Cad is PCB trípholl ann agus cén fáth go bhfuil sé tábhachtach phriontáilte chuaird? Éilíonn PCB trípholl nó tollphoill chun a shraitheanna a nascadh. Understanding the standard through-hole sizes used by PCB manufacturers can help you design boards to meet common bit sizes.

Caighdeán trí mhéid na bpoll

Tá a sraith féin de mhéideanna caighdeánacha poill ag déantúsóirí PCB le roghnú agus iad ag druileáil poill, ach de ghnáth is féidir leo aon mhéid poll caighdeánach a úsáid. Go ginearálta, is féidir le déantúsóirí PCB trastomhas PCB a dhéanamh trí phoill chomh beag le 0.15 mm, i gcomparáid leis an ngnáthmhéid 0.6 mm.

Ceanglais maidir le méid trí pholl PCB

Is staidéar domhain é seo ar na riachtanais méide.

PCB trí mhéid na bpoll

Is féidir le méid PCB trí pholl a bheith éagsúil ag brath ar a shuíomh, a úsáid, agus fachtóirí eile, agus is é sin an fáth go dtugann gach monaróir PCB roinnt méideanna giotán PCB. Most manufacturers can make holes as small as 0.15 mm or larger holes of 1 mm or larger. Agus méid an phoill atá ag teastáil á mheas agat, ní mór duit an fáinne nó an ceap copair timpeall an phoill a mheas, a chruthóidh.

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.

Caighdeán trí mhéid na bpoll

Ní gá go mbeadh aon mhéid caighdeánach trí-pholl PCB i ndéantúsaíocht PCB, mar is minic a athraíonn méid caighdeánach trí-pholl PCB ó mhonaróir go monaróir PCB. Mar sin féin, is fearr le go leor déantúsóirí PCB méideanna giotán coitianta a úsáid, ar féidir tagairt a dhéanamh dóibh mar mhéideanna giotán PCB caighdeánach. Is é 0.6 mm ceann de na méideanna is coitianta, ach úsáidtear 0.2 mm agus 0.3 mm go coitianta freisin.

Type of PCB through hole

Is féidir leat gach méid caighdeánach trípholl a úsáid chun cineálacha éagsúla trí-phoill PCB a chruthú, ag brath ar chiseal, tógáil, dearadh agus cuspóir an PCB. Is iad na trí chineál trí-pholl PCB is coitianta:

Plátáilte tríd an bpoll

Is trí-phoill iad trí-phoill leictreaphlátáilte (PTH) a ritheann trí gach sraith de PCB chun na sraitheanna barr agus bun a nascadh. Ba cheart go mbeifeá in ann PTH a fheiceáil ó cheann ceann an PCB go dtí an ceann eile. Féadfaidh PTH a bheith plátáilte nó neamhphlátáilte. Ní sheolann poill neamhphlátáilte trí phoill leictreachas, ach leictreaphlátáiltear trí phoill, rud a chiallaíonn go seolann siad leictreachas i ngach sraith den PCB.

Poll 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.

leabaithe

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. Ní fheiceann tú an t-ábhar adhlactha ar chiseal seachtrach an PCB.

Rudaí le machnamh

Tá cúpla rud le breithniú agus PCB á chruthú. Ar dtús, ba chóir go mbeadh a fhios agat cén cóimheas gné atá i ndearadh 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.

D’fhéadfadh poill leabaithe nó dall freastal ar do PCB níos fearr le cóimheas gné de 15: 1, agus is féidir le PTH oibriú go maith le cóimheas gné íseal de 2: 1. Conas a roghnaíonn tú tiús copair PCB? Usually, through holes in the outer layer (e.g., through holes) require a thicker layer of copper than the buried through holes inside. Bíonn tionchar ag an voltas a úsáideann an PCB ar thiús an chopair freisin. 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:

Tríd an puball

Cruthaíonn an puball trí pholl ciseal bacainn solder thar trípholl an PCB seachas an poll a líonadh le hábhar. 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.

Trí bhlocáil

Líonann an próiseas plugála trí pholl an poll le hábhar neamh-seoltaí agus séalaítear é le masc. Through-hole clogging also covers the ring and does not produce a smooth, glossy surface.

Trí líonadh

Úsáideann líonadh trí pholl roisín chun poll atá líonta go buan a chruthú. 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 trí iarratais plating poll

Féadfaidh monaróirí roinnt teicnící éagsúla a úsáid chun an PCB a chur i bhfeidhm trí phlátáil trí pholl chun a éifeachtúlacht a chinntiú. 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.

Modh eile is ea leictreaphlátáil, ina dtéann an PCB isteach i ndabhach leictreaphlátála. Sa phróiseas seo, clúdaíonn copar ballaí gach PCB trí phoill, agus mar thoradh air sin tá tiús cothrom an ábhair seoltaí ann. This method tends to be more lengthy and expensive than the inking process, but it can also form a more reliable coating and bond.

Sequential drilling blind drilling and deep drilling

Is féidir PCBS le poill dall a mhonarú ar dhá bhealach. 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.

Mar gheall ar an gcumas seichimh nascáil, druileála agus plating iomchuí a chur le chéile is féidir struchtúir iolracha poll dall a chruthú. Braitheann sé go léir ar cibé an féidir leis an bpoll dall pas a fháil trí shraitheanna cothroma ón gciseal seachtrach.

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.

PCB aspect ratio is defined as the ratio of the plate thickness to the diameter of the borehole. Blind holes require aspect ratios of 1 to 1 or greater.

When deep drilling is carried out, the depth of the hole is defined by setting up a pair of holes that specify the starting and ending layers from the side of the board. Ríomhtar an trastomhas giotán le haghaidh druileála domhain de réir na foirmle seo a leanas:

Méid druileála cúil = Méid poll poll / ceap + 2 x Rialacha dearaidh Tá méid druileála cúil ró-mhór

PCB overinductance calculator

Braitheann ionduchtú trí-pholl PCB ar roinnt fachtóirí, lena n-áirítear méid trí-pholl, méid fáinne, cóimheas gné, agus cruinneas druileála. Is féidir leat áireamháin ar líne a fháil chun cabhrú leat an PCB ceart a ríomh de réir an mhéid a chaithfidh tú a úsáid.