assembly method for LCD in a handheld device

[bhays]

Is there a preferred assembly method for mounting an LCD in an enclosure? The concerns are that the LCD be positioned correctly (not off-center or rotated) from the users view.

We have a small (2.4") LCD to be mounted in a handheld/portable device. The only connection for the LCD is a length of flat flex cable that will wrap around the PCB to which it connects.

When it comes to assembling the device, does it make more sense to make the LCD a part of the PCB assembly and worry about aligning the PCB to the enclosure, or is it better to mount the LCD to the enclosure, assemble the PCB to the enclosure, then connect the flat flex of the LCD to the PCB.

There is a scratch resistant window that protects the LCD that is presently planned to be assembled to the enclosure with adhesive foam. The LCD does have a couple of protrusions on the rear that could be used to position it on the PCB.

Thanks

 

[eng1ne]

I think that the method you choose will be entirely independent of the alignment that you can achieve.

It surely all depends on tolerance? You will only achieve the desired, or consistent alignment if you have appropriate tolerances. Regardless of how you assemble it, the weakest link will be the features with the widest tolerances.

Has the design already been finalised? Are you purely considering assembly method or do you have authority/scope to amend the design?

There are many other factors to consider: How will the two be tested? How will the parts be serviced? If for example, the LCD will be a replaceable item it might make more sense (or less depending on commercial influence) to have them mounted separately so the LCD can be replaced without needing to replace the PCB.

Assuming that the method you choose does not make a difference to what you can achieve, have you consulted the people that will be assembling them for their opinion?

I am not inclined to suggest one or the other without more understanding of the context and application - I have used both approaches before, each will have its own merits in different situations.