JPS60165041A - Manufacture of thin type sealed battery - Google Patents

Abstract

PURPOSE:To prevent the adhesion of solder to the side of a spacer and obtain a thin type battery without shortcircuit and with good sealing properties by performing the solder joint between the spacer and a plate using the laser local heating. CONSTITUTION:Presoldered positive electrode plate 6, negative electrode plate 5, and spacer 7 are loaded on a support jig 11 made of iron and pressurized and fixed by a press jig 12. Then the circumferential section of a battery is irradiated with pulse YAG laser and the negative electrode plate 5 and the spacer 7 are joined by melting presoldered solders 8a and 8b in the negative electrode 5 and the spacer 7. Furthermore, the support jig 12 is lifted and a battery is loaded on the support jig 11 by inverting the top and bottom of the battery, then the support jig 12 is lowered again. While the battery is being pressurized, the circumferential section of the battery is irradiated with pulse YAG laser and the positive electrode plate 6 and the spacer 7 are joined by melting solders 9a and 9b presoldered on the positive electrode plate 6 and the spacer 7.

Description

[Detailed description of the invention] 〔Technical field〕 The present invention relates to a method for manufacturing a thin sealed battery.

[Background technology]

Traditionally, this type of battery is sealed by metallizing the surface of a ceramic or glass spacer.
This has been accomplished by soldering the spacer and the electrode plate together by heating in a furnace. At this time, if the amount of solder is small, a sufficient seal cannot be obtained, and if it is too much, the solder will protrude and adhere to the sides of the spacer, and the battery will short circuit due to the solder attached to the sides of the spacer. It was extremely difficult to adjust and the yield was poor.

[Purpose of the invention]

An object of the present invention is to provide a thin sealed battery that prevents solder from adhering to the side surface of the spacer when joining a spacer and an electrode plate with solder, is free from short circuits, and has good sealing performance. .

[Summary of the invention]

The present invention prevents adhesion of solder to the side surfaces of the spacer by joining the spacer and the electrode plate with solder using local heating using a laser, thereby making it possible to obtain a thin battery that is free from short circuits and has good sealing performance. This is what I did.

When soldering a spacer and an electrode plate by laser heating, it is preferable to preheat the electrode plates to be joined to a temperature below the melting point of the solder. This is because laser heating locally heats up quickly and cools down quickly, so the temperature of the electrode plates and spacers hardly rises, which makes it difficult for the molten solder to wet, making it difficult to form a uniform solder joint, resulting in a stable and stable solder joint. It is difficult to obtain a highly sealed battery, so preheating the electrode plate improves the wetting of the solder to the electrode plate and spacer (heating the electrode plate causes the solder to pass through and the spacer also heats up). let me,
This is to ensure that a battery with stable and high sealing performance can be obtained.

〔Example〕

Example 1' The thickness is 0.7 + nm and the planar shape is 15 mm as shown in Figure 1.
A square thin battery measuring 15 mm in diameter was sealed and manufactured by the method shown in FIG.

The battery is a solid thin film secondary battery, and in the figure, 1 is a glass substrate, 2 is a positive electrode made of a TLS2 thin film formed on the glass substrate 1 by chemical vapor deposition, and 3 is a positive electrode made of a TLS2 thin film formed on the positive electrode 2 by sputtering. L formed by the method
A solid electrolyte layer made of a thin film of i4Si04-Li3PO4, and 4 is a negative electrode of the lithium thin film formed on the solid electrolyte layer 3. Reference numeral 5 denotes a negative electrode plate. Although not shown, the inner surface of the negative electrode plate 5 is coated with polyimide resin except for the central portion that contacts the negative electrode 4 to avoid internal short circuits. Reference numeral 6 denotes a positive electrode plate, and although not shown, the positive electrode plate 6 and the positive electrode 2 are electrically connected through a conductive paste. 7 is a ceramic spacer, and solder 8.9 is used between the spacer 7 and the negative electrode plate 5 and between the spacer 7 and the positive electrode plate 6.
The inside of the battery is sealed to form a hermetic structure.

Details of the above battery and its manufacturing method are as follows.

As the positive electrode plate 6 and the negative electrode plate 5, three-layer clad plates of copper-stainless steel-nisokel having a thickness of 0.1 mm were used, and the copper surface was used as the bonding surface.

The spacer 7 is made of alumina ceramics and has a thickness of 0.
．． It has a rectangular shape with a cross section of 4 mm and a cross section of 0.4 mm x 1.5 mm, and the planar shape has an external dimension of 15 mm x as shown in Figure 2.
It is molded into a 15 mm square ring shape.

The surface of the spacer 7 was coated with molybdenum-manganese metallization, and the metallized layer was further plated with copper to form a bonding surface.

The solder 8.9 used is a low melting point solder made of bismuth-tin-lead alloy with a melting point of about 145°C, and as shown in FIG. I pre-soldered it to a thickness of .

