A thaobh teicneòlas an latha an-diugh, tha an saoghal a ’fàs aig ìre gu math luath, agus faodaidh a buaidh a thighinn gu bith nar beatha làitheil. The way we live has changed dramatically and this technological advance has led to many advanced devices that we didn’t even think of 10 years ago. Is e cridhe nan innealan sin innleadaireachd dealain, agus is e an cridhe bòrd cuairteachaidh clò-bhuailte (PCB).

Mar as trice tha PCB uaine agus tha e na bhuidheann cruaidh le diofar phàirtean dealanach air. These components are welded to the PCB in a process called “PCB assembly” or PCBA. Tha am PCB air a dhèanamh suas de substrate air a dhèanamh le fiberglass, sreathan copair a tha a ’dèanamh suas an lorg, tuill a tha a’ dèanamh suas a ’phàirt, agus sreathan a dh’ fhaodas a bhith a-staigh agus a-muigh. Aig RayPCB, is urrainn dhuinn suas ri 1-36 sreathan a thoirt seachad airson PROTOTYPES ioma-fhilleadh agus sreathan 1-10 airson grunn bhagaichean de PCB airson cinneasachadh tomhas-lìonaidh. For single-sided and double-sided PCBS, an outer layer exists but no inner layer.

The substrate and components are insulated with solder film and held together with epoxy resin.The welding mask can be green, blue or red, as is common in PCB colors. Leigidh am masg tàthaidh leis a ’phàirt a bhith a’ seachnadh geàrr-chuairteachadh chun t-slighe no co-phàirtean eile.

Thathas a ’cleachdadh lorgan copair gus comharran dealanach a ghluasad bho aon phuing gu àite eile air PCB. These signals can be high-speed digital signals or discrete analog signals. Faodar na uèirichean sin a dhèanamh tiugh gus cumhachd / cumhachd a thoirt seachad airson solar cumhachd co-phàirteach.

Anns a ’mhòr-chuid de PCBS a bheir seachad bholtadh àrd no sruth, tha plèana talmhainn air leth ann. Components on the top layer are connected to the internal GND plane or internal signal layer via “Vias”.

Tha co-phàirtean air an cruinneachadh air a ’PCB gus leigeil leis a’ PCB obrachadh mar a chaidh a dhealbhadh. The most important thing is PCB function. Fiù mura h-eil na resistors SMT beag bìodach air an cur gu ceart, no eadhon ged a thèid slighean beaga a ghearradh bhon PCB, is dòcha nach obraich am PCB. Mar sin, tha e cudromach co-phàirtean a chruinneachadh ann an dòigh cheart. Canar PCBA no PCB cruinneachaidh ris a ’PCB nuair a bhios iad a’ cruinneachadh phàirtean.

A rèir nan sònrachaidhean a mhìnich an neach-ceannach no an neach-cleachdaidh, faodaidh gnìomh a ’PCB a bhith iom-fhillte no sìmplidh. PCB size also varies according to requirements.

The PCB assembly process has both automatic and manual processes, which we will discuss.

Còmhdach agus dealbhadh PCB

Mar a chaidh a ràdh gu h-àrd, tha grunn shreathan chomharran eadar na sreathan a-muigh. Now we will discuss the types of outer layers and functions.

Understand PCB board assembly process and feel the green charm of PCBD

1 – Stuth: Is e seo truinnsear teann air a dhèanamh de stuth FR-4 air a bheil na pàirtean “air an lìonadh” no air an tàthadh. Tha seo a ’toirt cruas don PCB.

2- Copper layer: Thin copper foil is applied to the top and bottom of the PCB to make the top and bottom copper trace.

Masg tàthaidh 3-: Tha e air a chur an sàs ann an sreathan àrda is ìosal a ’PCB. This is used to create non-conducting areas of the PCB and insulate the copper traces from each other to protect against short circuits. Bidh am masg tàthaidh cuideachd a ’seachnadh tàthadh pàirtean nach eileas ag iarraidh agus a’ dèanamh cinnteach gu bheil solder a ’tighinn a-steach don àite airson tàthadh, leithid tuill agus padaichean. These holes connect the THT component to the PCB while the PAD is used to hold the SMT component.

4- Screen: The white labels we see on PCBS for component codes, such as R1, C1 or some description on PCBS or company logos, are all made of screen layers. Tha an còmhdach sgrion a ’toirt seachad fiosrachadh cudromach mun PCB.

