Compatibility, forward/backward

There are many challenges still confronting the transition to Pb-free soldering. These include solder joint reliability (are the reliability models correct ), surface finish compatibility (forward and backward), mixed alloy soldering (SnPb solder and Pb-free EGAs), and, of course, the potential tin whisker time bomb. 

Backwards compatible multichannel coding adds the option of forward and backwards compatible coding of multichannel signals including the 5.1 channel configuration known from cinema sound. 

Generates views to -support both forward and backward compatibility, when formally possible... 

The second major contribution of PRISM is support for database versioning with backward and forward compatibility. When starting with version N of a database, if one uses SMOs to create version N + 1 of the database, PRISM will provide at least one of the following services to applications whenever the SMOs are deemed to be invertible or the user provides a manual workaround ... 

It likely that you are using different versions of Synopsys tools. In other words, the db file was generated by a more recent version of DC while you are trying to read the db file now into a previous version of DC. In short, db files are backward compatible but not forward compatible. To check the version of DC, use the following command ... 

Assuming that the components can meet the temperature requirements as discussed above, tin and Ni-Pd-Au platings are generally considered to be forward compatible with lead-free solder, as well as backward compatible with the tin-lead solder. This makes it much easier to manage production lines with the tin-lead solder and lead-free solder in co-existence within the same factory during the transition to lead-free. 

The ability of the supply chain to manage multiple PNs, BOMs for leaded, lead-free, and mixed configurations must be addressed. Given the fact that there is no standard alloy that will be utilized to replace eutectic Sn-Pb solder, and that the many OEMs and contract manufacturers are working to different schedules, this is a daunting task. It will be necessary to implement quality standards considering the nuances of each alloy. Standards must also be established to classify the specifications and limitations of each component as well as the components forward and backward compatibility. 

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