JPH05326347A - Package for electronic component - Google Patents

Abstract

PURPOSE:To provide a package for an electronic component having excellent adhesive properties and heat resistance between the package body and a resin layer. CONSTITUTION:A laminated board in which one surface of an aluminum plate is covered with polyester series resin having a melting point of 240 deg.C or higher is so drawn that a polyester resin layer becomes an outer layer. Thus, resin of an outer surface of a package is not deteriorated even if it is exposed with a high temperature at the time of soldering to hold its insulation. The package can be satisfactorily used for an aluminum electrolytic capacitor in which a lower part of the capacitor is brought into direct contact with a printed circuit board or for an aluminum electrolytic capacitor of a lateral erectable type in which a side face of a capacitor body is brought into contact with a circuit board.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an outer container for electronic parts in which a specific polyester resin layer is provided on the outer surface of a bottomed cylindrical container body made of an aluminum plate, and particularly, the lead is short and the lower part of the capacitor body is directly attached. It has excellent adhesiveness and heat resistance between the container body and the resin layer, which can be suitably used for aluminum electrolytic capacitors that come into contact with the printed circuit board and horizontal type aluminum electrolytic capacitors where the side surface of the capacitor body also comes into direct contact with the board. The present invention relates to an outer container for electronic parts.

[0002]

2. Description of the Related Art As an outer container for accommodating a capacitor element which constitutes an aluminum electrolytic capacitor,
Usually, it is a bottomed cylindrical container made by drawing an aluminum plate, and the outer surface of the container is covered with a shrinkable tube which is colored with various coloring agents for identifying the capacitor element and further printed with symbols and the like. It is used.

In recent years, electronic components mounted on a printed circuit board have been miniaturized, and aluminum electrolytic capacitors have also tended to be miniaturized. Further, the leads of the capacitors are shortened so that the lower part of the capacitor body directly contacts the substrate. By doing so, the space between the printed circuit board and the capacitor can be made smaller (lower profile),
It is being studied to eliminate wasted space and implement high density mounting. Similarly, for the purpose of high-density mounting, a horizontal type aluminum electrolytic capacitor in which the side surface of the capacitor body directly contacts the surface of the wiring board is under study.

In the case of a small-sized aluminum electrolytic capacitor having a low profile, a shrink tube made of, for example, polyvinyl chloride resin, which has been conventionally used as a coating material for the outer periphery of a capacitor outer container, is used as a coating material to print. When the solder is applied to the surface of the wiring board by the reflow method, it is in direct contact with the wiring board.If the temperature of the solder is too high, it is easily affected by the temperature of the solder. There was a problem of heat deterioration and melting.

Further, it has been studied to obtain a capacitor outer container by a drawing process using a laminated plate in which one surface or both surfaces of an aluminum plate is coated with a resin layer without using the shrinkable tube, but the same problem as described above occurs. It was difficult to solve.

[0006]

DISCLOSURE OF THE INVENTION The present invention has been found to solve the above problems by coating the outer surface of a container body with a specific polyester resin.
The gist of the invention resides in an outer container for electronic parts, which is obtained by drawing a laminated plate in which one surface of an aluminum plate is coated with a polyester resin having a melting point of 240 ° C. or more so that the polyester resin layer is an outer layer.

As the aluminum used for the container body, for example, JIS No. 1000 series No. 1000 and aluminum component of 99% by weight or more can be preferably used, and thickness of 0.2 to 0.4 mm is preferably used. it can.

As the polyester resin used for coating the aluminum plate, one having a melting point of 240 ° C. or higher must be used, and the melting point is a differential scanning calorimeter (DS).
The temperature value of the endothermic peak measured in C) is used. If the melting point is less than 240 ° C, there is a problem that the heat resistance is poor.

Specific polyester resins include polyethylene terephthalate, polyethylene naphthalate, poly-1,4 cyclohexane dimethylene terephthalate and the like. There are various methods for laminating the polyester-based resin on the surface of the aluminum plate, but a method in which a polyester-based resin film formed in advance is pressure-bonded to an aluminum plate heated to a temperature above the melting point of the resin to perform melt lamination Is preferable from the viewpoint of productivity. The thickness of the polyester resin layer is 10 to 100 μm,
Further, the range of 10 to 50 μm is preferable from the viewpoint of drawing and heat resistance.

