JP5303302B2 - Insulation structure of temperature detection circuit body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily accommodate a plurality of thermal sensors, at low cost, and to improve insulating reliability of a thermal sensing part. <P>SOLUTION: An insulating structure of a thermal sensing circuit 10 is adopted, in which a thin-foil shaped circuit 2 is formed on a flexible insulating sheet 1, a resistless part 7 with a solder resist film 6 on the insulating sheet removed is formed in the middle of the circuit, a thermal sensor 3 is solder-connected to the circuit in the resistless part, and the thermal sensor and a solder connection part 4 are covered with an insulating resin mold part 5 in the resistless part. The insulating resin mold part 5 is formed smaller than the resistless part 7. The insulating resin mold part 5 and a part in the vicinity thereof are covered with a printed insulating film 8. The printed insulating film 8 is formed larger than the resistless part 7. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to an insulation structure of a temperature detection circuit body for detecting the temperature of, for example, a battery of an electric vehicle.

  FIG. 7 shows one form of an insulation structure of a conventional temperature detection circuit body (see Patent Document 1).

  In this structure, a temperature sensor 32 such as a thermistor is soldered to the tips of two conductive metal lead wires 31, and both the lead wires 31 and the temperature sensor 32 are sandwiched between two insulating films 33 such as epoxy resin. Insulated from outside by bonding or welding. The two lead wires 31, the temperature sensor 32, and the two insulating films 33 constitute a temperature detection circuit body 34.

  The thermistor has a characteristic of decreasing the resistance value as the temperature rises. When a plurality of temperature sensors 32 are arranged, each pair of lead wires 31 and the temperature sensor 32 connected to each pair of lead wires 31 are sandwiched between two wide insulating films 33. It is also well known to use a PTC element instead of the thermistor.

  FIG. 8 shows one form of an insulating structure of a PTC element (POSITIVE TEMPERATURE COEFFICIENT) (see Patent Document 2).

  In this structure, a PTC element 43 is connected between two conductive metal plate-like leads 41 via a thin metal plate 42, and the periphery of the PTC element 43 is covered with an insulating resin material 44. The PTC element 43 has a characteristic of increasing the resistance value as the temperature rises. The PTC element 43 of this example is not used as a temperature sensor, but as a safety device when the batteries of a high voltage battery for an electric vehicle are connected by leads 41.

JP-A-8-128901 (FIG. 7) JP-A-7-57721 (FIG. 1)

  However, in the conventional insulating structure of the temperature detecting circuit body of FIG. 7, since the lead wire 31 and the temperature sensor 32 are sandwiched between two insulating films 33, the flexibility of the circuit body 34 is poor. For example, there is a concern that the wiring along the curved surface of the high-voltage battery, the wiring along each battery arranged in steps, and the like are difficult.

  Further, when a plurality of temperature sensors 32 are to be connected in series to the two lead wires 31, there is a concern that it is difficult to solder the temperature sensor 32 to the lead wires 31 separated from the insulating film 33. In addition, since the two insulating films 33 are used in the same (wide) area, there is a concern that the cost of the insulating structure is increased.

  In view of the above points, the present invention is excellent in flexibility as a circuit body, can easily correspond to the arrangement and shape of the detection target, can easily correspond to a plurality of temperature sensors, and is inexpensive. Another object of the present invention is to provide an insulating structure for a circuit body for temperature detection, which can increase the insulation reliability of the temperature detection section.

In order to achieve the above object, the insulating structure for a temperature detecting circuit body according to claim 1 of the present invention is such that a thin foil-like circuit is formed on a flexible insulating sheet, and the insulation is provided in the middle of the circuit. A resist removal portion from which the solder resist film on the sheet is removed is formed, and a temperature sensor is soldered to the circuit in the resist removal portion, and the temperature sensor and the solder connection portion are insulated resin mold portions in the resist removal portion. The insulating resin mold part is formed smaller than the resist removal part, and the insulation resin mold part is directly adhered to the surface of the insulating sheet in the resist removal part .

