Marka la eego tiknoolajiyadda casriga ah, adduunku si xawli ah ayuu u korayaa, saamayntiisuna si fudud ayay u geli kartaa nolol maalmeedkeena. 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. Ubucda aaladahaani waa injineernimada korontada, udub -dhexaaduna waa guddiga wareegsan oo daabacan (PCB).

PCB -ga badiyaa waa cagaar waana jidh adag oo ay ku jiraan qaybo kala duwan oo elektaroonik ah. These components are welded to the PCB in a process called “PCB assembly” or PCBA. PCB -gu wuxuu ka kooban yahay substrate ka samaysan fiberglass, lakabyo naxaas ah oo ka samaysan raad, godad ka kooban qaybta, iyo lakabyo noqon kara gudaha iyo dibaddaba. RayPCB, waxaan ku siin karnaa ilaa 1-36 lakab oo loogu talagalay PROTOTYPES-lakabka badan iyo 1-10 lakab oo loogu talagalay dufcado badan oo PCB ah oo loogu talagalay soosaarka mugga. 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. Maaskarada alxanka ayaa u oggolaan doonta qaybta inay ka fogaato in si gaaban loogu wareejiyo jidka ama qaybaha kale.

Raadka naxaasta waxaa loo isticmaalaa in lagu wareejiyo calaamadaha elektaroonigga ah hal dhibic ilaa mid kale PCB -ga. These signals can be high-speed digital signals or discrete analog signals. Fiilooyinkaas waxaa laga dhigi karaa kuwo qaro weyn si ay u siiyaan awood/awood qaybinta korontada.

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”.

Qaybaha waxaa lagu soo ururiyay PCB si PCB -ga loogu suurtogeliyo inuu u shaqeeyo sidii loogu talagalay. The most important thing is PCB function. Xitaa haddii iska -caabbinta yar -yar ee SMT aan si sax ah loo dhigin, ama xitaa haddii jidadka yaryar laga jaray PCB, PCB ma shaqayn karo. Sidaa darteed, waxaa muhiim ah in si habboon loo soo uruuriyo qaybaha. PCB -ga marka la isku keenayo qaybaha waxaa lagu magacaabaa PCBA ama PCB -ga shirarka.

Iyada oo ku xidhan tilmaamaha uu macmiilka ama isticmaalahu ku tilmaamay, shaqada PCB -gu waxay noqon kartaa mid adag ama fudud. PCB size also varies according to requirements.

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

Lakabka PCB iyo naqshadeynta

Sida kor ku xusan, waxaa jira lakabyo calaamado badan oo u dhexeeya lakabyada dibadda. Now we will discuss the types of outer layers and functions.

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

1-Substrate: Kani waa saxan adag oo ka samaysan walxaha FR-4 kaas oo ay qaybihiisu “buuxsan yihiin” ama alxamaan. This provides rigidity for the 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.

3- Maaskaro alxanka: Waxaa lagu dabaqaa lakabyada sare iyo hoose ee 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. Maaskarada alxanka ayaa sidoo kale iska ilaaliya alxanka qaybaha aan la rabin waxayna hubisaa in alxamdu uu soo galo aagga alxanka, sida godadka iyo suufka. 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. Lakabka shaashadu wuxuu bixiyaa macluumaad muhiim ah oo ku saabsan PCB.

There are 3 types of PCBS according to the substrate classification

1- Rigid PCB:

PCB -yadu waa aaladaha PCB -ga ee aan ku aragno noocyada kala duwan ee PCB -yada. Kuwani waa PCBS adag, adag oo adag, oo leh dhumucyo kala duwan. The main material is fiberglass or simple “FR4”. FR4 waxay u taagan tahay “olol-yare-4”. Tilmaamaha is-bakhtiinta ee FR-4 ayaa ka dhigaysa mid waxtar u leh adeegsiga aalado badan oo elektiroonig ah oo warshadeysan. The FR-4 has thin layers of copper foil on both sides, also known as copper-clad laminates. Fr-4 laminate-ka naxaasta ah ayaa inta badan loo adeegsadaa qalabka wax-weyneeya, beddelidda sahayda korontada, darawallada mootada, iwm. Dhinaca kale, substrate PCB kale oo adag oo inta badan loo adeegsado qalabka guryaha iyo alaabta IT -ga ayaa lagu magacaabaa PCB phenolic phenolic. Waa iftiin, cufnaanta hoose, jaban oo si sahlan loo feeri karo. Xisaabiyeyaasha, teebabka iyo jiirku waa qaar ka mid ah codsiyadiisa.

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.Noocyada PCBS -da waxaa loo adeegsan karaa codsiyada u baahan qaybaha kuleylka sida leds -ka awoodda sare leh, diod -yada laser, iwm.

