CN2439765Y

CN2439765Y - Gas filling protection box for electronic circuit

Info

Publication number: CN2439765Y
Application number: CN 00224262
Authority: CN
Inventors: 陈家山
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-02-29
Filing date: 2000-02-29
Publication date: 2001-07-18
Anticipated expiration: 2010-02-28

Abstract

The utility model relates to an inflation protecting box for electronic circuits. The utility model is characterized in that a printed circuit board which is provided with electronic elements, chips, etc. is arranged in a metal shielding box 1 which is arranged in a pressure-proof tank 7 which is first pumped into vacuum and then filled with pure noble gases; therefore, a small environment which has no oxygen, dust, salt mist and water vapor is formed in the metal shielding box 1, environment electromagnetic interference is isolated, and electrostatic shield is provided so that the electronic circuits are prevented from being corroded, oxidized and condensed and can work normally. The utility model is suitable for protecting electronic circuits and the complete set of devices thereof which work in severe environment, and the utility model is also suitable for protecting precision electronic detection and control devices which have high requirements on the environment.

Description

Electronic circuit gas-filled protective box

The utility model relates to a kind ofly provides protection to printed circuit board (PCB) together with the electronic component that is mounted thereon, chip etc., makes it avoid the device of the influence of steam, salt fog, dust, oxygen, electromagnetic field etc.

The electronic circuit of various functions is by printed circuit board (PCB) with the multiple electronic component of installing thereon, compositions such as chip, often be called " plate " or " card ", as mainboard, CPU board, data collecting card, address card etc., they often need be operated in the harsh natural environment and place, as high humility, high salt fog, many dust, the big temperature difference, forceful electric power magnetic etc., in order to make electronic circuit reliably working in such rugged environment, the way of often taking is to select the element and the chip of technical grade even army grade for use, plug is gold-plated, and be placed in the cabinet of sealing, keep the interior positive air pressure of case and install air cleaner additional, soft or hard dish closing door etc., thereby cost increases greatly, even also be affected its useful life like this.

The purpose of wood utility model is; a kind of electronic circuit gas-filled protective box is provided; it can be economically, reliably to printed circuit board (PCB) and go up electronic components mounted, chip etc. protection is provided; make its influence of avoiding harsh natural environment and operational environment, not reason corrosion oxidation, condensation and disturbed and cisco unity malfunction.And prolong its useful life.

The technical solution of the utility model is; it is by metallic shield box 1 and to its equipment autoclave of assembling 7; air exhauster 23; inertial gas tank 24 is formed; it is characterized in that; metallic shield box 1 is made of the box body 4 of an end opening and the lid 2 that is used to seal; on the described lid 2 air vent hole 3 is arranged; box body 4 outer surfaces have some ribs 5; be equipped with the printed circuit board (PCB) that electronic component, chip etc. have been installed in the box body 4; box body 4 sides have the wiring hole 6 that allows the bus plugboard of protected electronic circuit pass through, and are filled with inert gas in the box body 4 of sealing.Described autoclave 7 is made up of with the tank body 10 that is generally the garden tubular the cover 8 of garden shape, thermometer 11 and glass window 9 are installed on the cover 8, tank body 10 is for being equipped with the pressure vessel of vacuum gauge 12, have handle hole 13 on it, emgloves 14 is installed in the handle hole 13,15 sealings of handle hole 13 external application seal covers, incandescent lamp 16 and grid 17 are housed in the tank body 10, tank body 10 is dismountable being tightly connected with cover 9, tank body 10 lower ends are connected with base 20, tank body 10 lower ends are equipped with extraction valve 18 and intake valve 19, extraction valve 18 and intake valve 19 are through

flexible pipe

21,22 are connected with inertial gas tank 24 with air exhauster 23 respectively, and air exhauster is rotary type air exhauster or diffusion type air exhauster, and pure inert gas such as nitrogen or argon gas are housed in the inertial gas tank.

