PCB Libraries Forum : Assembly Reference Designator IPC Location https://www.PCBLibraries.com/forum/ Thu, 16 Apr 2026 01:39:30 +0000 Wed, 31 Jul 2019 15:07:34 +0000 http://blogs.law.harvard.edu/tech/rss Web Wiz Forums 12.07 360 https://www.PCBLibraries.com/forum/RSS_post_feed.asp?TID=2515 <![CDATA[PCB Libraries Forum]]> https://www.PCBLibraries.com/forum/forum_images/PCBLForumLogo.gif https://www.PCBLibraries.com/forum/ <![CDATA[Assembly Reference Designator IPC Location : If the customer wants to use the...]]> https://www.PCBLibraries.com/forum/assembly-reference-designator-ipc-location_topic2515_post10360.html#10360 Author: Tom H
Subject: 2515
Posted: 31 Jul 2019 at 3:07pm

If the customer wants to use the Silkscreen Legend Ref Des as the Assembly Ref Des then they are potentially creating a situation where two similar parts could get swapped. 

We did that at a company I worked for and sure enough, the assembly shop swapped two same size resistors by mistake and the PCB did not function properly and it took the EE engineer a couple of days to track down the problem. Very costly mistake. 

]]> Wed, 31 Jul 2019 15:07:34 +0000 https://www.PCBLibraries.com/forum/assembly-reference-designator-ipc-location_topic2515_post10360.html#10360 <![CDATA[Assembly Reference Designator IPC Location : Thanks for the confirmation...]]> https://www.PCBLibraries.com/forum/assembly-reference-designator-ipc-location_topic2515_post10359.html#10359 Author: AGONZ67
Subject: 2515
Posted: 31 Jul 2019 at 2:59pm

Thanks for the confirmation of that. 

This is how I have been using them, but we are working with someone who wants assembly ref des to match the silkscreen ref des, which defeats the purpose of the assembly ref des.
]]> Wed, 31 Jul 2019 14:59:31 +0000 https://www.PCBLibraries.com/forum/assembly-reference-designator-ipc-location_topic2515_post10359.html#10359 <![CDATA[Assembly Reference Designator IPC Location : There is no standard for the placement...]]> https://www.PCBLibraries.com/forum/assembly-reference-designator-ipc-location_topic2515_post10358.html#10358 Author: Tom H
Subject: 2515
Posted: 31 Jul 2019 at 11:05am

There is no standard for the placement of the Assembly reference designator. 

The assembly outline should be a closed polygon and the assembly ref des should be placed anywhere inside that polygon. 

This way, the assembly shop has clean data to work with and the chance of making a mistake is greatly reduced. 

When the ref des is placed outside the polygon, it can get confused with another part close by. 

]]> Wed, 31 Jul 2019 11:05:01 +0000 https://www.PCBLibraries.com/forum/assembly-reference-designator-ipc-location_topic2515_post10358.html#10358 <![CDATA[Assembly Reference Designator IPC Location : Is there a specific IPC specification...]]> https://www.PCBLibraries.com/forum/assembly-reference-designator-ipc-location_topic2515_post10357.html#10357 Author: AGONZ67
Subject: 2515
Posted: 31 Jul 2019 at 10:46am

Is there a specific IPC specification that specifies the location of the assembly reference designator?

Typically I have placed assembly ref des in the center of the component outline, which seems to be industry standard. 

Is there a specific IPC specification that I can refer to which states something to the effect of "Assembly ref des shall be placed in the center of component outline"?


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