Installation technology type:

SMT: SMT waxay u taagan tahay “tiknoolajiyadda buurta”. Qaybaha SMT aad bay u yar yihiin cabbirka waxayna ku jiraan baakado kala duwan sida 0402,0603 1608 oo loogu talagalay is -hortaagayaasha iyo koronto -yaqaannada. Sidoo kale, isku -dhafka wareegga isku -dhafan, waxaan leenahay SOIC, TSSOP, QFP iyo BGA.

Isku -duwaha SMT aad buu ugu adag yahay gacmaha aadanaha wuxuuna noqon karaa geedi socod waqti go’an, sidaa darteed waxaa ugu horreyn lagu sameeyaa soo -qaadis otomaatig ah iyo meelaynta meelaynta.

THT: THT waxay u taagan tahay farsamada daloolka. 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.

Shuruudaha habka shirka:

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. Soo -saareyaashu waa inay fuliyaan tallaabooyinkan asaasiga ah ee DFM si loo hubiyo PCB aan iin lahayn.

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. IC notch/head direction waa in la hubiyaa.

Cunsurka u baahan weelka kuleylka waa inuu lahaadaa meel ku filan si uu u dejiyo canaasiir kale si uusan weelka kuleylku u taaban.

2-Hole and through-hole spacing:

The spacing between holes and between holes and traces should be checked. Suufka iyo daloolka waa inaysan is -dul saarin.

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. RayPCB, waxaan u isticmaalnaa qalabka OEM ee casriga ah si aan u siino adeegyada OEM PCB, iibinta mawjadda, tijaabinta kaarka PCB iyo isu imaatinka SMT.

Golaha PCB (PCBA) geedi socod talaabo talaabo ah:

Tallaabada 1: Codso dhejiska alxanka adoo adeegsanaya template

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. Qaab -dhismeedka iyo PCB -ga waxaa isku haya qalab farsamo, dhejiska wax lagu iibiyo ayaa si siman loogu dabaqaa dhammaan furitaanka guddiga iyada oo loo marayo codsade. Apply solder paste evenly with applicator. Sidaa darteed, dhejiyaha dhejiska ku habboon waa in loo adeegsadaa codsadaha. Marka codsadaha laga saaro, dhejintu waxay ku sii jiri doontaa aagga la rabo ee PCB. Jinka alwaaxda leh 96.5% ka samaysan daasadda, oo ka kooban 3% lacag iyo 0.5% naxaas ah, oo aan lahayn macdanta “ lead ” After heating in Step 3, the solder paste will melt and form a strong bond.

Step 2: Automatic placement of components:

Tallaabada labaad ee PCBA waa in si toos ah loogu dhejiyo qaybaha SMT PCB -ga. Tan waxaa lagu sameeyaa iyada oo la adeegsanayo robot -ka wax -soo -saarka. Heerka naqshadeynta, naqshadeeye wuxuu abuuraa fayl wuxuuna siiyaa robot -ka iswada. Faylkan wuxuu leeyahay isku-duwayaasha X, Y ee horay loo qorsheeyay ee qayb kasta oo loo adeegsaday PCB-ga wuxuuna tilmaamayaa meesha ay ku yaalliin dhammaan qaybaha. 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.

Kahor imaanshaha mashiinnada soo qaadista iyo mashiinnada meeleynta, farsamayaqaannada waxay soo qaadan lahaayeen qaybo iyagoo adeegsanaya tweezers oo ku rida PCB iyagoo si taxaddar leh u fiirinaya goobta kana fogaanaya wax gacan qaad ah. This results in high levels of fatigue and poor vision for technicians, and leads to a slow PCB assembly process for SMT parts. Markaa kartida qaladku waa mid saraysa.

Marka ay tiknoolajigu qaangaadho, robotyada otomaatiga ah ee soo qaada oo dhigaya qaybaha ayaa yareeya culayska farsamoyaqaannada, taas oo awood u siinaysa meelaynta qayb degdeg ah oo sax ah. Robotyadani waxay shaqayn karaan 24/7 daal la’aan.

Tallaabada 3: Dib u celi alxanka

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. Heerkulku waa ku filan yahay in lagu dhalaaliyo alxanka. Alxanka dhalaalay ayaa markaa ku haya qaybta PCB -ga oo sameeya wadajirka. After high temperature treatment, the PCB enters the cooler. These coolers then solidify the solder joints in a controlled manner. Tani waxay abuuri doontaa xiriir joogto ah oo ka dhexeeya qaybta SMT iyo PCB. Marka laga hadlayo PCB-ga laba-gees leh, sida kor lagu sharaxay, dhinaca PCB-ga oo leh qaybo ka yar ama ka yar ayaa marka hore laga daaweyn doonaa tallaabooyinka 1 illaa 3, ka dibna dhinaca kale.