  With the above configuration, the insulating resin mold portion (insulating resin material) is firmly fixed and fixed to the ground surface of the insulating sheet in the resist removal portion. As a result, the temperature sensor and the solder connection part are reliably insulated and protected from external moisture and the like. The insulating resin mold part is formed by potting or the like, and the insulation of a plurality of temperature sensors on the circuit body is facilitated together with the resist removal part. The insulating sheet can be bent together with the solder resist film and the circuit.

In addition , a step is formed between the ground surface of the insulating sheet exposed at the resist-extracted portion and the solder resist film on the insulating sheet, and the fluid insulating resin mold portion stops against the step and spreads further. That is, sagging is prevented and the insulating resin mold part covers the three-dimensional temperature sensor without exposure.

Insulation structure for temperature sensing circuit body according to claim 2 is the insulation structure of the temperature detecting circuit of claim 1, wherein the insulating resin mold portion and its adjacent portion is covered with printed insulating film, the printing The insulating film is formed larger than the resist removal portion .

  With the above configuration, the circuit portion (mainly the solder connection portion) that could not be covered with the insulating resin mold portion in the resist removal portion is secondarily covered with the printed insulating film to be insulated and protected. The formation of the printed insulating film can be simultaneously performed on a plurality of temperature sensors. The printed insulating film is firmly bonded and fixed to the ground surface of the insulating sheet in the resist removal portion. Further, since the fluid insulating resin mold part is covered with the printed insulating film, further expansion (sagging) of the insulating resin mold part is prevented.

Further , the insulating resin mold portion and the exposed circuit portion (solder connection portion) in the resist removal portion are reliably covered with the printed insulating film without being exposed. The outer peripheral edge portion of the printed insulating film is in close contact with the solder resist film outside the resist removal portion.

  According to the first aspect of the present invention, the insulating resin mold part firmly adheres to the background of the insulating sheet in the resist removal part, so that the insulation of the temperature sensor and the solder connection part is enhanced. In addition, since a plurality of resist removal portions and insulating resin mold portions can be easily formed simultaneously or continuously, it is possible to easily mount and insulate a plurality of temperature sensors at low cost. Further, since the insulating sheet is easily bent together with the solder resist film and the thin foil circuit, the temperature sensor can be easily and surely arranged on the curved detection target or the detection target arranged in a stepped shape. it can.

Further , when forming the insulating resin mold portion, the fluid insulating resin mold portion is stopped by a step in the resist removal portion to prevent further expansion (sagging). The temperature sensor can be reliably covered without being exposed to improve insulation and protection.

According to the second aspect of the present invention, the solder connection portion and the circuit portion that are not covered with the insulating resin mold portion in the resist removal portion can be reliably insulated and covered with the printed insulating film. This further improves the insulation protection. In addition, by covering the fluid insulating resin mold part with a printed insulating film, it is possible to prevent further expansion (sagging) of the insulating resin mold part and to ensure that the three-dimensional temperature sensor is not exposed at the insulating resin mold part. Covering can improve insulation and protection. In addition, a printed insulating film can be formed simultaneously and at low cost corresponding to a plurality of temperature sensors.

The effect of the invention is promoting the large printing insulation coating of the registration cut-out portion.

The primary insulation state in one Embodiment of the insulation structure of the circuit body for temperature detection concerning this invention is shown, (a) is a top view, (b) is a front view. It is the top view which made the cross section partly which shows the principal part of the insulation structure of the circuit body for temperature detection similarly in detail. It is a top view which similarly shows the secondary insulation state (completed state) in the insulation structure of the circuit body for temperature detection. It is the front view which made the cross section the part which shows one use example of the circuit body for temperature detection. It is a top view which shows the modification of the circuit body for temperature detection. It is a longitudinal section showing an example of application of a circuit body for temperature detection similarly. It is a perspective view which shows one form of the insulation structure of the conventional circuit body for temperature detection. It is a longitudinal cross-sectional view which shows one form of the insulation structure of the conventional PTC element.

  1 to 3 show an embodiment of an insulating structure for a temperature detecting circuit body according to the present invention in the order of manufacturing steps.

