CAD/CAM

The ambition when making this page has been to make the recommendations as general as possible.

File Format

Primarily Gerber RS274X (also known as embedded apertures or extended Gerber). Apertures and advanced commandos are implemented inside the file.
We can also handle Gerber RS274D (Apertures in a separate file). Although the above two formats being the most commonly used we are also able to handle a number of other more rarely used files.
Click here to see a sample of RS274X
Click here to see a sample of RS274D

Drillfiles

Excellon (Clicke here to see a sample)
Sieb & Meyer (Click here to see a sample)

Zipfile

We strongly recommend you to Zip all files for a board to an archive file. This simplifies for us, and also makes it a lot safer.

Complexity

Do not design the board unnecessarily  complicated, and use minimum lines and spacing only where it is needed.
When using ground planes together with conductors it is good advice to be somewhat more generous with spacing, since the total length becomes very long thus increasing the possibility for a short.

Innerlayers

It is imperative to maintain a big enough spacing from the edge of a hole to the CU of another net. This applies to both PWR/GRND and signal inner layer regardless wether the hole has a land or not.
Graphic example: We recommend E to be 0.3-0.35 mm on a standard board.


 
On the page "Technology classes" under "Isolation Hole-Innerlayer foreign net"  you will find the most commonly used distances.

Soldermask

Normal spacing around pads is 3-4 MIL. However in some cases like for example BGA capsules we advise you to follow the recommendation made by the supplier. In this case the opening can be substantially less sometimes even negative. (Solder mask defined pads).

Graphic example A shows the clearance.

Symmetric

It is optimal, if  possible to have the CU surface evenly distributed over the entire board. It can be risky to design for example a 4-layer board where layer 3  is a ground plane and layer 2 is a signal layer wit almost no CU. This design can make the board bend in production or when soldered.

Markings

It is good practice to mark the layers in the CU  like 1,2,3,4 or L1,l2 and so forth.

Outline/ Routing

A drawing preferably in Gerber is very good. It is also OK with lines in one of the layers, where the centre of the layers is the board outline.
If the board is to be delivered on panels make sure that there is enough space for routing, brakeaway tabs or v-scoring which ever is to be used.
When routing inner radiuses keep in mind that a router Dia 2.4 mm makes a radius of 1.2 mm. It is possible to use a smaller router however this raise the price.