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

Tallaabada 4: Kormeerka iyo kormeerka tayada

Dib -u -iibinta dib -u -celinta, waxaa suurtogal ah in qaybo aan si khaldan loo habeynin sababtoo ah xoogaa dhaqdhaqaaq aan sax ahayn oo ku jira saxanka PCB, taas oo laga yaabo inay keento xiriiro wareeg oo gaaban ama furan. These defects need to be identified, and this identification process is called inspection. Baadhitaannadu waxay noqon karaan kuwo gacanta lagu sameeyo oo iswada.

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. Sidaa darteed, habkani suurtogal uma aha guddiyada SMT ee hore sababtoo ah natiijooyin aan sax ahayn. Si kastaba ha ahaatee, habkani waa suurtogal taarikada leh qaybaha THT iyo cufnaanta qaybaha hoose.

B. Ogaanshaha indhaha:

Habkani waa mid suurtogal u ah tiro badan oo PCBS ah. Habka wuxuu adeegsadaa mashiinno otomaatig ah oo leh awood sare iyo kamaradaha xallinta sare ee lagu rakibay xaglo kala duwan si loo eego kala -goysyada alxanka ee dhinac walba. Iyada oo ku xidhan tayada wadajirka alxanka, iftiinka ayaa ka tarjumi doona wadajirka alxanka dhinacyo kala duwan. 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. Baadhitaannada waxay u baahan yihiin in si joogto ah loo sameeyo si looga fogaado dib -u -dhaca, shaqada iyo kharashyada maaddiga.

Tallaabada 5: hagaajinta qaybta THT iyo alxanka

Qaybaha daloolku waxay ku badan yihiin looxyada PCB-ga. These components are also called plated through holes (PTH). Tilmaamaha qaybahaani waxay dhex mari doonaan godadka PCB -ga. Godadkan waxay ku xiran yihiin godad kale iyo daloolada raadadka naxaasta. Marka walxahan THT la geliyo oo la dhex geliyo godadkaas, waxay koronto ahaan ugu xiran yihiin godad kale oo isla PCB ah sida wareegga loogu talagalay. 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. Farsamo -yaqaan ayaa sida caadiga ah loo xilsaaray inuu geliyo hal qayb markiiba oo u gudbiyo guddiga farsamo -yaqaannada kale oo gelinaya qayb kale isla guddiga. Sidaa darteed, guddiga wareegga ayaa loo wareejin doonaa hareeraha xarigga isku -xirka si loo helo qaybta PTH si ay u buuxiso. Tani waxay geeddi -socodka ka dhigaysaa mid dheer, iyo shirkado badan oo PCB ah iyo shirkado wax -soo -saar ayaa iska ilaaliya inay u adeegsadaan qaybaha PTH naqshadaha wareegga. Laakiin qaybta PTH ayaa weli ah qaybta ugu jecel oo inta badan la isticmaalo inta badan naqshadeeyayaasha wareegga.

B. Alxanka mawjada:

Nooca otomaatiga ah ee alxanka gacanta waa alxanka mawjadda. Qaabkan, marka walxaha PTH la saaro PCB -ga, PCB -ga waxaa la saaraa suunka xamuulka waxaana loo wareejiyaa foorno u go’an. Halkaan, mowjadaha alxanka la dhalaaliyay ayaa ku soo qulqulaya hoosta PCB -ga halkaas oo ay ku yaalliin qaybta ay ka kooban tahay. Tani waxay isla markiiba bakhtiin doontaa biinanka. 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. Intaas ka dib, dhaqaaji PCB -ga si loo baaro kama dambaysta.

Tallaabada 6: Kormeerka kama dambaysta ah iyo imtixaanka shaqaynta

PCB wuxuu hadda diyaar u yahay baaritaan iyo baaritaan. 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

Tijaabadan waxaa loo adeegsadaa in lagu hubiyo sifooyinka shaqaynaya iyo korontada ee PCB -ga oo lagu ansixinayo hadda, korantada, signalada dhijitaalka ah iyo naqshadaha dhijitaalka ah ee lagu sharxay shuruudaha PCB

Haddii mid ka mid ah cabirrada PCB -ga ay muujiyaan natiijooyin aan la aqbali karin, PCB -ga waa la tuuri doonaa ama waa la tirtiri doonaa iyadoo la raacayo habraacyada caadiga ah ee shirkadda. Marxaladda imtixaanku waa muhiim maxaa yeelay waxay go’aamisaa guusha ama guuldarrada dhammaan hawsha PCBA.

Tallaabada 7: Nadiifinta kama dambaysta ah, dhammaystirka iyo dhoofinta:

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. Qalabyada nadiifinta cadaadiska sare ee birta ku salaysan ee birta ah oo isticmaalaya biyaha la kala siibay ayaa ku filan in lagu nadiifiyo dhammaan noocyada wasakhda. Biyaha deionized ma waxyeeleeyaan wareegga PCB. Ka dib markaad maydho, ku qalaji PCB hawo cadaadis leh. PCB -ga ugu dambeeya ayaa hadda diyaar u ah in la buuxiyo oo la raro.