JP2021131284A - Temperature sensor and manufacturing method thereof - Google Patents

Abstract

To provide a temperature sensor which enables the size of a joint area to be increased to thereby enable sufficiently high joint strength to be obtained, and a manufacturing method of the temperature sensor.SOLUTION: The temperature sensor comprises: an insulating substrate 2; a heat-sensitive element 3 provided on the surface of the insulating substrate; a pair of pieces of pattern wiring 4 which is patterned on the surface of the insulating substrate, and is connected at one end, to the heat-sensitive element ; a pair of recessed portions for jointing 5 which is formed in a recessed shape on both sides of the insulating substrate, and inside which a recessed-portion metal film is deposited; a pair of surface lands 6 which is formed with a metal film along the recessed portions for jointing on the surface of the insulating substrate and which is connected to the recessed-portion metal film, and to which the other end of the pair of pattern wirings is connected; and a pair of reverse-side land portions formed with metal films along the recessed portions for jointing on the reverse side of the insulating substrate and connected to the recessed-portion metal film.SELECTED DRAWING: Figure 1

Description

The present invention relates to a temperature sensor that can be easily surface-mounted and a method for manufacturing the same.

Generally, in order to measure the temperature of the surface of various parts and devices, a temperature sensor mounted directly on the surface and measuring the temperature is used.
For example, conventionally, as shown in FIG. 5A, a PCB substrate 102, a chip thermistor 103 installed on the PCB substrate 102, and one end connected to the chip thermistor 103 by forming a pattern on the PCB substrate 102. There is a temperature sensor 101 having a pair of pattern wirings 104 and a pair of surface land portions 105 having a pattern formed on the PCB substrate 102 and connected to the other end of the pair of pattern wirings 104.

In this temperature sensor, lead wires are usually joined to a pair of surface land portions 105 by soldering, conductive adhesive, welding, or the like, but when it is difficult to connect the lead wires, the PCB substrate 102 is directly connected to the object to be measured 106. May be surface mounted. In this case, as shown in (b) and (c) of FIG. 5, a conductive adhesive H such as solder is piled up from the pair of surface land portions 105 to the mounting land 106a of the object to be measured 106 to electrically connect and surface. I had to do with the implementation.

Further, in Patent Document 1, platinum glaze electrodes are formed on both ends of the substrate, resistors are formed between the electrodes, and silver electrodes, nickel and solder plating layers are formed on both ends of the substrate. A temperature sensor is described. In this platinum temperature sensor, a nickel and solder-plated layer is formed from the platinum glaze electrode on the surface of the substrate to the back surface via the side surface for surface mounting.

Japanese Unexamined Patent Publication No. 6-300643

The following problems remain in the above-mentioned conventional technique.
That is, as shown in FIG. 5, when the conductive adhesive H is piled up from the surface land portion 105 of the PCB substrate 102 to the mounting land 106a of the object to be measured 106 and surface mounted, the side surface of the substrate, the back surface of the substrate, and the mounting are used. It was difficult to secure a sufficient bonding area of the conductive adhesive H with respect to the land 106a.
Further, in the technique described in Patent Document 1, since only a part of the back surface of the substrate is bonded to the circuit board or the object to be measured, the bonding area is small and it is difficult to obtain sufficient bonding strength.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a temperature sensor capable of increasing the bonding area and obtaining a sufficiently high bonding strength, and a method for manufacturing the same.

The present invention has adopted the following configuration in order to solve the above problems. That is, the temperature sensor according to the first invention has an insulating substrate, a heat-sensitive element provided on the surface of the insulating substrate, and a pattern formed on the surface of the insulating substrate, and one end thereof is connected to the heat-sensitive element. A pair of pattern wirings, a pair of bonding recesses formed in recesses on both side surfaces of the insulating substrate and a concave metal film formed on the inner surface, and along the bonding recesses on the surface of the insulating substrate. A pair of surface land portions formed of a metal film and connected to the recess metal film and the other ends of the pair of pattern wirings, and a metal film along the bonding recess on the back surface of the insulating substrate. It is characterized by having a pair of back surface lands formed and connected to the recessed metal film.

