JPS6156862B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electronic device and a method for manufacturing the same, and particularly to a method for enclosing a flat electronic device and taking out an electrode.

In recent years, electronic devices such as calculators and electronic watches have been becoming smaller, especially thinner. Therefore, the capacitors, semiconductors,
Electronic devices such as batteries are also required to be thinner and flat products. This type of electronic device is easily deteriorated by gases such as oxygen and nitrogen in the air, as well as water vapor, so it is necessary to encapsulate the electronic device in an electrical insulator such as glass or synthetic resin to isolate it from the outside air. be. Conventional encapsulation methods include the immersion method in which electronic devices are immersed in a viscous liquid of synthetic resin such as epoxy and cured by heat, or the electronic device is immersed in a hot molten liquid of synthetic resin such as epoxy. The so-called mold forming method is mainly used, in which the material is extruded under pressure into a shaped mold, encapsulated, and then thermosetted. The dipping method has the disadvantage that it is difficult to control the thickness of the encapsulated resin to a constant level, and the thickness varies widely, making it impossible to produce products with a uniform shape. For this reason, electronic elements encapsulated by the dipping method are unsuitable for use in smaller, thinner electronic devices that require strict dimensions.
On the other hand, electronic elements encapsulated using the molding method are
Since it is molded using a mold with a fixed shape, electronic elements with uniform external dimensions can be obtained.On the other hand, electronic elements encapsulated using the molding method are subject to the pressure of the resin extruded under pressure during molding, and the pressure of the molten resin. In many cases, mechanical and thermal stress such as heat during hardening and heat during curing significantly deteriorate the electrical properties. Further, since the electronic element is molded by pushing resin into the mold, the electronic element contained within the resin layer is exposed from the resin layer even if the positioning of the electronic element and the dimensional accuracy of the mold are well taken care of. For this reason, the thickness of the resin contained in the molding method has to be relatively thick, and as a result, the shape of the electronic device cannot be fully satisfied as an electronic device that can be made smaller and thinner. . Furthermore, since the structure for drawing out the electrodes from the encapsulated electronic element to the outside becomes complicated, the structure of the mold for molding also becomes complex and highly precise, making it unsuitable for encapsulating electronic elements that are mass-produced at low cost. .

Among the electronic elements mentioned above, capacitors and
This is a drawback of conventional products related to resistors and semiconductors. Batteries are other electronic devices that are most required to be made smaller and thinner.Next, conventional drawbacks of batteries will be explained in detail with reference to the drawings.

Generally, a battery consists of a negative electrode active material 1 as shown in FIG.
The layered structure in which the electrolyte layer 2 is sandwiched between the positive electrode active material 3 and the positive electrode active material 3 becomes a basic battery component (hereinafter abbreviated as the element body 9). Normally, an electrode is formed on this element body 9 so that the electrode can be taken out from the outside.
The element body 9 is sealed. Due to the characteristics of the battery, the current value that can be taken out is also affected by the internal resistance of the battery, but if the internal resistance of the battery is the same, it is proportional to the contact area between the positive and negative active materials 3 and 1 and the electrolyte layer 2. and grow bigger. Further, the life of the battery is proportional to the amount of materials included in the product of the positive electrode active material 3 and the negative electrode active material 1. Therefore, the current value is large,
In order to design a long-life battery, it is necessary to use a sheet-like structure with a large contact area or to wind this sheet, but in terms of making it thinner, it is necessary to create a sheet-like battery element and use this as a structure. It is preferable to use a battery with a flat shape.

BACKGROUND ART Conventionally, as flat-shaped batteries, there are usually batteries called button-shaped or coin-shaped batteries. Although there are differences in the bottom area and thickness of the batteries, they all basically have the structure shown in Figure 1. The battery element body 9 has a negative electrode metal lid 4 which also serves as an electrode.
The lid 4 and the case 5 are electrically insulated by an electrically insulating packing 6, and the battery element body 9 is sealed. This requires a lid 4, a case 5, and a packing 6 with a special structure, and a special machining process usually called caulking is applied to the case 5 through the packing 6, so that the battery element body 9 is assembled. Because it has a complicated structure, such as being sealed, special parts and processing steps are required. Moreover, in order to increase the current value and increase the contact area between the electrolyte layer 2 and the active materials 1 and 3 of the negative and positive electrodes, there is a certain limit with a special structure as shown in FIG. Batteries with large current values cannot be used. Furthermore, due to the special structure, there is a certain limit to how thin it can be made.

