Kusukela kumjikelezo wesibonelo kumabhodi wesinkwa ukuklama okwethu ibhodi yesifunda ephrintiwe (PCBS), it was like getting off the training wheels. There’s a lot to learn about this process, so let’s get started. Idizayini ye-PCB yenziwa ngenqubo yobunjiniyela kagesi (EE). I-EE idala “ubuchopho” bokuthi amadivayisi asebenza kanjani. 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). Ubukhulu bomkhiqizo buchazwa ngesikhathi senqubo yokwakhiwa kobunjiniyela be-elekthronikhi. Ungabuka ividiyo ngakho lapha. Izendlalelo ze-PCB – Izendlalelo ezingaphezulu, lapho kukhiqizwa khona i-PCB kuyinkimbinkimbi ngokwengeziwe. (Qaphela: Ngisho ne-PCB eyodwa-ungqimba ingaba yi-PCB eyinkimbinkimbi, kepha lapha sikhuluma ngobunzima bokwenza i-PCB. Lapho izingqimba ezine-PCB ziningi, kubiza kakhulu ukukhiqiza.)

Layer 2 is usually used for simple toy products

Imikhiqizo ehlobene ne-Iot imvamisa inezendlalelo ezi-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.

Imininingwane odinga ukuyinikeza abakhiqizi be-PCB:

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

Izinto zokwakha (i-FR-2 (iphepha le-phenolic cotton), i-FR-3 (iphepha likakotini ne-epoxy), i-FR-4 (ingilazi yefayibha ne-epoxy… Etc.)

Thickness (0.5 mm, 1.0 mm… Etc.)

Color (red, black, green… Etc.)

Ukwelashwa ngaphezulu (i-ENIG (ukucwiliswa ngamakhemikhali / ukucwiliswa kwegolide), i-DIG (ukucwiliswa kwegolide okuqondile), i-OSP (okokuvikela okulondolozekayo okungokwemvelo, njll.)

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

Ifayela le-Gerber

PCB design process:

Umklamo wesekethe

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:

I-Altium

I-ExpressPCB

Imvamisa yedivayisi

I-KiCad

Cadence allegro

mat

Idizayini esizwa yikhompyutha

I-DipTrace

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. Ifayela lemodeli lizokusiza ukudweba okuhlelekile. 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: imininingwane yenqubo yokuklama izoncika kuthuluzi lesoftware elikhethiwe).

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. Ngaphezu kwalokho, umenzi angahlola idivayisi ngamaphoyinti okuhlola akule dokhumenti.

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. Ngokungafani nesikimu, ukwakheka kwe-PCB kunikeza izingxenye uqobo lwazo izindawo ngqo ku-PCB futhi kukhombisa amathrekhi axhumanisa ingxenye ngayinye ndawonye phakathi kwezendlalelo ze-PCB. 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 mfushane futhi unciphise umsindo nokuphazamiseka.

I-interface yomsebenzisi (i-UI) nayo idinga ukugcinwa engqondweni lapho kuklanywa i-PCB. Izinto ezinjengejack audio, izixhumi, ama-leds, njll. Zidinga ukulungiswa ukuze kuzuzwe umuzwa omuhle womsebenzisi.

Once the layout is designed, a Gerber file is generated. Umkhiqizi wakho we-PCBA uzosebenzisa leli fayela. There are many companies that offer these services, and from HWTrek’s expert library we recommend Kingbrother, NexPCB, and HQPCB.

Sample Gerber files

Ukubekwa kwezakhi ku-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. Lokhu kuzoba yisisekelo sokuqhubeka nokwakha isisekelo sokungeza izinto ku-PCB nokukhiqiza i-PCBA (inhlangano yebhodi lesifunda ephrintiwe).

Unassembled PCBS

PCBA (Assembly)

Ukulungiselela izinto ezibonakalayo

Kuleli qophelo kumklamo wakho we-EE, kufanele ngabe ukhethe izingxenye. You can ask the PCBA manufacturer to order the required components for you, or do it yourself if you choose a supplier. Izinto ezidinga ukunakwa:

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.

Ubuncane be-oda ubuningi: Bheka ubuncane be-oda lobuncane bento. Uma uthenga okungaphansi kobuncane, qiniseka ukuthi izingxenye ezikhethiwe zisesitokweni. For small batches (up to 50), you can order online from DigiKey or Mouser. Ukuze uthole amanani amaningi, sicela ufune izeluleko 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 (surface mount technology) iyindlela esetshenziswa kakhulu ekukhiqizweni. It is done by fast, accurate SMT machines that save you time, money and avoid human error.

Izinto okumelwe 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

Ukugcwalisa okokugcwala kwe-Reflow kuyinqubo yokwenza izingxenye “zinamathele” ku-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. Umakhi we-PCBA onokwethenjelwa uzobhekana nale nqubo, futhi konke okudingeka ukwenze ukubanikeza imininingwane yento.

Inqubo ye-Reflux.

Ezinye izindlela zokushisela:

I-Wave soldering isetshenziselwa kakhulu izinto ezingezwe ngesandla ngendlela embobo. Kulokhu, i-PCBA yakho izoqala idlule esithandweni se-welding esivuselelayo, bese ungeza ngesandla ezinye izinto ngemuva kokuthi idlule kumshini we-wave soldering.

Ukushisela insimbi kungasetshenziselwa izimo ezithile, kepha hhayi ukukhiqizwa ngobuningi.

Ukuhlolwa nokuhlolwa kwekhwalithi

Kulesi sinyathelo, amasampula e-PCBA ahlolwa ukuqinisekisa ikhwalithi. Amaphutha ajwayelekile yilawa: amasekhethi amafushane ezintweni ezinqanyuliwe, izinto ezihlelwe kabi nezingxenye zesifunda okungafanele zixhunywe. Ukuhlolwa okuvame kakhulu:

I-ICT (Ukuhlolwa okuku-inthanethi). When designing a PCB, some test points are usually reserved for debugging, programming, and other purposes. Umshini we-ICT uzosebenzisa lawa maphuzu okuhlola ekuvivinyweni kwesifunda okuvulekile / okufushane futhi uhlole ukuthi amanani wezinto zokwenziwa (ama-resistors, ama-inductors, ama-capacitors) aphakathi kwebanga lokucaciswa.

I-AOI (Ukuhlola okuzenzakalelayo kokukhanya). Manufacturers use a “gold sample” (reference PCBA) to compare with other samples. Kulesi sivivinyo, umakhi wehadiwe uzodinga ukunikela ngemininingwane nokubekezelelana kumenzi ukusetha amapharamitha.

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