In PCB lamination, “resin flow” (molten prepreg resin overflow under high temp\/pressure) often causes impedance deviation, especially impacting high-frequency signal transmission. This article concisely explains its impact paths and control measures.<\/p>\n\n\n\n
More resin flows at board edges, thinning dielectric (20%-30% vs inner board). Dielectric thickness correlates positively with impedance: 10% thickness reduction \u2192 5%-10% impedance drop. Edge impedance is usually 2-5\u03a9 lower, with higher resin content worsening deviation.<\/p>\n\n\n\n
Resin accumulates in areas with concentrated resin flow, making the dielectric constant 0.2-0.5 higher than that in normal areas (e.g., increasing from 3.5 to 4.0). The dielectric constant is negatively correlated with impedance, which, combined with the thinner dielectric layer at the board edges, further reduces impedance.<\/p>\n\n\n\n
In low-copper areas (<50%), resin fills line gaps, increasing equivalent line width and reducing dielectric thickness. This dual effect cuts impedance by 3-5\u03a9, causing poor high-frequency impedance consistency.<\/p>\n\n\n\n
Resin flow and impedance differ by area: high edge flow \u2192 2-5\u03a9 lower impedance (more signal reflection\/loss); low inner dense-line flow \u2192 target impedance (stable transmission); local high low-copper area flow \u2192 3-5\u03a9 lower impedance (high-frequency distortion).<\/p>\n\n\n\n
High frequency (\u226510Gbps): \u22655% impedance deviation worsens eye diagrams and bit error rates. Mass production: uneven flow cuts yield by 10%-20%. Controls include three aspects:<\/p>\n\n\n\n
In PCB lamination, “resin flow” (molten prepreg resin overflow under high temp\/pressure) often causes impedance deviation, especially impacting high-frequency signal transmission. This article concisely explains its impact paths and control measures. I. Three Core Paths of Resin Flow Affecting Impedance 1. Uneven Dielectric Thickness: Lower Edge Impedance More resin flows at board edges, thinning dielectric […]<\/p>","protected":false},"author":1,"featured_media":6952,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"_mi_skip_tracking":false,"footnotes":""},"categories":[1],"tags":[704,106,136,99,214,142,208],"class_list":["post-6951","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-technical-support","tag-electronics-manufacturing","tag-neoden","tag-pnp-machine","tag-qihe","tag-reflow-oven","tag-smt","tag-smt-pick-and-place-machine"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t