JPH04295752A - Manufacture of dew or moisture sensor - Google Patents

Abstract

PURPOSE:To manufacture a low-cost sensor having the high stability in quality with simple steps by omitting the steps for soldering and welding, bonding with bonding agent and the like at the time of manufacturing. CONSTITUTION:In the manufacturing method of a dew or moisture sensory a substrate holder having spring-shaped electrodes 14 and external connecting terminals 17 is coupled and fixed in positioning and fixing hole parts 16 opened in a hoop-shaped bracket plate 12. A substrate 10 wherein counter electrodes 9a and 9b are formed in the surface beforehand is inserted and coupled into the holder so that the electrodes and the spring-shaped electrodes are brought into contact with each other.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dew condensation or humidity sensor capable of detecting dew condensation on the surface of a subject or humidity in the atmosphere. For more details, see video tape recorders (VTRs) and digital audio tape decks (DA
T) relates to a method of manufacturing a sensor used in air conditioners, housing equipment, etc., to detect dew condensation and high humidity conditions.

0002

[Prior technology] Various precision electrical equipment, automobiles, air conditioning control,
Condensation has become a problem in various fields such as storage facilities and housing equipment, and there is a growing demand for accurate detection of high humidity or dew condensation conditions. For example, in home video tape recorders (VTRs), camera-integrated VTRs, digital audio tape decks (DATs), etc., if condensation forms on the cylinder of the rotating head that records on and plays back magnetic tape, tape winding and A condensation sensor is installed to prevent disconnection and equipment damage. In recent years, as these devices have become lighter, smaller, and cheaper, there is a growing demand for small, simple, and inexpensive dew condensation sensors. The method for manufacturing a dew condensation or humidity sensor described in the present invention was devised to meet these demands.

FIG. 5 shows a partially exploded perspective view of a conventional dew condensation sensor. These dew condensation sensors are, for example, disclosed in Japanese Patent Application Laid-Open No. 52-9
This method is disclosed in JP-A No. 2395, JP-A-62-123561, JP-A-2-49149, and the like. Since the humidity sensor also has substantially the same structure, the following description will take such a dew condensation sensor as an example.

The detection portion of these sensors is based on a moisture-sensitive resistor in which conductive powder is dispersed in a hygroscopic polymer resin that expands in volume when it absorbs moisture. The sensor may be one in which the moisture-sensitive resistor is formed as a film to cover a comb-shaped counter electrode formed on an insulating substrate (Fig. 5(a)), or one in which a large number of fine voids are formed. A fabric to which moisture-sensitive resistors are fixed in a substantially continuous and dispersed manner is placed on an insulating substrate and electrically connected to the electrodes on the substrate (Figure 5(b)). )and so on.

[0005] The structure of these conventional dew condensation sensors which are generally implemented will be explained in detail with reference to FIG. In FIG. 5, reference numeral 1 denotes a detection section of the sensor, and the detection section is formed on a substrate 3 such as an alumina or metal core substrate on one surface of which a pair of opposing electrodes 2a and 2b are formed. A part of the opposing electrodes 2a and 2b may be directly covered by the sensor detection part 1 and electrically connected to the detection part to form a conductive contact part 4 as shown in FIG. It is electrically connected to the detection part by forming a conductive contact part 4 such as a conductive paste as shown in FIG. Lead wires 5a and 5b are connected to the counter electrodes 2a and 2b, respectively, by solder. Generally, when the sensor substrate 3 is made of ceramic such as alumina, the sensor is
In order to attach it to R, a metal bracket plate 6 having screw fixing holes 13 to be used for attachment must be pasted with adhesive on the back side of the board where there is no detection part.

The operating principle of such a dew condensation sensor will be briefly explained. In these dew condensation sensors, when condensation occurs where the sensor is attached, moisture condenses on the surface of the sensor detection part 1 as condensation water, and the hygroscopic polymer resin in the humidity-sensitive resistor swells and expands, causing conductive powder (mainly As the distance between carbon powders increases, it becomes difficult for current to flow between the powders, and the electrical resistance value increases. Then, this change in resistance value is transferred to the lead wire 5 through the electrode parts 2a and 2b.
It is detected by taking it out from a and 5b.

However, the conventional dew condensation sensor described above requires a process of soldering the lead wires and a cleaning process of removing solder flux scattered on the sensor detection part and the board when manufacturing the sensor. Furthermore, sensor performance was likely to deteriorate due to flux adhesion and cleaning itself. Furthermore, since there are lead wires, during the manufacturing and assembly work of the sensor, the lead wires may get tangled, straighten the lead wires, or pick up each piece one by one. was lacking. Furthermore, there are also problems in that the lead wires tend to break near the soldered parts on the product.

