>>  Etching Processing

Precise etching processing is also called photo chemical etching. It's shortened as photo etching.

(A) Etching application:

Precise etching products can be applied to many professions such as machinery, electron, hardware, electrical appliances, communication, electronic computations electro-optic, automation.

(1) Correspondent product parts:

Handset metal pressed key piece (steel disk/sheet copper), handset decoration piece brake sack, handset receiver net, handset dust cover, handset kneading board.

(2) Electro-optic metal parts:

The electro-optical encoder metal coded disk, the diffraction grating, VFD meshwork, the electro-optical smoke feeling insect proofing network.

(3) Electric appliance fitting:

Fruit and vegetable juice extractor net, soybean milk machine net, wringer mixer strainer, coffeepot strainer, loudspeaker net, razor blade net, haircut shear blades, metal flexible electric heating membrane, IC wire frame and so on precise electronic parts.

(4) Computer peripheral products:

The notebook etching kneading board, the etching radiator fin, the printer disappear the static electricity belt, the computer hard disk skeleton and so on.

(5) Great width etching:

SMT steel mesh, stainless steel decoration top board, elevator arrogant shook and so on.

(6) Deep etching:

Etching knife mold, metal eyeglasses foot silk frame.

(B) Two photo etching merits:

(1) Sample manufacture:

In terms of manufacture of the photo etching tool, compared with the general ramming, the tool cost is inexpensive, quick, and the precision is higher. Moreover light etching tool has the elasticity. When product design needs changing, it's easier to change light tool than the traditional mold. Therefore, the photo etching craft is most suitable to the plate work sample manufacture. Especially in the advanced technical industry, this link must need.

(2) Small batch production:

Due to the high cost of production punching tool, the small quantity production does not conform to the cost of economic effective benefit. Using the photo etching tool to make the small quantity production is the solution.

(3) Volume production:

In terms of the output velocity operation, the photo etching processing is really inferior to the high speed punch press. Therefore in production of plate work components of simple shape, the photo etching processing cannot make the competition with the ramming technology. But as the complexity and difficulty of shapes of products increase, the punching tool cost then correspondingly enhances. When the quantitative requirement (quantity) is not enough to balance the tool cost benefit, we should use the photo etching processing production. The production of the great quantity 0f plate parts of complex shape has adopted photo etching of processing of the automated form. For example the production of integrated line lead frame in the electronic profession

(4) Distinctive quality of the craft:

For people who know the plate work manufacture, they know when thickness of the plate work components is ultra-thin, the shape is complex, and design precision achieves some degree, ramming craft is not greatly suitable either. Moreover in ramming process, shear plane of the components after blanking is rough. It can't achieve the request of precise etching products. So they need processing. If these products are processed, the cost increases. In order to avoid the above problem, reduce the cost, raise the production efficiency and make sure the product quality, the photo etching processing is the only feasible solution. If the light etching product thickness scope conforms to the economic efficiency of the volume production, it should be between 0.05mm and 1.0mm.

Chemical Etching Processing

(1) Clean

Clean each metal ban. Both sides must be clean and oil-removing. Because the uncleanness of surfaces affects possibility to paste the mucous membrane on the metal. After cleaning, spread photo-resist mucous membrane paste on both sides (This light reaction material will plasticize and produces corrosion-resist function to non-organism solution like acid liquor) if it's exposed in the light of some light wave. The photo protection mucous membrane pastes may divide into wet-resist film and dry-resist film. The wet-resist film can be spreaded on the metal surface by soaking or spraying.

The dry-resist film can be pasted on the metal surface. The dry-resist film is more often used. Because it can be easily controlled. The wet-resist film is better in the power of presenting and resolving pictures and the accuracy effect.

(2) Exposure

Two-sided etching metal boards must be carefully put between two-story photography negatives (light tool), but one-sided etching metal boards must be put under the light tool. Clamp them by compression or pulling out the vacuum. Expose them in proper lights. This makes exposed mucous membrane plasticized. Mucous membranes can response Actinic light. They response slightly only to yellow light. Exposure time is related to many factors such as the intensity of photo source, the types of mucous membrane pastes. The light tool craft begins with designing rough draft according to the enlargement proportion adjusts accurately the size and then retracts again the original proportion. It's convenient to control the size precision. According to the pattern, make a negative piece and a bottom piece and then clamp firmly the metal board in between. If the piece size is tiny and certain numbers of articles are requested to be etched on a metal board of some area, we can use the overlapping emissions machine to put the phantom redundantly on the negative piece. As for how the above and the below negative pieces guarantee absolute adjust of the phantom, it's know-how of the craft.

(3)Developments flush

The phantom development work is to soak and wash or spread and spurt the specific developing paste. The developing paste dissolve exposed parts of mucous membranes and plasticize the rest.

(4) Clean

The metal board should remove developing paste dregs by cleaning to guarantee that the etching part of the surface has not had the mucous membrane.

(5) Drying:

After the development, metal board should be dried twice.

(6) Etching

The phantom development part of the metal board is etched in the etching machine. The plasticized part is protected and isn't etched. There are many kinds of the corrosive such as the ferric chloride, the hydrofluoric acid and the water mixture. They are the corrosive to deal with the steel and the alloy copper. Some metals need to use the corrosive of alkalinity. When the metal surface is being etched, the position of its mucous membrane edge will be slightly hollow. Therefore the sheared edge is not 100-percently vertical. As a result of the above reason, after etching, the size has slight difference with the phantom size, that's the periphery size shrinks, but in encircles the size expands and the square corner position will turn the small fillet. After correcting these problems, the accuracy can be achieved. The correction of size can be carried on in the design rough draft. Of course, the accumulation of experience is the most important. With rich experience, the accuracy can be controlled.

(7) Cracking-off:

The mucous membrane remains should be cleaned with the suitable resolver scours after etching.

(8) Clean:

The working procedure is roughly completed. Clean it again with water.

(9) Season: