In PCB design, there are many places that need to consider the safety distance. Here, it is classified into two categories for the time being: one is electrical-related safety clearance, and the other is non-electrical-related safety clearance.

1. Umgama wokhuseleko onxulumene nombane
1. Izithuba phakathi kweengcingo

Ngokubhekiselele kubuchule bokusetyenzwa kwabavelisi be-PCB besiqhelo, ubuncinci besithuba phakathi kweengcingo akufunekanga sibe ngaphantsi kwe-4mil. Umgama omncinci womgca ukwangumgama ukusuka kumgca ukuya kumgca kunye nomgca ukuya kwiphedi. Ukusuka kwindawo yokujonga imveliso, inkulu ingcono ukuba kunokwenzeka, ixhaphake kakhulu yi-10mil.

2. Indawo yokuvula iphedi kunye nobubanzi beepadi

Ngokubhekiselele kubuchule bokucubungula abavelisi be-PCB abaqhelekileyo, ukuba i-pad aperture igrunjwe ngoomatshini, ubuncinci akufanele bube ngaphantsi kwe-0.2mm, kwaye ukuba i-laser drilling isetyenzisiweyo, ubuncinci akufanele bube ngaphantsi kwe-4mil. Ukunyamezelwa kwe-aperture kuhluke kancinane ngokuxhomekeke kwipleyiti, ngokubanzi inokulawulwa ngaphakathi kwe-0.05mm, kunye nobubanzi obuncinane bepadi akufanele bube ngaphantsi kwe-0.2mm.

3. Umgama phakathi kwepadi kunye nephedi

As far as the processing capabilities of mainstream PCB manufacturers are concerned, the distance between pads and pads should not be less than 0.2mm.

4. Umgama phakathi kwesikhumba sobhedu kunye nomda webhodi

Umgama phakathi kwesikhumba sobhedu esihlawuliweyo kunye nomda webhodi ye-PCB kukhethwa ukuba ungabi ngaphantsi kwe-0.3mm. Cwangcisa imigaqo yezithuba kwiphepha lolwandlalo lweBhodi yeMithetho yoYilo.

If it is a large area of ​​copper, it usually needs to be retracted from the edge of the board, generally set to 20mil. In the PCB design and manufacturing industry, under normal circumstances, due to the mechanical considerations of the finished circuit board, or to avoid curling or electrical short-circuiting due to the exposed copper skin on the edge of the board, engineers often spread copper on a large area The block is shrunk by 20 mils relative to the edge of the board, instead of spreading the copper to the edge of the board. There are many ways to deal with this kind of copper shrinkage, such as drawing a keepout layer on the edge of the board, and then setting the distance between the copper paving and the keepout. Here is a simple method to set different safety distances for copper paving objects. For example, the safety distance of the whole board is set to 10mil, and the copper paving is set to 20mil, and the effect of 20mil shrinkage of the board edge can be achieved. The dead copper that may appear in the device is removed.

2. Ukukhutshwa kokhuseleko olungelulo umbane
1. Ububanzi bomlinganiswa, ubude kunye nesithuba

Ifilimu yokubhaliweyo ayinakutshintshwa ngexesha lokusetyenzwa, kodwa ububanzi bomgca we-D-CODE ngaphantsi kwe-0.22mm (8.66mil) buqiniswe ukuya kwi-0.22mm, oko kukuthi, ububanzi bomgca we-crange L=0.22mm (8.66mil), kunye umlinganiswa wonke Ububanzi=W1.0mm, umphakamo wophawu lonke H=1.2mm, kunye nesithuba phakathi kweempawu D=0.2mm. Xa okubhaliweyo kuncinane kunomgangatho ongasentla, ukuqhubekekiswa noshicilelo kuya kuba lufiphalo.

2. Isithuba phakathi komngxuma kunye nomngxuma (isiphelo somngxuma ukuya kumngxunya)

Umgama phakathi kwe-vias (VIA) kunye ne-vias (i-hole edge ukuya kumngxuma edge) ingcono kakhulu kune-8mil.

3. Umgama ukusuka kwisikrini sesilika ukuya kwiphedi

Isikrini sesilika asivumelekanga ukuvala ipad. Ngenxa yokuba ukuba isikrini sesilika sigqunywe ngepadi, isikrini sesilika asiyi kufakwa kwi-tinning ngexesha le-tinning, eya kuchaphazela ukufakwa kwecandelo. Ngokubanzi, umzi-mveliso webhodi ufuna indawo eyi-8mil ukuba igcinwe. Ukuba ummandla we-PCB ulinganiselwe ngenene, i-pitch ye-4mil ayamkelekanga. Ukuba isikrini sesilika sivala ngempazamo ipad ngexesha loyilo, umzi-mveliso webhodi uya kuphelisa ngokuzenzekelayo inxalenye yesikrini sesilika esishiywe kwi-pad ngexesha lokwenziwa kwemveliso ukuze kuqinisekiswe ukuba iphedi intoti.

Ngokuqinisekileyo, iimeko ezithile zihlalutywa ngokweenkcukacha ngexesha loyilo. Ngamanye amaxesha isikrini se-silk sisondele ngamabomu kwi-pad, kuba xa iipads ezimbini zisondele kakhulu, isikrini se-silk esiphakathi sinokuthintela ngokufanelekileyo uxhulumaniso lwe-solder kwi-short-circuiting ngexesha le-soldering. Le meko ngomnye umcimbi.

4. Ubude be-3D kunye nesithuba esithe tye kwisakhiwo somatshini

Xa ufaka izixhobo kwi-PCB, qwalasela ukuba kuya kubakho iingxabano kunye nezinye izakhiwo zoomatshini kwicala elithe tye kunye nokuphakama kwendawo. Ngoko ke, xa kuyilwa, kuyimfuneko ukuqwalasela ngokupheleleyo ukulungelelaniswa phakathi kwamacandelo, imveliso ye-PCB kunye neqokobhe lemveliso, kunye nesakhiwo sendawo, kwaye ugcine umgama okhuselekileyo kwinto ekujoliswe kuyo ukuqinisekisa ukuba akukho ngquzulwano kwindawo.