Positive electrode plate 6 and negative electrode plate 5 pre-soldered as above
First, using the spacer 7 and a power generating element consisting of the positive electrode 2, the solid electrolyte N3, and the negative electrode 4 is placed on the center of the positive electrode plate 6 together with the glass substrate 1, the positive electrode 2 and the positive electrode plate 6 are electrically connected with a conductive paste, and the positive electrode A spacer 7 is attached to the periphery of the plate 6.
The negative electrode plate 5 was placed on the spacer 7, and as shown in FIG. 3, it was placed on an iron supporting jig 11, and the battery was pressurized and fixed using a holding jig 12.

Next, a pulsed YAG laser (output 100 W, speed 3
0mm/sec, pulse oscillation number 50pps) 13
is irradiated along the outer periphery of the battery, and the negative electrode plate 5 and spacer 7 are
The negative electrode plate 5 and the spacer 7 were joined by melting the solders 8a and 8b that had been pre-soldered to the electrodes. At this time, no melting of the negative electrode plate 5 was observed. Furthermore, since the entire battery was not heated excessively, no solder was attached to the side surface of the spacer 7.

Next, the holding jig 12 is pulled up, the battery is turned upside down and placed on the supporting jig 11, and the holding jig 12 is lowered again to pressurize the battery while applying the pulsed YAG laser in the same manner as above. The positive electrode plate 6 and spacer 7 were joined together by irradiating the outer periphery of the battery under certain conditions to melt the solders 9a and 9b that had been preliminarily soldered to the positive electrode plate 6 and spacer 7. Naturally, no melting of the positive electrode plate 6 was observed, and no adhesion of solder to the side surfaces of the spacer 7 occurred.

When the airtightness of the obtained battery was measured using a helium leak detector, the leakage was found to be IXl0-"atm*cc
/sec・air or less, and the airtightness was high.

One hundred solid thin film secondary batteries were produced in the manner described above, and all had open circuit voltages of 2.5 or more, and no short circuits were observed.

By the way, a solid thin film secondary battery similar to the above was heated in a furnace (1
Although 100 pieces were manufactured by sealing at 80° C. for 10 minutes, 10 pieces had an open circuit voltage of less than 2.5 μ.

Example 2 The support jig 11 and the presser jig 12 are heated in advance at 100° C. in an electric furnace, and the heated support jig 11 and presser jig 12 are used to separate the positive electrode plate 6 and the negative electrode plate before laser irradiation. A solid thin film secondary battery was produced in the same manner as in Example 1, except that Sample No. 5 was heated for about 10 seconds in advance.

According to the above method, since the electrode plates were heated in advance, a solid thin film secondary battery with good solder wetting and good sealing performance was stably obtained. Of course, there were no short circuits caused by solder adhesion to the spacers.

Although 1,000 batteries were manufactured using the method of preheating as described above, only 2 batteries did not reach an airtightness of 1 x 10-9a10-9at/5eclIair or less as measured by a helium leak detector. On the other hand, when the method of Example 1 was used, the airtightness due to the helium leak detector was 1× out of 1000 batteries manufactured.
There were 15 cases that did not reach 1O-9atIIl@cc/5ec-air or less.

In the example, a pulsed YAG laser was used as the laser, but the laser is not limited to this, and for example, a continuous wave YAG laser may be used.
An AG laser, continuous oscillation type carbon dioxide laser, pulse oscillation type carbon dioxide laser, etc. can also be used. Furthermore, although a jig preheated in an electric furnace was used as a preheating means, preheating does not necessarily have to be done using a jig.
Furthermore, the heating of the jig may also be performed by incorporating a heater into the jig, and is not limited to the method shown in the embodiment.

〔Effect of the invention〕

As described above, the present invention provides a thin sealed battery that is free from short circuits and has good sealing properties.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an example of a thin sealed battery according to the present invention, FIG. 2 is a plan view of a spacer used in the battery shown in FIG. 1, and FIG. 3 is a fabrication of the battery shown in FIG. Middle side view, 4th
The figure is an enlarged cross-sectional view of the main parts of the battery under manufacture shown in FIG. 3. 2...Positive electrode, 3...Solid electrolyte, 4...Negative electrode, 5...Negative electrode plate, 6...Positive electrode plate, 7...Spacer, 8.9...Solder, 13...・Left 2 diagram before laser irradiation

Claims (2)

[Claims] (1) A thin sealed battery in which a power generation element and a spacer made of ceramic or glass are placed between the positive electrode plate and the negative electrode plate, and the electrode plate and the spacer are joined with solder for an airtight seal. A method for manufacturing a thin sealed battery, characterized in that during manufacturing, joining by solder is performed by locally heating with a laser. (2) A method for manufacturing a thin sealed battery according to claim 1, characterized in that the electrode plate is used during laser heating.