JPH0998006A - Waterproof structure of electronic parts - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure an assured waterproof function in a simple structure by covering the peripheral part of an electronic parts with the water impermeable resin sheets and welding these sheets to make a waterproof seal for the electronic parts. SOLUTION: An antenna module 1 is vertically held between two polyvinyl chloride sheets (water impermeable resin sheets) 30, and both sheets 30 are adhered to each other around the module 1. Then the electrodes for a high frequency welding device are pressed to apply even temperature to the sheets 30 and the high frequency is applied between the electrodes. Thus both sheets 30 are welded to each other at a welding part by the generated heat and the module 1 is packed watertight in a bagged state. Furthermore, the upper and lower sheets 30 are welded to an outer insulation resin coat 21 when both sheets 30 are welded together since the coat 21 of a coaxial cable 20 is also polyvinyl. Thus the module 1 is surely sealed waterproof.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waterproof structure of electronic parts which is required to be waterproof against rainwater because it is installed outdoors and the like, and particularly to an antenna used for mobile communication such as a navigation system using GPS. The present invention relates to a waterproof structure for electronic components suitable as a waterproof structure for modules and the like.

[0002]

2. Description of the Related Art Since an antenna unit used for mobile communication such as a navigation system using GPS is generally installed outdoors (for example, a roof of a car), rainwater cannot enter the case. To prevent it, some kind of waterproofing is required.

Therefore, conventionally, as in Japanese Utility Model Laid-Open No. 6-38308, a waterproof ring is used between an upper cover and a lower cover forming a case to prevent rainwater from entering.

FIG. 7 shows an example of a waterproof structure of an antenna unit using a waterproof ring as shown in Japanese Utility Model Laid-Open No. 6-38308. In FIG. 7, reference numeral 1 denotes an antenna module in which a dielectric plate 4 having a patch antenna pattern (radiation electrode) 3 of a conductor film formed on an upper surface serving as a radio wave transmitting / receiving surface is fixed on a metal plate (ground conductor) 2. A microwave strip antenna for microwaves is configured, and a high frequency amplifier circuit 5 is installed on the back surface of the metal plate 2. The upper cover 6 and the lower cover 7 constituting the waterproof case are resin molded products, respectively, and when they are combined with each other, form a storage space 8 for storing the antenna module 1 therein. The coaxial cable 20 is connected to the antenna module 1 (that is, the output of the high frequency amplifier circuit),
A cable drawing groove 9 is formed in the lower cover 7. Further, mounting holes 11 for inserting the assembling screws 10 are formed in the lower cover 7, and nuts 13 screwed into these screws 10 are embedded in the upper cover 6 in advance as insert fittings. Although not shown in the drawings, a concave groove or the like for disposing the waterproof ring (gasket) 15 is usually formed on the abutting surfaces of the upper cover 6 and the lower cover 7.

Then, the antenna module 1 is placed in the storage space 8, and the coaxial cable 20 is inserted from the cable drawing groove 9.
Pull out and attach the waterproof ring 15 to the upper cover 6 and the lower cover 7.
And the screw 10 is screwed into the nut 13 on the upper cover 6 side through the lower cover 7 and tightened to complete the antenna unit.

[0006]

By the way, in the conventional waterproof structure shown in FIG. 7, the waterproof ring 15 must be crushed by an appropriate force by tightening the upper cover 6 and the lower cover 7. Actually, if the width and depth of the recessed grooves of the upper and lower covers 6 and 7 formed for housing the waterproof ring 15 are bad or the dimension accuracy is not good, a sufficient waterproof effect cannot be obtained and There was a risk that rainwater would enter the case.

Further, the use of the waterproof ring leads to an increase in material cost and an assembling process, which leads to an increase in cost. Further, when designing the case, a concave groove into which the waterproof ring 15 is inserted must be formed around the antenna module 1. There was also a problem that the degree of freedom in design was reduced.

