The printed circuit board design is based on the circuit schematic and implements the functions required by the circuit designer. Printed circuit board design also called layout design mainly, which needs to consider the layout of external connections. Optimized layout of internal electronic components. Optimized layout of metal wiring and vias. Electromagnetic protection. Various factors such as heat dissipation. Good PCB layout design can save you production costs and perform well with good heat dissipation.
The printed circuit board has copper tracks to connect the holes where the various components are located. It’s specially designed for each and every circuit and build construction easily. Though, making the PCB necessitates special tools. The different types of printed circuit boards mainly include the following Single-Sided PCBs, Double-Sided PCBs. Multilayer PCBs. Rigid PCBs. Flex PCBs. Rigid-Flex PCBs.
To meet the internet standards, we have ETF organization in PCB, the standards which are followed worldwide are IPC standards:
Design standards as defined by IPC:
• IPC-2221 Generic Standard on Printed Board Design
• IPC-2222 Sectional Design Standard for Rigid Organic Printed Boards
•IPC-2223 Sectional Design Standard for Flexible Printed Boards
• IPC-2224 Sectional Standard for Design of PWBs for PC Cards
•IPC-2225 Sectional Design Standard for Organic Multichip Modules (MCM-L) and MCM-L Assemblies
•IPC-2252 Design and Manufacturing Guide for RF/Microwave Circuit Boards
How to start designing PCB
Before starting designing your PCB, it’ would be a good idea to make a schematic of your circuit. The schematic will act as a blueprint for laying out the traces and placing the components on the PCB. Also, the PCB editing software can import all of the components. footprints, and wires into the PCB file. which will make the design process easier.
Prototyping occurs at the earliest stage of the design and involves individual engineers researching how to define a certain system or application. When the design has been validated. it can be passed to the latter stages of the design flow. The ultimate goal of the prototyping stage is to have a successful product that is accurate, efficient and meets specifications. You want to finish this with a few prototype iterations to maximize time and resources.
Product Development is enabling a PCB ready for a final application. The prototype has already met. the design specifications and it is now ready to take that design and to implement it using the best practices in design. Most companies have individuals that are layout experts and are involved in product development. During this design stage, you are developing for manufacturing and as such are concerned about increasing product yields and decreasing manufacturing re-spins.
It is important to understand this difference as there are various tools that are best fitted to each of these stages of the design flow.
For example, for prototyping you need to be able to :
- Define the circuit schematic speedily
- Validate circuit behavior with high-tech analysis techniques
- Transfer a schematic to layout easily
- Validate the behavior of the design accurately
TinyCAD is a good PCB design software tool suitable for electronics engineers that want a solution to supports standard, custom symbol libraries, and supports PCB layout programs with several netlist formats.
Key Features: Often used to draw one-line diagrams. block diagrams and presentation drawings.
Moko Technology’s in-house PCB design team uses IPC compliant industry-standard tools to support the schematic and layout of simple to complex PCB technologies. Industry approved the standard. tools help in increasing predictability and accelerate turnaround time. Moko Technology offers EMS service, they cannot only design but manufacture and assemble PCB designs.
Moko Technology exceptional dedicated team of PCB design engineers with flexible business models in house/onsite/offshore/near-shore makes sure that customer gets the best service with the best price.
How to design PCB layout
- Draw an overview plan of where the different circuit areas will be located One of the first parts of the circuit layout is to draw a rough plan of where the major components and component areas will be located. In this way, critical track runs can be assessed along with judging the mos convenient design.
- Choose reference points that suit the manufacturing process. It is normally necessary to have reference holes or points on the board. These are used for pick and place machines and test fixtures. Often they may be holes for fixtures.but they may also be crossed marks for optical sensors. They must be clear of components, and not obscured.
- Keep an adequate board area for the circuit. Usually, the dimensions of the board will be defined by the overall product size, but before the PCB design starts, estimates should be made regarding the size of the board and whether it can accommodate the components and their tracks.
- Determine the number of layers required It is wise to determine the number of track layers that are needed within the printed circuit board at the beginning of the design. Additional layers increase the production costs but may mean that the tracks can be accommodated. Complex designs may have many tracks, and it may not be possible to route them unless sufficient lavers are available.
- How the printed circuit board will be mounted at the beginning of the design is necessary to consider. Different methods of mounting require different areas of the board to be kept free.
How to decrease cost through PCB design
Rеduсing соѕt iѕ роѕѕiblе frоm the vеrу firѕt ѕtер in thе рrосеѕѕ. Yоur bаrе PCB dеѕign саn be орtimizеd tо рrеvеnt еrrоrѕ аnd reduce cost. You саn ѕubjесt уоur PCB’ѕ tо a dеѕign-fоr-mаnufасturing (DFM) tеѕt, оffеrеd frее оf сhаrgе bу ѕоmе manufacturers, tо diѕсоvеr роѕѕiblе аrеаѕ оf соnсеrn.
- Lауеr Count: This оnе iѕ оbviоuѕ, but thе mоrе lауеrѕ in уоur аѕѕеmblу, thе highеr thе соѕt. Yоu’ll аlѕо wаnt tо аѕk fоr сlеаrаnсеѕ between bоаrd lауеrѕ tо avoid highеr rеjесt rates.
- Sizе аnd Shаре: Thе lаrgеr thе bоаrd, thе mоrе еxреnѕivе it will be. Shаре саn bе a kеу fасtоr аѕ wеll. Kеерing уоur bоаrd tо соmmоn ѕԛuаrе аnd rесtаnglе shapes will аllоw fоr mоrе еffiсiеnt раnеlizаtiоn оf thе bоаrd. Alѕо, ѕtееr сlеаr of slotting when роѕѕiblе tо аvоid additional соѕtѕ.
