What is the most efficient method of providing a PCB manufacturer with artwork?
Gerber files are the standard today. If you only have 1:1 scale positives or negatives, we will be able to work with them also. For a small fee your artwork can be digitized and converted to gerber files for a more precise finished product. See below for further information regarding formats.
Apart from the data file of the track work, what other information does a PCB manufacturer need before production can begin?
Basic specification data is often omitted. We need to know finished board thickness, copper weight of inner and outer layers, silkscreen legend color, solder mask color, profile tolerance and ML build if impedance is critical.
What is the best way to dimension the finished profile of the board?
The profile of a board should always be referenced to an easily recognized datum. This can either be a component hole or the finger of a gold edge connector. Clear, uncluttered dimensions eliminate any chance of error or confusion. The golden rule must be keep it clear and simple.
What are the silkscreen legend restricitons?
We need at least 8 mil clearance from the soldermask artwork for workable silkscreen clearance. If we find any legend encroaching on a hole or pad we will clip to IPC specifications unless otherwise notified by our customer.
What is the practical limit for solder mask dams between surface mount pads?
Usually 0.25 mm is sufficient for the solder mask dams.
Do via holes need pads on the outer layers?
Yes, and it should be remembered that these must be at least 0.3mm larger than the finished hole size to ensure that the drilled hole is adequately surrounded by copper at all stages of manufacture.
Can I leave isolated tracks on the surface of the board?
This is a most unwise procedure. These isolated tracks will become over plated and will be difficult to cover with solder mask. If the design needs an isolated track then it is advisable to cross hatch the unpopulated area.
What is the smallest via hole that can be incorporated before incurring additional cost?
As boards are stacked for drilling, the size of the smallest hole determines the drilling stack height. Often via holes are unnecessarily made too small with the effect of increasing drilling costs. For most manufacturers, the smallest via before incurring a cost penalty would be around 0.45mm finished size.
What are the cost implications of buried vies?
The cost of a blind and buried via board depends upon the quantity of holes between different layers, as this will dictate the number of bonding and drilling operations. Typically a 50% increase in price occurs. It is often more cost effective to increase the layer count by 2 layers than move to blind and buried via.
What is your standard delivery?
We offer 15 days, but are currently working on our throughput time so that we can reduce this further.
What prototype service do you offer?
We offer same day/24 hour to 1 week turn on proto-types for single and double sided. 48 hours to 1 week turns are available for up to 6 to 8 layer boards. 1 week turns available for higher layer counts. Production deliveries of 2-3 weeks for single and double sided boards, with 3 week deliveries on multilayer boards is standard.
Is test included in the price?
An element of the testing charge is included in the board price and a small test fixture charge may also be included dependent upon the type of test, not required for proto-type orders.
What format can you read?
We prefer to receive Gerber (RS274X preferred)data. We can work with HPGL, ACAD DWG/DXF, but these formats may require conversion charges. If you cannot output in these formats or are unsure, send your design data and we will advise if any charges will be incurred.
Starting Requirements, Standards Specifications
The following is a list of the desired components needed to start a job.
1. Gerber Data for All Artwork Layers
2. Aperture* List or Lists for all layers.
3. Drill file in Gerber or Excellon format.
4. Prints that show:
(Print should be a hard copy, or in Gerber or HPGL format.) • Fab dimensions with tolerances.
• Hole coding.
• Overall thickness.
• Hole size reference with the following info. For each symbol.
• Finished Hole Size.
• Plated vs. Non plated.
• Hole quantity
5. Special Notes or "Read Me" file that pertains to:
• Color and type of solder mask.
• Color of Silkscreen.
• Plating thickness for Copper, Nickel and Gold
• Notes for Cross sectioning or Data code.
• Controlled Impedance Requirements and tolerances if any.
• Any other special requirements or instructions.
6. Standards and Specifications:
• IPC-A-600 Acceptability of printed wiring boards.
• IPC-RB-276 Qualification and performance specs.
( Class 2 )
• IPC-2221 Design standards for rigid printed boards.
• IPC-TM-650 Test methods manual.
• IPC-SM-840 Qualification and performance of permanent polymer coatings.