[0008] Furthermore, since the board is attached to the metal bracket plate using an adhesive, the process becomes longer, and there is also the problem that the adhesive tends to adhere to the sensor detection part and deteriorate the performance. had. In an attempt to solve and alleviate these problems,
A dew condensation sensor element 20 is mounted on a bracket made of a hoop material 12, as shown in FIG.
There is a method of manufacturing a dew condensation sensor in which the bracket and connector 21 are fixedly arranged with adhesive, the opposing silver electrode of the dew condensation sensor element and the lead pin of the connector are electrically connected by spot welding, and then the bracket is separated from the hoop material. ,
Although it is now possible to eliminate the soldering of the lead wires and the lead wires themselves, this method requires the spot welding process and the process of fixing the condensation sensor element and connector with adhesive (A and B in the figure). Since it still exists,
The possibility of poor performance due to the heat associated with spot welding and the adhesion of adhesive has not yet been resolved. In addition, since the dew condensation sensor element is simply adhesively and fixedly arranged on the flat plate of the bracket, it is likely to be misaligned on the bracket. If misalignment occurs, it is necessary to ensure reliable electrical connection when welding the silver electrode of the element and the lead pin of the connector. Another problem was that it was difficult to make a connection and it was easy to cause poor continuity.

[0009]

The present invention solves these conventional problems, and provides a sensor that can be used in practice simply by inserting and fitting a sensor chip into a pre-formed sensor chip holder. Since there are no lead wires, it is possible to eliminate both processes such as soldering and spot welding during sensor manufacturing, as well as the process of flux cleaning after soldering, which prevents performance deterioration due to heat, flux, and cleaning. It becomes possible to eliminate such problems, and it becomes an easy-to-handle method that does not cause entanglements during each manufacturing and installation process. At the same time, it becomes unnecessary to attach the metal bracket plate using an adhesive, so there is no need for an adhesive process, and problems such as performance deterioration caused by the adhesive can be eliminated. Furthermore, since the sensor chip is fixed and fitted into the connecting portion of the sensor chip holder without any displacement, electrical connection can be established reliably. As described above, an object of the present invention is to provide a method for manufacturing a dew or moisture-sensitive sensor that has high quality stability, is inexpensive, is suitable for automatic mechanization, and is highly suitable for mass production.

0010

[Means for Solving the Problems] The present invention involves fitting and fixing a board holder having spring-like electrodes and external connection terminals into the positioning and fixing opening of a hoop-shaped bracket plate, and attaching the board holder to the surface in advance. This method of manufacturing a dew or moisture-sensitive sensor is characterized in that a substrate on which a counter electrode is formed is inserted and fitted into the substrate holder so that the electrode and the spring-like electrode are in contact with each other.

The configuration of the present invention will be explained based on FIG. 1. First, as a first step, the substrate holder 11 having the spring-like electrode 14 and the external connection terminal 17 is fitted and fixed into the positioning and fixing opening 16 of the hoop-shaped bracket plate 12. The bracket plate has a positioning and fixing hole.

The shape and size of the positioning and fixing openings are not particularly limited, and the number is preferably two or more in order to prevent misalignment. As for the material, any material with good workability and good thermal conductivity may be used, and metal is generally preferred. Further, the board holder 11 has a protrusion, and the protrusion may be fitted into a positioning and fixing hole formed in the hoop-shaped bracket plate 12, and after fitting, it is necessary to fit the protrusion so that it does not come off. It is preferable to use a fitting form that utilizes elastic deformation of the protrusions, or to fix the protrusions by welding them with heat.

[0013] As for the format of the board holder, it may be of a type like a normal electrical connector, and the exterior is made of resin or the like, and a part of the exterior is used to securely hold the board so that it does not fall off. It is preferable that a fixing claw 19 or the like be formed on. The spring-like electrode 14 may be made of a plate spring type or sliding type metal piece.

The external connection terminal 17 is formed in a part of the board holder, and its types include soldering to the terminal electrode of the external circuit board, as shown in 17 in FIG.
It may be a terminal type that can be welded, or it may be a terminal type that can be welded.
As shown in Fig. 18, it may be a connector-like one to which a lead wire from the outside can be connected. The terminal type may be either a type formed in a part of the spring-like electrode and integrated with the spring-like electrode, or a dedicated separate type or a combined type. Regarding the material, it may be made of any metal as long as it is compatible with mounting on a normal circuit board and is based on the size and shape of the circuit board terminal electrode, and shapes such as pins and lead pieces may be used. preferable.

