Bohlokoa ba bophara ba mola oa PCB ho moralo oa PCB

Bophara ba line ke eng?

Ha re qale ka metheo. Hantle-ntle bophara ke bofe? Hobaneng ha ho le bohlokoa ho hlakisa bophara bo itseng ba mohlala? Morero oa PCB wiring ke ho hokela mofuta ofe kapa ofe oa lets’oao la motlakase (analog, dijithale kapa matla) ho tloha node e ‘ngoe ho ea ho e ngoe.

Node e ka ba pini ea motsoako, lekala la mosaletsa o moholo kapa sefofane, kapa sebaka se se nang letho kapa ntlha ea liteko bakeng sa tlhahlobo. Boholo ba mesaletsa hangata bo lekanyetsoa ka mils kapa lisenthimithara tse likete. Bophara bo tloaelehileng ba wiring bakeng sa matšoao a tloaelehileng (ha ho na litlhoko tse ikhethang) e kanna ea ba bolelele ba lisenthimithara tse fapaneng ho 7-12 mils, empa lintlha tse ngata li lokela ho tsotelloa ha ho hlalosoa bophara le bolelele ba wiring.

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Kopo e tloaetse ho khanna bophara ba wiring le mofuta oa wiring ho moralo oa PCB mme, ka nako e ‘ngoe, hangata e lekanyetsa litšenyehelo tsa tlhahiso ea PCB, botenya ba boto / boholo le ts’ebetso. Haeba boto e na le litlhokahalo tse ikhethileng tsa moralo, joalo ka ts’ebetso ea lebelo, lerata kapa khatello ea ho kopanya, kapa bophahamo bo phahameng ba motlakase / bophahamo, bophara le mofuta oa tatellano li ka ba bohlokoa ho feta ho ntlafatsa theko ea tlhahiso ea PCB e se nang letho kapa boholo ba boto ka kakaretso.

Ga tlhaloso mabapi le wiring ka ho etsa thepa PCB

Typically, the following specifications related to wiring begin to increase the cost of manufacturing bare PCB.

Metsoako e phahameng haholo e kopanyang ho nka sebaka sa PCB, joalo ka BGA e arohaneng haholo kapa libese tse phahameng tsa lipalo, e ka hloka bophara ba mola oa 2.5 mil, hammoho le mefuta e ikhethileng ea masoba a nang le bophara ba mil 6. joalo ka laser e ile ea phunya masoba. Ka lehlakoreng le leng, meralo e meng e nang le matla a phahameng e ka hloka likhoele kapa lifofane tse kholo haholo, ho ja likarolo tsohle le ho tšela li-ounese tse motenya ho feta maemo. Liketsong tse thibetsoeng ke sebaka, ho ka hlokahala lipoleiti tse tšesaane haholo tse nang le likarolo tse ‘maloa le botenya bo fokolang ba koporo ea halofo ea oun (0.7 mil botenya).

Maemong a mang, meralo ea puisano e lebelo haholo ho tloha pherifing e ‘ngoe ho ea ho e ngoe e ka hloka ho ts’oaroa ka mohala o nang le taolo e laoloang le bophara bo ikhethileng le karohano lipakeng tsa e’ ngoe ho fokotsa ponaletso le khokahano e kenang. Kapa moralo o ka hloka bolelele bo itseng ho tsamaisana le matšoao a mang a loketseng beseng. Lisebelisoa tse phahameng tsa motlakase li hloka likarolo tse itseng tsa polokeho, joalo ka ho fokotsa sebaka se lipakeng tsa matšoao a fapaneng a pepesang ho thibela ho koaloa. Ho sa tsotelehe litšobotsi kapa likarolo, ho latela litlhaloso ho bohlokoa, kahoo a re ke re hlahlobeng lits’ebetso tse fapaneng.

Mefuta e fapaneng ea bophara ba bophara le botenya

PCBS typically contain a variety of line widths, as they depend on signal requirements. Litsela tse ntle tse bontšitsoeng ke tsa matšoao a boemo bo akaretsang ba TTL (transistor-transistor logic) ebile ha li na litlhoko tse ikhethang bakeng sa ts’ireletso e phahameng ea hajoale kapa ea lerata.

Tsena e tla ba mefuta e tloaelehileng ka ho fetisisa ea wiring ka sekepeng.

Mehala e metenya e ntlafalitsoe bakeng sa bokhoni ba hona joale ba ho jara mme e ka sebelisoa bakeng sa lisebelisoa kapa mesebetsi e amanang le matla e hlokang matla a phahameng, joalo ka balateli, likoloi le phetisetso ea matla khafetsa ho likarolo tse tlase. Karolo e kaholimo ho le lets’ehali ea motho e bile e bonts’a lets’oao le fapaneng (lebelo le phahameng la USB) le hlalosang sebaka le bophara bo ikhethileng ho fihlela litlhoko tsa impedance tsa 90 ω. Setšoantšo sa 2 se bonts’a boto ea potoloho e tenyetsehang hanyane e nang le mekato e tšeletseng mme e hloka kopano ea BGA (ball grid array) e hlokang ho ts’oaroa hantle.

Tsela ea ho bala PCB mola bophara?