Engage accompanying drawing below operation principle of the present utility model and packaging technology are done detailed explanation.

Description of drawings: Fig. 1 is the structure chart of metallic shield box, and Fig. 2 is the cutaway view of autoclave, and Fig. 3 is the cutaway view of handle hole and seal cover, and Fig. 4 is electronic circuit gas-filled protective box package system figure of the present utility model, wherein;

1-metallic shield box, 2-lid, 3-air vent hole, 4-box body, the 5-rib, 6-wiring hole, 7-autoclave, 8-cover, the 9-glass window, 10-tank body, 11-thermometer, 12-vacuum gauge, the 13-handle hole, 14-emgloves, 15-seal cover, 16-incandescent lamp, the 17-grid, 18-extraction valve, 19-intake valve, 20-base, 21,22-flexible pipe, 23-air exhauster, 24-inertial gas tank.

Fig. 1 is the structure chart of metallic shield box l of the present utility model, the printed circuit board (PCB) that electronic component, chip etc. have been installed is placed in the box body 4, make the bus plugboard of circuit board pass wiring hole 6, cover lid 2, then with the slit of 4 of epoxy resin or vacuum compound such as silica gel sealing lid 2 and box bodys, and the slit between bus plugboard and wiring hole, treat that epoxy resin or silica gel are fixed after, metallic shield box 1 is promptly assembled and is finished.Several metallic shield boxes that assembled are put into the grid 17 of autoclave 7 respectively, seal cover 15 closes, should note getting rid of air in the emgloves 14 this moment, covers cover 8 again, more than as Fig. 2, shown in Figure 3, open extraction valve 18 then, starting ejector 23 extracts the air in the autoclave 7, the air in the metallic shield box 1, taken away through air vent hole 3 together with the dust that contains in the air, salt fog, steam etc., when vacuum gauge 12 shows that vacuum degree is 10 in the jar ^-2～1 ^-3During mmHg, can stop to bleed; If very high to the cleanliness factor requirement, then need then take out with the diffusion type air exhauster, make jar interior vacuum degree reach 10 ^-6～10 ^-7MmHg stops to bleed and closing extraction valve 18 then, all anaerobic, dustless, no salt fog in this moment autoclave 7 and the metallic shield box 1, no steam.Then open intake valve 19, pure inert gas such as nitrogen in the inertial gas tank 24 are entered in the autoclave 7, open incandescent lamp 16 simultaneously, be convenient to observe a jar interior situation on the one hand, heating enters a jar interior nitrogen on the other hand, the temperature that when thermometer 11 shows that temperature is lower than electronic circuit work slightly in the jar, will reach in the metallic shield box 1, when vacuum gauge 12 shows ambient atmosphere pressure when jar internal gas pressure equals metallic shield box 1 and works in the future such as 0.1MPa again, close intake valve 19, the nitrogen that vacuum in this moment autoclave 7 and the metallic shield box 1 all has been heated is filled up, the effect of heated nitrogen is that metallic shield box 1 is all just only being born when electronic circuit is worked and when at room temperature depositing, negative minute-pressure, more than as shown in Figure 4.Open seal cover 15 then, operator's both hands seal the air vent hole 3 of metallic shield box 1 after handle hole 13 years is gone up emgloves 14, after the sealing silica gel of sealing part is fixed, can open cover 8, and metallic shield box 1 is taken out.If what charge in the autoclave 7 is argon gas, because of the unit weight of argon gas is heavy than air, so can directly open cover 8 sealing air vent holes 3, this moment, argon gas can not overflowed outside the jar.What will finish at last is that sealing detects; detection method is that metallic shield box 1 is dropped in the hot water; the temperature that will reach in the box when temperature of water is worked with electronic circuit is the same; through after a while; be not out of shape as metallic shield box 1, no bubble produces in the water, shows that then the intensity of metallic shield box 1 meets the demands; seal intactly, electronic circuit gas-filled protective box so far of the present utility model can come into operation.