In view of the above points, the present invention uses a waterproof ring by covering an electronic component such as an antenna module, which requires a waterproofing measure against rainwater, with a water-impermeable resin sheet and welding it to seal watertightly. It is an object of the present invention to provide a waterproof structure of an electronic component that realizes a reliable waterproof function with a simple structure.

Other objects and novel features of the present invention will be clarified in embodiments described later.

[0010]

In order to achieve the above object, in a waterproof structure for an electronic component of the present invention, the periphery of the electronic component is covered with a water impermeable resin sheet, and the water impermeable resin sheet is welded. The watertightly sealed structure is provided.

Further, when a cable is connected to the electronic component, it is preferable that the non-water-permeable resin sheet is welded to an insulating resin outer coating of the cable.

Further, the electronic component may be a microwave antenna module.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a waterproof structure for electronic parts according to the present invention will be described below with reference to the drawings.

1 to 4 show a first embodiment of the present invention. In these figures, the antenna module 1 before waterproofing is the same as the conventional case of FIG. 7, in which a dielectric plate 4 having a patch antenna pattern 3 of a conductor film formed on the upper surface thereof is fixed on the metal plate 2. And a high frequency amplifier circuit 5 is installed on the back surface of the metal plate 2. A coaxial cable 20 is connected to the antenna module 1 (that is, the output of the high frequency amplifier circuit). The upper and lower covers 46 and 47 made of insulating resin that form the weatherproof case form the storage space 43 inside when integrated and do not use a waterproof ring. It is unnecessary and has a simple shape.

The upper and lower covers 46 and 47 have excellent weather resistance such as AES resin, ABS resin, ACS resin, polycarbonate, polypropylene, polyacetal, polyethylene, polystyrene, vinyl chloride, Teflon, styrene, PET (polyethylene terephthalate), acrylic and chloride. Such as vinylidene. The upper cover 46 is made of a material that transmits radio waves (non-conductive, non-magnetic) and has a low dielectric constant so as not to adversely affect transmitted / received radio waves.

Then, with respect to the antenna module 1, a vinyl chloride sheet 30 as a water impermeable resin sheet is provided.
As shown in FIG. 4, two electrodes are used to sandwich the antenna module 1 from above and below, and the upper and lower vinyl chloride sheets 30 are brought into close contact with each other so as to surround the antenna module 1 so as to surround the antenna module 1. Is pressed and a high frequency electric field is applied between the electrodes. Due to the heat generated at this time,
The upper and lower vinyl chloride sheets 30 are welded to each other at the welding portion 31, and the antenna module 1 is packed in a watertight manner in a bag. In other words, it will be enclosed in a vinyl chloride sealed bag.

Since the insulating resin outer coating 21 of the coaxial cable 20 is made of vinyl chloride, the outer coating 21 and the portion of the vinyl chloride sheet 30 in contact with each other are welded to each other during the welding process of the upper and lower vinyl chloride sheets 30. Will be
A reliable watertight seal is also provided at the lead-out portion of the coaxial cable 20.

The electrode shape of the electrode of the high-frequency welding device is devised so that the outer coating portion of the coaxial cable 20 connected to the antenna module 1 is sufficiently heated. To do.

The watertightly sealed antenna module pack 1A thus watertightly sealed is housed in the housing space 43 inside the upper and lower covers 46, 47 made of insulating resin having excellent weather resistance, and the lower cover is also housed. An antenna having weather resistance and waterproofness by pulling out the coaxial cable 20 from the cable pull-out groove 44 of 47 and adhering or screwing the upper and lower covers 46, 47 to each other to form a mating type structure or to integrate them by welding or the like. You get units.

The thickness of the vinyl chloride sheet 30 as the water-impermeable resin sheet is preferably as thin as possible in order to reduce the loss with respect to transmitted and received radio waves. A wall thickness between 0.2 mm and 1 mm, for example, about 0.3 mm is selected.

