USA PCB FABRICATION SERVICES

Board Outlines

The standard tolerance is +/- 0.010"
We rout to your board size using the center of the board outline.

Your printed circuit board outline does not have to be square or rectangular. You can submit round boards or boards with a complex shape. Our requirement is that we can convert your outline to a continuous unbroken path. By default, we will rout your board outline with a 0.0625" diameter rout bit. This will result in a minimum radius of approximately 0.032" on inside corners. If your design contains inside corners with radii of less than 0.032", then we will use a 0.03125" diameter rout tool to cut out your board. In this case, inside corners will have a minimum radius of 0.016". For tighter tolerances please request a custom quote.

Copper Trace Width/Space

This is the minimum air gap between any two adjacent copper features. Trace width is the minimum width of a copper feature, usually traces.
For trace width/spacing, we require a minimum of 0.005” for 1 oz. finished copper weight on outer layers. Premiums are added for trace/space specs less than 0.008"
For 1 oz. finished copper weight (inner layers), minimum trace width/space is 0.005"
For 2 oz. finished copper weight (inner & outer), minimum trace width/space is 0.007"
For 3 oz. finished copper weight (inner & outer), minimum trace width/space is 0.015"
For 4 oz. finished copper weight (inner & outer), minimum trace width/space is 0.020"

Conductor Width

+/- 20%

Edge Clearance

A minimum of 0.010” for outer layers and 0.014” for inner layers. For scoring, minimum of .015 for outer layers and .020 for inner layers. Copper features closer than the minimum specified edge clearance may be compromised during board routing.

Internal Cutouts

For plated slots, the minimum width is 0.020".
For non-plated slots, the minimum width is 0.024".

Your design can have both plated and non-plated internal cutouts. We suggest that you add one layer for each type of cutout (plated or non-plated). Just place elements in these layers that are the exact shape of the cutout that you want. For example, if you want a 0.050" x 1.00" slot cutout of the board, then just add a trace of this size to the appropriate layer. If you have a more complex shape, then just submit it as one or more polygons that describe the edge of the cutout. We suggest you draw the polygon with an "F-Type" shape (a line of zero width). If you choose, you can draw the polygons with any width trace. We assume that the centerline of the trace describes the edge of your internal cutout. Plated cutouts will have the inside of the cutout plated with the finish that you choose (Tin/Lead HASL or ENIG (Immersion Gold)). Non-plated cutouts will not have any plating on the internal edges. Name your plated cutouts layer "PlatedInternalRouts". Name your non-plated internal routs "NonPlatedInternalRouts". If you wish, you can also supply a drawing that details the internal cutouts and we will create the needed geometry for you.

Finish Thickness

Overall thickness tolerance is +/- 10%
Minimum finished thickness for 2-layer: 0.010”
Minimum finished thickness for 4-layers: 0.031”
Minimum finished thickness for 6-layers: 0.040”
Minimum finished thickness for 8-layers: 0.047”
Minimum finished thickness for 10-layers: 0.062”

Hole Size

Any hole size between 0.008" and 0.250"

Minimum Annular Ring

The minimum annular ring on vias is 0.006" (6 mils) each side of the hole. The pad must be large enough to tent over the hole otherwise you may lose the metal in the hole during outer layer etching resulting in plating voids.

Non-Plated Holes

If your design contains both plated and non-plated holes, then we prefer that you place these holes on separate layers. This will ensure that we understand your intent. Name your plated drill layer "PlatedDrills" and your non-plated drill layer "NonPlatedDrills"

Routing

The default rout tool diameter is 0.0625".
All features are cut out using this tool if possible (both internal features and the board outline). For smaller diameters please request a custom quote.

Panelization

V-Score and Tab Route available

We can panelize your boards for you. If you send us a panel drawing, we will follow it. Otherwise we can suggest one for you. Boards can be tab-routed (.093 typical spacing) or V-scored (0.0” typical spacing).

Stack-up

Solder Mask Swell

This is the expansion of mask relief over pad area. Our minimum is 0.005” over pad dimension or 0.0025” each side. PCB Unlimited will modify files to meet the minimum dimension.

When manufacturing your prototype circuit boards, there may be a small misregistration between the solder mask layers and the underlying copper layers. As a result, we recommend that you swell your solder mask layer so that it is 0.005" (0.0025" on a side) larger than the underlying copper elements. This way, if there is a misregistration, then your copper pads will not have any solder mask on them. You should also ensure that your design has a "Minimum Web" of at least 0.003" between adjacent pads. Smart DFM can pinpoint any problem areas for you.

Silkscreen

We recommend that your silk screen features have a width of at least 0.007", although the absolute minimum for clear legibility is 0.006". If you submit Gerber data or a .bin ViewMate file to us, then we will modify your silk screen layers if any features are less than 0.007". If possible, we will set all features so that the minimum trace width is 0.007". Where this is impractical, we will reduce the silk screen feature size to a minimum of 0.006".