The Lenovo Thinkpad X61 tablet has a “12.1-in Super Wide Angle SXGA+ TFT display with 1400 x 1050 resolution” option. The display panel is the BOE-Hydis HV121P01-101, an AFFS display with glass bonded to the LCD panel. The predecessor used in the X60 tablet (HV121P01-100) uses the same LCD panel but did not bond the cover glass to the LCD.
The display is prone to developing bubbles in the adhesive layer in between the LCD and glass. There’s a long thread at Lenovo forums (Air Bubble In LCD Screen X61 Tablet) about the bubbles and the difficulty of getting it replaced or repaired.
The bezel was sticky. This is the adhesive from the LCD, not the double-sided tape melting. It was gooey only along the bottom edge where the LCD adhesive was leaking.
To see what’s going on inside, the bezel was removed. There was a lot of leaked adhesive, especially along the bottom-left edge. It appeared as though the adhesive was being wicked out of the bottom edge of the LCD by adhering to and flowing along the plastic bezel piece, gumming up the buttons. Air bubbles entered to replace the loss of adhesive.
The most obvious repair method is to apply heat and pressure to squeeze out the air bubbles, with enough heat to redistribute the adhesive evenly across the entire display (resulting in a slightly thinner adhesive layer). That didn’t work: I successfully squeezed out the air bubbles, but the heated adhesive did not behave like a Newtonion fluid (non-zero shear stress at rest), so it tended to flow back to its original position, refusing to be evenly redistributed.
Some adhesive was lost during the repair attempt, there was continuing leakage out the bottom, and the adhesive refused to flow, so even more air was drawn in to replace the adhesive deficit along the bottom edge. This resulted in even more bubbles after the repair attempt.
This is the current state, after a second repair attempt using higher temperatures, also failing in the same way. I’m hoping I can get some fresh adhesive (of the same kind) to fill in the (big) bubble, since it seems hopeless to try to redistribute the existing adhesive.
There are many suppliers for optical adhesive:
The X61 tablet uses a Hydis HV121P01-101 screen, the same as those found in a Motion Computing LE1700 tablet. Motion Computing advertises later Hydis displays using DuPont Vertak bonding, so there’s a good chance the older Hydis HV121P01-101 also uses a DuPont adhesive (Vertak DBA1000/2000 or a predecessor?).
The Vertak adhesives have low elastic and shear modulus and strength, which might contribute to its tendency to flow out the side of the display. Qualitatively, the gooey adhesive I see in my display agrees with the properties listed in the datasheet.
I think I can make a decent repair of the bubbles by filling in the bubbles with fresh adhesive (ideally of the same kind), curing it, and then sealing the edge of the display with silicone to prevent future adhesive leaks. I don’t have a clean room, so I’m not able to completely replace the adhesive without getting dust into the display.