Since this temperature sensor is provided with a pair of bonding recesses formed in a concave shape on both side surfaces of the insulating substrate and having a concave metal film formed on the inner surface, a conductive adhesive such as solder can reach the bonding recesses. It is possible to obtain a higher bonding strength as compared with a flat side surface due to the anchor effect as well as the penetration to increase the bonding area. In particular, higher bonding strength can be obtained by wrapping the conductive adhesive from the front surface land portion to the back surface land portion via the side bonding recess. In addition, since a recess for joining is provided on the side surface of the insulating substrate, it is possible to reduce the size as compared with the case where a through hole is provided in the insulating substrate and a conductive adhesive is put in the through hole for joining. Become. That is, since the area of the joint recess is about half that of the through hole, space can be saved.

The temperature sensor according to the second invention is characterized in that, in the first invention, it includes a double-sided tape attached to the back surface of the insulating substrate.
That is, since this temperature sensor is provided with a double-sided tape attached to the back surface of the insulating substrate, the temperature sensor is temporarily fixed at a predetermined position on the object to be measured by the double-sided tape, and the temperature sensor is temporarily fixed and conductive. Positional deviation can be prevented by joining the bonding recess or the like with the object to be measured with an adhesive. In addition, the double-sided tape provides high adhesion between the insulating substrate and the object to be measured, and the temperature can be measured with high accuracy.

In the temperature sensor according to the third invention, in the second invention, the insulating substrate has a rectangular shape, the heat sensitive element is arranged on one end side of the insulating substrate, and the surface land portion, The bonding recess and the back surface land portion are arranged on the other end side of the insulating substrate, and the double-sided tape is arranged on one end side of the insulating substrate.
That is, in this temperature sensor, the front surface land portion, the bonding recess, and the back surface land portion are arranged on the other end side of the insulating substrate, and the double-sided tape is arranged on one end side of the insulating substrate. When the other end side of the insulating substrate is joined with a conductive adhesive, one end side of the insulating substrate is fixed with double-sided tape, so that one end side of the insulating substrate, which is the heat-sensitive element side, floats and the whole is tilted. Can be suppressed.

The method for manufacturing a temperature sensor according to a fourth aspect of the present invention is the method for manufacturing a temperature sensor according to the first to third inventions, which comprises a through-hole forming step of forming a plurality of through-holes in an insulating original plate and the through-hole forming method. The substrate cutting step comprises a metal film forming step of forming a metal film to be the recessed metal film on the inner peripheral surface and a substrate cutting step of cutting the insulating original plate into a plurality of the insulating substrates. , The through hole is cut to form the joining recess.
That is, this method of manufacturing a temperature sensor includes a substrate cutting step of cutting an insulating original plate to form a plurality of insulating substrates, and in the substrate cutting step, a through hole is cut to form a bonding recess. , The bonding recess can be easily formed only by cutting the through hole in the substrate cutting step.

According to the present invention, the following effects are obtained.
That is, according to the temperature sensor of the present invention, since the insulating substrate is provided with a pair of bonding recesses formed in a concave shape on both side surfaces and a concave metal film formed on the inner surface, conductive adhesion such as solder is provided. The agent penetrates into the bonding recess to increase the bonding area, and the anchor effect makes it possible to obtain higher bonding strength as compared with the flat side surface. In particular, higher bonding strength can be obtained by wrapping the conductive adhesive from the front surface land portion to the back surface land portion via the side bonding recess.
Further, according to the method for manufacturing a temperature sensor of the present invention, there is a substrate cutting step of cutting an insulating original plate into a plurality of insulating substrates, and in the substrate cutting step, a through hole is cut to form a concave portion for joining. Therefore, the bonding recess can be easily formed only by cutting the through hole in the substrate cutting step.

It is a top view which shows the temperature sensor in one Embodiment of the temperature sensor and its manufacturing method which concerns on this invention. It is a back view which shows the temperature sensor in this embodiment. In this embodiment, it is a side view which shows the temperature sensor. It is a conceptual perspective view for demonstrating the substrate cutting process in one Embodiment of the temperature sensor and its manufacturing method which concerns on this invention. In a conventional example of a temperature sensor and a method for manufacturing the same according to the present invention, a perspective view (a) of the temperature sensor, a perspective view (b) in a state where a conductive adhesive is piled up, and a cross-sectional view cut at a portion of the conductive adhesive. (C).

