There used to be a strong relationship and a financial bond between IPC, EIA and JEDEC.
Several years ago they broke up the consortium, split the bank revenue and went their own way.
EIA and JEDEC were the component package standards, but component manufacturer's did not use the same exact dimensions.
They all signed an agreement back in the 1990's where all the dimensional data was to be in Metric units. EIA was the first to break that agreement by caving into the American assembly shops lack of knowledge in the metric unit system. It also leads back to the assembly shop customers who also pushed back on using Metric Units.
When EIA published the PDP100 for the standard Chip and discrete packages in 1988 all the dimensions were millimeters. American companies did not understand these units of measure. So EIA provided the 1989 PDP100 with both units Metric and Imperial.
When the assembly shops saw the metric chip names 1608, 2012, 3216 they were confused and changed 1608 to 0603 and 2012 to 0805 and 3216 to 1206 and everything went downhill from there.
EIA and the PDP100 went away and from there on it was free for all for the component manufacturer's.
JEDEC created package dimensions for semiconductors (IC's).
IPC creates guidelines and standards for PCB fabrication, assembly and design. They tried to create package standards in the IPC-SM-782 but failed. No component mfr. ever used those dimensions.
The package dimensions were removed in the IPC-7351 and replaced by our IPC Calculator.
------------- Stay connected - follow us! https://twitter.com/PCBLibraries" rel="nofollow - X - http://www.linkedin.com/company/pcb-libraries-inc-/" rel="nofollow - LinkedIn
|