US 12,396,095 B2
Circuit board with low grain boundary density and forming method thereof
Chien Jung Chen, Taoyuan (TW); Jia Hao Liang, Taoyuan (TW); and Ching Ku Lin, Taiyuan (TW)
Assigned to Unimicron Technology Corp, Taoyuan (TW)
Filed by Unimicron Technology Corp., Taoyuan (TW)
Filed on Dec. 13, 2022, as Appl. No. 18/065,606.
Claims priority of application No. 111138447 (TW), filed on Oct. 11, 2022.
Prior Publication US 2024/0121896 A1, Apr. 11, 2024
Int. Cl. H05K 5/00 (2025.01); H05K 1/11 (2006.01); H05K 3/06 (2006.01); H05K 3/46 (2006.01)
CPC H05K 1/112 (2013.01) [H05K 3/062 (2013.01); H05K 3/4644 (2013.01)] 7 Claims
OG exemplary drawing
 
1. A circuit board, comprising:
a first circuit layer;
a dielectric layer on the first circuit layer;
a seed layer on the dielectric layer and directly contacting the first circuit layer, wherein a top surface of the seed layer comprises a levelled portion; and
a second circuit layer on the levelled portion of the seed layer, wherein a grain boundary density of the second circuit layer is lower than that of a portion of the seed layer directly contacting the first circuit layer.