Inson tanasidan, atrof -muhitdan va hatto elektron qurilmalar ichidan statik elektr toki nozik yarimo’tkazgichli chiplarga har xil zarar etkazishi mumkin, masalan, komponentlar ichidagi yupqa izolyatsion qatlamga kirishi; MOSFET va CMOS komponentlarining eshiklari shikastlanishi; Trigger lock in CMOS device; Short-circuit reverse bias PN junction; Qisqa tutashuvli ijobiy burilishli PN birikmasi; Payvandlash simini yoki alyuminiy simni faol qurilma ichida eritib oling. In order to eliminate the interference and damage of electrostatic discharge (ESD) to electronic equipment, it is necessary to take a variety of technical measures to prevent.

davomida PCB kartasi Dizayn, tenglikni ESD qarshiligi qatlamlar, to’g’ri joylashtirish va o’rnatish orqali amalga oshirilishi mumkin. Dizayn jarayonida dizayndagi o’zgarishlarning aksariyati bashorat qilish orqali komponentlarni qo’shish yoki olib tashlash bilan chegaralanishi mumkin. PCB sxemasi va simlarini sozlash orqali ESDni yaxshi oldini olish mumkin. Here are some common precautions.

How to realize ESD resistance design of PCB

1. Use multi-layer PCB as far as possible. Compared with double-sided PCB, the ground plane and power plane, as well as the close spacing between signal wire and ground wire can reduce the common-mode impedance and inductive coupling, and make it reach 1/10 to 1/100 of the double-sided PCB. Try to place each signal layer close to a power or ground layer. For high-density PCBS with components on both the top and bottom surfaces, very short connections, and lots of ground filling, consider using inner lines.

2. Ikki tomonlama PCB uchun bir-biri bilan chambarchas bog’langan elektr ta’minoti va tuproqli tarmoqdan foydalanish kerak. Quvvat kabeli erning yonida joylashgan va imkon qadar vertikal va gorizontal chiziqlar yoki to’ldirish zonalari o’rtasida ulangan bo’lishi kerak. The grid size of one side shall be less than or equal to 60mm, or less than 13mm if possible.

3. Har bir sxemaning iloji boricha ixcham ekanligiga ishonch hosil qiling.

4. Barcha ulagichlarni iloji boricha chetga surib qo’ying.

5. Iloji bo’lsa, elektr simini kartaning markazidan ESDning bevosita shikastlanishiga zaif joylardan uzoqlashtiring.

6, korpusdan chiqadigan ulagich ostidagi barcha PCB qatlamlarida (ESD tomonidan to’g’ridan -to’g’ri urish oson), keng shassis yoki ko’pburchak bilan to’ldirilgan erni joylashtiring va ularni teshiklari bilan taxminan 13 mm oralig’ida ulang.

7. Place mounting holes on the edge of the card, and the top and bottom pads of open flux are connected to the ground of the chassis around the mounting holes.

8, PCB assembly, do not apply any solder on the top or bottom pad. Use screws with built-in washers to provide tight contact between PCB and metal chassis/shield or support on ground surface.

9, shassi va elektron tuproq orasidagi har bir qatlamda bir xil “izolyatsiya zonasini” o’rnatish uchun; Iloji bo’lsa, masofani 0.64 mm oralig’ida saqlang.

10, in the top and bottom of the card near the installation hole position, every 100mm along the chassis ground and circuit ground with 1.27mm wide line together. Adjacent to these connection points, a pad or mounting hole for installation is placed between the chassis ground and the circuit ground. These ground connections can be cut with a blade to remain open, or jump with magnetic beads/high frequency capacitors.

11, if the circuit board will not be put into the metal box or shielding device, the top and bottom of the circuit board chassis ground wire can not be coated with solder resistance, so that they can be used as ESD arc put electrode.

12. Set a ring around the circuit in the following manner:

(1) In addition to the edge connector and chassis, the entire periphery of the ring access.

(2) Barcha qatlamlarning kengligi 2.5 mm dan katta ekanligiga ishonch hosil qiling.

(3) Teshiklar halqada har 13 mm ulanadi.

(4) halqali va ko’p qatlamli sxemaning umumiy erini bir-biriga ulang.

(5) For double panels installed in metal cases or shielding devices, the ring ground shall be connected to the common ground of the circuit. Himoyalanmagan ikki tomonlama zanjir uzukli erga ulangan bo’lishi kerak, halqali erni oqim bilan qoplamaslik kerak, shunda halqa zamini ESD tushirish tayog’i vazifasini bajarishi mumkin, halqa erida kamida 0.5 mm kenglikdagi bo’shliq qatlamlar), shuning uchun katta halqani oldini olish mumkin. Signal simlari halqa eridan 0.5 mm dan kam bo’lmasligi kerak.

