Ngokobuchwephesha bale mihla, ilizwe likhula ngesantya esikhawulezayo, kwaye ifuthe lalo linokubakho ngokulula kubomi bethu bemihla ngemihla. 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. Undoqo wezi zixhobo bubunjineli bombane, kwaye undoqo ngu ibhodi yesekethe eprintiweyo (IPCB).

I-PCB ihlala iluhlaza kwaye ngumzimba oqinileyo onamacandelo e-elektroniki ahlukeneyo kuyo. These components are welded to the PCB in a process called “PCB assembly” or PCBA. I-PCB ine-substrate eyenziwe nge-fiberglass, izingqimba zobhedu ezenza umkhondo, imingxunya eyenza icandelo, kunye namaleya anokuba ngaphakathi nangaphandle. E-RayPCB, sinokubonelela ukuya kuthi ga kwi-1-36 yamanqanaba ee-PROTOTYPES ezininzi kunye ne-1-10 yeebhetshi zebatch ezininzi zePCB kwimveliso yevolumu. 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. Isigqumathelo se-welding siya kuvumela icandelo ukuba liphephe ukujikeleza okufutshane kumkhondo okanye ezinye izinto.

Ukulandela umkhondo wobhedu kusetyenziswa ukuhambisa imiqondiso ye-elektroniki ukusuka kwindawo enye ukuya kwenye kwi-PCB. These signals can be high-speed digital signals or discrete analog signals. Ezi ngcingo zinokwenziwa zangqindilili ukuze zikwazi ukubonelela ngombane / umbane kumbane wombane.

In most PCBS that provide high voltage or current, there is a separate grounding plane. Components on the top layer are connected to the internal GND plane or internal signal layer via “Vias”.

Izinto ezihlanganisiweyo kwi-PCB ukwenza ukuba i-PCB isebenze ngendlela eyilwe ngayo. The most important thing is PCB function. Nokuba amachiza amancinci e-SMT akabekwanga ngokuchanekileyo, okanye nokuba iingoma ezincinci zinqunyiwe kwi-PCB, i-PCB isenokungasebenzi. Therefore, it is important to assemble components in a proper way. I-PCB xa kuhlanganiswa izinto kuthiwa yi-PCBA okanye i-PCB yendibano.

Kuxhomekeke kwinkcazo echazwe ngumthengi okanye ngumsebenzisi, umsebenzi wePCB unokuba nzima okanye ulula. PCB size also varies according to requirements.

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

Maleko PCB kunye noyilo

Njengoko sele kukhankanyiwe apha ngasentla, kukho imiqolo emininzi phakathi komaleko ongaphandle. Now we will discuss the types of outer layers and functions.

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

I-1 – Substrate: Le yipleyiti eqinileyo eyenziwe ngezinto ze-FR-4 apho izinto “zigcwalisiwe” okanye zenziwe nge welding. Oku kubonelela ukuqina kwePCB.

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

Imaski ye-3- ye-Welding: Isetyenziswa kwimaleko ephezulu nasezantsi yePCB. This is used to create non-conducting areas of the PCB and insulate the copper traces from each other to protect against short circuits. Isigqumathelo se-welding sikwaphepha ukuwelda iindawo ezingafunekiyo kwaye iqinisekisa ukuba i-solder ingena kwindawo ye-welding, efana nemingxunya kunye neepads. 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. Uluhlu lwesikrini lubonelela ngolwazi olubalulekileyo malunga ne-PCB.

