Kini PCB nipasẹ iho ati idi ti o ṣe pataki lori tejede Circuit ọkọ? PCB kan nilo awọn iho nipasẹ tabi awọn iho lati so awọn fẹlẹfẹlẹ rẹ pọ. Understanding the standard through-hole sizes used by PCB manufacturers can help you design boards to meet common bit sizes.

Standard nipasẹ iho iwọn

Awọn aṣelọpọ PCB ni eto tiwọn ti awọn iwọn iho boṣewa lati yan lati nigbati awọn iho liluho, ṣugbọn wọn le maa lo iwọn iho boṣewa eyikeyi. Ni gbogbogbo, awọn olupese PCB le ṣe iwọn ila opin ti PCB nipasẹ awọn iho kekere bi 0.15 mm, ni akawe si iwọn deede ti 0.6 mm.

PCB nipasẹ-iho awọn ibeere iwọn

Eyi jẹ iwadii inu-jinlẹ ti awọn ibeere iwọn.

PCB nipasẹ iwọn iho

Iwọn PCB nipasẹ iho le yatọ da lori ipo rẹ, lilo, ati awọn ifosiwewe miiran, eyiti o jẹ idi ti gbogbo olupese PCB nfunni ni ọpọlọpọ awọn iwọn bit PCB. Most manufacturers can make holes as small as 0.15 mm or larger holes of 1 mm or larger. Nigbati o ba gbero iwọn iho ti o nilo, o tun nilo lati gbero oruka tabi paadi idẹ ni ayika iho, eyiti yoo dagba.

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.

Standard nipasẹ iho iwọn

Nibẹ ni ko dandan eyikeyi boṣewa PCB nipasẹ-iho iwọn ni PCB ẹrọ, bi awọn boṣewa PCB nipasẹ-iho iwọn igba yatọ lati olupese to PCB olupese. Sibẹsibẹ, ọpọlọpọ awọn olupese PCB fẹ lati lo awọn iwọn bit ti o wọpọ, eyiti wọn le tọka si bi awọn iwọn bit PCB boṣewa. Ọkan ninu awọn titobi ti o wọpọ julọ jẹ 0.6 mm, ṣugbọn 0.2 mm ati 0.3 mm ni a tun lo nigbagbogbo.

Type of PCB through hole

O le lo boṣewa kọọkan nipasẹ iwọn iho lati ṣẹda ọpọlọpọ awọn oriṣi ti PCB nipasẹ awọn iho, da lori fẹlẹfẹlẹ, ikole, apẹrẹ, ati idi ti PCB. Awọn oriṣi PCB mẹta ti o wọpọ julọ nipasẹ awọn iho ni:

Plated nipasẹ iho

Awọn iho nipasẹ itanna (PTH) jẹ awọn iho-nipasẹ ti o ṣiṣẹ nipasẹ gbogbo awọn fẹlẹfẹlẹ ti PCB lati sopọ awọn fẹlẹfẹlẹ oke ati isalẹ. O yẹ ki o ni anfani lati wo PTH lati opin kan ti PCB si ekeji. PTH le wa ni abọ tabi ti kii ṣe. Ti kii ṣe palara nipasẹ awọn iho ko ṣe ina mọnamọna, lakoko ti a ti bo nipasẹ awọn iho jẹ itanna, eyiti o tumọ si pe wọn ṣe ina ni gbogbo awọn fẹlẹfẹlẹ ti PCB.

Iho afọju

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.

ifibọ

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. O ko le rii awọn ohun elo ti o sin lori fẹlẹfẹlẹ ti PCB.

Awọn nkan lati ronu

Awọn nkan diẹ lo wa lati ronu nigbati ṣiṣẹda PCB kan. Ni akọkọ, o yẹ ki o mọ kini ipin abala wa ninu apẹrẹ 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.

