Utloisisa thulaganyou e boto thulaganyou e kopano ‘me u utloe botle bo botala ba PCB

Mabapi le mahlale a morao-rao, lefatše le hola ka lebelo le potlakileng haholo, mme tšusumetso ea lona e ka kenella habonolo bophelong ba rona ba letsatsi le letsatsi. 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. Motsoako oa lisebelisoa tsena ke boenjiniere ba motlakase, ‘me mokokotlo ke boto ea potoloho e hatisitsoeng (PCB).

PCB hangata e tala ‘me ke’ mele o thata o nang le likarolo tse fapaneng tsa elektroniki ho eona. These components are welded to the PCB in a process called “PCB assembly” or PCBA. PCB e na le substrate e entsoeng ka khalase ea fiberglass, likarolo tsa koporo tse etsang mosaletsa, masoba a etsang karolo eo, le mekato e ka bang kahare le kantle. Ka RayPCB, re ka fana ka ho fihlela ho 1-36 le dikarolo bakeng sa selotlolo lera PROTOTYPES le le dikarolo 1-10 bakeng sa methaka multiple tsa PCB bakeng sa tlhahiso ea bophahamo ba modumo. For single-sided and double-sided PCBS, an outer layer exists but no inner layer.

ipcb

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. Mask ea ho tjheseletsa e tla lumella karolo ho qoba ho potoloha ha nakoana ho ea pina kapa likarolo tse ling.

Mesaletsa ea koporo e sebelisoa ho fetisetsa matšoao a elektroniki ho tloha ntlheng e ‘ngoe ho ea ho e’ ngoe ho PCB. These signals can be high-speed digital signals or discrete analog signals. Mehala ena e ka etsoa hore e be metenya e le hore e fane ka motlakase / motlakase bakeng sa phepelo ea motlakase oa motsoako.

Boholo ba li-PCBS tse fanang ka motlakase o phahameng kapa oa hona joale, ho na le sefofane se arohaneng se ikemetseng. Components on the top layer are connected to the internal GND plane or internal signal layer via “Vias”.

Likarolo li bokane ho PCB ho etsa hore PCB e sebetse joalo ka ha e entsoe. The most important thing is PCB function. Esita le haeba lihanyetsi tse nyane tsa SMT li sa beoa ka nepo, kapa leha lipina tse nyane li sehiloe ho PCB, PCB e kanna ea se sebetse. Ka hona, ho bohlokoa ho kopanya likarolo ka tsela e nepahetseng. The PCB ha bokana dikarolo o bitsoa PCBA kapa kopano PCB.

Ho latela litlhaloso tse hlalositsoeng ke moreki kapa mosebelisi, mosebetsi oa PCB o kanna oa ba thata kapa o bonolo. PCB size also varies according to requirements.

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

Lera la PCB le moralo

Joalokaha ho boletsoe kaholimo, ho na le likarolo tse ngata tsa matšoao lipakeng tsa likarolo tse kantle. Now we will discuss the types of outer layers and functions.

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1 – Substrate: Ena ke poleiti e thata e entsoeng ka thepa ea FR-4 eo likarolo tsa eona li “tlatsoang” kapa tse halikiloeng. Sena se fana ka ho satalla bakeng sa 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- ho tjheseletsa maske: E sebelisoa ho le dikarolo holimo le tlase ea PCB ea. This is used to create non-conducting areas of the PCB and insulate the copper traces from each other to protect against short circuits. Maske a ho tjheseletsa a boetse a qoba ho tjheseletsa likarolo tse sa batleheng mme a netefatsa hore solder e kena sebakeng sa ho tjheseletsa joalo ka masoba le mekotla. 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. Lera la skrineng le fana ka leseli la bohlokoa ka PCB.

There are 3 types of PCBS according to the substrate classification

1- Rigid PCB:

Li-PCB ke lisebelisoa tse ngata tsa PCB tseo re li bonang mefuteng e fapaneng ea li-PCB. Tsena ke li-PCBS tse thata, tse thata le tse tiileng, tse nang le botenya bo fapaneng. The main material is fiberglass or simple “FR4”. FR4 e emetse “flame retarder-4”. Litšobotsi tsa ho itima tsa FR-4 li etsa hore e be molemo bakeng sa ts’ebeliso ea lisebelisoa tse ngata tsa elektroniki tse thata. The FR-4 has thin layers of copper foil on both sides, also known as copper-clad laminates. Fr-4 laminates tse koahetsoeng ka koporo li sebelisoa haholo ho li-amplifiers tsa motlakase, phepelo ea motlakase oa mofuta, li-driver tsa servo motor, jj. Ka lehlakoreng le leng, karolo e ‘ngoe e thata ea PCB e sebelisoang haholo lisebelisoa tsa ntlo le lihlahisoa tsa IT e bitsoa pampiri ea phenolic PCB. Li bobebe, li tlase haholo, li theko e tlase ebile li bonolo ho phunya. Li-Calculator, li-keyboards le litoeba ke tse ling tsa ts’ebeliso ea eona.

