Maske a ho tjheseletsa, a tsejoang hape e le maseke a thibelang solder, ke lera le lesesaane la polima le sebelisitsoeng ho lona PCB boto ho thibela manonyeletso a solder ho theha Marokho. Maske a ho tjheseletsa a boetse a thibela ho kena moea ‘me a sebetsa ho mesaletsa ea koporo botong ea PCB.

What is PCB solder resistance type? The PCB welding mask acts as a protective coating on the copper trace line to prevent rust and prevent solder from forming Bridges that lead to short circuits. Ho na le mefuta e mene e meholo ea limaske tsa ho tjheseletsa tsa PCB – mokelikeli oa epoxy, mokelikeli o nkiloeng ka lifoto, o ommeng filimi o ka etsoang lifoto, le limaske tse holimo le tse tlase.

Mefuta e mene ea mask oa ho tjheseletsa

Lisebelisoa tsa ho tjheseletsa li fapana ka popeho le thepa. Mokhoa le hore na ke mask afe a ho tjheseletsa ao u ka a sebelisang ho latela ts’ebeliso.

Sekoahelo se kaholimo le tlase

Maske a ho tjheseletsa a holimo le a tlase Baenjineri ba elektroniki ba a sebelisa khafetsa ho khetholla likheo tse mokallong o motala oa solder. Lera le kentsoe pele ke epoxy resin kapa theknoloji ea filimi. Lithakhisa tsa likaroloana li kenella ka board ka ho sebelisa monyako o ngolisitsoeng ka mask.

The conductive trace pattern on the top of the circuit board is called the top trace. E ts’oana le maske a lehlakoreng le holimo, mask o ka tlase o sebelisoa ka lehlakoreng le ka morao la boto ea potoloho.

Mask ea solder epoxy mokelikeli

Epoxy resins are the cheapest alternative to welding masks. Epoxy is a polymer that is screen printed on a PCB. Screen khatiso ke ts’ebetso ea khatiso e sebelisang letlooa la lesela ho ts’ehetsa mokhoa oa ho thibela enke. The grid allows identification of open areas for ink transfer. In the final step of the process, heat curing is used.

Motsoako oa solder mask oa ho nka litšoantšo

Li-mask tsa Photoconductive tsa metsi, tse tsejoang hape e le LPI, ha e le hantle ke motsoako oa maro a mabeli a fapaneng. Liquid components are mixed prior to application to ensure a longer shelf life. It is also one of the more economical of the four different PCB solder resistance types.

LPI e ka sebelisoa bakeng sa khatiso ea skrine, penta ea skrine kapa lits’ebetso tsa spray. The mask is a mixture of different solvents and polymers. Ka lebaka leo, ho ka ntšoa liaparo tse tšesaane tse khomarelang bokaholimo ba sebaka se shebiloeng. Maske ena e etselitsoe masking a soldering, empa PCB ha e hloke liaparo tse ling tsa ho qetela tse fumanehang kajeno.

Ho fapana le liinki tsa khale tsa epoxy, LPI e nahanela khanya ea mahlaseli a kotsi. Phanele e hloka ho koaheloa ka mask. Kamora “potoloho ea pheko” e khuts’oane, boto e pepesetsoa leseli la mahlaseli a kotsi a sebelisa photolithography kapa laser ea ultraviolet.

Before applying the mask, the panel should be cleaned and free of oxidization. Sena se etsoa ka thuso ea tharollo e ikhethang ea lik’hemik’hale. Sena se ka etsoa hape ka ho sebelisa tharollo ea alumina kapa ka ho hlopha liphanele ka lejoe le emisitsoeng la pumice.

One of the most common ways to expose panel surfaces to UV is by using contact printers and film tools. The top and bottom sheets of the film are printed with an emulsion to block the area to be welded. Use the tools on the printer to fix the production panel and film in place. The panels were then simultaneously exposed to an ULTRAVIOLET light source.

Mokhoa o mong o sebelisa lasers ho etsa litšoantšo tse tobileng. But in this technique, no film or tools are needed because the laser is controlled using a reference mark on the panel’s copper template.