Here, the other surface of the aluminum plate coated with the polyester resin may be coated with a modified polyolefin resin in order to impart insulation to the capacitor element.

The modified polyolefin resin is a polyolefin resin obtained by graft-copolymerizing an unsaturated carboxylic acid or a derivative thereof, and the unsaturated carboxylic acid is acrylic acid, methacrylic acid, crotonic acid, maleic acid, or the like.
Examples of unsaturated carboxylic acid derivatives include maleic anhydride and itaconic anhydride, and examples of polyolefin resins include polyethylene, polypropylene, poly-1-butene,
Examples thereof include poly-4-methyl 1-pentene and ethylene-propylene copolymer.

The thickness of the modified polyolefin resin layer is 10 to 100 μm, like the above polyester resin.
m, preferably 10 to 50 μm, and the laminating method may be the melt laminating method as described above.

The laminated plate having the above structure is formed into a cylindrical container with a bottom by drawing the polyester resin layer as an outer layer by using a normal drawing machine. Further, the container obtained by drawing is heat-treated at a temperature range from the melting start temperature of the coated polyester resin to the weight loss upon heating of 10% by weight or less, whereby the adhesion between aluminum and the resin layer can be further improved.

The heat treatment temperature varies depending on the resin, but in the case of polyethylene terephthalate, the melting start temperature is 210 ° C.,
The temperature at which the weight loss by heating is 10% by weight is about 400 ° C.

The present invention will be described in detail below with reference to examples.

[0016]

EXAMPLE A film (thickness 20 μm) made of polyethylene terephthalate (melting point 260 ° C.) and polybutylene terephthalate (melting point 224 ° C.) was laminated on one surface of an aluminum plate (A1100P-H18, thickness 0.3 mm) with a laminating roll. Each laminate was obtained by melt lamination.

Using each of the obtained laminated plates, a lance progressive drawing die was used to draw 7 steps to prepare a bottomed cylindrical container having a diameter of 10 mm and a height of 20 mm, the outer surface of which was coated with resin. Place the resulting container on a hot plate heated to 240 ° C so that the top surface of the container is in contact with the container,
The state of the top surface portion was observed by applying a load of g for 30 seconds.

As a result, in the container coated with polybutylene terephthalate, the resin was melt-bonded to the hot plate and the heat resistance was poor, but there was no change in the container coated with polyethylene terephthalate. When a capacitor element was housed in the container and a practical test as an electrolytic capacitor was conducted, there was no problem in the container coated with polyethylene terephthalate as in the above.

[0019]

As described above, according to the outer container for electronic parts of the present invention, the resin on the outer surface of the outer container is not deteriorated even when exposed to the high temperature during soldering, the insulation is maintained, and the lower part of the capacitor is printed. It is widely used as an outer container for aluminum electrolytic capacitors that comes into direct contact with the wiring board and as a laterally rising aluminum electrolytic capacitor where the side surface of the capacitor body comes into contact with the wiring board.

Claims (3)

[Claims] 1. A melting point of 240 on one surface of an aluminum plate.
An outer container for electronic parts, which is obtained by drawing a laminated plate coated with a polyester resin having a temperature of ℃ or higher so that the polyester resin layer is an outer layer. 2. A melting point of 240 on one surface of an aluminum plate.
2. A laminated plate which is coated with a polyester resin at a temperature of not less than 0.degree. C. and which is coated with a modified polyolefin resin layer obtained by graft-copolymerizing an unsaturated carboxylic acid or its derivative on the other surface of the aluminum plate. Exterior container for electronic parts. 3. The method according to claim 1 or 2, wherein after drawing, the outer layer-coated polyester-based resin is heat-treated at a temperature range from a melting start temperature to a heating loss of 10% by weight or less. Exterior container for electronic parts.