According to the first embodiment, the following effects can be obtained.

(1) The antenna module 1 is sandwiched between vinyl chloride sheets 30 to be covered, and the vinyl chloride sheets 30 are welded for water-tight sealing, which is a sealing structure as compared with the conventional structure using a waterproof ring. Is simple and waterproof can be surely implemented.

(2) With the conventional structure using the waterproof ring, the dimensional accuracy of the case may be insufficient and the waterproof may be broken due to a design mistake, but such a problem can be completely solved.

(3) Since the waterproof ring is not used, the waterproof mechanism by the waterproof ring is not required, so that it is not necessary to provide the case with a groove for accommodating the waterproof ring. Therefore, the number of items to be considered when designing the case is reduced, and the degree of freedom in design is increased. Further, since the waterproof ring is not required and the case structure can be simplified, the cost of members can be reduced, the assembly can be easily performed, and the assembly cost can be reduced. Therefore, a low-cost and highly reliable waterproof structure can be realized.

(4) In the resin mold, which is one of the waterproofing methods, it is a general fact that stress is applied to the waterproof object because the resin is in direct contact with the object to be sealed. However, in the waterproof structure according to this embodiment, a space can be formed between the waterproof structure and the antenna module 1 as the object to be waterproofed, so that the stress due to waterproofing can be relieved.

FIG. 5 shows a second embodiment of the present invention.
In this case, a tubular vinyl chloride sheet 40 is used as the water impermeable resin sheet. Therefore, after housing the antenna module 1 in the tubular vinyl chloride sheet, the openings on both sides of the tubular vinyl chloride sheet 40 may be welded at the welding portions 41, respectively.

In the second embodiment, the upper and lower covers forming the weatherproof case can be the same as those in the first embodiment, and the same or corresponding portions as those in the first embodiment can be used. The same reference numerals are given.

In the case of the second embodiment, since both sides of the tubular vinyl chloride sheet 40 may be welded,
The welding points can be made smaller than in the first embodiment.

Further, when a bag-shaped vinyl chloride sheet having an opening on only one side is used, the welded portion is only on one side, and the welded portion can be further reduced.

In the above first and second embodiments, the dielectric plate 4 having the patch antenna pattern 3 of the conductor film formed on the upper surface thereof is fixed on the metal plate 2 to form a microwave microstrip pattern. Although the antenna is configured, a dielectric plate 4 in which a patch antenna pattern 3 is formed on one surface of a circuit board on which a high-frequency amplifier circuit is mounted is used as a full-scale conductor (a ground conductor that performs the same function as the metal plate 2). It is also possible to form a microstrip antenna structure in which the metal plate 2 is omitted by fixing.

The first and second embodiments described above are
Both are antenna units having a built-in antenna module for microwaves used in mobile communication such as a navigation system, but the present invention is not limited to this, and a booster amplifier for a TV installed outdoors or an electronic device for the outside of a car It is applicable to electronic parts used in places where parts may get wet. Therefore, a case where the present invention is applied to a booster amplifier of a television is shown in FIG. 6 as a third embodiment of the present invention.

In the third embodiment of FIG. 6, reference numeral 50 denotes a television booster amplifier for amplifying VHF to UHF antenna output signals. The booster amplifier 50 has a coaxial cable 51 for antenna connection and a television image reception. Machine-connecting coaxial cables 52 are respectively connected. Then, the booster amplifier 50 is sandwiched between vinyl chloride sheets 60 from above and below, and the booster amplifier 50 is welded to each other at a welding portion 61 so as to surround the circumference of the booster amplifier 50, and is sealed watertight. The watertightly sealed booster amplifier pack 50A after being sealed with the vinyl chloride sheet 60 may be housed in a required weatherproof case. Of course, the weatherproof case itself does not require electrical performance, but it does not need a strict waterproof structure as described in the first embodiment, and may be mechanically robust and excellent in weatherability.

