Teshikli PCB nima va u nima uchun muhim bosilgan elektron karta? PCB qatlamlarini ulash uchun teshiklar yoki quduqlarni talab qiladi. Understanding the standard through-hole sizes used by PCB manufacturers can help you design boards to meet common bit sizes.

Teshiklar orqali standart o’lcham

PCB ishlab chiqaruvchilari teshiklarni burg’ilashda tanlashlari mumkin bo’lgan standart teshik o’lchamlariga ega, lekin ular odatda har qanday standart teshik o’lchamidan foydalanishlari mumkin. Umuman olganda, tenglikni ishlab chiqaruvchilari oddiy o’lchamdagi 0.15 mm ga nisbatan 0.6 mm gacha bo’lgan teshiklar orqali tenglikni diametrini yasashlari mumkin.

Teshik teshiklari o’lchamiga qo’yiladigan talablar

Bu o’lchov talablarini chuqur o’rganishdir.

PCB teshik o’lchamlari orqali

Teshik orqali o’tadigan PCB o’lchami uning joylashishiga, ishlatilishiga va boshqa omillarga qarab farq qilishi mumkin, shuning uchun har bir PCB ishlab chiqaruvchisi bir nechta PCB bit o’lchamlarini taklif qiladi. Most manufacturers can make holes as small as 0.15 mm or larger holes of 1 mm or larger. Teshikning kerakli hajmini ko’rib chiqayotganda, siz teshik atrofidagi halqa yoki mis yostiqchani ham ko’rib chiqishingiz kerak.

How do you calculate rings? The ideal ring is equal to the sum of the diameter of the copper pad minus the diameter of the drill hole divided by 2, which gives the rig the best chance of hitting the center of the pad for optimal connectivity.

Teshiklar orqali standart o’lcham

PCB ishlab chiqarishda har qanday standart PCB teshik o’lchamlari bo’lishi shart emas, chunki teshiklarning standart o’lchami ko’pincha ishlab chiqaruvchidan PCB ishlab chiqaruvchisiga qarab o’zgaradi. Shunga qaramay, ko’pgina PCB ishlab chiqaruvchilari standart bit o’lchamlari deb atashlari mumkin bo’lgan umumiy bit o’lchamlarini ishlatishni afzal ko’rishadi. Eng keng tarqalgan o’lchamlardan biri 0.6 mm, lekin 0.2 mm va 0.3 mm ham tez -tez ishlatiladi.

Type of PCB through hole

PCB qatlamiga, tuzilishiga, dizayniga va maqsadiga qarab har xil turdagi teshiklarni yaratish uchun har bir standart teshik o’lchamidan foydalanishingiz mumkin. Teshikli PCBning eng keng tarqalgan uchta turi:

Teshik orqali qoplangan

Elektrolizlangan teshiklar (PTH)-bu yuqori va pastki qatlamlarni ulash uchun tenglikni barcha qatlamlaridan o’tuvchi teshiklar. Siz tenglikni bir chetidan boshqasiga PTH ni ko’rishingiz kerak. PTH qoplamali yoki qoplanmagan bo’lishi mumkin. Teshiklar orqali o’tkazilmagan elektr tokini o’tkazmaydi, teshiklari esa elektrokaplanadi, ya’ni ular tenglikni barcha qatlamlarida elektr o’tkazadi.

Ko’r teshik

Blind holes connect the outer (top or bottom) layers of the PCB to one or more inner layers, but do not completely drill through the board. Precise drilling of blind holes can be challenging, so they are typically more expensive to manufacture than PTH.

ichiga ko’milgan

Embedded holes can also increase the cost of PCB because they are difficult to manufacture. The holes are located in the inner layer of the PCB to connect two or more inner layers. Siz PCB tashqi qatlamida ko’milgan materialni ko’ra olmaysiz.

Ko’rib chiqilishi kerak bo’lgan narsalar

PCB yaratishda bir nechta narsani hisobga olish kerak. Birinchidan, siz PCB dizaynida qaysi nisbat nisbati borligini bilishingiz kerak. The aspect ratio is the PCB thickness relative to the diameter of the through hole, which determines the reliability of the copper plating on the PCB. The higher the ratio, the more difficult it is to obtain reliable plating, which affects the type of hole and plating method you choose.

