Any prototype is important as it is the semi-final version of your proposed product. An electronic prototyping company helps you catch any discrepancies and determine what works well before you spend valuable investment in launching your product only to face losses if has flaws. It is your prototype that will calculate accuracy, gauge further requirements and obtain market feedback.
Your electronic prototype combines both hardware and software designs of custom Printed Circuit Boards (PCB) to assemble a fully functional prototype. Business owners may often find themselves lost in the terminology of micro-controller programming. Add to this the involvement of technical skills such as soldering, circuitry, programming, wiring, it may all sound too complicated and daunting. But one word of advice, these skills do not require your expertise as a business owner, investor or entrepreneur, just know what they entail and make sure you have a solid team of electronics engineers to do the rest. After all, it makes sense to have basic electronics knowledge before deciding to initiate an electronics business.
Why choose to prototype?
If a business chooses not in invest in a working with an electronic prototyping company and creating a prototype, that decision may actually be a poor one in the long run. Your design on paper or screen, may not display its discrepancies. Your prototype on the other hand, shows your proposed product and verifies what works and what doesn’t.
Structural weaknesses in your will design will definitely affect functionality. Think ahead: if you’re launching a design that has not been prototyped it may end up costing you more as you discover flaws post-production. Finding pre-production glitches and fixing them curbs your costs. If there are any design loopholes you get to work on them before product launch
Yes, testing the prototype, uncovers potential deal breakers in terms of design or functionality flaws. And in working towards eliminating these issues, you begin to develop pre-production quality assurance testing methods and standards. It is these standards that can be used to gauge all further improvements of your initial design.
How to create a PCB prototype?
The first step towards creating your prototype is to review specifications and requirements. As a professional electronic prototyping company, this is done by our expert team of electrical engineers to design a well-defined system architecture and decide upon core technologies to utilize. After categorizing sub-systems, critical components are typically evaluated individually to reduce risk.
Next a big board prototype is fabricated using evaluation circuit boards. In doing so, the subsystems are combined into a pilot evaluation platform allowing designers to recommence software development. Prototype software functionality must be validated, and hardware components clearly defined, before merging the subsystems into a custom prototype printed circuit board (PCB). Know that the more complex your product design, the more it will cost. But asking your primary developers to simplify your product to save you a little budget-wise may not generate the results you require in the end result.
Is one prototype enough?
Developing the final fabricated PCB, may require multiple prototype reconstructs. This is especially true of prototypes that may have been developed for limited-function boards to test proof-of-concept of single functions. Then the integrated processes are checked to produce a more complex finished product. Since the steps are segregated, testing each would end up in producing different prototypes.
The PCB Prototyping Process
PCB prototyping takes time, especially since there are many sub-processes involved; from design conception, to plating to final PCB integration: the prototype may also require you to collaborate with a third-party PCB manufacturers and/or an electronic prototyping company. As such your design team’s primary task will be to develop and visualize the relevant design. Only by using a working concept and developed design that our electronics engineer(s) will conceptualize the end-result, plus it helps gather the right electronic components and topology your electronic product requires.
The electronics engineer must devise a circuit design before laying it out on the potential printed board, integrating the circuits to ensure PCB compatibility. You may also want to contact your electronic prototyping company or PCB manufacturer to get expert recommendations for PCB specifications in this regard. After laying out the PCB design, it can take up to two weeks for the manufacturer to produce and send you your first PCB prototype.
Corrections and modifications may be required on this first prototype, sometimes even two to three, before a final PCB prototype is perfected by your PCB manufacturer/company. If you get everything correct on the very first prototype, that is great; but it will diminish your stress to know that revisions are a normal part of the development process.
Exterior Designing of the Prototype
Your product design can only be worked on after your PCB prototype is ready. This stage focuses on the exterior design of the product along with the shell or mold that holds the PCB. In order to promote your product; design, aesthetics and functionality will affect how successful your product is.
Since electronic prototype development and manufacturing is now just as accessible to small businesses as to huge conglomerates, it is the best option for many small business who cannot afford to lose out big dollars on post-production flukes. Different electronic prototype companies have different preferences regarding electronic prototype development. Some may settle for viewing computer generated 3D models while others will only move forward after seeing how an actual product prototype will work. As such Design Rule Checking becomes a core step in development.
Design Rule Checking
Design rule checking or DRC confirms whether your designs meet the manufacturing capabilities of a PCB fabricator. This is an essential in design flow in order to ensure all necessary manufacturing tolerances are met. Manufacturing tolerance is the amount of variation allowable in measurements or other characteristics of objects being manufactured.
A professional designer at an electronic prototyping company will get the highest values of tolerances that PCB fabricator allow. These values are then loaded into specific design programs to run design rule checks. There are also several more sophisticated software that locate less obvious design discrepancies; these are offered by PCB fabricators as add-on services.
Two major PCB Tolerances
Most PCBs come in standard panel sizes of 18” × 24”, 18” × 12”, 9” × 24”, and 9” × 12”, with a ½” clearance around the panel border for handling panels. This required clearance can also be extend this out to 1” by some manufacturers, for multilayer boards.
The standard thickness of a PCB is normally around 1.6mm. Board thickness is not inclusive of copper weights. Such a board may have an allowable thickness tolerance of ± 0.15mm, which is ±10 percent of the actual thickness as per manufacturing specifications. Further note that for all boards the bow and twist should be 1.5 % or less. As a majority of PCB boards hold SMD components, the bow and twist on such boards should be 0.75% or less.
There are several other specifications with their relevant tolerance factors that have are detailed in our next blog: the above examples were used to explain the idea best.
Common PCB Prototype Manufacturing Design Issues
- Starved thermals. The integrated, insulated devices mounted on printed circuit boards (PCBs) that secure two or more wires together are its terminals. Starved thermals occur when the thermal relief traces connected to a pad are not properly connected to the copper plane.
- Acid traps are the acute angles in a circuit that can trap acid during PCB etching, causing an acid-build up. If the angle keeps the acid in the corner longer than the design requires, the corrosive will eat away extra, thus compromising the connection.
- Silvers are narrow wedges of copper or solder mask that may be produced whilst manufacturing PCBs. These can lead to PCB failure if they connect to other pieces of copper causing a short. Or they may expose copper plating that would normally be covered by the solder mask: resulting in corrosion of the copper over time.
- Tombstoning is when small surface mount components sometimes lift up on one end to form a “tomb stone” whilst being soldered to a PCB assembly using a reflow process. This defect drives up production costs and is often caused by incorrect landing patters or imbalanced thermal relief to the device pads.
Other faults may include
- Electromagnetic issues
- Poorly manufactured components
- Insufficient annular ring
- Via in pads
- Insufficient copper-to-edge clearance missing solder mask between pads
- Bad soldering
- Environmental factors
By not conducting a DFM or Design for Manufacturability check on your PCB, you may allow key issues to go unnoticed. Since these decrease manufacturing yields and increase costs, it is imperative to hire an experienced PCB manufacturer or electronic prototyping company to create an effective prototype and run DFM checks on your design. We provide the best services an electronic prototyping company can offer, ensuring that your PCB concept doesn’t just stay an idea, but becomes a viable working product getting you high ROIs.
