Dè a th ’ann am PCB tro tholl agus carson a tha e cudromach bòrd cuairteachaidh clò-bhuailte? Feumaidh PCB tro thuill no tuill-chladhaich gus na sreathan aige a cheangal. Understanding the standard through-hole sizes used by PCB manufacturers can help you design boards to meet common bit sizes.

Coitcheann tro mheud toll

Tha an seata fhèin de mheudan tuill àbhaisteach aig luchd-saothrachaidh PCB airson taghadh nuair a bhios iad a ’drileadh tuill, ach mar as trice faodaidh iad meud toll àbhaisteach sam bith a chleachdadh. San fharsaingeachd, faodaidh luchd-saothrachaidh PCB trast-thomhas PCB a dhèanamh tro thuill cho beag ri 0.15 mm, an coimeas ris a ’mheud àbhaisteach de 0.6 mm.

Riatanasan meud tro-tholl PCB

Is e sgrùdadh domhainn a tha seo de na riatanasan meud.

PCB tro mheud toll

Faodaidh meud PCB tro tholl atharrachadh a rèir far a bheil e, a chleachdadh, agus factaran eile, agus is e sin as coireach gu bheil gach neach-dèanamh PCB a ’tabhann grunn mheudan bit PCB. Most manufacturers can make holes as small as 0.15 mm or larger holes of 1 mm or larger. Nuair a bhios tu a ’beachdachadh air meud an toll a tha a dhìth, feumaidh tu cuideachd beachdachadh air an fhàinne no an ceap copair timcheall air an toll, a thig gu cruth.

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.

Coitcheann tro mheud toll

Chan eil feum air meud àbhaisteach tro-tholl PCB ann an saothrachadh PCB, oir bidh meud àbhaisteach tro-tholl PCB gu tric ag atharrachadh bho neach-dèanamh gu neach-dèanamh PCB. Ach, is fheàrr le mòran de luchd-saothrachaidh PCB meudan bit cumanta a chleachdadh, ris an can iad meudan àbhaisteach PCB. Is e aon de na meudan as cumanta 0.6 mm, ach tha 0.2 mm agus 0.3 mm air an cleachdadh gu cumanta cuideachd.

Type of PCB through hole

Faodaidh tu gach meud tro-tholl àbhaisteach a chleachdadh gus diofar sheòrsaichean tro-thuill PCB a chruthachadh, a rèir còmhdach, togail, dealbhadh agus adhbhar a ’PCB. Is iad na trì seòrsaichean tro tholl PCB as cumanta:

Air a chur tron ​​toll

Is e tro-thuill a th ’ann an tro-thuill electroplated (PTH) a bhios a’ ruith tro na sreathan uile de PCB gus na sreathan mullaich is ìosal a cheangal. Bu chòir dhut a bhith comasach air PTH fhaicinn bho aon cheann den PCB chun cheann eile. Faodaidh PTH a bhith plastaichte no neo-phlàtaichte. Cha bhith tuill gun phlàtadh a ’giùlan dealan, ach tha dealan tro phlocan air an taghadh, a tha a’ ciallachadh gum bi iad a ’giùlan dealan anns a h-uile sreathan den PCB.

Toll dall

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.

freumhaichte

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. Chan fhaic thu an stuth tiodhlaichte air còmhdach a-muigh PCB.

Rudan ri bheachdachadh

Tha rud no dhà ri bheachdachadh nuair a chruthaicheas tu PCB. An toiseach, bu chòir dhut fios a bhith agad dè an co-mheas taobh a tha ann an dealbhadh 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.

Is dòcha gum bi tuill freumhaichte no dall a ’frithealadh do PCB nas fheàrr le co-mheas taobh de 15: 1, fhad‘ s as urrainn dha PTH obrachadh gu math le co-mheas sealladh ìosal de 2: 1. Ciamar a thaghas tu tiugh copar PCB? Usually, through holes in the outer layer (e.g., through holes) require a thicker layer of copper than the buried through holes inside. Bidh am bholtachd a chleachdas am PCB cuideachd a ’toirt buaidh air tiugh a’ chopair. 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:

Tron teanta

Bidh an teanta tro tholl a ’cruthachadh còmhdach bacaidh solder thairis air an toll tro PCB seach a bhith a’ lìonadh an toll le stuth. 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.

Le bhith a ’bacadh

Bidh am pròiseas plugging tro tholl a ’lìonadh an toll le stuth neo-ghiùlain agus ga seuladh le masg. Through-hole clogging also covers the ring and does not produce a smooth, glossy surface.

Le bhith a ’lìonadh

Bidh lìonadh tro tholl a ’cleachdadh roisinn gus toll làn-sheasmhach a chruthachadh. 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 tro thagraidhean plating tuill

Faodaidh luchd-saothrachaidh grunn dhòighean eadar-dhealaichte a chleachdadh gus am PCB a chuir an sàs tro plathadh tro thuill gus dèanamh cinnteach gu bheil e èifeachdach. 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.

Is e dòigh eile electroplating, anns am bi am PCB a ’dol a-steach do amar electroplating. Anns a ’phròiseas seo, bidh copar a’ còmhdach ballachan gach PCB tro thuill, a ’leantainn gu tiugh eadhon den stuth giùlain. Tha an dòigh seo buailteach a bhith nas fhaide agus nas daoire na pròiseas inking, ach faodaidh e cuideachd còmhdach agus ceangal nas earbsaiche a chruthachadh.

Sequential drilling blind drilling and deep drilling

Faodar PCBS le tuill dall a dhèanamh ann an dà dhòigh. 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.

Tha an comas sreathan ceangail, drileadh agus plating iomchaidh a thoirt còmhla ga dhèanamh comasach iomadh structar toll dall a chruthachadh. Tha e uile an urra ri an urrainn don toll dall a dhol tro eadhon sreathan bhon fhilleadh a-muigh.

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. If using a signal layer results in long transversals, there will be a lot of distortion.

Tha co-mheas taobh PCB air a mhìneachadh mar an co-mheas de thiugh a ’phlàta ri trast-thomhas an toll-cladhaich. Feumaidh tuill dall co-mheasan feart 1 gu 1 no nas motha.

Nuair a thèid drileadh domhainn a dhèanamh, tha doimhneachd an toll air a mhìneachadh le bhith a ’stèidheachadh paidhir thuill a shònraicheas na sreathan tòiseachaidh is crìochnachaidh bho thaobh a’ bhùird. Tha an trast-thomhas beagan airson drileadh domhainn air a thomhas leis an fhoirmle a leanas:

Meud drile cùil = Meud toll toll / pad + 2 x Riaghailtean dealbhaidh Tha meud drile cùil ro mhòr

PCB overinductance calculator

Tha inductance tro-tholl PCB an urra ri grunn fhactaran, a ’gabhail a-steach meud tro tholl, meud fàinne, co-mheas taobh, agus mionaideachd drileadh. Gheibh thu àireamhairean air-loidhne gus do chuideachadh le bhith ag obrachadh a-mach am PCB ceart a rèir na meud a dh ’fheumas tu a chleachdadh.