Recently, in order to increase the current value, sheet-shaped batteries with a relatively large area and thinner thickness have been developed. FIGS. 2 and 3 show cross-sectional views of conventional sheet-shaped batteries. Figure 2 shows
The upper and lower sides of the battery element body 9 are covered with electrode layers of metal foils 7 and 7', and the metal foils 7 and 7' are attached to the electrically insulated structure of the battery via electrically insulating packing 8. be. This is because (a) if the upper and lower metal foils 7 and 7' are connected, an electrical short circuit will occur, so electrically insulating packing 8 is required to enclose the battery element body 9, and (b) is sufficient. In order to obtain good electrical insulation, the packing 8 must be relatively thick. (c) The manufacturing process is complicated because it is difficult to align the packing 8 with the battery element body 9, and (d) The adhesion between the metal foils 7 and 7' and the ring 8 made of synthetic resin is relatively poor. However, there are drawbacks such as insufficient sealing.

As an example of another conventional product, as shown in FIG. 3, there is one in which the battery element body 9 is enclosed in electrically insulating films 12, 12' made of synthetic resin, but in this case, as shown in FIG. Furthermore, the packing 8 is no longer necessary, and the adhesion is improved. On the other hand, it becomes complicated to take out the positive electrode and the negative electrode. In other words, as shown in FIG.
Metal foils 11 of positive electrodes are respectively provided. Therefore, (i) both electrode layers made of metal foils 10 and 11 are
The external electrodes cannot be taken out unless the electrically insulating films 12 and 12' of the exterior casing are cut and removed at appropriate locations so as to be exposed to the outside of the battery. (ii) Therefore, the battery becomes extra thick by the thickness of the metal foils 10 and 11 of the negative and positive electrode layers. (iii) Since the adhesion between the electrical insulating films 12, 12' and the metal foils 10, 11 is weak, there are drawbacks such as insufficient sealing, which makes it impossible to put it into practical use.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate such conventional drawbacks, to provide an electronic device having a thin layer, good sealing properties, and easy extraction of external electrodes, and a method for manufacturing the same.

According to the present invention, an anisotropically conductive sheet exhibiting conductivity in the thickness direction of the sheet and having electrical insulation properties in the surface direction of the sheet can be used to conduct device bodies such as semiconductors, resistors, capacitors, and batteries. An electronic device is obtained in which the upper and lower surfaces and the two side surfaces are continuously and closely enclosed, and the entire periphery of the device body is sealed to form external electrodes.

Furthermore, according to the present invention, element bodies such as semiconductors, resistors, capacitors, and batteries can be formed using a single anisotropically conductive sheet that exhibits conductivity in the thickness direction of the sheet and has electrical insulation properties in the sheet surface direction. A method for manufacturing an electronic device is obtained, which is characterized in that the tube is inserted into a tube consisting of a tube, the tube is brought into close contact with the device body, and the peripheral portion of the tube is sealed.

Next, FIGS. 4 and 5 are cross-sectional views showing specific examples of anisotropically conductive sheets having conductivity in the thickness direction and electrical insulation in the surface direction. FIG. 4 shows a conductive thin wire 13 made of metal such as stainless steel or copper, or carbon fiber, made of rubber elastic material such as butadiene rubber or silicone rubber, or made of polyethylene, polypropylene, polyvinyl chloride, etc.
It is made into a sheet or film by being embedded in an electrically insulating synthetic resin 14 such as plastic such as polyethylene terephthalate, nylon, or polyimide, parallel to the thickness direction, and a conductive thin wire 13 is formed on the surface of the sheet. exposed. Therefore, although it exhibits electrical insulation properties in the direction of the sheet surface,
On the other hand, the sheet exhibits conductivity in the thickness direction. FIG. 5 shows that conductive particles 15 made of metal such as copper, iron, nickel, or silver, or fine particles such as graphite,
FIG. 2 is a cross-sectional view of a sheet (or film) oriented and connected in the thickness direction in the synthetic resin 14 as described above. In this case as well, as in FIG. 4, conductivity is exhibited in the thickness direction of the sheet, and electrical insulation is exhibited in the sheet direction. When the element body 9 on which no electrodes are formed is tightly enclosed in such an anisotropically conductive sheet and sealed, the element body 9 is sealed and at the same time, the electrodes can be easily removed from an appropriate part on the sheet surface. can be taken out. Therefore, since the anisotropically conductive sheet is electrically insulating in the plane direction and electrically conductive only in the thickness direction, the element body 9 can be formed using only this sheet.
As shown in Figs.
In order to expose the load electrode and positive electrode 1, it is not necessary to cut and remove the electrical insulation 12, 12' of the outer case.
Therefore, the structure of the electronic device is simplified, which is particularly effective in making it smaller and thinner. In addition, since the sealing part of an electronic device is made of the same material as the anisotropically conductive sheets, for example, the sealing part is dissolved with a solvent that dissolves the synthetic resin of the anisotropically conductive sheet, and then the sealing part is sealed under pressure. The sealing methods are relatively simple, such as evaporation of the solvent, thermal melting and pressure welding, or adhesive sealing, and the sealability of the sealing part is also better than conventional methods. It is extremely good compared to

