One factor that affects the DoP may be seen in more detail in FIGS. 7C and 7D. One of skill in the art will appreciate that during the previously described development stage, the cross-linking of the film, e.g., the low-temperature cure polyimide, is weakened and the weakening of the cross-linkage can affect the films performance during the cure process. It has been determined that low-temperature cure polyimides exposed to the single wavelength I-line have stronger cross-linking than low-temperature cure polyimides exposed to the broadband GHI-line. The result is that the top corners of the film that define the via openings are rounder when the low-temperature cure polyimide is exposed to the I-line. In some embodiments the top corners are rounded in the range of approximately 0.3 to 0.5 Π rad (50-90 degrees) as shown in FIG. 7D. The rounder via corners may reduce the low-temperature cure polyimide dielectric stress in, by way of a non-limiting example, an integrated fan out (InFO) package.

As discussed above, the patterning process affects rounding of the top corners of the passivation layer that define the via opening. However, the patterning process further creates indentions next to the via opening in the top surface of the passivation layer. The amount or angle of the indention from the via opening also affects the DoP. The greater the angle of indention, the wavier the top surface of the passivation layer is, resulting in a lower DoP because of increases in the is value. In an illustrative embodiment low-temperature cure polyimides exposed to the I-line have an angle of indention of approximately 2 to 8 degrees, whereas those exposed to the GHI-line have an angle of indention of approximately 10 to 15 degrees.