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.Mefuta ena ea PCBS e ka sebelisoa bakeng sa lits’ebetso tse hlokang lisebelisoa tsa mocheso joalo ka li-leds tse phahameng tsa motlakase, li-laser diode, jj.

Installation technology type:

SMT: SMT e emetse “theknoloji ea” mount mount “. Lisebelisoa tsa SMT li nyane haholo ka boholo ‘me li tla ka lipakete tse fapaneng tse kang 0402,0603 1608 bakeng sa li-resistor le li-capacitor. Ka mokhoa o ts’oanang, bakeng sa li-ics tsa potoloho tse kopaneng, re na le SOIC, TSSOP, QFP le BGA.

Kopano ea SMT e thata haholo matsohong a batho mme e ka ba ts’ebetso ea nako, ka hona e etsoa haholo ke liroboto tse ikemetseng.

THT: THT e emetse theknoloji ea lesoba. 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.

Lintho tse hlokahalang bakeng sa kopano:

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. Baetsi ba tlameha ho etsa mehato ena ea mantlha ea DFM ho netefatsa PCB e se nang sekoli.

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 / hlooho tataiso e tlameha ho hlahlojoa.

Karolo e hlokang teba ea mocheso e lokela ho ba le sebaka se lekaneng ho amohela likarolo tse ling hore siling ea mocheso e se ame.

2-Hole and through-hole spacing:

The spacing between holes and between holes and traces should be checked. Pad le ka lesoba a ke ke a lepelela.

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. Ha re le RayPCB, re sebelisa lisebelisoa tsa boemo bo holimo tsa OEM ho fana ka lits’ebeletso tsa PCB OEM, soldering ea leqhubu, liteko tsa karete ea PCB le kopano ea SMT.

PCB Seboka (PCBA) mohato ka mohato thulaganyou e:

Hata 1: Etsa kopo ea solder u sebelisa 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. Thempleite le PCB li ts’oaroa hammoho ka sesebelisoa sa mochini, ‘me samente ea solder e sebelisoa ka mokhoa o ts’oanang le menyetla eohle ea boto ka sesebelisoa. Apply solder paste evenly with applicator. Ka hona, peista e loketseng ea solder e tlameha ho sebelisoa ho sesebelisoa. Ha sesebelisoa se tlosoa, peista e tla lula sebakeng se hlokoang sa PCB. Pente e sootho e sootho e entsoeng ka thini, e nang le silevera ea 96.5% le koporo ea 3%, e sa etelloang pele. After heating in Step 3, the solder paste will melt and form a strong bond.

Step 2: Automatic placement of components:

Mohato oa bobeli oa PCBA ke ho iketsa likarolo tsa SMT ka kotloloho ho PCB. Sena se etsoa ka ho sebelisa roboto ea ho khetha le ho e beha. Boemong ba moralo, moqapi o etsa faele mme oe fa roboto e ikemetseng. Faele ena e na le lihokelo tsa X, Y tse hlophisitsoeng esale pele tsa karolo ka ‘ngoe e sebelisitsoeng ho PCB mme e supa moo likarolo tsohle li leng teng. 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.

Pele ho ba le mechini ea ho lata liroboto le ho e beha, litsebi li ne li nka lintho tse sebelisang li-tweezers ebe li li beha ho PCB ka ho sheba ka hloko sebaka le ho qoba ho ts’oarana ka matsoho. This results in high levels of fatigue and poor vision for technicians, and leads to a slow PCB assembly process for SMT parts. Kahoo monyetla oa phoso o phahame.

Ha mahlale a ntse a hola, liroboto tse iketsang le ho beha likarolo li fokotsa mosebetsi oa litsebi, li nolofalletsa ho beha likarolo ka potlako le ka nepo. Liroboto tsena li ka sebetsa 24/7 ntle le mokhathala.

Mohato oa 3: Ho tjheseletsa hoa 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. Mocheso o lekane ho qhibilihisa solder. The solder e qhibilihisitsoeng e ntan’o tšoara motsoako ho PCB ebe e etsa selekane. After high temperature treatment, the PCB enters the cooler. These coolers then solidify the solder joints in a controlled manner. Sena se tla theha khokahano e sa feleng lipakeng tsa karolo ea SMT le PCB. Tabeng ea PCB e mahlakore a mabeli, joalo ka ha ho hlalositsoe kaholimo, lehlakore la PCB le nang le likarolo tse fokolang kapa tse nyane le tla phekoloa pele ho tloha mohato oa 1 ho isa ho 3, ebe le lehlakoreng le leng.