There are 3 types of PCBS according to the substrate classification

1- Rigid PCB:

Is e PCBan a ’mhòr-chuid de na h-innealan PCB a chì sinn ann an diofar sheòrsaichean PCB. Tha iad sin PCBS cruaidh, cruaidh agus làidir, le diofar thiugh. The main material is fiberglass or simple “FR4”. Tha FR4 a ’seasamh airson“ lasair retarder-4 ”. Tha feartan fèin-ghluasadach an FR-4 ga dhèanamh feumail airson a bhith a ’cleachdadh mòran de dh’ innealan dealanach gnìomhachais cruaidh. The FR-4 has thin layers of copper foil on both sides, also known as copper-clad laminates. Tha laminates còmhdaichte copar Fr-4 air an cleachdadh sa mhòr-chuid ann an innealan leudachaidh cumhachd, solar cumhachd modh atharrachaidh, draibhearan motair servo, msaa. Air an làimh eile, is e PCB phenolic pàipeir a chanar ri substrate teann PCB eile a chleachdar gu cumanta ann an innealan taighe agus toraidhean IT. Tha iad aotrom, dùmhlachd ìosal, saor agus furasta am punch. Is e àireamhairean, meur-chlàran agus luchagan cuid de na tagraidhean aige.

2- Flexible PCB:

Made from substrate materials such as Kapton, flexible PCBS can withstand very high temperatures while being as thick as 0.005 inches. It can be easily bent and used in connectors for wearable electronics, LCD monitors or laptops, keyboards and cameras, etc.

3-metal core PCB:

In addition, another PCB substrate can be used like aluminum, which is very efficient for cooling.Faodar na seòrsaichean PCBS seo a chleachdadh airson tagraidhean a dh ’fheumas co-phàirtean teirmeach leithid leds àrd-chumhachd, diodes laser, msaa.

Installation technology type:

SMT: Tha SMT a ’seasamh airson“ teicneòlas uachdar uachdar ”. Tha co-phàirtean SMT glè bheag ann am meud agus thig iad ann an grunn phasgan mar 0402,0603 1608 airson luchd-dùbhlain agus innealan-toraidh. San aon dòigh, airson ics cuairt aonaichte, tha SOIC, TSSOP, QFP agus BGA againn.

Tha seanadh SMT gu math duilich airson làmhan dhaoine agus faodaidh e a bhith na phròiseas giollachd ùine, agus mar sin tha e air a dhèanamh sa mhòr-chuid le innealan-togail fèin-ghluasadach agus innealan-fuadain àite.

THT: Tha THT a ’seasamh airson teicneòlas tro tholl. Components with leads and wires, such as resistors, capacitors, inductors, PDIP ics, transformers, transistors, IGBT, MOSFET, etc.

The components must be inserted on one side of the PCB on one component and pulled by the leg on the other side, cut the leg and welded. THT assembly is usually done by hand welding and is relatively easy.

Ro-ghoireasan pròiseas cruinneachaidh:

Prior to the actual PCB fabrication and PCB assembly process, the manufacturer checks the PCB for any defects or errors in the PCB that could cause the failure. This process is called the Manufacturing design (DFM) process. Feumaidh luchd-saothrachaidh na ceumannan DFM bunaiteach sin a choileanadh gus dèanamh cinnteach gu bheil PCB gun locht.

1- Component layout considerations: Through-holes must be checked for components with polarity. Like electrolytic capacitors must be checked polarity, diode anode and cathode polarity check, SMT tantalum capacitor polarity check. Feumar sgrùdadh a dhèanamh air stiùir IC notch / head.

Bu chòir àite gu leòr a bhith aig an eileamaid a dh ’fheumas an sinc teas gus eileamaidean eile a ghabhail a-steach gus nach bi an sinc teas a’ suathadh.

2-Hole and through-hole spacing:

The spacing between holes and between holes and traces should be checked. Cha ghabh pad agus tro tholl thairis.

3- Brazing pad, thickness, line width shall be taken into account.

By performing DFM inspections, manufacturers can easily reduce manufacturing costs by reducing the number of scrap panels. This will help in fast steering by avoiding DFM level failures. At RayPCB, we provide DFM and DFT inspection in circuit assembly and prototyping. Aig RayPCB, bidh sinn a ’cleachdadh uidheamachd OEM ùr-nodha gus seirbheisean OEM PCB, solder tonn, deuchainn cairt PCB agus seanadh SMT a thoirt seachad.