  As shown in FIGS. 1A and 1B, two circuits 2 are formed on the upper surface of a long flexible insulating sheet 1 so as to be separated in parallel in the insulating sheet width direction and separated in the longitudinal direction of the insulating sheet. Each terminal portion of the rectangular temperature sensor 3 is solder-connected to the opposing terminal portions of both circuits 2 (the solder connection portion is indicated by reference numeral 4), and the temperature sensor 3 and the solder connection portion 4 are insulated resin molds. It is covered and insulated by the part 5.

  Each circuit 2 is preferably formed by printing on an insulating sheet, and a copper foil can be fixed on the insulating sheet by bonding or the like. In any case, each circuit 2 can be bent in the thickness direction integrally with the insulating sheet 1. The temperature sensor 3 is preferably a PTC element.

  The insulating resin mold portion 5 is formed by, for example, potting (resin embedding) or the like. For example, a fluid insulating resin material is discharged toward the temperature sensor 3 from an upper nozzle (not shown) or a molding die (not shown). The resin is injected onto the temperature sensor in a state where it is set on the insulating sheet, and the resin is placed in a circular or oval dome shape around the temperature sensor 3 and its periphery.

  As the insulating resin material, a material such as epoxy or urethane that has flexibility at room temperature and can be bent integrally with the insulating sheet 1 and the circuit 2 is preferable. The temperature sensor 3 and its solder connection part 4 are insulated and protected from the outside by the insulating resin mold part 5.

  As shown in FIG. 2 (enlarged view of the main part of FIG. 1), the temperature-sensitive sensor 3 and the insulating solder resist film 6 covering the circuit 2 on the insulating sheet around the temperature sensor 3 are peeled off in a rectangular shape (the circuit body). When the circuit 2 on the insulating sheet is covered with the solder resist film 6 at the time of manufacture, the solder resist film 6 is not formed at or near the set position of the temperature sensor 3). The solder resist film 6 is for preventing the solder from adhering to the portion of the circuit 2 other than the terminal portion (represented by reference numeral 4).

  A portion (resist removal portion) 7 without the solder resist film 6 is formed larger (with a larger projected area) than the insulating resin mold portion 5 in FIG. The ground surface 1 a of the insulating sheet 1 is exposed in the rectangular resist removal portion 7.

  Since the diameter of the dome-shaped insulating resin mold portion 5 that integrally covers the rectangular parallelepiped (three-dimensional) temperature sensor 3 and the solder connection portion 4 is set in advance, the dimension (length) of the resist removal portion 7 is larger than the set value. 7a and width 7b) are set slightly larger. Preferably, the dimension in the XY direction of the resist removal part 7 is set to be equal to or slightly larger than the diameter of the insulating resin mold part 5 in the XY direction (insulating sheet width direction and longitudinal direction).

  The insulating resin mold portion 5 is formed within the range of the resist removal portion 7. When the insulating resin mold part 5 is formed on the solder resist film 6, the insulating resin mold part 5 is easy to peel off, but the insulating resin mold part directly on the surface (background) 1a of the insulating sheet 1 within the resist removal part 7 By sticking 5, the insulating resin mold part 5 is firmly fixed to the surface 1 a of the insulating sheet 1 with its own adhesive force. Accordingly, unnecessary expansion (sagging) of the insulating resin mold portion 5 is prevented, and the upper corner portion 3a (FIG. 1) of the three-dimensional temperature sensor 3 is reliably covered with the insulating resin mold portion 5 without being exposed.

  Further, a step (a portion indicated by reference numeral 7 in FIG. 2) corresponding to the thickness of the solder resist film 6 is formed between the surface of the solder resist film 6 and the surface 1a of the insulating sheet 1 by the resist removal portion 7 (on the insulating sheet). The resist removal portion 7 has a recess without the solder resist film 6), and the step (recess) prevents unnecessary expansion (sagging) of the insulating resin mold portion 5. The mold part 5 is surely covered without being exposed.

