Soldering LCD glass

Thread Starter

RichardO

Joined May 4, 2013
2,271
Is it possible to reflow solder LCD glass? I am not talking about a module with electronics but just the glass portion. I am thinking of a very high volume application that would not have pins attached to the glass.

These are the weaknesses that come to mind: Polarizer, metalization, seal, LC material, reflector. I have no idea which are likely to be a problem and which are not.
 

SLK001

Joined Nov 29, 2011
1,543
These are the weaknesses that come to mind: Polarizer, metalization, seal, LC material, reflector. I have no idea which are likely to be a problem and which are not.
All of them would be a problem. LCDs are definitely not solderable. Like Externet says, use zebra strips or spring clips to connect to the.
 

GopherT

Joined Nov 23, 2012
8,012
Is it possible to reflow solder LCD glass? I am not talking about a module with electronics but just the glass portion. I am thinking of a very high volume application that would not have pins attached to the glass.

These are the weaknesses that come to mind: Polarizer, metalization, seal, LC material, reflector. I have no idea which are likely to be a problem and which are not.
Come on. It took the chemical & plastics industry years to perfect the zebra connector. Now you want to use solder on glass?

Just joking. If you want to go that direction, you need to contact Indium Corporation. There are only two metals that will wet glass! Gallium and Indium. Stick with gallium for the price. Indium Corporation makes solders (tin, gallium, X, Y, Z alloys) that will solder to glass and silicon. Can you guess how lead wires are bonded to the chip and who supplies it? The gallium solders are very low temp and will not damage the glass but you will definitely need solder mask. Also, the conductive traces on the glass are indium-tin-oxide. That is all you really want to bond but the gallium solder is the way to go.

Zebra is the way to go. Open up your fluke meter and you will see how they work.
 

DickCappels

Joined Aug 21, 2008
6,179
Sometimes you can probably get away using a conductive paint or epoxy provided the connector pitch is not too fine and that your display and application can accept the slight increase in resistance.
 

jpanhalt

Joined Jan 18, 2008
8,712
Or ,tin the glass with Tollen's reagent (use the currently in vogue modification) then you might be able to solder to that. That's just an alternative, not a recommendation for LCD's.

John
 

ErnieM

Joined Apr 24, 2011
8,019
Only open your meter if you wish to see what parts were used.

Do not open your meter if you ever expect to see it working ever again.
 

GopherT

Joined Nov 23, 2012
8,012
Only open your meter if you wish to see what parts were used.

Do not open your meter if you ever expect to see it working ever again.
I've changed the display on a used fluke 87v. You just have to be careful and have a basic understand how a zebra connector works.
 

Thread Starter

RichardO

Joined May 4, 2013
2,271
Sometimes you can probably get away using a conductive paint or epoxy provided the connector pitch is not too fine and that your display and application can accept the slight increase in resistance.
I like the idea of conductive paint a lot. Cheap and simple! Since LCD's don't draw any significant current, the resistance is absolutely no problem. It could probably even be a carbon loaded ink saving the cost of silver or nickel.
 

ramancini8

Joined Jul 18, 2012
473
I tried reflow soldering to an LCD for a gas pump display during 1977. Production could never get it to work (we used an IR heat source to reflow solder), so we went to the more expensive zebra strip. Problem with soldering is that some wires will come loose because of vibration, temp changes, and stress.
 
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