Hereinafter, an embodiment of the temperature sensor and the manufacturing method thereof according to the present invention will be described with reference to FIGS. 1 to 4. In the drawings used in the following description, there is a part where the scale is appropriately changed as necessary in order to make each member recognizable or easily recognizable.

As shown in FIGS. 1 to 3, the temperature sensor 1 of the present embodiment has a pattern formed on the surface of the insulating substrate 2, the heat sensitive element 3 provided on the surface of the insulating substrate 2, and the surface of the insulating substrate 2. A pair of pattern wirings 4 having one end connected to the heat-sensitive element 3, a pair of bonding recesses 5 formed in a concave shape on both side surfaces of the insulating substrate 2 and a concave metal film formed on the inner surface, and an insulating substrate. On the surface of 2, a pair of surface land portions 6 formed of a metal film along the bonding recess 5 and connected to the recess metal film and the other ends of the pair of pattern wirings 4 and the insulating substrate 2 On the back surface, a pair of back surface land portions 7 formed of a metal film along the bonding recess 5 and connected to the recess metal film are provided.

Further, the temperature sensor 1 of the present embodiment includes a double-sided tape 8 attached to the back surface of the insulating substrate 2.
The insulating substrate 2 is a rectangular PCB substrate, and the heat-sensitive element 3 is arranged on one end side of the insulating substrate 2, and the front surface land portion 6, the bonding recess 5 and the back surface land portion 7 are insulating. It is arranged on the other end side of the substrate 2, and the double-sided tape 8 is arranged on one end side of the insulating substrate 2.
That is, the double-sided tape 8 is arranged directly under the heat-sensitive element 3, and has a rectangular shape having a larger area than the heat-sensitive element 3.

The thermal element 3 is a chip thermistor mounted on the surface of the insulating substrate 2. Electrodes are formed at both ends of this chip thermistor.
The pair of pattern wirings 4 are formed of, for example, copper foil, and one end thereof is connected to a pair of electrodes of the thermal element 3.
The bonding recess 5 is an arcuate recess, and the recess metal film formed on the inner surface is, for example, a laminated film of Cu and Au.

The metal film of the front surface land portion 6 and the back surface land portion 7 is also, for example, a laminated film of Cu and Au.
As the double-sided tape 8, for example, a tape in which adhesives are applied to both sides of a copper foil can be adopted. As the double-sided tape 8, a double-sided tape mainly composed of a metal foil tape or the like having a higher thermal conductivity than the insulating substrate 2 is preferable because a heat collecting effect can be obtained.

On the surface of the insulating substrate 2, the pattern wiring 4 excluding the surface land portion 6 and the connection portion with the heat sensitive element 3 may be covered with a protective film such as a solder resist.

Next, a method of manufacturing the temperature sensor 1 of the present embodiment will be described with reference to FIG.
As shown in FIG. 4, the method for manufacturing the temperature sensor 1 of the present embodiment includes a through hole forming step of forming a plurality of through holes 25 in the insulating original plate 22 and a recessed metal film on the inner peripheral surface of the through holes 25. It has a metal film forming step of forming the metal film, and a substrate cutting step of cutting the insulating original plate 22 into a plurality of insulating substrates 2.
In the substrate cutting step, the through hole 25 is cut to form the bonding recess 5.

The insulating original plate 22 is a large-sized PCB substrate, which is a plurality of insulating substrates 2.
Prior to the through hole forming step, the pattern wiring 4 is formed in advance on the surface of the insulating original plate 22.
In the through hole forming step, through holes 25 having a predetermined diameter are formed at a plurality of predetermined positions to be joint recesses 5 by a drill or the like.

In the metal film forming step, the front surface land portion 6 is patterned with a laminated film of Cu and Au on the front surface of the insulating original plate 22, and the back surface land portion 7 is laminated on the back surface of the insulating original plate 22 with Cu and Au. A pattern is formed with a film. At this time, a concave metal film is also formed on the inner peripheral surface of the through hole 25 with a laminated film of Cu and Au.

In the substrate cutting step, the insulating original plate 22 is cut in a grid pattern by dicing with the dicing blade D or the like, and the insulating substrate 2 is separated and cut into a plurality of insulating substrates 2.
The heat-sensitive element 3 of the chip thermistor may be mounted at a predetermined position on the insulating original plate 22 or the insulating substrate 2 before or after the substrate cutting step.

