Layers of Glass in LG Laptop LCD

I have a broken laptop LCD display module that I’m taking apart. It is a LG LP133WF2(SP)(A1) and it came from a Toshiba Chromebook 2 which was retired due to said cracked screen. I was able to split it into its two main components, the backlight and the display, both connected to the integrated driver circuit board. The backlight connector was something I could disconnect and reconnect, which is not something I could say for the high density connectors to the front display panel. Fortunately the screen is already cracked and nonfunctional so the majority of risk of disassembly is from broken glass.

The edge of this display module made it clear there is a complex multi-layer sandwich within.

There are at least three layers. The topmost layer is very thin and feels like plastic. The middle and bottom layers feel like glass. They don’t come apart easily, so I thought I’d try peeling the top plastic layer like a sticker. It is indeed backed by some adhesive, pretty tenacious ones at that.

I tried to keep the glass layers as flat as I could while I peeled, a difficult task with the strength of that glue which resulted in some alarming flex in the glass. I double and triple checked to make sure my eye protection is in place while peeling. After several centimeters of progress, scary bending and all, I felt a “pop” as the flexing freed whatever had held the middle and bottom glass layers together around their edges. Once this corner popped free, it was trivial to travel around all edges to peel the two glass layers apart.

It was damp between these two layers, presumably a thin layer of the “liquid” in Liquid Crystal Display (LCD). It was easily absorbed by a single sheet of paper towel, and its oily residue cleaned up nicely with 70% isopropyl alcohol. As far as I know, this is not a toxic material and I had not just cut years off my life, but I went and washed my hands before proceeding.

The bottom layer is where the original crack had lived, and these cracks had gotten worse due to the recent flexing. I don’t see anything of interest in this layer so I set it aside for safe disposal.

The two glass layers each had a grating that can be barely felt with my fingertips. They are also visible if I shined light through each layer. They are orthogonal to each other which would make sense if one set controlled horizontal pixels and the other controlled vertical pixels. Also, once the two glass layers separated, I was able to confirm the passive polarization filter (one of the objectives for salvaging) is the flexible sheet of plastic I had been tugging on. I resumed peeling that layer but didn’t get much further. Now that I only have one glass layer instead of two, it shattered under stress.

Even though I expected this as a potential (likely, even) outcome, it was still a surprise when things finally let go. Three cheers for eye protection! I picked out a few tiny shards of glass from my fingertips, but none of them found a blood vessel so there was no bleeding. And I think I managed to collect all the pieces scattered around the table. I had thought this would be a minor setback and I could continue peeling but just with smaller pieces of glass, but I was wrong. I don’t know my glass properties very well, but something happened here to change the mechanical properties of the glass. Once the first break happened, it has almost no strength at all. Continuing to peel — even at a lower force — causes new breaks. Brute strength will take me no further. And when brute strength fails, I turn to chemistry.

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