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Mohato oa 4: Tlhahlobo le tlhahlobo ea boleng

Mora reflow kulo, ho ka etsahala hore dikarolo ba misaligned ka lebaka la ho ba bang ba mokhatlo o fosahetseng ka floating PCB, e leng se ka fella ka dikgokelo lekgutshwanyane kapa bulehileng oa potoloho. These defects need to be identified, and this identification process is called inspection. Litlhahlobo li ka tsamaisoa ka matsoho le ka boiketsetso.

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. Ka hona, mokhoa ona ha o khonehe bakeng sa liboto tsa SMT esale pele ka lebaka la liphetho tse sa nepahalang. Leha ho le joalo, mokhoa ona o khonahala bakeng sa lipoleiti tse nang le likarolo tsa THT le botenya ba likarolo tse tlase.

B. Phumano ea Optical:

Mokhoa ona o khonahala bakeng sa li-PCBS tse ngata. Mokhoa ona o sebelisa mechini e ikemetseng e nang le matla a phahameng le likhamera tse nang le tharollo e phahameng tse kenngoeng ka mahlakore a fapaneng ho bona manonyeletso a solder ho tsoa hohle. Ho latela boleng ba kopane ea solder, leseli le tla khantša lenonyeletso la solder ka mahlakore a fapaneng. 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. Litlhahlobo li hloka ho etsoa khafetsa ho qoba ho lieha, litšenyehelo tsa basebetsi le thepa.

Mohato oa 5: Ho lokisa karolo ea THT le ho tjheseletsa

Likarolo tsa lesoba li tloaelehile libotong tse ngata tsa PCB. These components are also called plated through holes (PTH). Tsamaiso ea likarolo tsena e tla feta masoba a PCB. Masoba ana a hokahane le masoba a mang le ka masoba ke masale a koporo. Ha likarolo tsena tsa THT li kentsoe le ho kenella ka masobeng ana, li hokahane ka motlakase le masoba a mang ho PCB e le ‘ngoe le potoloho e raliloeng. 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. Kahoo mefuta e ‘meli ea mantlha ea likarolo tsa THT tse sotelitsoeng kapa tse kopantsoeng ke

A. Manual tjheseletsa:

Manual welding methods are common and often require more time than an automated setup for SMT. Setsebi se abeloa ho kenya karolo e le ‘ngoe ka nako ebe se fetisetsa boto ho litsebi tse ling tse kenyang karolo e’ ngoe ka har’a boto e le ‘ngoe. Ka hona, boto ea potoloho e tla tsamaisoa ho potoloha mohala oa kopano ho fumana karolo ea PTH ho e tlatsa. Sena se etsa hore ts’ebetso e be telele, ‘me lik’hamphani tse ngata tsa moralo le liindasteri tsa tlhahiso li qobe ho sebelisa likarolo tsa PTH mererong ea tsona ea potoloho. Empa karolo ea PTH e lula e le karolo ea thatohatsi ebile e sebelisoang haholo ke baqapi ba potoloho ba bangata.

B. Ts’ebetsong ea leqhubu:

Mofuta o iketselitseng oa ho tjheseletsa ka letsoho ke ho tjheseletsa leqhubu. Ka mokhoa ona, hang ha karolo ea PTH e behiloe ho PCB, PCB e beoa lebanteng la conveyor ebe e isoa ka ontong e inehetseng. Mona, maqhubu a solder e qhibilihisitsoeng a phatloha kahare ho substrate ea PCB moo karolo e etellang pele e leng teng. Sena se tla tiisa lithakhisa tsohle hanghang. 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. Ka mor’a sena, susumelletsa hore PCB bakeng sa tlhahlobo ea ho qetela.

Mohato oa 6: Tlhahlobo ea ho qetela le liteko tsa ts’ebetso

PCB e se e loketse liteko le tlhahlobo. 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

Teko ena e sebelisetsoa ho lekola litšobotsi tse sebetsang le tsa motlakase tsa PCB le ho netefatsa lets’oao la hajoale, voltage, analog le dijithale le meralo ea potoloho e hlalositsoeng ho litlhoko tsa PCB

Haeba efe kapa efe ea mekhahlelo ea PCB e bontša sephetho se sa amoheleheng, PCB e tla lahloa kapa e hlakoloe ho latela lits’ebetso tse tloaelehileng tsa k’hamphani. Karolo ea liteko e bohlokoa hobane e khetholla katleho kapa ho hloleha hoa ts’ebetso eohle ea PCBA.

Mohato oa 7: Ho hloekisa ho qetela, ho phethela le ho tsamaisa:

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. Lisebelisoa tse sa hloekeng tse thehiloeng ho khatello ea khatello e sebelisang metsi a nang le metsi a lekaneng ho hloekisa mefuta eohle ea mobu. Metsi a nang le maiketsetso ha a senye potoloho ea PCB. Kamora ho hlatsoa, ​​omisa PCB ka moea o petelitsoeng. PCB ea ho qetela e se e loketse ho paka le ho romelloa.