There are 3 types of PCBS according to the substrate classification

1- Rigid PCB:

Ii-PCB zizona zixhobo ze-PCB esizibona kwiintlobo ngeentlobo zee-PCB. Ezi zilukhuni, ziqinile kwaye ziqinile ii-PCBS, ezinobukhulu obahlukeneyo. The main material is fiberglass or simple “FR4”. I-FR4 imele “idangatye-4”. Iimpawu zokuzicima ze-FR-4 zenza ukuba kube luncedo ekusetyenzisweni kwezixhobo ze-elektroniki ezinzima. The FR-4 has thin layers of copper foil on both sides, also known as copper-clad laminates. I-fr-4 laminates enxibe ilaminates isetyenziswa ikakhulu kwizikhulisi zamandla, ukutshintshela amandla emowudi yokuhambisa, abaqhubi beemoto ze-servo, njl. Kwelinye icala, enye ye-PCB engqongqo esetyenziswa rhoqo kwizixhobo zasekhaya nakwimveliso ye-IT ibizwa ngokuba yi-phenolic PCB. Zikhaphukhaphu, zixineneyo, zitshiphu kwaye kulula ukuzibetha. Iikhalityhuleyitha, iikeyboard kunye neempuku zezinye zezicelo zayo.

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.Ezi ntlobo ze-PCBS zinokusetyenziselwa usetyenziso olufuna izinto ezishushu ezinje ngeeds zamandla aphezulu, ii-laser diode, njl.

Installation technology type:

SMT: SMT stands for “surface mount technology”. Izinto ze-SMT zincinci kakhulu ngobukhulu kwaye ziza kwiiphakheji ezahlukeneyo ezinje nge-0402,0603 1608 ye-resistors kunye ne-capacitors. Ngokufanayo, kwii-ics zesekethe ezihlanganisiweyo, sine-SOIC, i-TSSOP, i-QFP kunye ne-BGA.

Indibano ye-SMT inzima kakhulu kwizandla zabantu kwaye inokuba yinkqubo yokuqhubekeka kwexesha, ke oko kwenziwa ikakhulu ziirobhothi ezizenzekelayo kunye nokubekwa.

I-THT: I-THT imele itekhnoloji yangaphakathi. Components with leads and wires, such as resistors, capacitors, inductors, PDIP ics, transformers, transistors, IGBT, MOSFET, etc.

Izixhobo kufuneka zifakwe kwicala elinye le-PCB kwelinye icandelo kwaye zitsalwe ngumlenze kwelinye icala, zinqumle umlenze kwaye zidityaniswe. THT assembly is usually done by hand welding and is relatively easy.

Izinto ezifuneka kuqala kwiinkqubo zeNdibano:

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. Abavelisi kufuneka benze la manyathelo asisiseko e-DFM ukuqinisekisa i-PCB engenasiphako.

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. Inotshi ye-IC / yentloko kufuneka ihlolwe.

Into efuna ukuba isinki yokufudumeza kufuneka ibe nendawo eyaneleyo ukulungiselela ezinye izinto ukuze isinki yobushushu ingachukumisi.

2-Hole and through-hole spacing:

The spacing between holes and between holes and traces should be checked. Iphedi kunye nomngxuma awuyi kungqubana.

I-3- I-pad ye-Brazing, ubukhulu, ububanzi bomgca buya kuthathelwa ingqalelo.

By performing DFM inspections, manufacturers can easily reduce manufacturing costs by reducing the number of scrap panels. Oku kuya kunceda ukuqhuba ngokukhawuleza ngokuphepha ukusilela kwinqanaba le-DFM. At RayPCB, we provide DFM and DFT inspection in circuit assembly and prototyping. E-RayPCB, sisebenzisa izixhobo ze-OEM zikarhulumente ukubonelela ngeenkonzo ze-PCB ze-OEM, isloting wave, uvavanyo lwekhadi le-PCB kunye nendibano ye-SMT.

