Izinhlobo ezine ze-PCB zokushisela amaski

Imaski yokushisela, eyaziwa nangokuthi imaski yokuvimba i-solder, ungqimba oluncane lwe-polymer olusetshenzisiwe PCB ibhodi ukuvimbela amalunga we-solder ekwakheni amabhuloho. Imaski yokushisela ibuye ivimbele uketshezi futhi isebenze ekulandeleni kwethusi ebhodini le-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. Kunezinhlobo ezi-4 eziyinhloko zamamaski wokushisela we-PCB – i-epoxy liquid, i-liquid photograble, ifilimu eyomile ifotokhopuwe, namaski aphezulu nangaphansi.

ipcb

Izinhlobo ezine zamaski wokushisela

Amaski wokushisela ayahlukahluka ekwakhiweni nasezintweni ezibonakalayo. Indlela futhi imaski yokushisela oyisebenzisayo incike kuhlelo.

Isembozo sohlangothi oluphezulu nolwezansi

Imaski yokushisela ephezulu naphansi Oonjiniyela be-elekthronikhi bavame ukuyisebenzisa ukukhomba ukuvuleka kusendlalelo esivimba i-solder barrier. Isendlalelo sengezwe ngaphambili yi-epoxy resin noma ubuchwepheshe befilimu. Izikhonkwane zezinto ziyashiselwa ebhodini kusetshenziswa imbobo ebhaliswe nesifihla-buso.

The conductive trace pattern on the top of the circuit board is called the top trace. Ngokufana nesifihla esingenhla, imaski eseceleni engezansi isetshenziswa ohlangothini oluphindayo lwebhodi lesifunda.

I-epoxy liquid solder mask

Epoxy resins are the cheapest alternative to welding masks. Epoxy is a polymer that is screen printed on a PCB. Ukuphrinta kwesikrini kuyinqubo yokuphrinta esebenzisa inetha lendwangu ukusekela iphethini lokuvimba uyinki. The grid allows identification of open areas for ink transfer. In the final step of the process, heat curing is used.

I-mask ye-liquid imaging solder imaski

Izifihla-buso ezithwala uketshezi, ezaziwa nangokuthi i-LPI, empeleni ziyingxube yeziphuzo ezimbili ezihlukene. 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.

I-LPI ingasetshenziselwa ukuphrinta kwesikrini, ukudweba kwesikrini noma izinhlelo zokusebenza zokufafaza. The mask is a mixture of different solvents and polymers. Ngenxa yalokhu, kungakhishwa izembozo ezincanyana ezihambisana nobuso besifunda esihlosiwe. Le maski yenzelwe ukunamathisela ubuso kumaski, kepha i-PCB ayidingi noma yiziphi izembozo zokugcina zokugcwala ezivame ukutholakala namuhla.

Ngokuphambene no-inki abadala be-epoxy, i-LPI iyazwela ekukhanyeni kwe-ultraviolet. Iphaneli idinga ukumbozwa ngemaski. Ngemuva “komjikelezo wokwelapha” omfishane, ibhodi livezwa ekukhanyeni kwe-ultraviolet kusetshenziswa i-photolithography noma i-ultraviolet laser.

Before applying the mask, the panel should be cleaned and free of oxidization. Lokhu kwenziwa ngosizo lwezixazululo ezikhethekile zamakhemikhali. Lokhu kungenziwa futhi kusetshenziswa isisombululo se-alumina noma ngokuhlikihla amaphaneli ngetshe le-pumice elimisiwe.

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.

Enye inqubo isebenzisa ama-lasers ukudala izithombe eziqondile. 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.

Ama-mask e-LPI angatholakala ngemibala ehlukahlukene, kufaka phakathi okuluhlaza (matte noma semi-gloss), okumhlophe, okuluhlaza okwesibhakabhaka, okubomvu, okuphuzi, okumnyama, nokuningi. Imboni ye-LED kanye nokusetshenziswa kwe-laser embonini ye-elekthronikhi kukhuthaza abakhiqizi nabaqambi ukuthi bathuthukise izinto ezinamandla ezimhlophe nezimnyama.

Ifilikhi eyomile ye-solder mask

A dry film photoimagable welding mask is used, and vacuum lamination is used. Ifilimu eyomile iyavezwa bese ithuthukiswa. After the film is developed, openings are positioned to produce patterns. Ngemuva kwalokhu, i-elementi ifakwe nge-pad yokubhalela. Ithusi bese linamathiselwe ebhodini lesifunda kusetshenziswa inqubo kagesi.

Ithusi ligqinsiwe emgodini nasendaweni elandelanayo. Tin was eventually used to help protect copper circuits. In the final step, the membrane is removed and the etching mark is exposed. Le ndlela isebenzisa nokwelapha ukushisa.

Dry film welding masks are commonly used for high-density patch boards. Ngenxa yalokho, ayitheli emgodini ophakathi. These are some of the positives of using a dry film welding mask.

Ukunquma ukuthi imaski yokushisela ozoyisebenzisa incike ezintweni ezahlukahlukene – kufaka phakathi usayizi we-PCB, isicelo sokugcina esizosetshenziswa, izimbobo, izinto ezizosetshenziswa, abaqhubi, ukwakheka komhlaba, njll.

Imiklamo eminingi yesimanje ye-PCB ingathola amafilimu wokumelana nama-solder. 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.

Noma kunjalo, kukhona ukwehla kokusebenzisa i-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

Building a solder resist film into your design is indispensable to ensure the mask application is at the optimal level. 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. Kufanele futhi ushiye ubuncane obungu-8mm phakathi kwamapayipi ukuqinisekisa ukuthi amabhuloho awenzi.

Thickness of welding mask

Thickness Welding mask will depend on the thickness of the copper trace on the board. Ngokuvamile, imaski yokushisela engu-0.5mm incanyelwa ukufihla imigqa yokulandela umkhondo. If you are using liquid masks, you must have different thicknesses for different features. Izindawo ezingenalutho ezingenamicikilisho zingaba nobukhulu obungu-0.8-1.2mm, kanti izindawo ezinezici eziyinkimbinkimbi ezifana namadolo zizoba nezandiso ezincanyana (cishe u-0.3mm).

isiphetho

Ngokufingqa, ukwakhiwa kwemaski yokushisela kunomthelela omkhulu ekusebenzeni kwesicelo. Idlala indima ebalulekile ekuvikeleni ukugqwala nokushisela amabhuloho, okungaholela kumasekhethi amafushane. Ngakho-ke, isinqumo sakho sidinga ukubheka izinto ezahlukahlukene ezishiwo kule ndatshana. Ngiyethemba ukuthi le ndatshana ingakusiza uqonde kangcono i-TYPE yefilimu yokumelana ne-PCB. Uma unemibuzo, noma udinga nje ukuxhumana nathi, sihlala sikujabulele ukukusiza.