Menene PCB ta cikin rami kuma me yasa yake da mahimmanci akan buga kewaye hukumar? PCB yana buƙatar ramuka ko ramuka don haɗa matakan sa. Understanding the standard through-hole sizes used by PCB manufacturers can help you design boards to meet common bit sizes.

Daidaita ta girman rami

Masu kera PCB suna da nasu madaidaicin girman rami don zaɓar daga lokacin da ake haƙa ramuka, amma galibi suna iya amfani da kowane madaidaicin girman rami. Gabaɗaya, masana’antun PCB na iya yin diamita na PCB ta cikin ramukan ƙarami kamar 0.15 mm, idan aka kwatanta da girman 0.6 mm na al’ada.

Abubuwan buƙatun girman rami na PCB

Wannan bincike ne mai zurfi na buƙatun girman.

PCB ta girman rami

Girman PCB ta rami na iya bambanta dangane da wurin sa, amfani, da sauran abubuwan, wanda shine dalilin da yasa kowane mai ƙera PCB ke ba da ƙimar bitar PCB da yawa. Most manufacturers can make holes as small as 0.15 mm or larger holes of 1 mm or larger. Lokacin yin la’akari da girman ramin da ake buƙata, kuna kuma buƙatar la’akari da zobe ko kushin jan ƙarfe a kusa da ramin, wanda zai yi.

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.

Daidaita ta girman rami

Ba lallai ba ne kowane daidaitaccen girman PCB ta cikin rami a masana’antar PCB, kamar yadda daidaitaccen girman PCB ta hanyar rami sau da yawa ya bambanta daga mai ƙira zuwa mai ƙera PCB. Koyaya, yawancin masana’antun PCB sun gwammace yin amfani da girman bit na kowa, wanda za su iya magana da shi azaman daidaitaccen girman bitar PCB. Ofaya daga cikin mafi girman girma shine 0.6 mm, amma kuma ana amfani da 0.2 mm da 0.3 mm.

Type of PCB through hole

Kuna iya amfani da kowane madaidaicin girman rami don ƙirƙirar nau’ikan PCB ta cikin ramuka, gwargwadon matakin, gini, ƙira, da manufar PCB. Nau’ikan PCB guda uku na yau da kullun sune:

Plated ta rami

Zaɓuɓɓukan ramukan lantarki (PTH) ramuka ne waɗanda ke ratsa dukkan layukan PCB don haɗa saman da ƙasa. Ya kamata ku iya ganin PTH daga ƙarshen PCB zuwa wancan. PTH na iya zama plated ko non-plated. Wadanda ba rufi ba ta cikin ramuka ba sa gudanar da wutar lantarki, yayin da rufin ta cikin ramukan ana amfani da wutar lantarki, wanda ke nufin cewa suna gudanar da wutar lantarki a duk layukan PCB.

Makafi rami

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.

saka

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. Ba za ku iya ganin kayan da aka binne ba a saman saman PCB.

Abubuwan la’akari

Akwai ‘yan abubuwa da za a yi la’akari da su yayin ƙirƙirar PCB. Na farko, yakamata ku san menene rabe -rabe a cikin ƙirar PCB. 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.

Ramukan da aka saka ko makafi na iya yiwa PCB ɗinku mafi kyau tare da rabo na 15: 1, yayin da PTH na iya yin aiki da kyau tare da ƙarancin yanayin 2: 1. Ta yaya za ku zaɓi kaurin PCB jan ƙarfe? Usually, through holes in the outer layer (e.g., through holes) require a thicker layer of copper than the buried through holes inside. Irin ƙarfin lantarki da PCB ke amfani da shi yana shafar kaurin jan ƙarfe. 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:

Ta alfarwar

Alfarwa ta cikin rami tana haifar da wani shinge mai shinge akan PCB ta cikin rami maimakon cika ramin da kayan. 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.

Ta hanyar toshewa

Tsarin toshe-ramin yana cika ramin tare da kayan da ba su da inganci kuma yana rufe shi da abin rufe fuska. Through-hole clogging also covers the ring and does not produce a smooth, glossy surface.

Ta hanyar cikawa

Cika rami ta amfani da resin don ƙirƙirar rami mai cike da dindindin. 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.

PCB ta aikace -aikacen plating rami

Masu kera na iya amfani da dabaru daban-daban don amfani da PCB ta hanyar ramin rami don tabbatar da ingancin sa. 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.

Wata hanyar ita ce electroplating, wanda PCB ke shiga cikin wanka mai ƙona wutar lantarki. A cikin wannan tsari, jan ƙarfe yana rufe bangon kowane PCB ta cikin ramuka, yana haifar da kauri na kayan aikin. Wannan hanyar tana ɗaukar tsayi da tsada fiye da tsarin inking, amma kuma tana iya samar da ingantaccen abin rufewa da haɗin gwiwa.

Sequential drilling blind drilling and deep drilling

Ana iya kera PCBS da ramukan makafi ta hanyoyi biyu. 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.

Ikon haɗa haɗin da ya dace, hakowa da jerawa jere yana ba da damar ƙirƙirar tsarin ramin makafi da yawa. Duk ya dogara ne akan ko ramin makaho na iya wucewa har ma da yadudduka daga saman waje.

Simultaneous deep drilling or reverse drilling is the process of removing any unused copper drum residue from the through hole. This usually happens when high-speed signals are distorted as they pass through copper tubes between PCB layers. Idan yin amfani da layin siginar yana haifar da tsallake -tsallake, za a sami murdiya da yawa.

An bayyana rabe -raben PCB a matsayin rabo na kaurin farantin zuwa diamita na rijiyar burtsatse. Makafi ramukan suna buƙatar rabo na 1 zuwa 1 ko mafi girma.

Lokacin da ake yin hakowa mai zurfi, ana bayyana zurfin ramin ta hanyar kafa ramukan guda biyu waɗanda ke tantance farawa da ƙarewa daga gefen jirgin. An kirga diamita na bit don hakowa mai zurfi ta hanyar dabara mai zuwa:

Girman rami na baya = Girman rami/kushin rami + 2 x Dokokin ƙirar Girman rawar rawar baya yayi yawa

PCB overinductance calculator

Haɗin PCB ta cikin rami ya dogara da dalilai da yawa, gami da girman rami, girman zobe, rabe-raben yanayi, da daidaiton hakowa. Kuna iya nemo masu lissafin kan layi don taimaka muku lissafin PCB daidai gwargwadon girman da kuke buƙatar amfani da shi.