ʻO ka mea nui o ka laulā laina PCB i ka hoʻolālā PCB

He aha ka laula o ka laina?

E hoʻomaka kākou me nā kumu. He aha ke kiko kiko o ka laulā? No ke aha he mea nui e wehewehe i kahi laulā kikoʻī kikoʻī? Ke kumu o PCB hoʻohui ka pilina i kekahi ʻano hōʻailona uila (analog, digital a i ʻole ka mana) mai kekahi piko i kekahi.

Hiki i kahi node ke pine o kahi mea, kahi lālā o kahi ala nui a i ʻole mokulele, a i ʻole kahi papa hakahaka a kahi hōʻike hoʻāʻo no ka hoʻāʻo ʻana. Hoʻomaʻamaʻa pinepine ʻia ka laulā i nā mils a i ʻole nā ​​kaukani iniha. ʻO nā laulā maʻamau maʻamau no nā hōʻailona maʻamau (ʻaʻohe koi kūikawā) he mau ʻīniha paha ka lōʻihi i ka 7-12 mils, akā pono e noʻonoʻo ʻia nā kumu he nui i ka wehewehe ʻana i ka laula a me ka lōʻihi o ka uila.

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Hoʻokomo ka palapala noi i ka laula o ka uea a me ke ʻano o ka hoʻopili ʻana i ka hoʻolālā PCB a, i kekahi manawa, kaulike i ke kumukūʻai hana PCB, ka nui / ka nui o ka papa, a me ka hana. Inā loaʻa nā koi kikoʻī i ka papa, e like me ka wikiwiki wikiwiki, ka leo a i ʻole ke kāohi ʻana i ka hoʻopili ʻana, a i ʻole ke kiʻekiʻe o ke au / uila, ʻoi aku ka nui o ka laulā a me ke ʻano o ke kumumanaʻo ma mua o ka hoʻonui ʻana i ka uku hana o PCB hone a i ʻole ka nui o ka papa.

Hōʻike kikoʻī e pili ana i nā pilina i ka hana PCB

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

Hoʻolālā nā hoʻolālā kiʻekiʻe e hoʻohui i ka hakahaka o PCB, e like me ka BGA spaced maikaʻi loa a i ʻole nā ​​helu pahi hōʻailona like, e koi paha i ka laina ākea o 2.5 mil, a me nā ʻano kūikawā o nā puka-i me nā anawaena a hiki i 6 mil, e like me e like me ka laser drilled microthrough-hole. ʻO ka mea ʻē aʻe, koi paha kekahi mau mana mana kiʻekiʻe i nā aho nui a i ʻole nā ​​mokulele, e hoʻopau ana i nā papa āpau a ninini i nā auneke ʻoi aku ka mānoanoa ma mua o ka maʻamau. I nā noi ākea ākea, nā papa lahilahi loa i piha i kekahi mau papa a me ka mānoanoa o ka hoʻoheheʻe keleawe o ka hapalua o ka auneke (0.7 mil mānoanoa) e pono ai.

I nā hihia ʻē aʻe, nā hoʻolālā no ke kamaʻilio wikiwiki wikiwiki mai kahi ākea a i kekahi ʻē aʻe e koi paha i nā uea me ka impedance kaohi a me nā laulā kikoʻī a me ke ākea ma waena o kekahi e hoʻoliʻiliʻi i ka noʻonoʻo a me ka hoʻopili inductive. A i ʻole e koi paha ka hoʻolālā i kekahi lōʻihi e kūlike me nā hōʻailona pili ʻē aʻe i ka kaʻa kaʻa. Noi nā noi uila kiʻekiʻe i kekahi mau hiʻohiʻona palekana, e like me ka hoʻohaʻahaʻa ʻana i ka mamao ma waena o ʻelua mau hōʻailona hoʻokaʻawale e pale aku i ke hoʻopaʻa ʻana. Nānā ʻole i nā ʻano a i ʻole nā ​​hiʻohiʻona, he mea nui ka huli ʻana i nā wehewehe, no laila e ʻimi i nā noi like ʻole.

Nā laulā a me nā mānoanoa o ka pilina

PCBS typically contain a variety of line widths, as they depend on signal requirements. Hōʻike ʻia nā meheu finer no nā hōʻailona pae kiʻekiʻe TTL (transistor-transistor logical) a ʻaʻohe koi kūikawā no ka pale kiʻekiʻe i kēia manawa a i ʻole ka walaʻau.

E lilo kēia i mau ʻano kelepaʻi maʻamau o ka papa.

Ua hoʻonui maikaʻi ʻia nā uea ʻoi aku ka nui no ka hiki ke hali i kēia manawa a hiki ke hoʻohana ʻia no nā peripheral a i ʻole nā ​​hana e pili ana i ka mana e koi ai i ka mana kiʻekiʻe, e like me nā pā, nā kaʻa, a me nā hoʻololi mana maʻamau i nā ʻāpana pae haʻahaʻa. Hōʻike ka ʻaoʻao hema hema o ke kiʻi i kahi hōʻailona ʻokoʻa (wikiwiki wikiwiki ʻo USB) e wehewehe ana i kahi kikoʻī kikoʻī a me ka laulā e hoʻokō i nā koi impedance o 90 ω. Hōʻike ka Nānā 2 i kahi papa kaapuni liʻiliʻi i ʻeono mau papa a koi i kahi hui BGA (grid grid array) e koi ai i nā uwea finer.

Pehea e helu ai i ka laulā laina PCB?

