JPS5998575A - Connecting method for lead wirings of high molecular element - Google Patents

Abstract

PURPOSE:To enable to utilize the characteristic of a high molecular element by interposing an anisotropic conductive rubber or pressure conductive rubber between the electrodes and lead wirings of high molecular substrate, and lightly applying pressure thereto, thereby electrically connecting reliably the lead wirings to the high molecule. CONSTITUTION:An anisotropic conductive rubber 5 or pressure conductive rubber 5 is installed on a necessary electrode 2a which is provided on a high molecular substrate 1, lead wirings 4 formed of so-called flexible printed board such as glass epoxy resin is matched, and pressure is lightly applied from above. In this manner, the electrode 2a provided on the substrate is electrically connected to the wirings 4 through the anisotropic rubber 5 or the pressure rubber 5. In this case, the other of the wirings 4 provided on the substrate can be connected to the wirings by normal soldering or connector, and lead wirings may be mounted on the wirings 4 in advance as required.

Description

[Detailed Description of the Invention] [Technical Field to which the Invention Pertains] The present invention relates to a polymer element that has an electrode on a polymer substrate, such as a piezoelectric polymer element, a pyroelectric polymer element, or an electret element. Regarding the method of electrically connecting wires, or in other words, the method of connecting lead wires that is effective for pattern recognition sensors, conventional methods for electrically connecting the electrodes of polymer elements and lead wires are conductive. It is known to adhere lead wires to electrodes using adhesives such as polymeric or silver-based adhesives. However, this method has the drawbacks of weak adhesive strength and easy peeling, as well as changes over time such as a decrease in adhesive strength and an increase in resistance. Furthermore, it is easily peeled off due to vibration or thermal cycling of the element, and cannot be used in devices that involve vibration, such as piezoelectric elements, or elements that involve thermal cycling, such as pyroelectric elements.

Furthermore, since the adhesive has fluidity, this method cannot be used when the electrode is small. Ultrasonic bonding methods, melt bonding methods, and the like are also known as methods for overcoming the problem of top bonding. With these methods, it is possible to firmly connect the lead wire and the electrode, but the adhesion between the polymer element and the electrode decreases, and vibration of the element, heat shock, etc. can cause peeling or detachment of the electrode and lead wire. The disadvantage is that separation is likely to occur. However, this method generally requires heating the entire surface or part of the electrode part of the polymer element, which may cause deformation or depolarization in piezoelectric polymer elements, pyroelectric polymers, electret elements, etc. As a result, disadvantages such as deterioration of characteristics are likely to occur. In addition, photoconductive polymer elements are susceptible to decomposition and deterioration due to heating, and are similarly susceptible to deterioration of characteristics, making them impractical.

[Purpose of the invention]

The present invention has been devised to eliminate the drawbacks of the prior art, and allows lead wires to be connected reliably and easily, with reliability and reproducibility, without changing the characteristics of the polymer element and regardless of the area and shape of the electrode. The object of the present invention is to provide a method for electrically connecting a polymer element and a lead wire.

[Summary of the invention]

The present invention provides an anisotropic conductive rubber between an electrode surface of a polymer element and a lead wire in a method for electrically connecting a lead wire to an electric cedar of a polymer element in which an electrode is installed on a polymer substrate. Alternatively, there is a method for connecting a polymer element with glue and helix, which is characterized by sandwiching pressurized rubber and applying pressure to the electrode surface and the lead interlayer. The present invention will be explained in detail below.

FIG. 1 is a sectional view showing both molecular elements before lead wires are connected, and FIG. 2 is a sectional view showing the polymer element after lead wires are connected. In the figure, (1) is a polymer substrate, (2
a) (2b) is 1[!] provided on the polymer substrate (1).
Indicates the pole J-14, lead wire mount, polyester,
This is a so-called lead wire portion of a printed circuit board in which electrodes (4) are arranged on the surface of polyimide, glass epoxy resin (3a), (3b), etc.

Next, an overview of the present invention will be explained with reference to figures.

First, an anisotropic conductive rubber (5) or a pressurized conductive rubber (5) is placed on the electrodes (2a) at required locations provided on the polymer substrate 1.
), connect the lead wire (4) from a so-called flexible printed circuit board made of glass epoxy resin, etc., and apply light pressure to the furnace from above.

Accordingly, the electrode 2a provided on the polymer substrate is also connected to the lead wire (4) through the anisotropically conductive rubber (5) and the pressurized conductive rubber (5). In this case,
For example, the other lead wire part (4) provided on the flexible printed circuit board can be connected by normal soldering or a connector, and if necessary, the lead wire can be connected to the lead wire part 0) in advance. You can leave it attached.

In the present invention, an anisotropic conductive rubber (5) or a pressurized conductive rubber (5) is used to maintain good electrical connection between the electrode 2a and the lead wire 4 provided on the polymer substrate 1. In order to improve reproducibility and reliability, it is desirable to apply a certain pressure between the lead wire 4 and the polymer substrate 1.

That is, the electrical resistance of the anisotropically conductive rubber (5) or the pressurized conductive rubber (5) generally rapidly decreases when pressurized, resulting in good conductivity. For this purpose, as described above, an anisotropic conductive rubber (5) is installed between the electrical wire 2a provided on the polymer substrate IK and the lead wire 4, and a pressurized conductive rubber (
5) and applying pressure from either side of the polymer substrate 1 or the lead wire 4.

In the present invention, the anisotropic conductive rubber (5) or pressurized conductive rubber (5) is generally made by dispersing carbon black, metal, conductive fine powder, or thin metal wire in a polymer matrix such as silicone rubber. Inside the tortoise, by applying pressure to a book (anisotropically conductive rubber) that has different conductivity in the plane direction and in the direction perpendicular to the plane, only the pressed part becomes conductive in the same direction as the pressure.