Furthermore, in the present invention, as shown in FIGS. 6a to 6e,
The element body 9 is inserted into the tube 16 made of a single anisotropically conductive sheet, and the element body 9 is inserted into the tube 16 by heat-shrinking the sheet or by reducing the pressure inside the tube 16. The manufacturing method is extremely simple, as the seal is sealed after being brought into close contact with the body. Furthermore, since the number of sealing portions 18 is small, the shape is simple and the sealing performance is excellent. In addition, tube 1
By inserting a large number of element bodies 9 into the device 6 and sealing the peripheral portions of the element bodies 9, a mass production method can be obtained in which external electrodes can be formed at the same time as sealing a large number of electronic elements. There are advantages.

Embodiments of the present invention will be described in detail below with reference to the drawings.

Example A lithium metal sheet was cut into a plate shape of 115 mm long, 30 mm wide, and 0.3 mm thick under an argon gas atmosphere. This lithium metal plate is used as negative electrode active material 1,
This is crimped onto a stainless steel electrode part 19, which will serve as a negative electrode and is 15 mm long, 30 mm wide, and 50 μm thick. next,
Vertical, 15.1, pre-soaked with a propylene carbonate solution of lithium perchlorate on the negative electrode active material 1.
An electrolyte layer 2 made of polypropylene nonwoven fabric measuring 30.5 mm in length and 100 μm in thickness is placed on top of the electrolyte layer 2, and a mixed powder of 95% by weight of manganese dioxide powder and 5% by weight of carbon black powder is pressure molded. 30mm,
The positive electrode active material 3 formed into a rectangular parallelepiped with a thickness of 0.3 mm is placed, and on top of this, a positive electrode of 15 mm in length and 30 mm in width is placed.
An electrode portion 19' made of stainless steel with a thickness of .mu.m and a thickness of .mu.m was crimped to obtain a battery element body 9. FIG. 6a shows the battery element body 9 obtained as described above.
As shown in Fig. 4, thin stainless steel wires 13 with a diameter of 30 μm are embedded in a synthetic resin 14 of polyethylene terephthalate with a thickness of 0.2 mm at intervals of 0.3 mm.
A heat-shrinkable tube 16 made of an anisotropically conductive sheet with an inner diameter of 33 mm was cut into a length of 34 mm. The element body 9 is inserted into the tube 16 as shown in FIG. . Next, make this 17mm long, 31mm wide,
Place it on a Teflon plate (not shown) with a groove 0.4 mm deep, and place it 17 mm vertically and horizontally from the top surface of the element body 9.
A trench of 31 mm and 5 mm depth was dug, and the temperature was
Pressure is applied using a Teflon-coated square metal press jig (not shown) heated to 230°C to fuse the peripheral parts 16a and 16b of the tube 16, and the element body 9 is inserted into the anisotropically conductive sheet tube 16. sealed in. FIG. 6c is a perspective view obtained as described above, and FIGS. 6d and e are lateral and longitudinal cross-sectional views, respectively, of the cell of FIG. 6c.
In this case, the sealing parts 18, 18' of the chew part 16 are
It comes to the center of the element body 9.

When we measured the electromotive force of this battery with a load resistance of 1KΩ, it maintained 3V for a long time, showing good battery characteristics. Furthermore, even when this battery was left in a high humidity environment, no moisture intrusion was observed and very good sealing performance was exhibited.

Example 2 A coredenser element body 20 having electrode portions 19 and 19' formed with silver-based conductive paste on the upper and lower surfaces of a ceramic dielectric 17 measuring 7 mm in length, 10 mm in width, and 0.1 mm in thickness, respectively, was mounted on the inner diameter. It is inserted into a heat-shrinkable tube 16 of 16 mm and 12 mm length similar to that of Example 1, and heated with hot air at a temperature of several 100° C. or higher to bring the tube 16 into close contact with the element body 20. Place this on a Teflon plate, and place it vertically from the top surface of the element body 20.
By applying pressure with a metal press jig (not shown) coated with pre-heated Teflon and having a groove of 11 mm wide and 1 mm deep, the peripheral parts 16a and 16b of the tube 16 are fused and the element is assembled. The body 20 was sealed within an anisotropic conductive sheet.