ESD to’g’ridan -to’g’ri urilishi mumkin bo’lgan hududda har bir signal chizig’i yaqinida topraklama simini yotqizish kerak.

14. The I/O circuit should be as close to the corresponding connector as possible.

15. The circuit susceptible to ESD should be placed near the center of the circuit, so that other circuits can provide a certain shielding effect for them.

16, usually placed in series resistor and magnetic beads at the receiving end, and for those cable drivers vulnerable to ESD, can also consider placing a series resistor or magnetic beads at the driver end.

17. Vaqtinchalik himoyachi odatda qabul qiluvchi uchiga joylashtiriladi. Shassi tagiga ulanish uchun qisqa qalin simlardan (kengligi 5xdan kam, eng yaxshisi 3xdan kam) foydalaning. Ulagichdan keladigan signal va tuproqli chiziqlar, kontaktlarning qolgan qismini ulashdan oldin, vaqtinchalik himoyachiga to’g’ridan -to’g’ri ulangan bo’lishi kerak.

18. Filtr kondansatörünü ulagichga yoki qabul qilish sxemasidan 25 mm masofada joylashtiring.

(1) Shassi yoki qabul qilish sxemasini ulash uchun qisqa va qalin simni ishlating (uzunligi kengligidan 5 baravaridan kam, yaxshisi kengligidan 3 baravaridan kam).

(2) Signal chizig’i va topraklama simlari birinchi navbatda kondansatkichga, so’ngra qabul qilish pallasiga ulanadi.

19. Signal chizig’i iloji boricha qisqa ekanligiga ishonch hosil qiling.

20. Signal kabellarining uzunligi 300 mm dan katta bo’lsa, parallel ravishda topraklama kabelini yotqizish kerak.

21. Signal chizig’i va unga mos keladigan halqa orasidagi pastadir maydoni imkon qadar kichik bo’lishiga ishonch hosil qiling. Uzoq signalli chiziqlar uchun, uzatish maydonini kamaytirish uchun signal chizig’i va er chizig’ining holati bir necha santimetrda o’zgarishi kerak.

22. Tarmoq markazidan signallarni bir nechta qabul qilish davrlariga o’tkazing.

23. Ensure that the loop area between the power supply and the ground is as small as possible. Place a high frequency capacitor near each power pin of the IC chip.

24. Har bir ulagichdan 80 mm masofada yuqori chastotali bypass kondansatörünü joylashtiring.

25. Where possible, fill the unused areas with land, connecting all layers of fill at 60mm intervals.

26. Tuproqni har qanday katta erni to’ldirish maydonining qarama -qarshi uchlari bilan bog’langanligiga ishonch hosil qiling (taxminan 25 mm*6 mm dan katta).

27. Quvvat manbai yoki er tekisligida ochilish uzunligi 8 mm dan oshganda, teshikning ikki tomonini tor chiziq bilan ulang.

28. Qayta tiklash liniyasi, uzilish signal chizig’i yoki chekka tetik signal chizig’i tenglikni chetiga yaqin joylashtirilmasligi kerak.

29. O’rnatish teshiklarini kontaktlarning zanglashiga ulang yoki ularni ajratib qo’ying.

(1) Metall qavsni metall himoya moslamasi yoki shassis bilan ishlatish kerak bo’lganda, ulanishni amalga oshirish uchun nol ohmli qarshilikdan foydalanish kerak.

(2) metall yoki plastmassa tayanchni ishonchli o’rnatishga erishish uchun o’rnatish teshigining o’lchamini aniqlang, katta teshikni o’rnatish uchun o’rnatish teshigining yuqori va pastki qismida, pastki yostiq oqim qarshiligini ishlata olmaydi va pastki pad payvandlash uchun to’lqinli payvandlash jarayonidan foydalanmaydi.

30. Himoyalangan signal kabellari va himoyalanmagan signal kabellari parallel joylashtirilishi mumkin emas.

Qayta tiklash, uzilish va nazorat signal liniyalarining simlariga alohida e’tibor qaratish lozim.

(1) Yuqori chastotali filtrlashdan foydalanish kerak.

(2) Kirish va chiqish davrlaridan uzoq turing.

(3) Elektron kartaning chetidan uzoqroq tuting.

32, tenglikni shassiga kiritish kerak, ochilish joyiga yoki ichki bo’g’inlarga o’rnatmang.

Magnit boncuk ostidagi, yostiqchalar orasidagi signal chizig’ining simlariga e’tibor bering va magnit boncuk bilan aloqa qilishi mumkin. Ba’zi boncuklar elektr tokini yaxshi o’tkazadi va kutilmagan o’tkazuvchan yo’llarni keltirib chiqarishi mumkin.

Agar korpus yoki anakart bir nechta elektron platalarni o’rnatsa, o’rtadagi statik elektr platasiga eng sezgir bo’lishi kerak.