Regarding the shape of the connector, depending on the shape of the external lead wire, there are three types: lead wire connector connection type (FIG. 3(a)), lead wire terminal connection type (FIG. 3(b)), The shape may be suitable for each type, such as the FPC wiring connection type (Fig. 3(c)), and each connection part may be an integral or separate body shaped so that the other end of the spring-like electrode can be connected in this way. It suffices if it is a connecting contact pin.

As a second step, the substrate 10, on which the counter electrodes 9a and 9b have been formed in advance, is placed in the substrate holder 11 so that the counter electrodes and the spring electrodes are in contact with each other.
Insert and mate. The substrate 10 may be of any type as long as it is used in conventional dew condensation sensors or general electronic components, but due to the nature of the sensor, the temperature condition of the object to which the sensor is attached must be well transmitted to the sensor. Therefore, it is preferable to use a substrate with good thermal conductivity, such as a metal-based metal core substrate, a ceramic (alumina, etc.) substrate with good thermal conductivity, or a thin insulating film with the electrode part on it. Examples include a substrate in which the formed material is attached to a hard plate-like material with good thermal conductivity. It is necessary to form counter electrodes 9a and 9b on the surface in advance. The sensor detection portion 7 on the substrate may be formed by a conventional method for forming a dew condensation sensor, and there is no need to use a special method according to the configuration of the present invention. The order of formation may be before fitting the substrate to the substrate holder,
It may be done after mating.

[0017] The method of manufacturing a dew condensation or humidity sensor of the present invention includes fitting and fixing a substrate holder to the base of a metal bracket plate made of hoop material as described above, and fitting a substrate on which a counter electrode is previously formed. achieved by. With this configuration, a change in the resistance value of the sensor when a dew condensation state is detected is transmitted to the external lead wire through the external connection terminal via the spring electrode in contact with the counter electrode on the board, and is displayed. .

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 2 shows a diagram of a dew or moisture sensitive sensor according to an embodiment of the present invention. Figure 2 (a), (b)
(c) is a perspective view of the same as seen from two different directions, and (c) is a cross-sectional view of the same as seen from the side. In FIG. 2, 10 is an alumina substrate (thickness 0.64 mm), 9a and 9b are silver-palladium counter electrodes, and 7 is substantially continuous and dispersed so that many fine voids are formed. The detection portions 8a and 8b of the dew condensation or humidity sensor are made of a cloth to which a moisture-sensitive resistor is fixed as a base material, and 8a and 8b are conductive contact portions made of conductive paste. Reference numeral 11 denotes a substrate holder made of PBT resin, which has a spring-like electrode 14 and an external connection terminal 17, and a claw 19 for fixing and holding the substrate after insertion is formed in a part thereof. 12 is a hoop-shaped aluminum bracket plate (thickness 0.50 mm) provided with screw holes 13, and has an opening 16 for positioning and fixing. The board holder 11 has a protrusion, and after fitting the protrusion into a positioning and fixing hole 16 made in a hoop-shaped aluminum bracket plate 12 as shown in (■) in FIG. 1, the protrusion is welded by heat. The board is fixed and integrated as a board holder in advance.

The board 10 is slid into and fitted into the series of board holders lined up in the shape of hoop material from the board insertion direction (direction parallel to the surface of the bracket), as shown in (2) in FIG. This establishes an electrical connection between the substrate and the substrate holder. If a sensor detection section is formed on the substrate first, the characteristics of the detection section may be tested in advance. However, from the perspective of the present invention, after the above-mentioned insertion and fitting, the external connection terminal of the substrate holder is It is preferable to perform a series of characteristic tests on the hoop material as it is, and then to separate it from the hoop material and package and ship it, since this allows for continuous production.

The operation of the dew condensation or humidity sensitive sensor of this embodiment manufactured as described above will be briefly explained below. In these dew condensation sensors, when dew condenses where the sensor is attached, moisture condenses on the surface of the sensor detection part 7 as dew condensation, causing the hygroscopic polymer resin in the moisture-sensitive resistor to swell.
The expansion causes the distance between the conductive powders (mainly carbon powder) to increase, making it difficult for current to flow between the powders and increasing the electrical resistance value. And this resistance change is
Via the silver-palladium counter electrode parts 9a, 9b, the signal is transmitted to a spring-like electrode 14 in the substrate holder 11 which is in contact with the electrode and is detected. The external connection terminal (17 or 18) at the other end is connected to a circuit of a device such as a VTR to which the sensor is attached, thereby transmitting the electric resistance value of the sensor to the outside.