O’rnatilgan yoki ko’r teshiklar sizning tenglikni tenglikni nisbati 15: 1 bilan yaxshiroq xizmat qilishi mumkin, PTH esa 2: 1 past nisbati bilan yaxshi ishlashi mumkin. PCB misining qalinligini qanday tanlaysiz? Usually, through holes in the outer layer (e.g., through holes) require a thicker layer of copper than the buried through holes inside. PCB tomonidan ishlatiladigan kuchlanish misning qalinligiga ham ta’sir qiladi. High voltage applications typically require thicker PCB copper than low voltage applications.

By filling program

Sometimes PCB through-holes need to be filled, for example to reduce the risk of trapping air or increase electrical conductivity. Some common ways to fill through holes include:

Chodir orqali

Teshikli chodir, teshikni material bilan to’ldirish o’rniga, tenglikni teshik orqali lehim to’siq qatlamini hosil qiladi. This can be a quick, easy and cost-effective option to cover the through-holes, but the tent-style through-holes may reopen over time.

Bloklash orqali

Teshik orqali ulash jarayoni teshikni o’tkazmaydigan material bilan to’ldiradi va uni niqob bilan yopadi. Through-hole clogging also covers the ring and does not produce a smooth, glossy surface.

To’ldirish orqali

Teshik orqali to’ldirish qatron yordamida doimiy to’ldirilgan teshik hosil qiladi. A through-hole fill is a common through-hole fill in which the manufacturer fills the through-hole with conductive material, coats the surface with copper, and then trims the surface. This process can route signals to other areas of the PCB.

Teshik qoplamali ilovalar orqali tenglikni

Ishlab chiqaruvchilar, uning samaradorligini ta’minlash uchun, tenglikni teshik yordamida qoplash uchun bir necha xil texnikani qo’llashlari mumkin. One common method is to use a low viscosity ink that covers the inside of the through-hole to form a conductive layer. Then through the heat curing process to bond the ink.

Boshqa usul – bu elektrokaplama, bu erda PCB elektrokaplama hammomiga kiradi. Bu jarayonda mis har bir tenglikni devorlarini teshiklar orqali yopadi, natijada o’tkazuvchi materialning qalinligi teng bo’ladi. Bu usul siyohlash jarayoniga qaraganda ancha uzun va qimmatroq bo’ladi, lekin u yanada ishonchli qoplama va bog’lanish hosil qilishi mumkin.

Sequential drilling blind drilling and deep drilling

Ko’r teshikli PCBS ikki xil usulda ishlab chiqarilishi mumkin. This can be done by laser drilling or by a method called continuous layer construction. Using the sequential construction method, pairs of layers can be drilled and electroplated before bonding is applied. Because they have holes at both ends, electroplating is easy to penetrate for chemical coatings. It also allows blind holes to be designed in such a way that they can pass through multiple layers.

Tegishli biriktirish, burg’ulash va qoplama ketma -ketligini birlashtirish qobiliyati bir nechta ko’r teshikli tuzilmalarni yaratishga imkon beradi. Bularning barchasi ko’r teshik tashqi qatlamdan hatto qatlamlar orqali o’tishi mumkinligiga bog’liq.

Simultaneous deep drilling or reverse drilling is the process of removing any unused copper drum residue from the through hole. Bu odatda PCB qatlamlari orasidagi mis quvurlar orqali o’tayotganda yuqori tezlikdagi signallar buzilganda sodir bo’ladi. Agar signal qatlamidan foydalanish uzoq transversatsiyaga olib kelsa, buzilishlar ko’p bo’ladi.

PCB tomonlarining nisbati plastinka qalinligining quduq diametriga nisbati sifatida aniqlanadi. Yopiq teshiklar uchun 1 dan 1 gacha yoki undan yuqori nisbatlar talab qilinadi.

Chuqur burg’ulash olib borilganda, teshikning chuqurligi taxtaning yon tomonidan boshlanadigan va tugaydigan qatlamlarni belgilaydigan juft teshiklarni o’rnatish orqali aniqlanadi. Chuqur burg’ulash uchun diametri quyidagi formula bo’yicha hisoblanadi:

Orqa burg’ulash o’lchami = Teshik/yostiq teshigi o’lchami + 2 x Dizayn qoidalari Orqa burg’ulash o’lchami juda katta

PCB overinductance calculator

Teshikli teshikli indüktans bir nechta omillarga bog’liq, ular teshik o’lchamiga, halqaning o’lchamiga, nisbati va burg’ulash aniqligiga bog’liq. Siz kerakli o’lchamdagi PCBni to’g’ri hisoblashingizga yordam beradigan onlayn kalkulyatorlarni topishingiz mumkin.