E hele i loko o ke kaʻina hana o ka helu ʻana i kekahi ākea o ka laulā no kahi hōʻailona mana e hoʻoneʻe i kēia manawa mai kahi mana i kahi mea kikowaena. I kēia laʻana, e helu mākou i ka laulā laina liʻiliʻi o ke ala uila no ka motika DC. Hoʻomaka ke ala uila ma ka fuse, keʻa i ke alahaka H (ka mea i hoʻohana ʻia e hoʻokele i ka lawe ʻana o ka mana ma o ka wili ʻana o ka motika DC), a hoʻopau ʻia i ka mea hoʻohui o ka kaʻa. ʻO ka awelika hoʻomau i kēia manawa koi ʻia e ka motika DC e pili ana i 2 amperes.

I kēia manawa, hana nā ueaea PCB ma ke ʻano he resistor, a ʻo ka lōʻihi a me ka liʻiliʻi o ka uea ʻana, hoʻohui ʻia ka mea kūʻē. Inā ʻaʻole e wehewehe pono ʻia nā pilina, hiki i ke au kiʻekiʻe ke hoʻopōʻino i nā uea a / a i ʻole ke kumu o ka hāʻule ʻana o ka uila i ke kaʻa (e hoʻoliʻiliʻi ana ka wikiwiki). Inā mākou e noʻonoʻo i kekahi mau kūlana maʻamau, e like me 1 auneke o ka ninini ʻana o ke keleawe a me ka mahana o ka lumi i ka wā o ka hana maʻamau, pono mākou e helu i ka laulā laina liʻiliʻi a me ka hāʻule ʻana o kaomi i manaʻo ʻia i kēlā ākea.

ʻO PCB ke kaula uila a me ka lōʻihi

No nā hoʻolālā kikohoʻe me nā kamaʻilio wikiwiki, hiki ke koi ʻia kahi kikoʻī kikoʻī a me nā lōʻihi i hoʻoponopono ʻia e hoʻoliʻiliʻi i ka crosstalk, ka hoʻopili ʻana, a me ka noʻonoʻo. No kēia kumu, ʻo kekahi o nā noi maʻamau he USB a me nā hōʻailona ʻokoʻa kaulike me ka RAM. ʻO ka maʻamau, e koi ana ʻo USB 2.0 i ka hoʻohuli ʻokoʻa ma 480Mbit / s (papa kiʻekiʻe wikiwiki USB) a ʻoi aku paha. ʻO kēia kekahi ma muli o ka hana o ka wikiwiki wikiwiki i ka nui o nā voltage a me nā ʻokoʻa, e lawe ana i ka pae hōʻailona holoʻokoʻa i kahi walaʻau o hope.

ʻEkolu mau mea nui e noʻonoʻo ai ke kuhikuhi ʻana i nā kaula USB wikiwiki loa: ka laula o ka uea, ke ākea kēpau, a me ka lōʻihi o ke kaula.

He mea nui kēia mau mea āpau, akā ʻo ka mea koʻikoʻi loa o nā mea ʻekolu e hōʻoia i ka lōʻihi o nā laina ʻelua e like me ka hiki. 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 hoʻohālikelike impedance kahi kikoʻī maʻamau no nā pilina paʻa ʻelua. No ka hoʻokō ʻana i kēia pahuhopu, pono e hoʻonui ʻia i ke ala ʻana i ka laulā a me ka spacing.

Hōʻike ka helu 5 i kahi laʻana o ka pālua ʻokoʻa no ka hoʻopili pono USB interface wikiwiki i loaʻa i nā pilina ākea 12 mil i nā manawa he 15 mil.

Interfaces for memory-based components that contain parallel interfaces will be more constrained in terms of wire length. ʻO ka hapanui o ka polokalamu hoʻolālā PCB kiʻekiʻe loa e loaʻa i nā hiki ke hoʻoponopono lōʻihi e hoʻonui pono i ka lōʻihi o ke laina e kūlike me nā hōʻailona kūpono āpau i ka kaʻa kaʻa like. Hōʻike ka helu 6 i kahi laʻana o kahi hoʻonohonoho DDR3 me nā uea hoʻoponopono lōʻihi.

Nā meheu a me nā mokulele o ka hoʻopihapiha honua

ʻO kekahi mau noi me nā ʻāpana leʻaleʻa walaʻau, e like me nā uea uila ʻole a i ʻole nā ​​antennas, e koi paha i kahi pale keu. ʻO ka hoʻolālā ʻana i nā pilina a me nā mokulele me nā lua lepo i hoʻokomo ʻia hiki ke kōkua nui i ka hōʻemi ʻana i ka hoʻopili ʻana o nā uea kokoke a i ʻole ke koho ʻana i nā mokulele a me nā hōʻailona off-board e kolo ana i nā kaʻe o ka papa.

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. Kōkua kēia i ka hoʻokaʻawale ʻana i ka antenna mai nā kaapuni onboard a me nā mokulele.

This alternative method of routing through the ground can be used to protect the board circuit from external off-board wireless signals. Hōʻike ka huahelu 8 i kahi PCB pili i ka walaʻau me ka papa i hoʻokomo ʻia i loko o ka puka ma kahi o ka papa.

Nā hana ʻoi loa no ka uila PCB

Hoʻoholo nā kumu he nui i nā ʻano pilina o ke kahua PCB, no laila e mālama pono i nā hana ʻoi aku ke pili ʻana i kāu PCB aʻe, a ʻike ʻoe i ke kaulike ma waena o PCB fab cost, circuit density, a me ka holoʻokoʻa hana.