Pròiseas ceum air cheum Seanadh PCB (PCBA):

Ceum 1: Cuir a-steach paste solder a ’cleachdadh teamplaid

First, we apply solder paste to the area of the PCB that fits the component. This is done by applying solder paste to the stainless steel template. Tha an teamplaid agus PCB air an cumail còmhla le tàmh-àirneis meacanaigeach, agus tha am pas solder air a chuir an sàs gu cothromach anns a h-uile fosgladh sa bhòrd tro inneal-tagraidh. Apply solder paste evenly with applicator. Mar sin, feumar paste solder iomchaidh a chleachdadh anns an applicator. Nuair a thèid an tagraiche a thoirt air falbh, fuirichidh am pas anns an raon a tha thu ag iarraidh den PCB. Pasgan solder liath 96.5% air a dhèanamh le staoin, anns a bheil 3% airgead agus 0.5% copar, saor bho luaidhe. After heating in Step 3, the solder paste will melt and form a strong bond.

Step 2: Automatic placement of components:

Is e an dàrna ceum de PCBA na pàirtean SMT a chuir gu fèin-ghluasadach air a ’PCB. Tha seo air a dhèanamh le bhith a ’cleachdadh inneal-fuadain tagh is àite. Aig ìre dealbhaidh, bidh an dealbhaiche a ’cruthachadh faidhle agus ga thoirt don inneal-fuadain fèin-ghluasadach. Anns an fhaidhle seo tha na co-chomharran X, Y ro-phrògramaichte de gach co-phàirt a tha air a chleachdadh sa PCB agus a ’comharrachadh far a bheil na pàirtean uile. Using this information, the robot only needs to place the SMD device accurately on the board. The pick and place robot will pick up components from its vacuum fixture and place them accurately on the solder paste.

Mus do nochd innealan togail is suidheachadh robotach, bhiodh luchd-teicneòlais a ’togail phàirtean le bhith a’ cleachdadh tweezers agus gan cur air a ’PCB le bhith a’ coimhead gu faiceallach air an àite agus a ’seachnadh crathadh sam bith. This results in high levels of fatigue and poor vision for technicians, and leads to a slow PCB assembly process for SMT parts. Mar sin tha an comas mearachd àrd.

Mar a bhios an teicneòlas a ’tighinn gu ìre, bidh innealan-fuadain fèin-ghluasadach a bhios a’ togail agus a ’suidheachadh phàirtean a’ lughdachadh eallach obrach luchd-teicneòlais, a ’comasachadh suidheachadh phàirtean luath agus ceart. Faodaidh na h-innealan-fuadain sin obrachadh 24/7 gun sgìth.

Ceum 3: tàthadh reflow

The third step after setting up the elements and applying the solder paste is reflux welding. Reflow welding is the process of placing the PCB on a conveyor belt with components. The conveyor then moves the PCB and components into a large oven, which produces a temperature of 250 o C. Tha an teòthachd gu leòr airson an solder a leaghadh. Bidh an solder leaghte an uairsin a ’cumail a’ phàirt chun PCB agus a ’cruthachadh a’ cho-phàirt. After high temperature treatment, the PCB enters the cooler. These coolers then solidify the solder joints in a controlled manner. Stèidhichidh seo ceangal maireannach eadar a ’phàirt SMT agus am PCB. A thaobh PCB le dà thaobh, mar a chaidh a mhìneachadh gu h-àrd, thèid an taobh PCB le nas lugha no nas lugha de phàirtean a làimhseachadh an toiseach bho cheumannan 1 gu 3, agus an uairsin chun taobh eile.

Understand PCB board assembly process and feel the green charm of PCBD

Ceum 4: Sgrùdadh agus sgrùdadh càileachd

Às deidh solder reflow, tha e comasach gu bheil co-phàirtean air am mì-dhealbhadh mar thoradh air cuid de ghluasad ceàrr anns an treidhe PCB, a dh ’fhaodadh leantainn gu ceanglaichean cuairte ghoirid no fosgailte. These defects need to be identified, and this identification process is called inspection. Faodaidh sgrùdaidhean a bhith làimhe agus fèin-ghluasadach.

A. Manual check:

Because the PCB has small SMT components, visual inspection of the board for any misalignment or malfunction can cause technician fatigue and eye strain. Mar sin, chan eil an dòigh seo ion-dhèanta airson bùird SMT ro-làimh mar thoradh air toraidhean mearachdach. Ach, tha an dòigh seo ion-dhèanta airson plaidean le co-phàirtean THT agus dùmhlachd co-phàirtean nas ìsle.

B. Lorgaireachd optigeach:

Tha an dòigh seo comasach airson meudan mòra de PCBS. Bidh an dòigh a ’cleachdadh innealan fèin-ghluasadach le camarathan àrd-chumhachd agus àrd-rùn air an cur suas aig diofar cheàrnan gus na ceanglaichean solder fhaicinn bho gach taobh. A rèir càileachd a ’cho-phàirt solder, bidh an solas a’ nochdadh far a ’cho-phàirt solder aig ceàrnan eadar-dhealaichte. This automatic optical inspection (AOI) machine is very fast and can process large quantities of PCBS in a very short time.