Assembly PCB (PCBA) inyathelo ngenyathelo-nkqubo:

Inyathelo 1: Faka uncamathiso kwi-solder usebenzisa itemplate

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. Itemplate kunye nePCB zibanjwa kunye nolungelelwaniso loomatshini, kwaye isincamathelisi sokuncamathelisa sisetyenziswa ngokulinganayo kuzo zonke iindawo ezivulekileyo ebhodini ngokusebenzisa isixhobo. Apply solder paste evenly with applicator. Ke ngoko, isincamathelisi esifanelekileyo kufuneka sisetyenziswe. Xa umfaki sicelo esusiwe, uncamathiselo luya kuhlala kwindawo efunwayo ye-PCB. Unamathisela okungwevu okungwevu okungama-96.5% okwenziwe nge-tin, equkethe i-3% yesilivere kunye ne-0.5% yobhedu, mahala. After heating in Step 3, the solder paste will melt and form a strong bond.

Step 2: Automatic placement of components:

Inyathelo lesibini le-PCBA kukubeka ngokuzenzekelayo izinto ze-SMT kwi-PCB. Oku kwenziwa ngokusebenzisa ipiki kunye nendawo yokubeka iirobhothi. Kwinqanaba loyilo, umyili uyila ifayile kwaye wayinika irobhothi ezenzekelayo. Le fayile ine-X elungelelaniswe kwangaphambili, i-Y yolungelelwaniso lwento nganye esetyenziswe kwi-PCB kwaye ichonga indawo yazo zonke izinto. 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.

Ngaphambi kokufika koomatshini bokurhola iirobhothi kunye nokubekwa koomatshini, amagcisa ayeza kuthatha izinto esebenzisa ii-tweezers kwaye azibeke kwi-PCB ngokujonga ngononophelo indawo kunye nokuphepha ukubamba izandla. This results in high levels of fatigue and poor vision for technicians, and leads to a slow PCB assembly process for SMT parts. Ke ukubanakho kwempazamo kuphezulu.

Njengoko itekhnoloji ikhula, iirobhothi ezizenzekelayo ezithatha kwaye zibeka izinto zanciphisa umthwalo womsebenzi wegcisa, lenza ukubekwa ngokukhawuleza nangokuchanekileyo kwezinto. Ezi robhothi zinokusebenza i-24/7 ngaphandle kokudinwa.

Inyathelo 3: Ukuhamba kwakhona kwe-welding

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. Iqondo lobushushu lanele ukunyibilika kwi-solder. I-solder enyibilikileyo emva koko ibamba icandelo kwi-PCB kwaye yenze ngokudibeneyo. After high temperature treatment, the PCB enters the cooler. These coolers then solidify the solder joints in a controlled manner. Oku kuyakwenza unxibelelwano olusisigxina phakathi kwecandelo le-SMT kunye ne-PCB. Kwimeko ye-PCB enamacala amabini, njengoko kuchaziwe apha ngasentla, icala le-PCB elinamacandelo ambalwa okanye amancinci liya kunyangwa kuqala ukusuka kumanqanaba 1 ukuya kwi-3, emva koko liye kwelinye icala.

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

Inyathelo 4: Ukuhlolwa komgangatho kunye nokuhlolwa

Emva kokugcwalisa ukugoba, kungenzeka ukuba izinto zenziwe gwenxa ngenxa yentshukumo ethile engachanekanga kwitreyi yePCB, enokubangela unxibelelwano lwesekethe olufutshane okanye oluvulekileyo. These defects need to be identified, and this identification process is called inspection. Ukuhlolwa kunokuba yincwadana kunye nokuzenzekelayo.

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. Ke ngoko, le ndlela ayinakwenzeka ukuqhubela phambili iibhodi ze-SMT ngenxa yeziphumo ezingachanekanga. Nangona kunjalo, le ndlela inokwenzeka kumacwecwe anezinto ze-THT kunye noxinano lwento esezantsi.

B. Ukufumanisa okubonakalayo:

Le ndlela inokwenzeka ngobuninzi bePCBS. Le ndlela isebenzisa oomatshini abazenzekelayo abanamandla aphezulu kunye neekhamera zesisombululo esiphakamileyo ezixhonywe kwii-engile ezahlukeneyo ukujonga amalungu e-solder macala onke. Ngokuxhomekeke kumgangatho we-joint solder, ukukhanya kuya kubonakalisa ukudibanisa kwe-solder kwii-angles ezahlukeneyo. 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. Uhlolo kufuneka lwenziwe rhoqo ukunqanda ukulibaziseka, iindleko zabasebenzi kunye nezinto eziphathekayo.

