Mai nā huakaʻi prototype ma nā papa berena a hoʻolālā ʻana i kā mākou iho papa kaapuni i paʻi ʻia (PCBS), it was like getting off the training wheels. There’s a lot to learn about this process, so let’s get started. Lawe ʻia ka hoʻolālā PCB i kahi kaʻina hana uila (EE). Hoʻokumu ʻo EE i ka “lolo” pehea e holo ai nā hāmeʻa. 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). Hoʻomaopopo ʻia nā ana huahana i ka wā o ka hoʻolālā ʻenekini uila. You can watch a video about it here. 2. Pākuʻi PCB – Ka nui o nā papa, ʻoi aku ka paʻakikī o ka MANUFACTURE o PCB. (Kahakaha: ʻOiai ʻo ka PCB hoʻokahi papa hiki ke lilo i PCB paʻakikī, akā eia mākou e kamaʻilio nei e pili ana i ka paʻakikī o ka hana ʻana i kahi PCB. ʻO ka nui o nā papa o ka PCB, ʻoi aku ka pipiʻi o ka hana ʻana.)

Layer 2 is usually used for simple toy products

ʻO nā huahana pili Iot he mau papa 4 mau

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.

ʻO ka ʻikepili āu e pono ai e hoʻolako i nā mea hana PCB:

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

Nā Pono Hana (FR-2 (pepa pulupulu phenolic), FR-3 (pepa pulupulu a me epoxy), FR-4 (aniani puluniu a me epoxy … Etc.)

Mānoanoa (0.5 mm, 1.0 mm … Etc.)

Color (red, black, green… Etc.)

Ka mālama ʻana i ka ʻili (ENIG (nika kemika / immersion gula), DIG (kaomi ʻana i ke gula pololei), OSP (nā mea hoʻoweliweli solderable meaola, a pēlā aku.)

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

Waihona Gerber

PCB design process:

Hoʻonohonoho kiʻi

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

Hāmeʻa pinepine

KiCad

ʻO Cadence allegro

moena

Computer aided design

ʻO 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. E kōkua ka faila hoʻohālikelike iā ʻoe e kahakiʻi i ka hoʻolālā. 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. (Nānā: e pili ana nā kikoʻī o ke kaʻina hoʻolālā i ka pono polokalamu i koho ʻia).

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. Eia hou, hiki i ka mea hana ke hoʻāʻo i ka hāmeʻa ma o nā helu hōʻike ma kēia palapala.

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. ʻAʻole like me kahi skema, hāʻawi kahi hoʻonohonoho PCB i nā ʻāpana maoli i nā wahi kikoʻī ma ka PCB a hōʻike i nā ala e hoʻohui pū i kēlā me kēia mea ma waena o nā papa 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. I kēia ala, hiki iā ʻoe ke mālama i ke ala conductive pōkole a hoʻoliʻiliʻi i ka walaʻau a me ke ākea.

Pono e hoʻomanaʻo i ka ʻōnaehana hoʻohana (UI) i ka wā e hoʻolālā ana i kahi PCB. Pono e hoʻoponopono i nā mea e like me jack jack, nā mea hoʻopili, nā leds, a pēlā aku.

Once the layout is designed, a Gerber file is generated. E hoʻohana kāu mea hana PCBA i kēia faila. There are many companies that offer these services, and from HWTrek’s expert library we recommend Kingbrother, NexPCB, and HQPCB.

Sample Gerber files

He mea nui ke kau ʻana i nā mea ma ka PCB. 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. ʻO kēia ke kumu e kūkulu hou i ke kahua no ka hoʻohui ʻana i nā ʻāpana i ka PCB a me ka hana ʻana i ka PCBA (ʻaha hui kaapuni).

Unassembled PCBS

PCBA (Assembly)

Hoʻomākaukau mea

I kēia manawa i kāu hoʻolālā EE, pono ʻoe i koho i nā ʻāpana. You can ask the PCBA manufacturer to order the required components for you, or do it yourself if you choose a supplier. Nā mea e pono ai ka nānā ʻana:

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. Inā kūʻai ʻoe ma lalo o ka palena iki, e ʻike pono i nā mea i wae ʻia i ka waihona. For small batches (up to 50), you can order online from DigiKey or Mouser. No nā mea hou aku, e ʻimi i ka ʻōlelo aʻo mai kāu mea hana.

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)

ʻO SMT (ʻenehana kuʻuna pae kiʻekiʻe) ka hana i hoʻohana nui ʻia i ka hana nuipaʻa. It is done by fast, accurate SMT machines that save you time, money and avoid human error.

Nā mea e hoʻomanaʻo ai:

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

ʻO ka soldering Reflow ke ʻano o ka hana ʻana i nā ʻāpana “stick” i ka 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. ʻO kahi mea hana pono PCBA e kuleana no kēia hana, aʻo nā mea āu e pono ai e hāʻawi iā lākou i nā kikoʻī kikoʻī.

Kaʻina reflux.

Other welding methods:

Hoʻohana nui ʻia ka soldering wave no nā mea i hoʻohui ʻia e ka hana ma o ka puka ma o. I kēia hihia, e hele mua kāu PCBA ma waena o ka umu hoʻoheheʻe reflow, a laila hana lima i nā mea ʻē aʻe ma hope o ka hele ʻana i loko o ka mīkini soldering nalu.

Hiki ke hoʻohana i ka hao hao no nā kūlana kikoʻī, akā ʻaʻole no ka hana nuipa a.

ʻO ka hoʻāʻo a me ka nānā pono ʻana

I kēia anuu, ua hoʻāʻo ʻia nā laʻana PCBA e hōʻoia i ka maikaʻi. ʻO nā hewa maʻamau nā: pōkole pōkole i nā ʻāpana i hoʻohui ʻia, nā ʻāpana misaligned a me nā ʻāpana o ke kaapuni ʻaʻole pono e pili. ʻO nā hōʻike maʻamau loa:

ICT (hoʻāʻo pūnaewele). When designing a PCB, some test points are usually reserved for debugging, programming, and other purposes. E hoʻohana ka mīkini ICT i kēia mau helu ho’āʻo no ka hoʻāʻo hāmama hāmama / pōkole a nānā i nā waiwai o nā mea passive (resistors, inductors, capacitors) i loko o ka laulā kikoʻī.

AOI (Nānā ʻike ʻōnohi). Manufacturers use a “gold sample” (reference PCBA) to compare with other samples. No kēia ho’āʻo, pono i ka mea hana lako pono e hoʻolako i nā kikoʻī a me nā ahonui i ka mea hana e hoʻonohonoho i nā palena.

X kukuna The PCBA manufacturer will use X-rays to check the welding conditions of the BGA (ball Grid Array) components. E nānā i ka hōʻike X-ray i kēia wikiō.