Awọn iho ifibọ tabi awọn afọju le ṣe iranṣẹ PCB rẹ dara julọ pẹlu ipin ti 15: 1, lakoko ti PTH le ṣiṣẹ daradara pẹlu ipin ipin kekere ti 2: 1. Bawo ni o ṣe yan sisanra ti Ejò PCB? Usually, through holes in the outer layer (e.g., through holes) require a thicker layer of copper than the buried through holes inside. Foliteji ti PCB tun lo tun ni ipa lori sisanra ti idẹ. 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:

Nipasẹ agọ

Agọ nipasẹ-iho ṣẹda Layer idankan idena lori PCB nipasẹ-iho dipo ki o kun iho pẹlu ohun elo. 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.

Nipa ìdènà

Ilana ifilọlẹ nipasẹ iho kun iho pẹlu awọn ohun elo ti ko ni idari ati fi edidi di pẹlu iboju-boju. Through-hole clogging also covers the ring and does not produce a smooth, glossy surface.

Nipa kikun

Nkun nipasẹ iho nlo resini lati ṣẹda iho ti o kun patapata. 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 nipasẹ awọn ohun elo plating iho

Awọn aṣelọpọ le lo ọpọlọpọ awọn imuposi oriṣiriṣi lati lo PCB nipasẹ ṣiṣan iho lati rii daju ipa rẹ. 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.

Ọna miiran jẹ electroplating, ninu eyiti PCB lọ sinu iwẹ electroplating. Ninu ilana yii, bàbà bo awọn odi ti PCB kọọkan nipasẹ awọn ihò, ti o yọrisi paapaa sisanra ti ohun elo idari. Ọna yii duro lati jẹ gigun diẹ ati gbowolori ju ilana inki lọ, ṣugbọn o tun le ṣe agbero igbẹkẹle ti o gbẹkẹle diẹ sii.

Sequential drilling blind drilling and deep drilling

PCBS pẹlu awọn iho afọju le ti ṣelọpọ ni awọn ọna meji. 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.

Agbara lati ṣajọpọ isọdọmọ ti o yẹ, liluho ati awọn tito lẹẹ jẹ ki o ṣee ṣe lati ṣẹda awọn ẹya iho afọju lọpọlọpọ. Gbogbo rẹ da lori boya iho afọju le kọja nipasẹ awọn fẹlẹfẹlẹ paapaa lati ori ita.

Simultaneous deep drilling or reverse drilling is the process of removing any unused copper drum residue from the through hole. Eyi maa n ṣẹlẹ nigbati awọn ifihan agbara iyara ba daru bi wọn ti n kọja nipasẹ awọn ọpọn idẹ laarin awọn fẹlẹfẹlẹ PCB. Ti o ba ti lilo awọn ifihan agbara ifihan esi ni gun transversals, nibẹ ni yio je pupo ti iparun.

Ipele abala PCB jẹ asọye bi ipin ti sisanra awo si iwọn ila opin ti iho. Awọn iho afọju nilo awọn ipin abala ti 1 si 1 tabi tobi julọ.

Nigbati a ba ṣe liluho jinlẹ, ijinle iho naa ni asọye nipa ṣiṣeto awọn iho meji ti o ṣalaye ibẹrẹ ati ipari awọn fẹlẹfẹlẹ lati ẹgbẹ ti igbimọ. Iwọn iwọn kekere fun liluho jinle jẹ iṣiro nipasẹ agbekalẹ atẹle yii:

Iwọn liluho ẹhin = Iwọn iho/paadi iwọn + 2 x Awọn ofin apẹrẹ Apẹrẹ liluho ti tobi pupọ

PCB overinductance calculator

PCB nipasẹ-iho inductance da lori ọpọlọpọ awọn ifosiwewe, pẹlu iwọn-nipasẹ iho, iwọn oruka, ipin abala, ati deede liluho. O le wa awọn iṣiro ori ayelujara lati ṣe iranlọwọ fun ọ lati ṣe iṣiro PCB ti o tọ ni ibamu si iwọn ti o nilo lati lo.