Online PCB Quote Help
Top Reasons Your Order May Go On CAM Hold
Below you will find some of the most common issues we see in regards to online circuit board orders. A lot of these can easily be resolved with the correct information provided in your circuit board engineering data files.
What is a CAM Hold?
A CAM hold is a delay in engineering caused by issues in the PCB files submitted for the job. The most common reason for CAM hold is DRC errors in the PCB file.
What are DRC Errors?
DRC stands for Design Rule Check. A PCB must pass a set of rules in order for it to be manufacturable, such as copper-to-copper spacing, and minimum via hole diameter. The manufacturer provides these design rules to the designer, and the designer uses his/her PCB software to run a DRC on the PCB layout. Any violation of the design rules constitutes a DRC error.
1. Missing Gerber Files or Incomplete Data Package:
- Your Solution: Before Uploading Gerber data, ensure that there is one gerber image layer for each conductive layer of the PCB (Including: Solder Layer, Component Layer, Soldermask Layer(s), Silkscreen Layer(s)) preferably in 274x format and a Fabrication Drawing (print) supplied either as a gerber layer, or PDF
2. Your Data Does Not Match Your Quote:
If there are any discrepancies between the order information and what the supplied documentation calls out, this can cause a hold on the order.
- Your Solution: Prior to uploading your Gerber data, double check to make sure the board specs that you selected are accurately reflected in your data. Most common errors are:
- Laminate Type (i.e.: 130 Tg v 170 Tg)
- Board Finish (i.e.: HASL v. ENIG)
3. Missing Aperture List:
Your aperture list specifies what size and shape of an object to draw at a given location (Dcode). A single comprehensive aperture list for all layers should be sent with your Gerber files, rather than a separate aperture list for each layer.
- Your Solution: One comprehensive list for all layers in English units (DO NOT modify the list your software outputs)
4. Missing Excellon Drill File:
Drill files are used to determine what size holes to drill and where. Plated and non-plated holes can be included in one drill file, with plated and non-plated holes having different tool numbers.
- Your Solution: Excellon Format, ASCII, Odd/None etc (DO NOT require step and repeat files).
5. Missing Tool List:
Where a drill file specifies where to place the hole while a tool list specifies what size tool to use. A tool list should be embedded in your Excellon drill file or sent as a separate text file. Using a tool list provided on a fabrication drawing is not preferable, as it eliminates many of the automatic verifications and makes data entry errors far more likely.
- Your Solution: Include either the list embedded in the Excellon Drill file, or sent as a separate text file.
6. Missing Array Drawing:
- Your Solution: Provide a clear array layout that is required per your quote (Can be multiple formats: PDF, DXF, DWG, Gerber, etc.)
7. Insufficient Annular Ring:
An annular ring is the ring created when your drill pierces a copper layer. For example, a .030" pad with a .020" hole would have a .005" annular ring. This is required to allow for complete plating on vias, as well as solderability on component holes. A minimum of .005" annular ring for vias or a minimum of .007" for component holes is required for manufacturing.
- Your Solution: A minimum of .005" annular ring for vias and .007" for component holes.
8. Insufficient Inner Layer Clearances:
Inner clearance is the minimum distance from the edge of a hole to any adjacent, unconnected, inner layer copper. Sufficient inner clearances help ensure that your drill does not cause shorts to your inner copper layers. This is important for both plated and non-plated holes, as non-plated holes may either cut into an adjacent trace or cause shorts during assembly.
- Your Solution: We require a minimum of .010" inner clearance, and .015" is preferred.
9. Insufficient Copper Trace Width/Spacing (Trace and space):
Copper spacing is the minimum air gap between any two adjacent copper features. Trace width is the minimum width of a copper feature, usually traces.
- Your Solution: We require a minimum of .005" trace with and spacing.
- For 1 oz. finished copper weight (inner layers), the minimum trace width/space is 0.005".
- For 2 oz. finished copper weight (inner and outer), the minimum trace width/space is 0.006".
- For 3 oz. finished copper weight (inner and outer), the minimum trace width/space is 0.010".
- For 4 oz. finished copper weight (inner and outer), the minimum trace width/space is 0.012".
Anything less will require a custom quote through our Customer Service department (firstname.lastname@example.org)
10. Missing Board Rout Outline:
A board outline/rout path needs to be included with your file set. Gerber files are preferred, but a dimensioned drawing will work provided it is simple to make an outline from, and we can determine how to align it correctly relative to the circuitry. As long as we can identify a line that is the perimeter of your board and it matches your ordered dimensions, we will use it for your board outline.
The most common method that customers use for communicating how to cut out their board is to place a 10 mil line on the top copper layer around the perimeter of their circuit, centered on where they want us to cut. We prefer a 10 mil wide line on the mask layer. The edge of the router bit will cut to the center of the given line unless we are told otherwise in the notes. Some customers put the board outline on all layers.
The board outline/route path can be found on an assortment of layers depending on the PCB software program used. We commonly see the board outline on one of the mechanical layers (.gm1 to .gm10). Some software packages have the outline on the .out (outline), .mil (milling layer), .fab (fabrication layer) or the drill symbols layer. The drill symbols layer usually has the drill chart, symbols showing where the drill hits are and the board outline along with any internal cutouts for the board.