Issue link: https://iconnect007.uberflip.com/i/1426508
NOVEMBER 2021 I DESIGN007 MAGAZINE 23 Pre-release DFM level data has the same issue as quote data. It is common to have pre- liminary material stackups sent back and forth between the fabricator and engineer until a final decision is made. Partial data files are also sent to get DFM requirements early in the lay- out process, before the routing is complete. Design Data Build Package Revision Control Now let's discuss revision control. Who actually owns the data used to create a PCB? Is it the designer, the CM, or the fabricator? Let's look at examples (Table 1) of who requests a change compared to who performs and owns the final dataset. Changes may be requested by many people within a company, or from multiple companies. It is essential that the allowed change approv- ers are determined when data is received to ensure proposed modifications are correctly approved. Every board manufactured by excellent companies will have an internal part number, internal revision, original part num- ber, and original dataset revision numbers for the dataset using in manufacturing. is allows all changes to be tracked. ese revisions may be made by a tool—for example, a single art- work layer—or for an entire dataset. Change management is complicated, because a com- mon change request may be sent to multiple suppliers who may implement the change dif- ferently. Many OEMs/ODMs will ask the manufac- turer to revise the data instead of having an updated dataset resent. ey say, "It takes too long to get a change approved using our inter- nal ECO process." It is also essential that a sin- gle point-of-contact from the ordering com- pany be provided who will be responsible for providing responses to all technical questions. at person may be the person who generates the response or the person who coordinates/ filters responses from team members. Manufacturing Build Data Management Data used on/in manufacturing equipment is fundamentally the master data. e editing, storage, and transmission of the data must be retained and traceable to the individual board, ECO, specific equipment/line, operators, and/ or production lot. is include the material that is shipped within the product. Traceability and defect tracing is error prone and lengthy when this information is recorded on paper or in a non-integrated work cell computer. Table 1: Who requests the change, who implements the change, and who owns the change.