Kama sehemu muhimu ya bidhaa za elektroniki, printed mzunguko bodi (PCB) ina jukumu muhimu katika kutambua kazi ya bidhaa za elektroniki, ambayo inasababisha umuhimu unaozidi kuongezeka wa muundo wa PCB, kwa sababu utendaji wa muundo wa PCB huamua moja kwa moja kazi na gharama ya bidhaa za elektroniki. Ubunifu mzuri wa PCB unaweza kuweka bidhaa za elektroniki kutoka kwa shida nyingi, na hivyo kuhakikisha kuwa bidhaa zinaweza kutengenezwa vizuri na kukidhi mahitaji yote ya matumizi ya vitendo.

Kati ya vitu vyote vinavyochangia muundo wa PCB, Ubunifu wa utengenezaji (DFM) ni muhimu sana kwa sababu inaunganisha muundo wa PCB na utengenezaji wa PCB ili kupata shida mapema na kuzitatua kwa wakati katika kipindi chote cha maisha cha bidhaa za elektroniki. One myth is that the complexity of PCB design will increase as manufacturability of electronics is considered at the PCB design stage. In the design life cycle of electronic products, DFM can not only make electronic products participate in automatic production smoothly, and save labor costs in the manufacturing process, but also effectively shorten the manufacturing time to ensure the timely completion of the final electronic products.

Uzalishaji wa PCB

Kwa kuchanganya utengenezaji wa bidhaa na muundo wa PCB, muundo wa utengenezaji ni jambo muhimu linaloongoza kwa utengenezaji bora, ubora wa hali ya juu na gharama nafuu. The research of PCB manufacturability covers a wide range, usually divided into PCB manufacturing and PCB assembly.

LPCB production

For PCB manufacturing, the following aspects should be considered: PCB size, PCB shape, process edge and Mark point. Ikiwa hali hizi hazizingatiwi kikamilifu katika hatua ya muundo wa PCB, mashine za kukometa chip moja kwa moja zinaweza kukosa kukubali bodi za PCB zilizopangwa isipokuwa hatua za ziada za usindikaji zichukuliwe. Kufanya mambo kuwa mabaya zaidi, sahani zingine haziwezi kutengenezwa kiatomati kwa kutumia kulehemu kwa mikono. As a result, the manufacturing cycle will be longer and labor costs will increase.

1. PCB size

Kila kisakinishi cha chip kina saizi yake inayotakiwa ya PCB, ambayo hutofautiana kulingana na vigezo vya kila kisakinishi. Kwa mfano, kisakinishi cha chip kinakubali kiwango cha juu cha PCB cha 500mm * 450mm na saizi ndogo ya PCB ya 30mm * 30mm. Hii haimaanishi kwamba hatuwezi kushughulikia vipengee vya bodi vya PCB vidogo kuliko 30mm na 30mm, na tunaweza kutegemea bodi za jigsaw wakati saizi ndogo zinahitajika. Wakati unaweza kutegemea tu usanikishaji wa mwongozo na gharama za kazi zinaongezeka na mizunguko ya uzalishaji imedhibitiwa, mashine za chip SMT hazitakubali bodi za PCB ambazo ni kubwa sana au ndogo sana. Therefore, in the PCB design stage, the PCB size requirements set by automatic installation and manufacturing must be fully considered, and it must be controlled within the effective range.

Takwimu ifuatayo inaonyesha hati ya muundo wa bodi ya PCB iliyokamilishwa na programu ya Huaqiu DFM. Kama bodi ya 5 × 2, kila kitengo cha mraba ni kipande kimoja, kupima 50mm na 20mm. The connection between each unit is achieved by V-cut/V-scoring technology. In this image, the entire square is shown with a final size of 100mm by 100mm. Kulingana na mahitaji hapo juu, inaweza kuhitimishwa kuwa saizi ya bodi iko ndani ya anuwai inayokubalika.

2. PCB shape

In addition to PCB size, all chip SMT machines have requirements for PCB shape. PCB ya kawaida inapaswa kuwa na sura ya mstatili na urefu na urefu wa upana wa 4: 3 au 5: 4 (bora). If the PCB is irregularly shaped, additional measures must be taken prior to SMT assembly, resulting in increased costs. Ili kuzuia hili kutokea, PCB lazima iliyoundwa kwa sura ya kawaida wakati wa awamu ya muundo wa PCB ili kukidhi mahitaji ya SMT. Walakini, hii ni ngumu kufanya katika mazoezi. Wakati umbo la bidhaa zingine za elektroniki lazima ziwe za kawaida, mashimo ya stempu yanapaswa kutumiwa kuipatia PCB ya mwisho umbo la kawaida. Wakati wa kukusanyika, baffles za ziada zinazosaidiwa zinaweza kuondolewa kutoka kwa PCB ili kukidhi mahitaji ya ufungaji na nafasi moja kwa moja.

Picha hapa chini inaonyesha PCB na sura isiyo ya kawaida, na makali ya usindikaji yanaongezwa na programu ya Huaqiu DFM. The whole circuit board size is 80mm * 52mm, and the square area is the size of the actual PCB. The size of the upper right corner area is 40mm by 20mm, which is the auxiliary craft edge produced by the bridge of the stamp hole.

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3. Mchakato upande

To meet the requirements of automatic manufacturing, process edges must be placed on the PCB to secure the PCB.