Ha re feteng mokhoa oa ho bala bophara bo itseng ba lets’oao la motlakase le fetisang hona joale ho tloha karolong ea motlakase ho ea sesebedisweng sa pheriferale. Mohlala ona, re tla bala bophara ba moeli oa ‘mila oa motlakase oa DC. Tsela ea matla e qala ho tsoaka, e tšela H-borokho (karolo e sebelisetsoang ho tsamaisa phetisetso ea matla ho parola motlakase oa DC), ebe e emisa sehokelong sa enjene. Boemo bo tloaelehileng bo tsoelang pele bo hlokehang ba koloi ea DC bo ka ba 2 amperes.

Hona joale, wiring ea PCB e sebetsa e le sehanyetsi, ‘me ha mohala o le molelele hape o bile o fokolitse, khanyetso e ea eketsoa. Haeba wiring e sa hlalosoa ka nepo, matla a holimo a ka senya wiring le / kapa a baka ho theoha ho hoholo hoa motlakase (ho ka baka lebelo le fokotsehileng). Haeba re nka maemo a akaretsang, joalo ka ho tšela koporo e le ‘ngoe le mocheso oa kamore nakong ea ts’ebetso e tloaelehileng, re hloka ho bala bophara ba mohala le phokotso ea khatello e lebelletsoeng bophara boo.

Katleho ea cable ea cable le bolelele

Bakeng sa meralo ea dijithale e nang le likhokahanyo tse potlakileng, ho ka hlokahala hore ho be le sebaka se ikhethileng le bolelele bo itseng ho fokotsa crosstalk, coupling le ponahatso. Bakeng sa morero ona, lits’ebetso tse ling tse tloaelehileng ke matšoao a fapaneng a thehiloeng ho USB le lipontšo tse fapaneng tsa RAM. Ka tloaelo, USB 2.0 e tla hloka phapang e fapaneng ho 480Mbit / s (sehlopha se lebelo sa USB) kapa ho feta. Lebaka le leng ke hore USB e lebelo haholo e sebetsa ka mekhahlelo le liphapang tse tlase haholo, e leng se etsang hore boemo ba matšoao ka kakaretso bo be haufi le lerata le ka morao.

Ho na le lintho tse tharo tsa bohlokoa tseo u lokelang ho nahana ka tsona ha u tsamaisa mehala ea USB e lebelo le phahameng: bophara ba terata, sebaka sa lead, le bolelele ba cable.

Tsena tsohle li bohlokoa, empa tse hlokolosi ka ho fetisisa ho tse tharo ke ho etsa bonnete ba hore bolelele ba mela e ‘meli bo tsamaisana ka hohle kamoo ho ka khonehang. As a general rule of thumb, if the lengths of the cables differ from each other by no more than 50 mils, this significantly increases the risk of reflection, which may result in poor communication. 90 ohm e lekanang le impedance ke lintlha tse akaretsang tsa mehala e fapaneng ea mehala. Ho fihlela sepheo sena, ho tsamaisa litsela ho lokela ho ntlafatsoa ka bophara le sebaka.

Setšoantšo sa 5 se bonts’a mohlala oa para ea phapang bakeng sa mehala e potlakileng ea USB e nang le lithapo tse 12 mil ka bophara likhoeling tse 15 mil.

Interfaces for memory-based components that contain parallel interfaces will be more constrained in terms of wire length. Boholo ba software ea moralo o phahameng oa PCB e tla ba le bokhoni ba ho lokisa bolelele bo tla ntlafatsa bolelele ba mohala ho ts’oana le matšoao ohle a loketseng ka beseng e tšoanang. Setšoantšo sa 6 se bontša mohlala oa sebopeho sa DDR3 se nang le wiring ea phetoho e telele.

Mekhoa le lifofane tsa ho tlatsa fatše

Lisebelisoa tse ling tse nang le likarolo tse mamelang lerata, joalo ka likhalase tse se nang mohala kapa li-antenna, li ka hloka tšireletso e nyane. Ho rala wiring le lifofane tse nang le masoba a kenngoeng fatše li ka thusa haholo ho fokotsa ho hokahana ha likhoele tse haufi kapa lipontšo tsa ho khetha sefofane tse kenang ka mathoko a boto.

Figure 7 shows an example of a Bluetooth module placed near the edge of the plate, with its antenna outside a thick line containing embedded through-holes connected to the ground formation. Sena se thusa ho arola lenakana ho lisekete le lifofane tse ling.

This alternative method of routing through the ground can be used to protect the board circuit from external off-board wireless signals. Setšoantšo sa 8 se bonts’a PCB e mamelang lerata e nang le sefofane se kenngoeng ka har’a lesoba haufi le poto ea boto.

Mekhoa e metle bakeng sa wiring ea PCB

Ho na le lintlha tse ngata tse khethollang litšobotsi tsa wiring tsa tšimo ea PCB, ka hona etsa bonnete ba hore o latela mekhoa e metle ha o ts’oara PCB ea hau e tlang, ‘me o tla fumana teka-tekano lipakeng tsa litšenyehelo tsa boleng ba PCB, letsoalo la potoloho le ts’ebetso e akaretsang.