Pcb Design Checklist Manual Versus Automation

PCB design rule file, pad and via libraries have been imported to prototype PCB project Schematic components are connected according to datasheet specifications (eg. Pull-up-or-down resistors, etc.) and schematic compiles without errorCu Weight Internal Layers: Do your Cu weight internal layers fall within 1/2 oz - 2 oz & line/space в‰Ґ.003 - Min. Line/space в‰Ґ.006?240 5.10 Manual Versus Automation in PCB Design 241 5.11 Photoplotter 242 5.11.1. 251 5.14 PCB Design Checklist 252 5.15 Useful Relevant Standards 254 6.Cu Weight External Layers: Do your Cu weight external layers fall within 1/2 oz - 2 oz & line/space в‰Ґ.003 - Min. Line/space в‰Ґ.006?Are holes and conductive surfaces plated per IPC-6012 Class II?Is solder mask required? For example: component side only, solder side only or both sides & color.Do you know which surface finish to use? For example: ENIG, HASL, Silver, ENEPIG, etc.Is silk screen required? For example: component side only, solder side only or both sides & color.Is the vendor UL logo & date code required?Do you know what tolerances you will be using (finished hole tolerance в“ mils, linear tolerance в‘0 mils, or PCB thickness tolerance 10% в‰Ґ 3 mils)?Will you be requiring fabrication and acceptance guidelines that fall within IPC-6012 Class 2?Are you able to supply manufacturing files? Example: drill/gerbers or ODB++.Do you have a fabrication drawing with specifications, tolerances, etc.?Do you have local fiducials for assembly?Do you have a BOM (bill of materials with part #s and notes), pick and place file (X & Y coordinates of the components), and an assembly drawing with reference designators, pin 1 locations, anode/cathode locations?Do you know what type of assembly this will be? (RoHS/leaded or clean/no clean)Here's an example of an assembly drawing: Fab Drawing Example.pdfHere's an example of a Bill of Materials for PCB Manufacturing: Example BOMNow that you have your manufacturing checklist, youвЂ™ll know exactly what you need to have a seamless manufacturing process. To support the Connected World, todayвЂ™s PCB design tools today are reliability-oriented, providing an array of tools and capabilities to improve design success.

Mistakes, oversights and omissions can delay project releases. Electronics design services can be a complex undertaking over several weeks or months. You can refer to this checklist while you place a quote through our website.At SFC, our specialty is advanced PCB fabrication and assembly producing excellent multi-layered PCBs and unparalleled technical expertise at competitive prices. Many of our customers request PCB production with higher expectations compared to other normal circuit board providers.Are you looking for PCB fabrication or PCB assembly? WeвЂ™ve got you covered. We hope the notes and manufacturing checklist above are helpful for you.

They have been seen so regularly that it is very difficult to spot errors, which in some cases are obvious to a fresh pair of eyes.Design reviews, especially those performed by a different engineer to the designer, can be invaluable in identifying issues before sending designs out for manufacture. This is why an in-depth design review is highly recommended.Familiarity with the schematic, printed circuit board or source code can quickly make the design engineer blind to these errors. Additionally, if not spotted until after product release, they can even cause product recalls or warranty claims.

We then review the PCB layout. At Ignys weвЂ™ve split these reviews into:This is to ensure that the schematic is correct prior to putting effort into a printed circuit board (PCB) layout. While ensuring that the designed circuits are free from errors.If you are new to design reviews, or if your company hasnвЂ™t previously embraced them, itвЂ™s useful to create a design review checklist. Typically for a design review, we want to check that all aspects of the design requirements have been addressed. The process helps to avoid missing out review steps and, in a multi-engineer environment, helps keep review consistency. There are dangers in doing so, as you will review the design with the same assumption you used to design the electronics in the first place.Related service: Borrow an Engineer The processMost complex tasks are made easier and more repeatable with a process.

More importantly, is to capture the collective prior experience of the team. Such as ensuring each sheet of the schematic has a company drawing box, page numbers, change control and is legible. They can include part of your quality standards. For a guide to Gerber files and general electronics see our brief guide to CAD for electronic PCBs.The checklists should include everything you need to check during the design reviews. The Gerber files need to include all of the copper, silkscreen, solder mask, paste mask and layer stack information for manufacturing.

This should then be worked through with the designer to ensure the identified issues are understood and worked through. It is often enough to mark up the schematic, checklist and requirements and then scan them in as a design review pack. It is also worth checking at this point that the design is as simple as it can be, complexity adds component cost and engineering time.There is little value in the formal write up of design reviews. This is to check that best practise has been followed and that the circuitry will perform as required. For each circuit work through the previously created checklist, and any design simulations or notes. The aim is to verify that each of the required functions has been addressed.

A second benefit comes from another engineer having some familiarity with the design. This can be from best practice observations, which should be added to an up-issued version of the design review checklists. Additional benefits come from the spreading of knowledge within the design team. The benefitsThe most obvious benefit of design reviews is capturing mistakes and omissions early on in the design process before prototypes are manufactured.

Having a review process is not an excuse for sloppy work to be picked up by someone else later. The challengesDesign engineers should know it is expected that their work is completed to a high standard, which could go straight to prototyping. They can more quickly to pick up the project if there are resourcing or illness issues.

Design reviews should take enough time for each aspect of the review checklist to be verified. This approach can be worse than having no review at all. In a pressured engineering environment, where time is precious, there is a temptation for design reviews to be a quick tick box exercise.

Contrast this with the time and cost for a prototype to be manufactured and then tested. Whereas a more complex one may take up to a few days.Following the review, there is also additional time required to address the issues identified. A thorough design review takes between 2 hours for a fairly simple design. Each check should be made fully.

unexpected behaviour from the integrated circuits used The unfortunate reality is that, even with design reviews in place, most designs need a second spin of printed circuit boards to address unforeseen issues. DonвЂ™t fear missed errorsThere is a danger of allocating too much time and effort to design reviews through fear of having to have designs right first time especially after spending extra time on reviews.

We hope weвЂ™ve shown you why this is the case here and, of course, if you would like to talk about how we can help you to design or implement a design review process, get in touch. For first off builds, only manufacture a small number of prototypes as the more you build the lower their quality, see FletcherвЂ™s Law for more information on this.Reviews must be an integral part of any design process. unforeseen interactions between circuitryThere comes a point where prototypes simply must be manufactured and tested to verify their operation and performance. design mistakes missed by both the design and reviewing engineer