Desain PCB

Ing desain sumber daya sing ngalih, desain fisik saka Papan PCB is the last link. If the design method is improper, the PCB may radiate too much electromagnetic interference, resulting in the unstable work of the power supply. The following is an analysis of the matters needed to pay attention to in each step.

Saka diagram skema nganti proses desain PCB

Set up component parameters – > Input principle netlist – > Setelan parameter desain -> Tata letak manual -> Manual cabling – > Desain validasi -> Review – & gt; Output CAM.

Setelan Parameter

Jarak antarane kabel sing jejer kudu memenuhi persyaratan keamanan listrik, lan supaya gampang operasi lan produksi, jarak kudu jembarake. The minimum spacing should be suitable for the voltage at least. When the wiring density is low, the spacing of signal lines can be appropriately increased. For the signal lines with high and low level disparity, the spacing should be as short as possible and the spacing should be increased.

Jarak antarane pojok bolongan utama pad lan pinggiran papan sing dicithak kudu luwih saka 1mm kanggo ngindhari cacat pad nalika mesin. Nalika kabel sing disambungake karo pad kasebut cukup lancip, sambungan antara bantalan lan kabel dirancang dadi bentuk droplet. Kauntungane yaiku bantalan ora gampang dikupas, nanging kabel lan pad kasebut ora gampang dicopot.

Component layout

Practice has proved that even if the circuit schematic design is correct and the printed circuit board design is improper, the reliability of electronic equipment will be adversely affected.

For example, if two thin parallel lines of a printed board are close together, there will be a delay in the signal waveform, resulting in reflected noise at the end of the transmission line. Gangguan sing disebabake dening pasokan listrik lan kabel grounding bakal ngrusak kinerja produk. Mula, nalika ngrancang papan sirkuit cetak, kudu diwenehi perhatian marang cara sing bener.

Saben pasokan listrik ganti duwe papat puteran saiki:

① Ac circuit of power switch

② Sirkuit AC penyearah output

Input saiki sumber sinyal

④ Load output saiki loop Input

Kanthi ngisi kapasitor input kanthi arus kira-kira dc, kapasitor filter utamane duwe peran panyimpenan energi broadband. Kajaba iku, kapasitor saringan output digunakake kanggo nyimpen energi frekuensi dhuwur saka penyearah output nalika ngilangi energi dc saka daur ulang output.

Therefore, the wiring terminals of the input and output filter capacitors are very important. The input and output current loops should be connected to the power supply only from the wiring terminals of the filter capacitor respectively. Yen sambungan antarane sirkuit input / output lan sirkuit listrik / sirkuit penyearah ora bisa langsung nyambung karo terminal kapasitor, energi ac bakal ngliwati input utawa kapasitor filter output lan sumunar menyang lingkungan.

Sirkuit AC saklar pasokan listrik lan penyearah ngemot arus trapezoidal kanthi amplitudo tinggi, sing nduweni komponen harmonik sing dhuwur lan frekuensi sing luwih dhuwur tinimbang frekuensi dhasar switch kasebut. Amplitudo puncak bisa nganti 5 kaping luwih saka arus input / output terus-terusan. Wektu transisi biasane udakara 50n.

Rong sirkuit kasebut bisa ngasilake gangguan elektromagnetik, mula kabel liyane sing dicithak ing sumber daya kanggo kain sadurunge sirkuit AC kasebut, saben loop telung komponen utama kapasitor filter, saklar daya utawa penyearah, induktor utawa trafo bakal dipasang ing jejere kanggo saben liyane, atur dalan saiki ing antarane posisi elemen supaya bisa sesingkat.

Cara paling apik kanggo nggawe tata letak pasokan listrik sing padha karo desain listrik, proses desain paling apik yaiku:

① Transformator papan

② Design the power switch current loop

③ Design the output rectifier current loop

④ The control circuit connected to the AC power supply circuit

kabel

Pasokan listrik ngoper ngemot sinyal frekuensi dhuwur, lan garis sing dicithak ing PCB bisa dadi antena. Dawane lan jembaré garis cetak bakal mengaruhi impedansi lan reaktifitas induktif, saengga mengaruhi respon frekuensi. Even printed lines that pass through dc signals can be coupled to rf signals from adjacent printed lines and cause circuit problems (or even re-radiate interference signals).

All printed lines running through ac current should therefore be designed to be as short and wide as possible, which means that all components connected to printed lines and to other power lines must be placed close together.

The length of the printed line is directly proportional to its inductance and impedance, and the width is inversely proportional to the inductance and impedance of the printed line. Dawane nuduhake dawa gelombang tanggapan garis sing dicithak. Yen dawa maneh, frekuensi garis cetakan luwih murah bisa ngirim lan nampa gelombang elektromagnetik, lan energi RF sing luwih akeh bisa sumringah.

Miturut ukuran arus papan sirkuit sing dicithak, sing paling dawa kanggo nambah jembaré kabel listrik, nyuda resistensi daur ulang. At the same time, make the power line, ground line and current direction consistent, which helps enhance the anti-noise ability.

Grounding minangka cabang dhasar saka papat sirkuit arus pasokan listrik, sing dadi peran penting banget minangka titik referensi umum sirkuit, lan minangka cara penting kanggo ngontrol gangguan. Mula, tliti kanthi tliti kabel grounding ing tata letak. Campuran kabel grounding bisa nyebabake pasokan listrik sing ora stabil.

dipriksa

Wiring design is completed, it is necessary to carefully check the wiring design by the designers is in line with the rules, rules at the same time also need to confirm whether accord with the demand of the PCB production process, general inspection line to line, line and element bonding pad, the line and communicating pores, element bonding pad and communicating pores, through hole and the distance between the through hole is reasonable, whether to meet the production requirements.

Apa jembaré kabel listrik lan kabel lemah cocog, lan apa ana jembaré kabel lemah sing bakal amba ing PCB. Cathetan: Sawetara kesalahan bisa diabaikan, umpamane, bagean saka Outline sawetara konektor dilebokake ing njaba pigura papan, mula bakal salah mriksa jarak kasebut; Kajaba iku, sawise saben modifikasi kabel lan bolongan, kudu dipasang maneh tembaga.

Review according to the “PCB checklist”, including design rules, layer definition, line width, spacing, pads, hole Settings, but also focus on the review of the rationality of device layout, power supply, grounding network wiring, high-speed clock network wiring and shielding, decoupling capacitor placement and connection.

Output desain

Notes for output light drawing files:

(1) Kudu output lapisan lapisan kabel (ngisor), lapisan percetakan layar (kalebu percetakan layar ndhuwur, cetakan layar ngisor), lapisan las (las ngisor), lapisan pengeboran (ngisor), uga kanggo ngasilake file pengeboran (Bor NC)

② Nalika nyetel Layer Layer nyithak layar, aja milih Tipe Bagian, pilih Outline, Teks lan Baris ing sisih ndhuwur (ngisor) lan Layer nyithak layar

③ Nalika nyetel Layer saben Lapisan, pilih Outline Papan. Nalika nyetel Layer layar Layer, aja pilih Tipe Bagian, banjur pilih Outline lan Teks ing sisih ndhuwur (ngisor) lan Layer cetak layar.