- Hole Sizе and Quаntitу: Holes аnd аnnulаr ringѕ аrе just thе opposite. Smаllеr hоlеѕ rеԛuirе thе uѕе оf mоrе рrесiѕе mасhinеrу аnd роѕѕiblу аdditiоnаl сhеmiсаl рrосеѕѕing, inсrеаѕing thе price аѕ a rеѕult. Uѕе hоlеѕ 0.4” аnd ringѕ 0.3” оr lаrgеr whеn роѕѕiblе to maintain lоwеr соѕt.
- Cоmрlеxitу: Anоthеr оbviоuѕ one, but thе mоrе соmрlеx уоur bоаrd iѕ, thе highеr thе рriсing tеndѕ tо bе. Fосuѕ on dеѕigning a ѕimрlеr board thаt’ѕ utilizеd to itѕ full еxtеnt withоut ѕасrifiсing соmроnеnt сlеаrаnсе.
- Cорреr Thiсknеѕѕ: Whеrе possible, trу tо kеер сорреr tо ½” thiсknеѕѕ аnd PCB’ѕ tо 1/16” thickness.
- Utilizе Mаnufасturеrѕ’ Sоurсing Sеrviсеѕ: Cоmроnеnt ѕоurсing rеԛuirеѕ a lоt оf timе and dеdiсаtiоn. Iѕѕuеѕ likе оbѕоlеtе раrtѕ саuѕе hеаdасhеѕ аnd соmрliсаtе mаttеrѕ furthеr. Fоr that rеаѕоn, it mаkеѕ ѕеnѕе for smaller соmраniеѕ tо rely оn mаnufасturеrѕ tо hаndlе thеѕе dutiеѕ. Most PCB assemblers оffеr ѕоmе ѕоrt оf ѕtrаtеgiс sourcing ѕеrviсе аnd саn uѕuаllу рrосurе соmроnеntѕ аt whоlеѕаlе prices.
- Deliver a Cоmрlеtе, Aссurаtе BOM: Thе bill оf materials iѕ ѕimрlу a liѕt оf раrtѕ аnd components used оn a PCB. It соntаinѕ сritiсаl infоrmаtiоn likе раrt numbеr, mаnufасturеr’ѕ nаmе, ԛuаntitу, аnd соmроnеnt replacements. Bе ѕurе to accurately include all nесеѕѕаrу infоrmаtiоn whеn ѕubmitting уоur bill tо rеduсе bасk-аnd-fоrth timе.
- Dоn’t Skimр On Inѕресtiоn: Inѕресtiоn ѕеrviсеѕ uѕuаllу add tо соѕt, but thе bеnеfitѕ аrе fаr mоrе important. Mаnу mаnufасturеrѕ оffеr in-hоuѕе inѕресtiоn, ѕаving уоu frоm оutѕоurсing tо another third раrtу соmраnу. Thе uѕе оf in-line inѕресtiоn еԛuiрmеnt оr burn-in tеѕting hеlрѕ аѕѕurе thе ԛuаlitу оf your рrоduсt bеfоrе it ever lеаvеѕ the mаnufасturing flооr. Research whiсh tуре оf inѕресtiоn еԛuiрmеnt iѕ bеѕt fоr уоur аѕѕеmblу. Sеrviсеѕ burn-in test, аutоmаtеd аnd x-rау inѕресtiоn аrе аll орtiоnѕ that dереnd оn уоur bоаrd’ѕ соmроnеnt tуре, lауеr соunt аnd уоur оwn рrеfеrеnсе.
How to reduce PCB design risks
If we can predict the possible risk, then a Printed circuit board design will succeed more easily. The key point to reach the target is about signal integrity in the PCB design. Let’s find out the relevant content together.
For electronic system design, the chip suppliers have finished manufacturing many product solutions. including what kind of chip to use. how to build external circuits and so on. Hardware engineers often rarely do not need to consider the principle of the circuit, they only have to make printed circuit boards on their own.
However, problems would occur during PCB design, such as PCB design is out of instability, or the printed circuit board assembly boards do not work. For some large companies, many chip manufacturers will provide technical support for PCB design guidance. But some small and medium enterprises are difficult to get this support. Therefore, we must find a way to fix it on their own and there are a lot of problems that occurred, maybe they have to make a printed circuit board prototype for times, or cost a very long time on debugging. In fact. all of this can be avoided if we understand the system design methods.
Three skills to reduce the PCB design risk:
• Firstly, we must regard the signal integrity issues in the layout planning stage, let’s layout in this way: is the signal properly received from one PCB to another PCB? We have to evaluate this early. and this is not difficult to do. only if we know a little signal integrity knowledge and awareness of the simple software operation,
• Secondly, during the PCB design process, using the simulation software to assess the specific alignment, to see if the signal quality can meet the requirements or not, the simulation process is not that complex, the key is to understand the principle of signal integrity knowledge, and use it for guiding.
• Thirdly, we must do well on risk control in PCB design. There are many problems that cannot be solved by the simulation software, must be controlled by the PCB designer.
If we can master the PCB design tips well, it will help to reduce the failure possibility and no need to make times of PCB boards to save cost & time, also the debugging is relatively easy.
How to protect PCB design from PCB manufacturer
To avoid your design being copied by the PCB manufacturers or even turnkey contractor manufacturer, there are many ways.
• You can request the manufacturer to sign the NDA with you so you will get your design legally protected.
• To get a real product, like components, there are many things need to be done, software, enclosure, etc. Without programming and software, you can not get a “product” run.
• The contract manufacturer will not copy your design, because their core business is different from yours. There is much more work that needs to be done rather than manufacturing a product. for example sales& marketing etc.