  In FIG. 2, a circuit portion 2a (mainly a part of the solder connection portion 4) that is not covered with the insulating resin mold portion 5 is generated in the resist removal portion 7. However, as shown in FIG. The insulating resin mold part 5 is covered with a printed insulating film 8 by silk (screen) printing to completely insulate the uncovered circuit part 2a from the outside, and the temperature sensor 3 and the solder connection part 4 are insulated with an insulating resin. The mold part 5 and the printed insulating film 8 are double insulated.

  The printed insulating film 8 is formed with a larger (larger projected area) than the resist-extracted portion 7, and the XY dimensions 8 a and 8 b of the printed insulating film 8 are larger than the XY dimensions 7 a and 7 b of the resist-extracted portion 7. That is, the insulating resin mold part 5 and the circuit part 2 a in the resist removal part 7 are completely covered with the printed insulating film 8.

  Thereby, the insulation of the temperature sensor connection part 4 in a circuit body increases. Further, the insulating resin mold part 5 is covered with the printed insulating film 8 while it is fluid (before it is completely hardened), so that unnecessary spreading (sagging) of the insulating resin mold part 5 is prevented.

  A circuit body main body 9 is composed of the insulating sheet 1, the insulating solder resist film 6, and each circuit 2 in FIG. 2, and the circuit body main body 9, the insulating resin mold portion 5, and the printed insulating coating 8 in FIG. The temperature detection circuit body 10 is configured.

  In FIG. 2, the insulating resin mold part 5 can be filled in the entire resist removal part 7 without a gap (the temperature sensor 3 and the circuit part 2 a in the resist removal part 5 can be completely covered with the insulation resin mold part 5). It is. However, in this case, the dome-shaped insulating resin mold portion 5 is enlarged.

  Further, the resist removal portion 7 is not rectangular but can be round or oval according to the shape of the insulating resin mold portion 5. In this case, the printed insulating coating 8 is preferably circular or oval according to the shape of the resist removal portion 7. The printing insulating film 8 is preferably screen printing, but offset printing, letterpress printing, gravure printing, or the like can also be used.

  FIG. 4 shows a state in which the temperature detection circuit body 10 is brought into contact with the detected object 11 such as a battery of a high voltage battery to detect the temperature of the battery 11. The high voltage battery is a battery of an electric vehicle including a hybrid vehicle.

  As shown in FIG. 4, the circuit body 10 is bent, and the temperature sensor 3 is pressed into contact with the battery 11 through the insulating sheet 1. The temperature sensor 3 is pressed against the battery 11 by the elastic force generated when the insulating sheet 1 is bent, and the temperature of the battery 11 is accurately detected. In FIG. 4, the code | symbol 5 has shown the insulating resin mold part, and 8 has shown the printing insulation film, respectively.

  In the above embodiment, the temperature sensor 3 is used as an example, but actually, as shown in FIGS. It is preferable to use the sensor 3 connected in series. 5 and 6, description will be made using the same reference numerals as in FIGS.

As shown in FIG. 5, the circuit 2 on the insulating sheet 1 is formed and arranged by bending a substantially crank shape, for example, to one end of the first circuit 2 ₁ terminal portion of the first temperature sensor 3 ₁ + pole Solder connection is performed (the solder connection portion is indicated by reference numeral 4), and the other end portion of the _first circuit 21 is solder connected to the negative terminal portion of the second temperature sensor 3 ₂ (the solder connection portion is indicated by reference numeral 4). shown), the second circuit 2 ₂ of one end a first temperature sensor 3 ₁ - are soldered to the terminal portions of the electrode, the one end portion of the third circuit 2 ₃ of the second temperature sensor + pole Soldered to the terminal. In this way, a plurality (number corresponding to the number of each battery 11 of the high voltage battery) of temperature sensors 3 are connected to the circuit 2 in series. In FIG. 5, reference numeral 5 is an insulating resin mold part, 8 is a printed insulating film, and 6 is a solder resist film.