CX – ray inspection:

The X-ray machine allows technicians to scan the PCB to see internal defects. This is not a common inspection method and is only used for complex and advanced PCBS. If not used properly, these inspection methods may result in rework or PCB obsoletion. Feumar sgrùdaidhean a dhèanamh gu cunbhalach gus dàil, cosgaisean saothair agus stuthan a sheachnadh.

Ceum 5: Ceartachadh agus tàthadh phàirtean THT

Tha co-phàirtean tro tholl cumanta air mòran de bhùird PCB. These components are also called plated through holes (PTH). Thèid stiùirichean nan co-phàirtean sin tro thuill anns a ’PCB. Tha na tuill sin ceangailte ri tuill eile agus tro thuill le comharran copair. Nuair a thèid na h-eileamaidean THT sin a chuir a-steach agus an tàthadh a-steach do na tuill sin, tha iad ceangailte gu dealanach ri tuill eile air an aon PCB ris a ’chuairt dhealbhaichte. These PCBS may contain some THT components and many SMD components, so the welding method described above is not suitable for THT components in the case of SMT components such as reflow welding. So the two main types of THT components that are welded or assembled are

A. Manual welding:

Manual welding methods are common and often require more time than an automated setup for SMT. Mar as trice bidh teicneòlaiche air a shònrachadh gus aon phàirt a chuir a-steach aig an aon àm agus am bòrd a thoirt do luchd-teicneòlais eile a ’cuir a-steach co-phàirt eile air an aon bhòrd. Mar sin, thèid am bòrd cuairteachaidh a ghluasad timcheall an loidhne cruinneachaidh gus am faigh thu am pàirt PTH airson a lìonadh. Tha seo a ’dèanamh a’ phròiseas fada, agus bidh mòran de chompanaidhean dealbhaidh is saothrachaidh PCB a ’seachnadh a bhith a’ cleachdadh co-phàirtean PTH anns na dealbhaidhean cuairteachaidh aca. Ach is e am pàirt PTH am pàirt as fheàrr leotha agus as cumanta leis a ’mhòr-chuid de dhealbhadairean cuairteachaidh.

B. Solarachadh tonn:

Is e an tionndadh fèin-ghluasadach de tàthadh làimhe tàthadh tonn. San dòigh seo, aon uair ‘s gu bheil an eileamaid PTH air a chuir air a’ PCB, tha am PCB air a chuir air crios giùlain agus air a ghluasad gu àmhainn sònraichte. An seo, bidh tonnan de solder leaghte a ’frasadh a-steach do substrate a’ PCB far a bheil na luaidhe phàirtean an làthair. Bidh seo a ’tàthadh a h-uile prìne sa bhad. However, this method only works with single-sided PCBS and not double-sided PCBS, as melted solder on one side of the PCB can damage components on the other. Às deidh seo, gluais am PCB airson sgrùdadh deireannach.

Ceum 6: Sgrùdadh deireannach agus deuchainn gnìomh

Tha PCB a-nis deiseil airson deuchainn agus sgrùdadh. This is a functional test in which electrical signals and power are given to the PCB at the specified pins and the output is checked at the specified test point or output connector. This test requires common laboratory instruments such as oscilloscopes, digital multimeters, and function generators

Tha an deuchainn seo air a chleachdadh gus sgrùdadh a dhèanamh air feartan gnìomh agus dealain a ’PCB agus gus dearbhadh a dhèanamh air na dealbhaidhean cuairteachaidh, cuairteachaidh, analog agus didseatach agus comharra a tha air am mìneachadh ann an riatanasan PCB

Ma sheallas gin de pharamadairean an PCB toraidhean neo-iomchaidh, thèid am PCB a chuir air falbh no a dhubhadh às a rèir modhan àbhaisteach na companaidh. Tha an ìre dearbhaidh cudromach oir tha e a ’dearbhadh soirbheachas no fàilligeadh a’ phròiseas PCBA gu lèir.

Ceum 7: Glanadh deireannach, crìochnachadh agus lìbhrigeadh:

Now that the PCB has been tested in all aspects and declared normal, it is time to clean up unwanted residual flux, finger grime and oil. Tha innealan glanaidh bruthadh àrd stèidhichte air stàilinn a ’cleachdadh uisge deionized gu leòr gus gach seòrsa salachar a ghlanadh. Cha bhith uisge deionized a ’dèanamh cron air cuairt PCB. An dèidh a nighe, tiormaich am PCB le èadhar teann. Tha am PCB mu dheireadh a-nis deiseil airson a phacaigeadh agus a chuir air falbh.