From prototype circuits on bread boards to designing our own buga kewaye hukumar (PCBS), it was like getting off the training wheels. Akwai abubuwa da yawa da za a koya game da wannan tsarin, don haka bari mu fara. PCB design is carried out in an electrical engineering (EE) process. EE yana ƙirƙirar “kwakwalwa” na yadda na’urori ke aiki. 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). An ayyana girman samfur yayin aikin ƙirar injiniyan lantarki. You can watch a video about it here. 2. PCB yadudduka – Da yawa yadudduka, mafi rikitarwa MANUFACTURE na PCB. (Lura: Ko da PCB-Layer guda ɗaya na iya zama PCB mai rikitarwa, amma a nan muna magana ne game da sarkakiyar yin PCB. Da yawa yadudduka da PCB ke da shi, mafi tsada shine ƙira.)

Layer 2 is usually used for simple toy products

Samfuran da ke da alaƙa yawanci suna da yadudduka 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.

Bayanin da kuke buƙatar bayarwa ga masana’antun PCB:

Yawan yadudduka (misali 2, 4, 6, da dai sauransu)

Kayan aiki (FR-2 (takarda auduga na phenolic), FR-3 (takarda auduga da epoxy), FR-4 (fiber glass da epoxy… Etc.)

Thickness (0.5 mm, 1.0 mm… Etc.)

Color (red, black, green… Etc.)

Maganin farfajiya (ENIG (nickel na sinadarai/nutsewar zinare), DIG (nutsewar zinare kai tsaye), OSP (abubuwan da ke hana ruwa narkewa, da sauransu)

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

Gerber fayil

PCB design process:

Kirkirar da’ira

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:

Altium

ExpressPCB

Na’urar mita

KiCad

Cadence allegro

mat

Computer aided design

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. Fayil ɗin samfurin zai taimaka muku zana ƙira. 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. (Lura: cikakkun bayanai kan tsarin ƙira zai dogara ne akan kayan aikin software da aka zaɓa).

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

Kyakkyawan tsari yana da mahimmanci da gaske, saboda za a yi amfani da shi azaman takaddar tunani yayin ɓarna kuma kayan aikin sadarwa ne mai kyau tare da wasu injiniyoyi. Bugu da ƙari, mai ƙera zai iya gwada na’urar ta wuraren gwajin akan wannan takaddar.

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. Ba kamar tsari ba, tsarin PCB yana sanya ainihin abubuwan da aka gyara zuwa ainihin wurare akan PCB kuma yana nuna waƙoƙin da ke haɗa kowane ɓangaren tare tsakanin matakan 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. Ta wannan hanyar, za ku iya takaitaccen alama mai gudana kuma ku rage amo da tsangwama.

Hakanan ana buƙatar kiyaye ƙirar mai amfani (UI) yayin zayyana PCB. Abubuwan da aka haɗa kamar jakar sauti, masu haɗawa, leds, da sauransu suna buƙatar daidaitawa don cimma mafi kyawun ƙwarewar mai amfani.

Once the layout is designed, a Gerber file is generated. Mai ƙera PCBA ɗinku zai yi amfani da wannan fayil ɗin. Akwai kamfanoni da yawa waɗanda ke ba da waɗannan sabis ɗin, kuma daga ɗakin karatun ƙwararrun HWTrek muna ba da shawarar Kingbrother, NexPCB, da HQPCB.

Sample Gerber files

Sanya abubuwan da aka gyara akan PCB yana da mahimmanci. 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. Wannan zai zama tushe don ƙara gina tushe don ƙara abubuwan da aka haɗa a cikin PCB da kera PCBA (taron kwamitin da’irar bugawa).

Unassembled PCBS

PCBA (Assembly)

Shirya kayan

A wannan lokacin a cikin ƙirar EE, yakamata ku zaɓi abubuwan da aka gyara. You can ask the PCBA manufacturer to order the required components for you, or do it yourself if you choose a supplier. Batutuwa masu bukatar hankali:

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. Idan ka sayi ƙasa da mafi ƙanƙanta, tabbatar cewa abubuwan da aka zaɓa suna cikin jari. For small batches (up to 50), you can order online from DigiKey or Mouser. Don ƙarin adadi, da fatan za a nemi shawara daga masana’anta.

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)

SMT (fasahar dutsen saman) ita ce hanya mafi yadu da ake amfani da ita wajen samar da taro. It is done by fast, accurate SMT machines that save you time, money and avoid human error.

Abubuwan da za su tuna:

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

Reflow soldering shine tsari na yin abubuwan ” sanda ” akan 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. Amintaccen mai ƙera PCBA zai ɗauki nauyin wannan tsari, kuma duk abin da kuke buƙatar yi shine samar musu da ƙayyadaddun abubuwa.

Tsarin reflux.

Other welding methods:

Wave soldering is mainly used for manually added components by the through-hole method. A wannan yanayin, PCBA ɗinku za ta fara shiga cikin tanderun wutar walda na reflow, sannan ta ƙara wasu abubuwan da hannu bayan za ta bi ta mashin ɗin kaɗa.

Ana iya amfani da walda baƙin ƙarfe don takamaiman yanayi, amma ba don samar da taro ba.

Gwaji da ingancin dubawa

A wannan matakin, ana gwada samfuran PCBA don tabbatar da inganci. Kurakurai na yau da kullun sune: gajerun da’irori a cikin abubuwan da ba a yanke ba, abubuwan da ba daidai ba da sassan sassan da bai kamata a haɗa su ba. Mafi yawan gwaje -gwaje:

ICT (Gwajin kan layi). When designing a PCB, some test points are usually reserved for debugging, programming, and other purposes. Na’urar ICT za ta yi amfani da waɗannan wuraren gwajin don buɗewa/gajeriyar gwajin kewaye kuma duba cewa ƙimar abubuwan da aka haɗa (resistors, inductors, capacitors) suna cikin kewayon ƙayyadewa.

AOI (Binciken gani na atomatik). Manufacturers use a “gold sample” (reference PCBA) to compare with other samples. Don wannan gwajin, mahaliccin kayan aikin zai buƙaci samar da ƙayyadaddun bayanai da haƙuri ga mai ƙira don saita sigogi.

X ray. The PCBA manufacturer will use X-rays to check the welding conditions of the BGA (ball Grid Array) components. Kalli gwajin X-ray a cikin wannan bidiyon.