1. Material characterization requirements
\nLow dielectric constant (Dk) with low loss factor (Df)
\nHigh frequency applications (e.g., 5G, millimeter wave) require low Dk\/Df materials (e.g., Panasonic MEGTRON, Rogers RO4000 series) to minimize signal delay and loss.
\nExample: Dk value needs to be stabilized below 3.5 and Df value below 0.005@10GHz.
\nHigh Glass Transition Temperature (Tg)
\nLead-free soldering process requires Tg \u2265 170\u00b0C (e.g. FR-4 High Tg) to avoid high temperature delamination.
\nCoefficient of Thermal Expansion (CTE) Matching
\nZ-axis CTE needs to be close to copper layer (14-18 ppm\/\u00b0C) to prevent hole wall fracture after multiple reflow soldering.
\nInterlayer Interconnect Technology
\nMicrovia structure
\nBlind\/buried holes \u2264150\u03bcm in diameter (commonly used laser drilling), depth to diameter ratio \u22641:1, e.g. 0.1mm hole diameter \/ 0.1mm depth. Stacked Vias or Staggered Vias to optimize signal path.
\nPlated Vias Filling (Via Filling)
\nFilling with copper fill or conductive\/non-conductive paste to ensure a flat surface to support fine pitch BGA packages.
\n3. Line Design Specifications
\nFine line width\/spacing
\nLine width\/spacing \u22643mil (75\u03bcm), high order HDI up to 1.5mil (38\u03bcm), need to be combined with etching compensation.
\nImpedance control: \u00b110% tolerance, stacking optimization through simulation tools (e.g. Polar Si9000) is required.
\nAny Layer HDI (Any Layer Interconnect)
\nThe whole layer uses laser holes to realize more than 10 layers of arbitrary interlayer connection, and the wiring density is increased by more than 50%.
\n4. Surface treatment process
\nLeveling and Reliability
\nElectroless Nickel-Palladium (ENEPIG): Suitable for ultra-fine pitch components (e.g., 0.35mm pitch BGA) with high oxidation resistance.
\nImmersion Silver (Immersion Silver): low cost, but need anti-sulfur treatment; OSP is suitable for short cycle assembly.
\n5. Manufacturing process key points
\nLaser drilling precision
\nUV laser precision \u00b115\u03bcm, CO2 laser for large aperture, need to control the hole wall roughness (Ra <1\u03bcm).
\nLamination alignment
\nLayer alignment error \u226425\u03bcm, calibrated by X-ray alignment system.
\nPlating uniformity
\nPulse plating ensures that the copper thickness in the hole is \u226520\u03bcm to avoid the \u201cDog-bone effect\u201d.
\n6. Reliability Test Standards
\nThermal stress test
\nIPC-TM-650 2.6.8: 5 times 288\u2103 solder heat resistance test (no delamination).
\nResistance change <10% after 1000 times -40\u2103~125\u2103 thermal cycling (TCT).
\nMechanical Reliability
\nDrop test (e.g. JEDEC JESD22-B111): 30 times 1m drop without breakage.
\nBending test (for flexible HDI): dynamic bending >1000 times (radius 3mm).
\n7. Typical application scenario optimization
\nConsumer electronics (e.g. cell phones)
\nAdopt any layer of HDI (more than 10 layers), line width\/spacing 2\/2mil, with Via-in-Pad design.
\nAutomotive electronics
\nHigh temperature resistant material (Tg\u2265180\u2103), AEC-Q100 certified, stricter CTE control.
\nHigh Frequency Communication
\nHybrid dielectric layer (e.g. FR-4+Rogers material), combined with grounded via array to suppress signal crosstalk.<\/p>","protected":false},"excerpt":{"rendered":"
1.Low dielectric constant (Dk) with low loss factor (Df)
\n2.Line width\/spacing \u22643mil (75\u03bcm), high order HDI up to 1.5mil (38\u03bcm), need to be combined with etching compensation.
\n3.Laser drilling precision
\n4.The whole layer uses laser holes to realize more than 10 layers of arbitrary interlayer connection, and the wiring density is increased by more than 50%.<\/p>","protected":false},"featured_media":1122,"comment_status":"open","ping_status":"closed","template":"","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"default","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"set","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""}}},"product_brand":[],"product_cat":[45],"product_tag":[],"class_list":{"0":"post-1121","1":"product","2":"type-product","3":"status-publish","4":"has-post-thumbnail","6":"product_cat-pcb","7":"desktop-align-left","8":"tablet-align-left","9":"mobile-align-left","11":"first","12":"instock","13":"shipping-taxable","14":"product-type-simple"},"yoast_head":"\n