wall surface portions. The notch is formed in the adjacent part, so even if the lead frame is downsized or the lead frame is misaligned, the notch increases the distance between the lead frame and the wall surface, ensuring insulation. can do.

The temperature sensor according to a second invention is characterized in that, in the first invention, the cutout portion extends to a part of the bottom portion and is cut out.
That is, in this temperature sensor, the notch extends to a part of the bottom surface and is cut away, so that the distance between the exposed lead frame and the bottom surface is also increased, thereby ensuring more insulation. Can do.

A temperature sensor according to a third invention is characterized in that, in the first or second invention, a rear end portion of the insulating film protrudes from the bottom surface portion.
That is, in this temperature sensor, since the rear end portion of the insulating film protrudes from the bottom surface portion, the rear end portion of the insulating film is interposed between the exposed lead frame and the bottom surface portion, Insulation with the bottom portion can be further ensured.

The present invention has the following effects.
That is, according to the temperature sensor of the present invention, the element mounting portion includes a bottom surface portion to which the insulating film is bonded, and a pair of wall surface portions erected on both sides of the bottom surface portion. Since the notch is formed in the rear end and the part close to the bottom, even if the lead frame is downsized or the lead frame is displaced, the notch increases the distance between the lead frame and the wall surface. Thus, insulation can be ensured.
Therefore, the temperature sensor of the present invention can ensure insulation even if it is downsized in a device or the like that needs to be attached to a measurement object, and can have high reliability.

It is the perspective view seen from the lower part which shows one Embodiment of the temperature sensor which concerns on this invention. In this embodiment, it is the perspective view seen from the top which shows a temperature sensor. In this embodiment, it is a top view which shows a temperature sensor. In this embodiment, it is a bottom view which shows a temperature sensor. In this embodiment, it is the perspective view seen from the top which shows the temperature sensor before resin sealing. In this embodiment, it is a top view of the principal part which shows a temperature sensor.

  Hereinafter, an embodiment of a temperature sensor according to the present invention will be described with reference to FIGS. 1 to 6. In each drawing used for the following description, the scale is appropriately changed in order to make each member recognizable or easily recognizable.

  As shown in FIGS. 1 to 4, the temperature sensor 1 of the present embodiment includes a thermal element portion 2, a pair of lead frames 3 connected to the thermal element portion 2, and screws that can be fixed to a measurement object with screws. A crimping terminal 6 having an attachment portion 4 on the front end side and an element attachment portion 5 to which the thermosensitive element portion 2 is attached is provided on the rear end side.

  As shown in FIGS. 5 and 6, the thermal element portion 2 includes an insulating film 7 bonded to the crimp terminal 6, a thermistor element 8 provided on the surface of the insulating film 7, and an insulating film 7. A pair of pattern wirings 9 formed on the surface and having one end connected to the thermistor element 8 and the other end connected to the pair of lead frames 3, and a sealing resin portion 10 covering the thermistor element 8 on the insulating film 7 And has.

The element mounting portion 5 includes a bottom surface portion 5a to which the insulating film 7 is bonded, a pair of wall surface portions 5b erected on both sides of the bottom surface portion 5a, and a bottom surface portion 5a on the tip side of the pair of wall surface portions 5b. And a front surface portion 5c.
That is, a U-shaped region in plan view by the pair of wall surface portions 5b and the front surface portion 5c on the bottom surface portion 5a is an installation region for the heat sensitive element portion 2 that surrounds the heat sensitive element portion 2 from three directions.

A pair of cutout portions 5d is formed in a portion close to the rear end portion and the bottom surface portion 5a of the pair of wall surface portions 5b.
That is, at least a part of a portion of the wall surface portion 5b located just beside the front end portion of the lead frame 3 is cut out to form a cutout portion 5d.

The cutout portion 5d is cut out so as to extend to a part of the bottom surface portion 5a. That is, the cutout portion 5d is constituted by a portion cut out in an arc shape at the rear end portion of the wall surface portion 5b and a portion cut out in an arc shape at the rear end portion of the bottom surface portion 5b.
The size of the cutout portion 5d is appropriately set according to the distance A between the lead frame 3 and the wall surface portion 5b without the cutout portion 5d and the maximum value of the assembly error.

  The wall surface portion 5b is erected on the bottom surface portion 5a by being bent from a flat plate state, but the notch portion 5d is previously cut in a semicircular shape in a flat plate state before the wall surface portion 5b is bent. Thereafter, the wall surface portion 5b is bent to form the corner portion of the element mounting portion 5.

