The shallow and normal position of the NG sample marked by the shallow and normal position of the NG sample are analyzed to be shallow on the left and middle of the NG sample.

2. morphological analysis

Open the FPC gold finger and glass surface, the shallow position for observation found that the ACF glue mainly residue in the glass surface, FPC edge, gold finger and gold finger between the denser particles, FPC surface has more black spots, glass surface ACF adhesive surface has more density of larger particles.

Conductive particles obvious area ACF glued to the FPC surface and glass surface, FPC surface no obvious black point, glass surface no obvious scattered particles.

3. Sliced analysis

The shallow position and normal position of the NG sample are observed: there is a layer of material on the surface of the FPC in the shallow position, the two sides of the FPC are more serious, and the area with thicker edge foreign objects has a layered phenomenon. There is no obvious substance on the surface of the FPC in the normal position.

4. Elemental analysis

For elemental analysis of the shallow position of the NG sample sample, the ACF glue surface particles contain Ni, Cu, Cl and other elements; the slicing FPC surface material mainly contains Ni, Cu, Au, O, Cl and other elements, mainly Ni, Cu corrosion products.

5. FTIR analysis

From the infrared spectator, it can be seen that the NG sample sample shallow position and normal position, both of which are polyurethane, of which 3410~3435cm-1 belongs to the N-H telescopic vibration absorption peak of polyurethane; 1725~1735cm-1 belongs to the C=O telescopic vibration absorption peak in polyurethane; the two absorb peak position and strength are not significantly different, and there is no obvious difference in curing degree as shown in Figure 6-1.

6. Analysis and Summary

Sample of NG:

From the morphological analysis and slicing results, it can be seen that the light position, the ACF glue is mainly glued to the glass surface, and the normal position ACF glue is glued to both the FPC and the glass surface; the shallow side position FPC is more dense particles (BSE backscatter mode, the greater the density, the whiter the color), and most of the elements embedded in the glue interior, combined with the elements analysis results, the main elements of the particles are Ni, Cu, Cl, O, K and other elements.

The mechanism of nickel and copper corrosion caused by Cl ions is mostly electrochemical corrosion, which is caused by pitting, producing nickel oxide, nickel hydroxide, copper oxide and so on.

In summary, the following conclusions can be drawn:

The reason for the shallow FPC is that the FPC is corroded by the Cl element, and the corrosion product overflows to the surface and inside of the glue, causing shallow phenomena.