From the above, major advantage of the present utility model is:

1, protection is reliable.The metallic shield box is operated in the subenvironment of anaerobic, dustless, no salt fog, no steam electronic circuit, and completely cut off the environment electromagnetics interference, electrostatic screen is provided, the heat that indifferent gas physical efficiency in the box produces when taking away electronic circuit work, rib on the box body had both improved radiating effect, had increased the intensity of box body again.

2, easy for installation.The planar dimension of metallic shield box only is slightly larger than protected circuit board, and institute takes up space less, installs easily, and being connected all by the bus plugboard of the electronic circuit in the box and external equipment, easy-to-connect easily is assembled into the complete sets of equipment.

3, cost is lower.Owing to adopt autoclave to bear the pressure that produces when vacuumizing, so the metallic shield box can be made with thin plate, in general environment, assemble, the special-less process requirement, so weight is lighter, cost is lower.

4, object of protection is wider.The metallic shield box not only can be protected various electronic circuits, if on it mechanical actuation device is installed, also can provide reliable protection to it.

The utility model is suitable for the electronic circuit of open air installation and the complete sets of equipment thereof are protected;

The utility model also is fit to the various industry samplings that move in adverse circumstances, and control and communication device are protected;

The utility model also is suitable for to providing protection to environmental requirement high various precise electronics detections and control device.

Illustrate enforcement of the present utility model below.

A kind of electronic circuit the complete sets of equipment that the operation conditions of outdoor transformer is monitored; be installed near the step down side in the open; its sampling becomes the planar dimension send plate and CPU board and is respectively 179 * 184 and 171 * 146mm; the metallic shield box that gas-filled protective is used is made by the cold-rolled steel sheet of thick 1.2mm; and through pickling, zinc-plated processing; planar dimension is respectively 185 * 190mm and 177 * 152mm; high 40mm; respectively there are four ribs on its upper and lower surface; the change of will sampling is sent plate and CPU board to put into box respectively and with behind the epoxy sealing, is put into autoclave again.Autoclave is made by the 15MnP pressure vessel plate of thick 2.5mm, its internal diameter 400mm, and high 600mm has the grid of being made by No. 2 equal leg angles in jar, steel shielding box that once can 10 above-mentioned sizes placed apart in the grid.In jar two 100W incandescent lamps are installed also.Adopt the rotary type air exhauster to vacuumize, can is that purity is 99.99% nitrogen in the inertial gas tank.

Claims

1, a kind of electronic circuit gas-filled protective box; it is characterized in that; metallic shield box 1 is made of the box body 4 of an end opening and the lid 2 that is used to seal; on the described lid 2 air vent hole 3 is arranged; box body 4 outer surfaces have some ribs 5; be equipped with the printed circuit board (PCB) that electronic component, chip have been installed in the box body 4, box body 4 sides have the wiring hole 6 that allows the bus plugboard of protected electronic circuit pass through, and are filled with inert gas in the box body 4 of sealing.

2; the described electronic circuit gas-filled protective of claim 1 box; its feature also is; the mounting equipment of electronic circuit gas-filled protective box has autoclave 7; air exhauster 23; inertial gas tank 24; described autoclave 7 is made up of with the tank body 10 that is generally the garden tubular the cover 8 of garden shape; thermometer 11 and glass window 9 are installed on the cover 8; tank body 10 is for being equipped with the pressure vessel of vacuum gauge 12; have handle hole 13 on it, be pressed with emgloves 14 in the handle hole 13,15 sealings of handle hole 13 external application seal covers; incandescent lamp 16 and grid 17 are housed in the tank body 10; tank body 10 is dismountable being tightly connected with cover 9, and tank body 10 lower ends are connected with base 20, and tank body 10 lower ends are equipped with extraction valve 18 and intake valve 19; extraction valve 18 and intake valve 19 are connected with inertial gas tank 24 with air exhauster 23 respectively through flexible pipe 21,22.