As described above, the temperature sensor 1 of the present embodiment is provided with a pair of bonding recesses 5 formed in a concave shape on both side surfaces of the insulating substrate 2 and having a concave metal film formed on the inner surface, so that solder or the like can be used. The conductive adhesive penetrates into the bonding recess 5 to increase the bonding area, and the anchor effect makes it possible to obtain higher bonding strength as compared with the flat side surface. In particular, higher bonding strength can be obtained by wrapping the conductive adhesive from the front land portion 6 to the back surface land portion 7 via the side bonding recess 5 and piling it.

Further, since the bonding recess 5 is provided on the side surface of the insulating substrate 2, the size can be reduced as compared with the case where the insulating substrate 2 is provided with a through hole and a conductive adhesive is put in the through hole for joining. Becomes possible. That is, since the area of the joining recess 5 is about half that of the through hole, space can be saved.

Further, since the double-sided tape 8 attached to the back surface of the insulating substrate 2 is provided, the temperature sensor 1 is temporarily fixed at a predetermined position on the object to be measured by the double-sided tape 8 and conductively adhered in the temporarily fixed state. Positional deviation can be prevented by joining the bonding recess 5 and the like with the object to be measured with an agent. Further, the double-sided tape 8 provides high adhesion between the insulating substrate 2 and the object to be measured, so that the temperature can be measured with high accuracy.

Further, since the front surface land portion 6, the bonding recess 5 and the back surface land portion 7 are arranged on the other end side of the insulating substrate 2, and the double-sided tape 8 is arranged on one end side of the insulating substrate 2, the insulating property is improved. When the other end side of the substrate 2 is joined by the conductive adhesive, one end side of the insulating substrate 2 is fixed with the double-sided tape 8, so that one end side of the insulating substrate 2 which is the heat sensitive element 3 side is It is possible to prevent the whole from floating and tilting.

Further, the method for manufacturing the temperature sensor 1 of the present embodiment includes a substrate cutting step of cutting the insulating original plate 22 to form a plurality of insulating substrates 2, and the through hole 25 is cut in the substrate cutting step. Since the bonding recess 5 is formed, the bonding recess 5 can be easily formed by simply cutting the through hole 25 during the substrate cutting step.

The technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the above embodiment, the chip thermistor is mounted on the insulating substrate as the heat sensitive element, but a thin film thermistor, a pyroelectric element, a resistor such as platinum, or the like may be adopted as the heat sensitive element.

1 ... Temperature sensor, 2 ... Insulating substrate, 3 ... Heat sensitive element, 4 ... Pattern wiring, 5 ... Concave for joining, 6 ... Front land part, 7 ... Back land part, 8 ... Double-sided tape, 22 ... Insulating original plate, 25 ... Through hole

Claims (4)

Insulating board and
The heat-sensitive element provided on the surface of the insulating substrate and
A pair of pattern wirings that are patterned on the surface of the insulating substrate and one end of which is connected to the thermal element.
A pair of recesses for joining, which are formed in a concave shape on both side surfaces of the insulating substrate and have a concave metal film formed on the inner surface.
A pair of surface land portions formed of a metal film along the bonding recess on the surface of the insulating substrate and connected to the recess metal film and the other ends of the pair of pattern wirings.
A temperature sensor characterized by having a pair of back surface lands formed of a metal film along the bonding recess on the back surface of the insulating substrate and connected to the recess metal film. In the temperature sensor according to claim 1,
A temperature sensor including a double-sided tape attached to the back surface of the insulating substrate. In the temperature sensor according to claim 2,
The insulating substrate has a rectangular shape.
The heat-sensitive element is arranged on one end side of the insulating substrate, and the front surface land portion, the bonding recess, and the back surface land portion are arranged on the other end side of the insulating substrate.
A temperature sensor characterized in that the double-sided tape is arranged on one end side of the insulating substrate. The method for manufacturing a temperature sensor according to any one of claims 1 to 3.
A through-hole forming process for forming a plurality of through-holes in an insulating original plate,
A metal film forming step of forming a metal film to be the recessed metal film on the inner peripheral surface of the through hole,
It has a substrate cutting step of cutting the insulating original plate into a plurality of the insulating substrates.
A method for manufacturing a temperature sensor, which comprises cutting the through hole to form the bonding recess in the substrate cutting step.

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