Also in the third embodiment, it is possible to use a tubular vinyl chloride sheet or a bag-shaped vinyl chloride sheet for watertight sealing.

In the first to third embodiments of the present invention, when the antenna unit or the television booster amplifier is used under high temperature conditions, the plasticizer is removed from the vinyl chloride sheet in a high temperature atmosphere. It may come out. In that case, in order to prevent the corrosion caused by the decomposed plasticizer, the electronic components such as the antenna module and the booster amplifier may be protected by previously laying polyester or vinylidene chloride on the inside of the vinyl chloride sheet.

Further, in the first to third embodiments of the present invention, the vinyl chloride sheet is used as the water impermeable resin sheet, but it is not limited to the vinyl chloride sheet and any impermeable water impermeable resin can be used. good. For example, polyethylene, polyester, nylon, polypropylene, acrylic, PE
Thermoplastic resins such as T resin, vinylidene chloride, polycarbonate, ABS resin, AES resin, ACS resin and AS resin can be used.

Further, depending on the material to be welded, the most suitable welding method is a high-frequency welding, an ultrasonic welding, a direct heating welding with a heater, a welding by impulse heating (instantaneous heating), etc. according to the resin. Should be selected.

When electronic parts such as an antenna module and a television booster amplifier are watertightly sealed with a water-impermeable resin sheet, dew condensation occurs in the sealed sheet internal space at low temperature or swells at high temperature. In order to prevent this, it is desirable that the inside air be sufficiently vented during the sheet welding process. Also, welding treatment in clean and dry air is desirable.

Although the embodiment of the present invention has been described above, it is obvious to those skilled in the art that the present invention is not limited to this and various modifications and changes can be made within the scope of the claims. Ah

[0039]

As described above, according to the waterproof structure for electronic parts of the present invention, waterproofing of electronic parts such as an antenna module, which has been conventionally obtained by a waterproof ring or the like, is simply performed by welding a water-impermeable resin sheet. As a result, it is possible to prevent the waterproof from being broken due to insufficient dimensional accuracy of the case, distortion due to design error or aging, which is a problem when using the conventional waterproof ring. Further, it is possible to obtain a highly reliable waterproof structure at a low cost by preventing an increase in member costs such as a waterproof ring and an assembling cost.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing the overall configuration of a first embodiment of a waterproof structure for an electronic component according to the present invention.

FIG. 2 is a perspective view of the same when the assembly is completed.

FIG. 3 is a plan view showing a main configuration of an antenna module packed (watertightly sealed) with a vinyl chloride sheet.

FIG. 4 is a side sectional view of the same.

FIG. 5 is a plan view showing a configuration of a main part according to a second embodiment of the present invention.

FIG. 6 is a plan view showing a configuration of a main part according to a third embodiment of the present invention.

FIG. 7 is an exploded perspective view showing a waterproof structure using a conventional waterproof ring.

[Explanation of symbols]

 1 Antenna Module 2 Metal Plate 3 Patch Antenna Pattern 4 Dielectric Plate 5 High Frequency Amplifier Circuit 6,46 Upper Cover 7,47 Lower Cover 8,43 Storage Space 9,44 Cable Lead-out Groove 15 Waterproof Ring 20,51,52 Coaxial Cable 21 Insulating resin outer coating 30,40,60 Vinyl chloride sheet 31,41,61 Welding part 50 Booster amplifier

Claims (3)

[Claims] 1. A waterproof structure for an electronic component, characterized in that the periphery of the electronic component is covered with a water-impermeable resin sheet, and the water-impermeable resin sheet is welded and watertightly sealed. 2. The waterproof structure for an electronic component according to claim 1, wherein a cable is connected to the electronic component, and the water-impermeable resin sheet is welded to an insulating resin outer coating of the cable. 3. The waterproof structure for an electronic component according to claim 1, wherein the electronic component is a microwave antenna module.