Ukusuka kwisekethe yomzekelo kwibhodi yesonka ukuyila eyethu ibhodi yesekethe eprintiweyo (PCBS), it was like getting off the training wheels. There’s a lot to learn about this process, so let’s get started. Uyilo lwePCB lwenziwa kwinkqubo yobunjineli bombane (EE). I-EE idala “ingqondo” yendlela izixhobo ezisebenza ngayo. Without electronics, you’re left with little more than a pile of metal and plastic.

Things to know before starting PCB design: 1. PCB size – this depends on your product size (or case size). Imilinganiselo yemveliso ichazwa ngexesha lenkqubo yoyilo lobunjineli. Ungabukela ividiyo malunga nayo apha. 2.Imaleko ye-PCB -Ukuba kukho ukungqimba okungaphezulu, kokukhona kuyinkimbinkimbi ukwenziwa kwePCB. (Qaphela: Nokuba i-PCB enye inokuba yi-PCB entsonkothileyo, kodwa apha sithetha ngobunzima bokwenza i-PCB. Okukhona i-PCB inamatye ngakumbi, kokukhona kubiza kakhulu ukuyivelisa.)

Layer 2 is usually used for simple toy products

Iimveliso ezinxulumene ne-Iot zihlala zinamaleko ama-4

Typically used for floors 6 to 8 of a smartphone or smartwatch.

3. Your PCB manufacturer’s requirements. Be sure to read the guidelines for rhythm, trace size, power isolation, and file naming before you start designing.

Ulwazi ekufuneka ulunikeze kubenzi be-PCB:

Number of layers (e.g. 2, 4, 6, etc.)

Izixhobo (i-FR-2 (iphepha le-phenolic cotton), i-FR-3 (iphepha lomqhaphu kunye ne-epoxy), i-FR-4 (ifayibha yeglasi kunye ne-epoxy… Etc.)

Thickness (0.5 mm, 1.0 mm… Etc.)

Color (red, black, green… Etc.)

Unyango olungaphezulu komhlaba (i-ENIG (i-nickel yemichiza / ukuntywiliselwa kwegolide), i-DIG (ukuntywiliselwa ngokuthe ngqo kwegolide), i-OSP (i-organic solderable preservatives, njl.

Copper weight (1 oz (35 microns), 2 oz (70 microns), 0.5 oz (18 microns)… Etc.)

Ifayile yeGerber

PCB design process:

Uyilo lwesekethe

For this step, you need to create the schematic. This is a document, like a blueprint, that describes how components relate to each other and work together. To create the schematic file, you will need a software tool. We like Quadcept because it is optimized for designing PCBS for manufacturing (for example, you can export a Bill of Material (BoM) directly from the tool) and is cloud-based, so it can be easily used anywhere. (They also offer a free community version of the tool for manufacturers and students.)

There are many other options you can choose from:

IAltium

I-ExpressPCB

Isixhobo esihamba rhoqo

I-KiCad

Cadence allegro

imethi

Uyilo oluncedisiweyo lwekhompyuter

IDipTrace

After you install the selected tools, you need to obtain the component specifications for each selected component. They can often be found on the supplier’s website. Imodeli yefayile iya kukunceda uzobe isikimu. This component becomes available in the database when you upload the model to the software tool. Then, all you have to do is follow the data manual and connect the wire to each pin in the component. (Qaphela: iinkcukacha zenkqubo yoyilo ziya kuxhomekeka kwisixhobo esikhethiweyo sesoftware).

Each schematic symbol needs to have an associated PCB space area to define the physical dimensions of the component and the location of the through holes on the brazing pad or PCB. You should have selected the components (or are now selecting them), and we describe this process in the EE Design Process video (see video).

Example diagram

A good schematic is really important, as it will be used as a reference document during debugging and is a good communication tool with other engineers. Ukongeza, umenzi unokuvavanya isixhobo ngamanqaku ovavanyo kolu xwebhu.

PCB layout + Gerber file

To design the PCB layout and create Gerber files, you can use the same software tools we mentioned in circuit design. Ngokungafaniyo nesikimu, uyilo lwePCB lubeka ezona ndawo ngqo kwiPCB kwaye ibonisa imikhondo edibanisa icandelo ngalinye kunye phakathi kweengqimba zePCB. As mentioned at the beginning of this article, the more layers, the more complex the manufacturing required, and the higher the cost.

Divide the PCB into logical parts based on functions (e.g. power supply, audio output, etc.). Then, be sure to group the components of each section into the same area. Ngale ndlela, ungagcina umkhondo wokuqhuba ube mfutshane kwaye unciphise ingxolo kunye nokuphazamiseka.

Ujongano lomsebenzisi (UI) kufuneka ligcinwe engqondweni xa kuyilwa i-PCB. Izinto ezinje ngeejack zomsindo, izihlanganisi, ii-leds, njl njl.

Once the layout is designed, a Gerber file is generated. Umenzi wakho wePCBA uza kuyisebenzisa le fayile. There are many companies that offer these services, and from HWTrek’s expert library we recommend Kingbrother, NexPCB, and HQPCB.