Katika hatua ya muundo wa PCB, makali ya mchakato wa 5mm inapaswa kuwekwa kando mapema, bila kuacha vifaa na wiring. Mwongozo wa kiufundi kawaida huwekwa kwa upande mfupi wa PCB, lakini upande mfupi unaweza kuchaguliwa wakati uwiano wa kipengele unazidi 80%. Baada ya kusanyiko, makali ya mchakato yanaweza kuondolewa kama jukumu la uzalishaji msaidizi.

4. Mark point

For PCBS with components installed, Mark points should be added as a common reference point to ensure that component locations are accurately determined for each assembly device. Kwa hivyo, alama za Alama ni alama za utengenezaji za SMT zinazohitajika kwa utengenezaji wa kiotomatiki.

Components require 2 Mark points and PCBS require 3 Mark points. These marks should be placed on the edges of the PCB board and cover all SMT components. Umbali wa katikati kati ya alama ya Alama na makali ya sahani inapaswa kuwa angalau 5mm. Kwa PCBS zilizo na pande mbili za vifaa vya SMT, alama za alama zinapaswa kuwekwa pande zote mbili. If the components are too close together to place Mark points on the board, they can be placed on the edge of the process.

LPCB assembly

Mkutano wa PCB, au PCBA kwa kifupi, kwa kweli ni mchakato wa vifaa vya kulehemu kwenye bodi zilizo wazi. Ili kukidhi mahitaji ya utengenezaji wa moja kwa moja, mkutano wa PCB una mahitaji kadhaa ya kifurushi cha mkutano na mpangilio wa mkutano.

1. Ufungaji wa vifaa

Wakati wa muundo wa PCBA, ikiwa vifurushi vya sehemu havikidhi viwango sahihi na vifaa viko karibu sana, usakinishaji wa moja kwa moja hautatokea.

Ili kupata ufungaji bora wa vifaa, programu ya uundaji wa EDA inapaswa kutumiwa kufuata viwango vya ufungaji vya sehemu ya kimataifa. During PCB design, the aerial view area must not overlap with other areas, and the automatic IC SMT machine will be able to accurately identify and mount the surface.

2. Component layout

Mpangilio wa vifaa ni kazi muhimu katika muundo wa PCB kwa sababu utendaji wake unahusiana moja kwa moja na ugumu wa kuonekana kwa PCB na mchakato wa utengenezaji.

Wakati wa mpangilio wa sehemu, sehemu za kusanyiko za vifaa vya SMD na THD zinapaswa kuamuliwa. Hapa, tunaweka mbele ya PCB kama sehemu A upande na nyuma kama sehemu B upande. The assembly layout should consider the assembly form, including single layer single package assembly, double layer single package assembly, single layer mixed package assembly, Side A mixed package and side B single package assembly and side A THD and side B SMD assembly. Mkutano tofauti unahitaji michakato na mbinu tofauti za utengenezaji. Therefore, in terms of component layout, the best component layout should be selected to make manufacturing simple and easy, so as to improve the manufacturing efficiency of the whole process.

In addition, consideration must be given to the orientation of component layout, spacing between components, heat dissipation, and component height.

Kwa ujumla, mwelekeo wa vifaa unapaswa kuwa sawa. Components are laid out in accordance with the principle of minimum tracking distance, based on which components with polarity markers should have uniform polarity directions, and components without polarity markers should be neatly aligned along the X or Y axis. Urefu wa sehemu inapaswa kuwa hadi 4mm, na mwelekeo wa usambazaji kati ya sehemu na PCB inapaswa kuwa 90 °.

Ili kuboresha kasi ya kulehemu ya vifaa na kuwezesha ukaguzi unaofuata, nafasi kati ya vifaa inapaswa kuwa sawa. Vipengele kwenye mtandao huo vinapaswa kuwa karibu na kila mmoja na umbali salama unapaswa kushoto kati ya mitandao tofauti kulingana na kushuka kwa voltage. Skrini na pedi hazipaswi kuingiliana, vinginevyo vifaa havitawekwa.

Due to the actual operating temperature of the PCB and the thermal characteristics of the electrical components, heat dissipation should be considered. Mpangilio wa vifaa unapaswa kuzingatia utaftaji wa joto. Ikiwa ni lazima, tumia shabiki au sinki ya joto. Radiator zinazofaa zinapaswa kuchaguliwa kwa vifaa vya umeme na vifaa nyeti vya joto vinapaswa kuwekwa mbali na joto. Sehemu ya juu inapaswa kuwekwa baada ya sehemu ya chini.

Maelezo zaidi yanapaswa kulenga PCB DFM, na uzoefu unapaswa kukusanywa katika mazoezi. Kwa mfano, mahitaji ya muundo wa ishara ya kasi ya PCB yana mahitaji maalum ya impedance na inapaswa kujadiliwa na mtengenezaji wa bodi kabla ya utengenezaji halisi kuamua impedance na habari ya kuweka. Ili kujiandaa kwa utengenezaji wa bodi ndogo ndogo za PCB zilizo na waya mnene, upana wa chini wa wiring na uwezo wa utengenezaji wa kipenyo-shimo inapaswa kujadiliwa na mtengenezaji wa PCB ili kuhakikisha uzalishaji laini wa PCBS hizi.