〔Effect of the invention〕

The method for connecting lead wires of a polymer element according to the present invention is to install an anisotropically conductive rubber between an electrode provided on a polymer substrate and a lead wire, and to apply light pressure by sandwiching a pressurized conductive rubber. The lead wire can be reliably electrically connected to the cylindrical molecular element. Therefore, since there is no heating means for the polymer element, it is impossible to prevent thermal deformation of the polymer substrate, and it is absolutely impossible to cause problems such as depolarization and thermal deterioration, making the best use of the characteristics of the initial polymer element. be able to.

Generally, anisotropically conductive rubber or pressurized conductive rubber is generally made of silicone rubber or the like as a base material and is highly elastic. It is resistant to vibration and bending, maintains electrical connection between the electrodes of polymer elements and lead wires for a long period of time, and has the effect of preventing electrode peeling of polymer elements.

In addition, anisotropic conductive rubber or pressurized conductive rubber has excellent resistance to temperature changes, weather resistance, corrosion resistance, and chemical resistance, so connections between polymer elements and lead wires can be made under most ambient conditions. When applied in

Another effect is that it not only enables a reliable electrical connection with the lead wire regardless of the shape or size of the polymer element's utility pole, but also ensures reliable electrical connection with a circular or curved utility pole in some cases. connection with lead wires is possible.

[Embodiments of the invention]

Next, specific examples of the method according to the present invention will be described.

Example 1 A polyvinylidene fluoride film with a thickness of 50 mμ is used as a polymer substrate (1) and the width of the unit element is 0.9 as shown in Fig. 3.
A piezoelectric film with 64 elements was formed by etching strip-shaped electrodes 2a having a length of 13 m and a unit element interval of 0.1+m. In this case, the electrode surface 2b, which is opposite to the surface on which the strip-shaped electrodes are formed, is partially formed in a pattern corresponding to the strip-shaped electrodes.

The PvF2 piezoelectric films were stacked in three layers in a folded manner, and the strip-shaped electrodes were stacked correctly vertically. This laminated PVF2 piezoelectric film is shown in FIG. λ/4
A Cu plate with a thickness of 400 μm that corresponds to a plate and also serves as a back electrode.
A glass epoxy board with a thickness of 3 cm (6) was installed in advance (
7) was attached with adhesive. A large number of thin metal wires (gold-plated wires) are placed on the upper electrode surface 2a of the PvF2 film.
Pressure conductive rubber embedded in the thickness direction of Con rubber (5)
(Toshi elastic connector ws type) width 5f
i Cut it to a length of 70+m and install it, and then attach the electrode lead surface on top of it in advance with PV1! ``2 Polyimide flexible printed circuit board patterned in the same shape as the piezoelectric film (3)
The electrode surface (4) was placed on a pressurized conductive rubber.

Back side of polyimide flexible printed circuit board (3) (
Insulating properties] 1) PVF2//7In conductive rubber/
Place the pressure plate (8) (a glass plate with a width of 7 x length and 75 days and thickness of 2) to evenly press the flexible printed circuit board and apply pressure of about g/crl to the top of the plate. Add.

The connection resistance between the electrode surface 2a of the polymer element obtained in this way and the electrode surface (4) of the polyimide flexible printed circuit board (3) was 10Ωm, and in this state, at 50°C and 90% FLH. After conducting an environmental test, the result was 50.
Even after 0H had passed, the connection resistance was 1.5 x 10' Ω, and stable operation was confirmed.

Comparative Example 1 The PVF2 piezoelectric film used in Example 1 was coated with a conductive resin material, Dotite Paint (D-7s3, manufactured by Fujikura Kasei), on a polymer substrate in the same manner as above, and then a film with a diameter of 50 mμ was applied. A gold wire was placed and dried to electrically connect the electrode on the polymer substrate and the lead wire. Approximately 1 connection point
．． There were many short-circuits between 0 to 1.5 mg and the potash strip-shaped elements. In this case, the contact resistance between the polymer element electrode and the lead wire was 6.5Ω^, but it was 01 to 0.25Kg.
The lead wire came off due to the heavy load.

In addition, the contact resistance between this polymer element JR pole and the lead wire was 1 to 65Ω2 immediately after connection in an environmental test at 50°C and 90%RH.
After one week, 58Q/1-r
After changing to R, the contact resistance increased rapidly.

[Brief explanation of drawings]

FIGS. 1 and 2 are cross-sectional views of a polymer substrate and a polymer element showing an example of a method for electrically connecting the polymer substrate and lead wires for explaining the present invention in detail. FIG. 3 is a perspective view of a polymer substrate used in an example of the present invention, and FIG. 4 is a sectional view of a polymer element obtained in the example. 1... Polymer substrate 2.2a, 2b... Electrode 3.3a, 3b... Printed board substrate 4... Lead wire or electrode surface 5... Anisotropically conductive rubber or pressurized conductive material Rubber 6...
・Copper plate 7... Board 8... Pressure plate attorney Kensuke Norichika (and 1 other person) Figure 3 Figure 4

Claims (1)

[Claims] In a method of electrically connecting the electrodes and lead wires of a polymer element with electrodes installed on a polymer substrate, anisotropically conductive rubber or pressurized conductive material is used between the electrode surface of the polymer element and the lead wires. 1. A method for connecting lead wires of a polymer element, which is characterized by sandwiching rubber and applying pressure between an electrode surface and the lead wires.