The rear end portion of the insulating film 7 protrudes from the bottom surface portion 5a.
The protrusion amount B from the bottom surface portion 5a of the rear end portion of the insulating film 7 is appropriately set according to the maximum value of the assembly error.
In addition, the recessed part 5e is formed in the outer surface center part of a pair of wall surface part 5b, respectively, and the convex part 5f is formed in the inner surface center part, respectively.
The convex portion 5 f is in a state where it is difficult to enclose the inner sealing resin portion 10, and has a function of strengthening the fixing of the sealing resin portion 10.

The sealing resin portion 10 is made of, for example, epoxy resin, and the thermistor element 8, the insulating film 7, and the tip of the lead frame 3 are disposed in a portion surrounded by the pair of wall surface portions 5 b and the front surface portion 5 c on the bottom surface portion 5 a. It covers and fills the part.
The insulating film 7 is bonded onto the bottom surface portion 5a with an adhesive containing a metal filler, for example.
The insulating film 7 is formed of, for example, a polyimide resin sheet having a thickness of 7.5 to 125 μm.

The ends of the pair of pattern wirings 9 are connected to both end electrode portions of the thermistor element 8.
The pair of pattern wirings 9 are patterned with a metal film such as a Cu film.
As the thermistor element 8, for example, a chip-like or flake-like thermistor element can be employed.

The pair of lead frames 3 is connected to a pad portion at the other end of the pair of pattern wirings 9 by a solder material 3a. Note that the lead frame 3 and the pattern wiring 9 may be joined by welding or a conductive adhesive.
The screw attachment portion 4 has a screw attachment hole 4a.

  As described above, in the temperature sensor 1 of the present embodiment, the element mounting portion 5 includes the bottom surface portion 5a to which the insulating film 7 is bonded, and the pair of wall surface portions 5b provided upright on both sides of the bottom surface portion 5a. Since the notch portion 5d is formed in the rear end portion of the pair of wall surface portions 5b and in the vicinity of the bottom surface portion 5a, even if the lead frame 3 is downsized or displaced, the notch portion 5d The distance between the lead frame 3 and the wall surface portion 5b is increased, and insulation can be ensured.

Further, since the cutout portion 5d is cut out so as to extend to a part of the bottom surface portion 5a, the distance between the projecting and exposed lead frame 3 and the bottom surface portion 5a is also increased, thereby further ensuring insulation. be able to.
Further, since the rear end portion of the insulating film 7 protrudes from the bottom surface portion 5a, the rear end portion of the insulating film 7 is interposed between the protruding lead frame 3 and the bottom surface portion 5a, so that the bottom surface Insulation with the portion 5a can be further ensured.

  The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

For example, in the above-described embodiment, a so-called round terminal R terminal crimping terminal is employed. However, any other screw mounting portion such as a Y terminal may be used as long as the screw mounting portion can be screwed.
Moreover, although the thermistor element employs a chip-like or flake-like thermistor element, a thin film thermistor or the like may be adopted as the thermistor element.

  DESCRIPTION OF SYMBOLS 1 ... Temperature sensor, 2 ... Thermal sensitive element part, 3 ... Lead frame, 4 ... Screw attachment part, 5 ... Element attachment part, 5a ... Bottom face part, 5b ... Wall surface part, 5d ... Notch part, 6 ... Crimp terminal, 7 ... Insulating film, 8 ... Thermistor element, 9 ... Pattern wiring, 10 ... Sealing resin part

Claims (3)

A thermal element part;
A pair of lead frames connected to the thermal element portion;
A crimping terminal having a screw attachment part that can be fixed to the measurement object with a screw on the front end side and an element attachment part to which the thermal element part is attached on the rear end side;
The thermal element part is formed on the surface of the insulating film, the insulating film bonded to the crimp terminal, the thermistor element provided on the surface of the insulating film, and one end is connected to the thermistor element. And a pair of pattern wires connected to the pair of the lead frames at the other end,
The element mounting portion includes a bottom surface portion to which the insulating film is bonded, and a pair of wall surface portions erected on both sides of the bottom surface portion,
A temperature sensor, wherein a pair of notches are formed in a portion adjacent to the rear end of the pair of wall surfaces and the bottom surface. The temperature sensor according to claim 1,
The temperature sensor, wherein the cutout portion is cut out so as to extend to a part of the bottom surface portion. The temperature sensor according to claim 1 or 2,
A temperature sensor, wherein a rear end portion of the insulating film protrudes from the bottom surface portion.

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