Elektron mahsulotlarning ajralmas qismi sifatida, bosilgan elektron karta (PCB) elektron mahsulotlar funktsiyasini amalga oshirishda asosiy rol o’ynaydi, bu esa PCB dizaynining tobora muhim ahamiyatiga olib keladi, chunki PCB dizaynining ishlashi elektron mahsulotlarning funktsiyasi va narxini bevosita belgilaydi. PCB -ning yaxshi dizayni elektron mahsulotlarni ko’plab muammolardan saqlay oladi, shuning uchun mahsulotlarni muammosiz ishlab chiqarish va amaliy dasturlarning barcha ehtiyojlarini qondirish imkonini beradi.

PCB dizayniga hissa qo’shadigan barcha elementlardan Dizaynni ishlab chiqarish (DFM) juda muhim, chunki u elektron mahsulotlarning hayotiy tsikli davomida muammolarni erta aniqlash va o’z vaqtida hal qilish uchun PCB dizaynini PCB ishlab chiqarish bilan bog’laydi. 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.

PCB ishlab chiqarish qobiliyati

Ishlab chiqarish qobiliyatini PCB dizayni bilan birlashtirib, ishlab chiqarish dizayni samarali ishlab chiqarish, yuqori sifat va arzon narxga olib keladigan asosiy omil hisoblanadi. 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. Agar PCBni loyihalash bosqichida bu jihatlar to’liq hisobga olinmasa, qo’shimcha ishlov berish choralari ko’rilmaguncha, avtomatik chipli laminatlash mashinalari oldindan tayyorlangan PCB plitalarini qabul qila olmaydi. Eng yomoni, qo’lda payvandlash yordamida ba’zi plastinkalarni avtomatik tarzda yasash mumkin emas. As a result, the manufacturing cycle will be longer and labor costs will increase.

1. PCB size

Har bir chip o’rnatuvchining o’zi xohlagan PCB o’lchamiga ega, bu har bir o’rnatuvchining parametrlariga qarab o’zgaradi. Masalan, chip o’rnatuvchi maksimal PCB o’lchamini 500 mm * 450 mm va minimal PCB o’lchamini 30 mm * 30 mm qabul qiladi. Bu shuni anglatadiki, biz 30 mm dan 30 mm gacha bo’lgan kichik o’lchamdagi PCB kartalari komponentlarini ishlay olmaymiz va kichikroq o’lchamlar kerak bo’lganda, jigsaw taxtalariga tayanamiz. Qachonki siz faqat qo’lda o’rnatishga tayansangiz va mehnat xarajatlari oshsa va ishlab chiqarish tsikllari nazoratdan chiqsa, chip SMT mashinalari hech qachon juda katta yoki juda kichik tenglikni kartalarini qabul qilmaydi. 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.

Quyidagi rasmda Huaqiu DFM dasturi bilan to’ldirilgan tenglikni kartalari konstruktorlik hujjati ko’rsatilgan. 5 × 2 taxta sifatida har bir kvadrat birligi bitta bo’lak bo’lib, o’lchami 50 mm dan 20 mm gacha. 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. Yuqoridagi talablarga ko’ra, taxtaning o’lchami qabul qilinadigan diapazonda degan xulosaga kelish mumkin.

2. PCB shape

In addition to PCB size, all chip SMT machines have requirements for PCB shape. Oddiy tenglikni to’rtburchaklar shaklida bo’lishi kerak – uzunligi 4: 3 yoki 5: 4 (eng yaxshisi). If the PCB is irregularly shaped, additional measures must be taken prior to SMT assembly, resulting in increased costs. Bunga yo’l qo’ymaslik uchun, tenglikni loyihalash bosqichida tenglikni SMT talablariga javob beradigan tarzda umumiy shaklda ishlab chiqish kerak. Biroq, amalda buni qilish qiyin. Qachonki ba’zi elektron mahsulotlarning shakli notekis bo’lishi kerak bo’lsa, oxirgi PCBga normal shakl berish uchun shtampli teshiklardan foydalanish kerak. O’rnatilganda, avtomatik o’rnatish va bo’sh joy talablariga javob beradigan ortiqcha yordamchi panellar tenglikni olib tashlanishi mumkin.

