Solder paste printing is part of the assembly process - next stage after PCB have been completed - it is part of the customers process. But, we supply solder paste files to the customer after the PCB factory have completed the CAM process. Part of that process is to convert files for a the single unit to array format. You may say the solder paste file is a "product" ordered by the customer. Customer have in his files designed one unit - and need the same design in array format to order solder paste stencil for his first process.
A typical order can be :
2) xxx PCBs
3) Array Solder paste file (normally free of charge)
A suggestion could be to add solder paste file as a layer that is supplied to the customer as a file. In reality it is a layer in the files. But, it is not part of the PCB itself.
Josse, Andreas , Bruce, Athanasios - or any other - comments please? Hos can we handle solder pate files in CD?
I would think that if solder paste is to be included then it should be described as a layer, much in the same manner that peelable_tape is a layer. But it might be more general to add a layer function "assy_mask" to cover solder paste, glue and other potential materials. Which might also lead to the need of expanding the scope of supported material function/group.
The bigger question is whether or not the scope of CircuitData intends to cover all of the files that could be included in a job, or if the scope should rather be limited to the parameters involved in quoting/purchasing/manufacturing an unpopulated PCB.
If CircuitData's scope is to include assembly related parameters, then that raises the question not only of solder paste, but also of pick & place, BOM and more.
Jan implies that the solder paste file only exists for the assembly array. But this is not entirely true. Frequently, a single board solder mask file is generated by the designer's CAD system. Stepping that up to an assembly array can be done by PCB CAM or by EMS CAM. The EMS people may want to modify the actual pad shapes to suit their soldering processes before stepping the mask up to an array.
Bruce McKibben you are correct, solderpaste are used for single units as well, but what I try to say is the customer only orders a solderpaste file when boards are delivered in an array.
Even though Elias concludes to discard the data for solderpaste files for his activity, we may need to have an option for specifying solderpaste files in CD.
And, CD is for bare boards today, but who knows romorrow....