Script – Front-End Data Pararation
The journey towards an assembled printed circuit board starts with your data. To produce the bare boards, we need Gerber-files or if you use EAGLE or KiCad the actual CAD files of your design.
The data preparation for the bare board is done the same way whether you include assembly or not.
If you include assembly then we need to pay special attention to how we combine the individual boards in a panel for the assembly process.
We focus on the rotation of the individual boards in the panel for better panel stability during the assembly process. This is because we need to allow space on the panel for overhanging components and we create cut-outs in the panel frame for side/edge components.
To assemble the boards and source the components we also need you to upload a BOM file (Bill Of Materials), this specifies the parts and the quantity of each part to be mounted.
Generally, the parts are identified by their MPN or Manufacturer Part Number.
Next, we need to know where each part is located on the board, its rotation and which is pin 1 (for none passive components).
This information is defined in the CPL file (Component Placement List) which contains Reference Designators for the parts and the coordinates of each location, rotation, pin1 etc.
Front-End Data Preparation for assembly is all about verifying the BOM and CPL against the bare board layout. This includes checking the parts footprints and specifications against the availability of the parts in our stock or with distributors and against manufacturing technology requirements.
Let’s look at these items one by one.
Based on the information in your BOM file, we identify the parts to be mounted and cross-reference the identified parts with the Reference Designators.
We check the type of components (SMD, Through-hole, mechanical, fine pitch, etc…) to define the manufacturing technology and the extra components needed for that technology.
We check the availability of the parts with our component suppliers. This part of the preparation is done in cooperation with the sourcing team, sitting next to us in the same office.
During the CPL check we verify the placement of the components on the board. We have developed our own tools for this purpose.
Which are also available to all our customers as part of the PCBA Visualizer.
For each component that is new to us, we create a footprint according to the IPC recommendations and store it in our eC-verified component database. This is maintained by our engineering team in India.
Next to footprints, all information that we find in datasheets and that is useful for production is stored there as well.
Currently, we have information for more than 200.000 components stored in this database and it continues to grow.
Having this database speeds up the verification process as for most identified components we do not need to consult online datasheets as we have all information needed in our own verified database.
Each IPC recommended footprint is compared with the footprint in your design, and potential problems are identified by the system. Our Front-End engineers walk through the flagged items and decide, based on their experience, what actions are required.
They can consult their colleagues and production engineers when required.
If we find issues that may cause problems during the assembly or soldering process we add them into a report for our customer. We always try to suggest solutions, alternative parts, or design modifications to achieve a design that is fit for manufacturing.
As soon as all issues are resolved the job moves to pre-production for the bare board manufacturing, the sourcing of the parts, Solder paste stencil preparation, Pick & Place setup and to all other steps that are required based on the technology used to assemble the boards and then finally to production planning to create the production flow.