Inyathelo 5: Ukulungiswa kwecandelo le-THT kunye nokuwelda

Amacandelo-emngxunyeni aqhelekile kwiibhodi ezininzi zePCB. These components are also called plated through holes (PTH). Izikhokelo zala macandelo ziya kudlula kwimingxunya kwi-PCB. Le mingxunya idityaniswe neminye imingxunya nangokwemingxunya yimikhondo yobhedu. Xa ezi zinto ze-THT zifakwa zaza zadityaniswa kule mingxunya, ziqhagamshelwe ngombane kweminye imingxunya kwi-PCB efanayo naleyo yesekethe eyiliweyo. 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. Ukuwelda Manual:

Manual welding methods are common and often require more time than an automated setup for SMT. Igcisa libelwe ukuba lifake icandelo elinye ngexesha kwaye lidlulise ibhodi liye kwamanye amagcisa afaka elinye icandelo kwibhodi enye. Ke ngoko, ibhodi yesekethe iya kushenxiswa kumgca wendibano ukuze kufumaneke icandelo le-PTH ukuba lizalise. Oku kwenza ukuba le nkqubo inde, kwaye uninzi lwe-PCB yoyilo kunye neenkampani ezivelisa ziyakuphepha ukusebenzisa izinto ze-PTH kuyilo lwesekethe. Kodwa icandelo le-PTH lihlala liyinto ethandwayo kunye neyona isetyenziswa ngokuxhaphakileyo kuninzi lwabayili beesekethe.

B. Ukuthengiswa kwe-Wave:

Uhlobo oluzenzekelayo lwe-welding olwenziweyo yi-welding ye-wave. Kule ndlela, nje ukuba into ye-PTH ibekwe kwi-PCB, i-PCB ibekwe kwibhanti lokuhambisa kwaye ihanjiswe kwi-oveni ezinikeleyo. Apha, amaza e-solder etyhidiweyo atshiza kwi-substrate ye-PCB apho kukho icandelo elikhokelayo. Oku kuyakudibanisa zonke izikhonkwane kwangoko. 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. Emva koku, hambisa i-PCB kuhlolo lokugqibela.

Inyathelo 6: Uvavanyo lokugqibela kunye novavanyo olusebenzayo

I-PCB ngoku ikulungele ukuvavanywa kunye nokuhlolwa. 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

Olu vavanyo lusetyenziselwa ukujonga ukusebenza kunye nombane kweempawu zePCB kunye nokuqinisekisa ukusebenza ngoku, amandla ombane, i-analog kunye nomqondiso wedijithali kunye noyilo lwesekethe oluchazwe kwiimfuno zePCB

Ukuba nayiphi na iparameter yePCB ibonisa iziphumo ezingamkelekanga, i-PCB iya kulahlwa okanye ikhutshwe ngokungqinelana nenkqubo esemgangathweni yenkampani. Isigaba sokuvavanya sibalulekile kuba sigqiba impumelelo okanye ukusilela kwayo yonke inkqubo ye-PCBA.

Inyathelo 7: Ukucoca okokugqibela, ukugqiba kunye nokuthumela:

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. Insimbi engenasiseko esekwe kwizixhobo zokucoca uxinzelelo oluphezulu kusetyenziswa amanzi akhutshiweyo anele ukucoca zonke iintlobo zobumdaka. Amanzi akhethiweyo akonakalisi isekethe yePCB. Emva kokuhlamba, yome i-PCB ngomoya oxineneyo. I-PCB yokugqibela ngoku ikulungele ukupakishwa kwaye ithunyelwe.