Quyidagi rasmda notekis shaklga ega tenglikni ko’rsatilgan va ishlov berish qirrasi Huaqiu DFM dasturi bilan qo’shilgan. 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. Jarayon tomoni

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

PCB dizayn bosqichida, 5 mm kenglikdagi texnologik chekkani hech qanday tarkibiy qismlar va simlar qoldirmasdan oldindan ajratish kerak. Texnik qo’llanma, odatda, tenglikni qisqa tomoniga joylashtiriladi, lekin tomonlar nisbati 80%dan oshganda qisqa tomonni tanlash mumkin. Yig’ishdan so’ng, texnologik chekka yordamchi ishlab chiqarish roli sifatida olib tashlanishi mumkin.

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. Shuning uchun, Mark punktlari avtomatlashtirilgan ishlab chiqarish uchun zarur bo’lgan SMT ishlab chiqarish ko’rsatkichlari hisoblanadi.

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. Mark va plastinka chetlari orasidagi masofa kamida 5 mm bo’lishi kerak. Ikki tomonlama SMT komponentlari bo’lgan PCBS uchun markirovka nuqtalarini har ikki tomonga qo’yish kerak. 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

PCBni yig’ish yoki qisqacha aytganda, PCBA – bu qismlarni yalang’och taxtalarga payvandlash jarayoni. Avtomatik ishlab chiqarish talablariga javob berish uchun, tenglikni yig’ish yig’ish to’plami va yig’ish tartibiga ba’zi talablarga ega.

1. Komponentlarni qadoqlash

PCBA dizayni paytida, agar komponentlar to’plami tegishli standartlarga javob bermasa va komponentlar bir -biriga juda yaqin bo’lsa, avtomatik o’rnatish amalga oshmaydi.

Eng yaxshi komponentli qadoqlarni olish uchun, komponentalarni qadoqlashning xalqaro standartlariga mos keladigan professional EDA dizayn dasturidan foydalanish kerak. 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

Komponentlarning joylashuvi PCB dizaynida muhim vazifadir, chunki uning ishlashi tenglikni ko’rinishi va ishlab chiqarish jarayonining murakkabligi bilan bevosita bog’liq.

Komponentlarni joylashtirish jarayonida SMD va THD komponentlarini yig’ish yuzalarini aniqlash kerak. Bu erda biz tenglikni old qismini A komponentli tomoni va orqasini B komponenti sifatida o’rnatdik. 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. Turli xil yig’ish turli ishlab chiqarish jarayonlari va texnikasini talab qiladi. 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.

Umuman olganda, komponentlarning yo’nalishi izchil bo’lishi kerak. 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. Komponentning balandligi 4 mm gacha, komponent va tenglikni orasidagi uzatish yo’nalishi 90 ° bo’lishi kerak.

Komponentlarning payvandlash tezligini yaxshilash va keyingi tekshirishni osonlashtirish uchun komponentlar orasidagi masofa mos bo’lishi kerak. Xuddi shu tarmoqdagi komponentlar bir -biriga yaqin bo’lishi kerak va kuchlanish pasayishiga qarab turli tarmoqlar o’rtasida xavfsiz masofa qolishi kerak. Silkscreen va pad bir -biriga mos kelmasligi kerak, aks holda komponentlar o’rnatilmaydi.

Due to the actual operating temperature of the PCB and the thermal characteristics of the electrical components, heat dissipation should be considered. Komponentlarning joylashuvi issiqlik tarqalishiga qaratilishi kerak. Agar kerak bo’lsa, fan yoki issiqlik qabul qilgichdan foydalaning. Quvvat komponentlari uchun mos radiatorlar tanlanishi va issiqlikka sezgir komponentlar issiqdan uzoqda joylashtirilishi kerak. Yuqori komponentni past komponentdan keyin qo’yish kerak.

Batafsil ma’lumot PCB DFMga qaratilishi va tajriba amalda to’planishi kerak. Masalan, yuqori tezlikli signalli PCB dizayn talablari maxsus impedans talablariga ega va impedans va qatlam ma’lumotlarini aniqlash uchun haqiqiy ishlab chiqarishdan oldin taxta ishlab chiqaruvchisi bilan muhokama qilinishi kerak. Kichik o’lchamli PCB plitalarida zich simli ishlab chiqarishga tayyorgarlik ko’rish uchun, bu tenglikni ishlab chiqarishning tengligini ta’minlash uchun, paychalarining minimal kengligi va teshik diametri ishlab chiqarish quvvati tenglikni ishlab chiqaruvchisi bilan muhokama qilinishi kerak.