FIG. 7 is a sectional view of the capacitor thus obtained. The sealing parts 18 of the peripheral parts 16a and 16b of the tube 16 have a shape that is offset toward the lower surface of the element body 20 (unlike the shape in which the sealing parts 18 are located in the center of the element body 9 as in the first embodiment). become. The thin wires 13 of the anisotropic conductive sheet exposed on the upper and lower surfaces of this capacitor were connected to constant terminals on each side, and the capacitance value and dielectric loss (Tanδ) were determined at a frequency of 1 KHz. The value was exactly the same as the value of the capacitor element body 20 before being enclosed in a conductive sheet. Furthermore, as a result of conducting a moisture resistance test on this capacitor, the characteristics of the capacitor were not changed at all from before the test.

Example 3 FIG. 8 shows a total of 10 battery element bodies 9 obtained by the same method as in Example 1, in a state as shown in FIG. 6b, and one long anisotropic conductor. Insert it into a tube 16 similar to the embodiment made of a plastic sheet,
After being arranged at intervals, the tubes 16 were heated with hot air at a temperature of about 100° C. or higher to thermally shrink them, and the tubes 16 were brought into close contact with the element body 9. This was installed on a Teflon plate, and the peripheral parts 16a and 16b of the tube 16 were coated with Teflon, which had been preheated to a temperature of 230°C, from the top surface of the element body 9. Pressure is applied using a metal press jig (not shown), and the peripheral part 1 of the tube 16 is pressed.
6a and 16b are fused together to form a total of 10 element bodies 9.
It was sealed in an individual tube 16. The central portion of the sealed portion 18 of the tube was cut to obtain 10 battery elements sealed within the tube 16. When the voltage of each of these batteries was measured with a load resistance of 1KΩ, it showed 3V as in Example 1, and the sealing properties were all good.

As described above, according to the present invention, it is possible to mass-produce small and thin electronic devices by simultaneously performing the external sealing and the electrode extraction.

Note that the present invention is not limited to the batteries and capacitors described in the embodiments, but can also be applied to other general electronic devices such as semiconductors and resistors. Moreover, it goes without saying that the shape of the electronic element can be applied to shapes other than those of this example, if necessary. Furthermore, even if the element body of the electronic element enclosed by the anisotropic conductive sheet does not have an electrode part formed in advance,
It can be applied to any case even if an electrode part is formed.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventional button-shaped or coin-shaped battery, and FIGS. 2 and 3 are sectional views of a conventional sheet-shaped battery. FIGS. 4 and 5 are cross-sectional views of anisotropically conductive sheets used in the present invention. FIG. 6 is an assembled view of a battery according to an embodiment of the present invention, and FIG. 6a is a perspective view of an element body of the battery.
FIG. 6b is a perspective view of the battery element inserted into a tube made of an anisotropic conductive sheet and brought into close contact; FIG. 6c is a perspective view of the element after it is sealed; Figures d and 6e are lateral and longitudinal cross-sectional views of Figure 6c, respectively. FIG. 7 is a sectional view of a capacitor according to another embodiment of the present invention, and FIG. 8 is a cross-sectional view of a capacitor according to another embodiment of the present invention.
FIG. 2 is a top view of a battery according to a mass-produced example. 1... Negative electrode active material, 2... Electrolyte layer, 3... Positive electrode active material, 4... Lid (made of negative electrode metal), 5...
Case (made of positive electrode metal), 6, 8... (electrically insulating) packing, 7, 7', 10, 11... metal foil, 9... (battery) element body, 12, 12'...
...electrical insulating film, 13... (conductive) thin wire, 14... synthetic resin layer, 15... (conductive)
Particles, 16...Tube (of anisotropic conductive sheet), 16a, 16b...periphery of tube, 17
... Ceramic dielectric, 18, 18'... (Tube 16a, 16) Sealing part, 19, 19'...
...(element body) electrode part, 20...(capacitor)
element body.

Claims (1)

[Claims] 1. An anisotropically conductive sheet that exhibits conductivity in the thickness direction of the sheet and has electrical insulation in the surface direction of the sheet, can be used to connect the upper and lower surfaces of element bodies such as semiconductors, capacitors, and batteries. The two side surfaces are continuously and tightly enclosed, and the entire periphery of the element body is sealed,
An electronic device characterized in that an external electrode is formed. 2 Element bodies such as semiconductors, resistors, capacitors, and batteries are inserted into a tube made of a single anisotropically conductive sheet that is conductive in the thickness direction and electrically insulating in the surface direction of the sheet. . A method of manufacturing an electronic device, characterized in that after the tube is brought into close contact with the device body, the peripheral portion of the tube is sealed.