Sample Gerber files

Ukubekwa kwezinto kwi-PCB kubaluleke kakhulu. Some components can interfere with each other and cause unexpected behavior. For example, if you have both Bluetooth and Wi-Fi modules, they have the same 2.4ghz bandwidth and can interfere with each other if incorrectly placed.

PCB production

When you send the Gerber file to the PCB manufacturer, they can print the board. Oku kuya kuba sisiseko sokuqhubeka nokwakha isiseko sokongeza izinto kwi-PCB kunye nokwenza i-PCBA (indibano yebhodi yesekethe eprintiweyo).

Unassembled PCBS

PCBA (Assembly)

Ukulungiswa kwezinto

Okwangoku kuyilo lwe-EE, kuya kufuneka ukhethe izinto. You can ask the PCBA manufacturer to order the required components for you, or do it yourself if you choose a supplier. Izinto ezifuna ingqalelo:

Lead time: As these components come from different suppliers, keep the lead time in mind. For some components, it can take up to 8-16 weeks.

Packaging: Order components from reels that are automatically picked up by SMT machines instead of packaging them individually.

Minimum order quantity: Check the minimum order quantity of the component. Ukuba uthenga ngaphantsi kobuncinci, qiniseka ukuba izinto ezikhethiweyo zikhona kwisitokhwe. For small batches (up to 50), you can order online from DigiKey or Mouser. Ngobuninzi obungaphezulu, nceda ufune iingcebiso kumenzi wakho.

Loss: Order 10% more to cover loss (not for expensive components)

Install components on the PCB

There are two main ways to place components on a PCB surface:

Through-holes (through-holes) are manual methods of assembling assemblies with wires into holes on the surface of a PCB. It is also commonly known as DIP or dual in-line packaging process. (See SMT in progress in this video)

I-SMT (iteknoloji yokunyuka komhlaba) yeyona ndlela isetyenziswa kakhulu kwimveliso ezininzi. It is done by fast, accurate SMT machines that save you time, money and avoid human error.

Izinto okumele uzikhumbule:

Your component type number must not exceed the number of reels that the manufacturer’s SMT machine can support.

Optimize and consolidate your components so that only one SMT runs.

Check manufacturer supported footprint pad sizes. Otherwise, the SMT machine will not install components correctly.

Some larger components cannot be installed by machine and still require manual through-hole work. Therefore, both technologies can be used on the same board.

Any components you need to manually add via the through-hole method add to the manufacturing cost.

Reflow soldering

Ukugcwaliswa kwe-soldering yinkqubo yokwenza izinto “zincamathele” kwi-PCB. The PCBA heats the circuit board through a reflow furnace or an infrared lamp until the solder melts, thereby permanently attaching the component to the circuit board.

The trickiest part here is not to overheat or damage the components, because the thermal characteristics of each package are different. Umenzi wePBA othembekileyo uya kuba noxanduva kule nkqubo, kwaye konke okufuneka ukwenze kukubanika iinkcukacha zecandelo.

Inkqubo yeReflux.

Other welding methods:

I-wave soldering isetyenziselwa izinto ezongezwe ngesandla ngendlela yemingxunya. Kule meko, i-PCBA yakho iya kuqala ukudlula kwisithando somlilo esivuselelayo, kwaye emva koko yongeze ngesandla amanye amacandelo emva kokuba iza kuhamba ngomatshini otshangatshangiswayo.

I-iron welding inokusetyenziselwa iimeko ezithile, kodwa hayi kwimveliso ngobuninzi.

Ukuvavanywa kunye nokuhlolwa komgangatho

Kweli nqanaba, iisampulu ze-PCBA ziyavavanywa ukuqinisekisa umgangatho. Iimpazamo eziqhelekileyo zezi: imijikelezo emifutshane kumacandelo aqhawuliweyo, izinto ezingalunganga kunye neenxalenye zesekethe ezingafanelekanga ukuba zidityaniswe. Olona vavanyo luqhelekileyo:

ICT (ukuvavanywa kwi-Intanethi). When designing a PCB, some test points are usually reserved for debugging, programming, and other purposes. Umatshini we-ICT uya kuzisebenzisa ezi ndawo zovavanyo kuvavanyo oluvulekileyo / olufutshane kwaye ujonge ukuba amaxabiso ezinto ezenziwayo (i-resistors, i-inductors, ii-capacitors) ziphakathi kuluhlu lweenkcukacha.

I-AOI (Uvavanyo lokujonga ngokuzenzekelayo). Manufacturers use a “gold sample” (reference PCBA) to compare with other samples. Kolu vavanyo, umyili wehardware kuya kufuneka anike iinkcukacha kunye nokunyamezelana kumenzi ukuseta iiparameter.

X ray. The PCBA manufacturer will use X-rays to check the welding conditions of the BGA (ball Grid Array) components. Jonga uvavanyo lwe-X-ray kule vidiyo.