Li-mask tsa LPI li ka fumanoa ka mebala e fapaneng, ho kenyeletsoa botala (matte kapa semi-gloss), tšoeu, putsoa, ​​khubelu, bosehla, botsho le tse ling. Indasteri ea LED le lits’ebetso tsa laser indastering ea elektroniki li khothaletsa baetsi le baqapi ho nts’etsapele lisebelisoa tse matla tse tšoeu le tse ntšo.

Mask e omileng ea lifoto tsa solder

A dry film photoimagable welding mask is used, and vacuum lamination is used. Filimi e ommeng e ea senoloa ebe ea ntlafatsoa. After the film is developed, openings are positioned to produce patterns. Kamora sena, elemente e kenella ka har’a sethala sa brazing. Koporo e ntan’o tšeloa ka boto ea potoloho ka ts’ebetso ea motlakase.

Koporo e koahetsoe ka sekoting le sebakeng sa marang-rang. Qetellong thini e ile ea sebelisoa ho thusa ho sireletsa lipotoloho tsa koporo. In the final step, the membrane is removed and the etching mark is exposed. Mokhoa ona o sebelisa pheko ea mocheso.

Dry film welding masks are commonly used for high-density patch boards. Ka lebaka leo, ha e tšele ka lesoba le phunyang. These are some of the positives of using a dry film welding mask.

Ho nka qeto ea hore na o sebelisa mask ea ho tjheseletsa ho latela mabaka a fapaneng – ho kenyeletsoa boholo ba ‘mele oa PCB, ts’ebeliso ea hoqetela e tla sebelisoa, masoba, likarolo tse tla sebelisoa, batsamaisi, sebopeho sa bokaholimo, jj.

Boholo ba meralo ea sejoale-joale ea PCB e ka fumana lifoto tsa solder tse hanelehang. Therefore, it is either LPI or dry film resistance film. The surface layout of the board will help you determine your final choice. If the surface topography is not uniform, the LPI mask is preferred. If a dry film is used on uneven terrain, gas may be trapped in the space formed between the film and the surface. Therefore, LPI is more suitable here.

Leha ho le joalo, ho na le litla-morao tsa ho sebelisa LPI. Its comprehensiveness is not uniform. You can also get different finishes on the mask layer, each with its own application. For example, in cases where solder reflow is used, the matte finish will reduce solder balls.

Build solder masks into your design

Ho aha filimi e hanang ho rekisa molemong oa moralo oa hau ho bohlokoa ho netefatsa hore ts’ebeliso ea mask e maemong a nepahetseng. When designing a circuit board, the welding mask should have its own layer in the Gerber file. In general, it is recommended to use a 2mm border around the function in case the mask is not fully centered. U lokela hape ho tlohela bonyane ba 8mm lipakeng tsa mekotla ho netefatsa hore Marokho ha a thehe.

Thickness of welding mask

Thickness Welding mask will depend on the thickness of the copper trace on the board. Ka kakaretso, mask ea ho tjheseletsa ea 0.5mm e khethoa ho pata masela a marang-rang. If you are using liquid masks, you must have different thicknesses for different features. Libaka tse se nang letho tsa laminate li kanna tsa ba le botenya ba 0.8-1.2mm, ha libaka tse nang le likarolo tse rarahaneng tse kang mangole li tla ba le li-extensions tse tšesaane (tse ka bang 0.3mm).

bofello

Ka kakaretso, moralo oa mask oa welding o na le tšusumetso e matla ts’ebetsong ea ts’ebeliso. E bapala karolo ea bohlokoa ho thibeleng mafome le marokho a ho tjheseletsa, a ka lebisang ho lipotoloho tse khutšoane. Ka hona, qeto ea hau e hloka ho nahanela lintlha tse fapaneng tse boletsoeng sengoloeng sena. Kea ts’epa hore sengoloa sena se ka u thusa ho utloisisa betere Mofuta oa filimi ea ho hanyetsa PCB. Haeba u na le lipotso, kapa u hloka feela ho iteanya le rona, re lula re thabela ho u thusa.