As described above, according to this embodiment according to the manufacturing method of the present invention, electrical connection and an operating configuration as a sensor can be established simply by inserting and fitting the board into the board holder. Since there are no lead wires, it is possible to eliminate both processes such as soldering and spot welding and the flux cleaning process after soldering during sensor manufacturing, making it possible to eliminate problems such as performance deterioration due to heat, flux, and cleaning. . In addition, the structure is easy to handle and does not tangle during each manufacturing and installation process, and at the same time, there is no need to use adhesive to attach the metal bracket plate, so there is no need for an adhesive process. Problems such as performance deterioration caused by agents can also be eliminated. Furthermore, since the board is fixed and fitted into the board holder without any displacement, electrical connection can be made reliably. therefore,
It is possible to provide a dew or humidity sensor that has high quality stability, is inexpensive, is suitable for automatic mechanization, and is highly mass-producible.

[0022]

[Effects of the Invention] The method for manufacturing a dew condensation or humidity sensor of the present invention includes fitting a substrate holder into a positioning and fixing opening of a hoop-shaped bracket plate, and further inserting and fitting a substrate. Since there are no lead wires required, both processes such as soldering and spot welding as well as the flux cleaning process due to soldering can be eliminated during sensor manufacturing. It is possible to eliminate problems such as performance deterioration due to cleaning, and it also has a structure that is easy to handle without getting tangled during each manufacturing and installation process, and at the same time, the metal bracket plate can be attached using adhesive. Since this is also unnecessary, there is no need for an adhesion process, and problems such as performance deterioration due to adhesives can also be eliminated. Furthermore, since the board is fixed and fitted into the connecting portion of the board holder without any displacement, electrical connection can be made reliably. Therefore, it is possible to manufacture a dew or moisture-sensitive sensor that has high quality stability, is inexpensive, is suitable for automatic mechanization, and is highly mass-producible.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a specific manufacturing process of the manufacturing method of the present invention.

FIG. 2 is a diagram of a dew or moisture-sensitive sensor manufactured by the manufacturing method of the present invention, in which (a) and (b) are perspective views of the sensor as seen from two different directions, and (c) is a cross-sectional view of the sensor as seen from the side. It is a diagram.

FIG. 3 is a perspective view showing an embodiment of a connector-shaped external connection terminal of a dew condensation or humidity sensor manufactured by the manufacturing method of the present invention; Connection type (Figure 3(a)), lead wire terminal connection type (Figure 3(b)), FPC wiring connection type (Figure 3(c)
)).

[Fig. 4] An example of a conventional manufacturing method (Japanese Patent Application Laid-Open No. 2-69650
(described in the publication).

FIG. 5 is a partially exploded perspective view of a conventional dew condensation sensor;
(a) is a type in which a moisture-sensitive resistor is formed as a film covering a comb-shaped counter electrode formed on an insulating substrate; (b)
In this method, a fabric on which moisture-sensitive resistors are fixed in a substantially continuous and dispersed manner so as to form a large number of fine voids is placed on an insulating substrate, and electrical connections are made with electrodes on the substrate. This is the format that was taken.

[Explanation of symbols]

1 Sensor detection parts 2a, 2b Pair of opposing electrodes 3 Substrate 4 Conductive contact parts 5a, 5b Lead wire 6 Metal bracket plate 7 Sensor detection parts 8a, 8b Conductive contact parts 9a, 9b Counter electrode 10 Substrate 11 Substrate holder 12 Hoop Material-like bracket plate 13 Screw fixing hole 14 Spring-like electrode 15 Contact part between spring-like electrode and counter electrode 16 Positioning and fixing hole 17 External connection terminal 18 Connector-like external connection terminal 19 Board fixation in the board holder Holding claw 20 Condensation sensor element 21 Connector

Claims (1)

[Claims] Claim 1: A substrate having a hoop-shaped bracket plate with a substrate holder having a spring-like electrode and an external connection terminal fitted and fixed into a positioning and fixing opening, and a counter electrode formed on the surface in advance. A method of manufacturing a dew condensation or moisture sensitive sensor, comprising inserting and fitting into the substrate holder so that the electrode and the spring-like electrode are in contact with each other.