  As shown in FIG. 6, the temperature detecting circuit body 10 is bent into a substantially wave shape and accommodated in a case 12 made of insulating resin, and each protruding portion 10 a of the wave shape of the circuit body 10 has a rectangular shape on the bottom wall 13 of the case 12. The temperature sensor 3 and the insulating parts (insulating resin mold part and printed insulating film) 5 and 8 are located on the inner surface of the tip part of the protruding part 10a.

  In FIG. 6, the protruding portion 10 a of the circuit body 10 illustrates an initial state when each battery 11 is not present, and the tip of the protruding portion 10 a actually contacts the upper surface 11 a of the battery 11. The protruding portion 10a is compressed and bent upward, and the restoring force of the protruding portion 10a, that is, the temperature sensor 3 elastically contacts the upper surface 11a of the battery 11 via the insulating sheet 1. The tip of the protruding portion 10a may contact the upper surface 11a of the battery 11 in a planar manner, or may contact a curved shape (arc shape).

  The case 12 is formed in a bowl shape with three sides of the left and right sides and the bottom portion surrounded by wall portions 13 and 15, the opening 14 of the bottom wall 13 continues to the upper inclined wall 13a, and the upward projection 16 of the bottom wall 13 is a circuit. The circuit body 10 is fixed by passing through a small hole (not shown) of the insulating sheet 1 of the body 10 and heat-sealing. The fixing means of the circuit body 10 and the shape of the case 12 can be set as appropriate. In FIG. 6, reference numeral 17 denotes an insulating partition between the batteries 11 in the battery 18. At the front and rear end portions of the insulating sheet 1 in the longitudinal direction, each circuit 2 is connected to a circuit (not shown) on the control unit side via a terminal (not shown), and the control unit is an abnormality display unit or the like (not shown). Connected to.

  In the above embodiment, the temperature sensor 3 is arranged on the curved portion (FIG. 4) or the protruding portion 10 a of the insulating sheet 1. However, for example, along a curved object (not shown). It is also possible to detect the temperature of the object to be detected by the temperature sensor 3 in a state where the insulating sheet 1 is bent two-dimensionally or three-dimensionally.

  In addition to the temperature detection circuit body insulation structure, the present invention provides a temperature detection circuit insulation structure, a temperature detection circuit body itself, a temperature detection circuit body insulation method, or a temperature detection circuit body insulation section. It is also effective as a method for manufacturing the temperature detecting circuit body or the temperature detecting circuit body.

  The insulation structure of the temperature detection circuit body according to each of the present invention can be used for detecting the temperature of the battery of the electric vehicle including the hybrid vehicle for each battery and notifying an abnormal temperature rise. Other than the battery, for example, it can be used to notify an abnormal temperature rise of components such as a control circuit unit and a relay of an electric connection box mounted on a vehicle.

DESCRIPTION OF SYMBOLS 1 Insulation sheet 2 Circuit 3 Temperature sensor 4 Solder connection part 5 Insulation resin mold part 6 Solder resist film 7 Resist removal part 8 Print insulation film 10 Temperature detection circuit body

Claims (4)

A thin foil-like circuit is formed on the flexible insulating sheet, and a resist removal portion from which the solder resist film on the insulation sheet is removed is formed in the middle of the circuit, and the temperature is applied to the circuit in the resist removal portion. The sensor is soldered, the temperature sensor and the solder connection part are covered with an insulating resin mold part in the resist removal part, the insulation resin mold part is formed smaller than the resist removal part, An insulating structure of a circuit body for temperature detection, wherein the insulating resin mold part is adhered directly to the surface of an insulating sheet . The insulating resin mold portion and its adjacent portion is covered with printed insulating film, insulation temperature detecting circuit of claim 1 wherein said printed insulating film is characterized by being larger than the resist vent portion Construction. 3. The temperature detection circuit body insulating structure according to claim 2, wherein the printed insulating film is adhered to the surface of the insulating sheet in the resist removal portion. The insulating sheet protrudes from an opening provided in the bottom wall of the insulating resin case to form a protruding portion, and the temperature sensor and the insulating resin mold portion are disposed inside the protruding portion, and the protruding portion is 2. The temperature detection circuit body insulating structure according to claim 1, wherein the temperature detection circuit body is pressed against each detected body.

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