PCB · PCB ASSEMBLY · DESIGN · PROCUREMENT AND ACCEPTANCE
Isola 370HR Tg, Td, Z-axis expansion, and frequency-dependent Dk/Df address different decisions. This article organizes conditions for manufacturer typical values, uses thermal-expansion calculations to explain high-Tg boundaries, and outlines hole-wall failure analysis, material substitution, and representative-structure verification.
Read ArticleBefore comparing Rogers materials, align process Dk, design Dk, frequency, and test methods, then check Df, copper foil, dielectric thickness, and thermomechanical conditions. This article provides material cards, propagation-delay sensitivity calculations, a substitution-review checklist, and troubleshooting for simulation/measurement differences.
Read ArticleCompare dielectric thickness, thermal conductivity, area-normalized thermal resistance, and insulation conditions together for Thermal Clad metal substrates. Using thermal-path decomposition and a 10 W heat-source example, this article explains why higher conductivity may not reduce component temperature rise and provides records for material selection, mounting contact, and specimen measurements.
Read ArticleRoHS material review starts with manufacturer part numbers, material composition, and declaration coverage. This article compares supplier declarations, screening, and targeted testing, using a connector substitution example to explain documentation coverage, change approval, lot traceability, and common gaps.
Read ArticleCompare high-frequency, hybrid, and rigid-flex budgets by grade, stackup, copper foil, bending, and testing. Retain historical references' currencies and missing conditions, with three structural calculations, material-substitution conditions, and a complete RFQ checklist.
Read ArticleSeparate heavy copper, gold fingers, beveling, and HDI via treatment into preparation, manufacturing, and verification costs. Compare inclusions by via-layer pairs and surface zones, using three engineering-allocation and reorder examples to avoid duplicate charges and scope omissions.
Read ArticleFor standard FR-4 prototype budgets, align individual boards, delivery panels, and billable area first, then check package or itemized quotations against layers, copper weight, vias, and inspections. Examples using 5 boards, 50 boards, and panels with rails explain batch totals and per-board allocation.
Read ArticleRemote PCB purchasing must connect controlled files, engineering approvals, packaging/shipping, receipt, and acceptance. This article adds delivery-responsibility tables, split-count and chargeable-weight examples, remote revision confirmation, and exception-evidence processes. It distinguishes dispatch, logistics receipt, and technical acceptance without promising city-specific delivery times or local factories.
Read ArticlePCB supplier assessment should verify business entities, actual manufacturing responsibilities, and project-specific engineering responses. This article adds a visit-location confirmation table, on-site meeting inputs/outputs, and a quotation-scoring method using identical drawings. It explains how to confirm appointments, visit scope, collection, and exception contacts without inferring local manufacturing or uniform lead times from a Shenzhen address.
Read ArticlePCB reorders should reference approved manufacturing packages and actual supply batches; historical order numbers cannot replace revision control. This article adds criteria distinguishing unchanged and modified reorders, split-quantity examples, and traceability tables. It explains how materials, engineering compensation, and inspection records carry forward, how batch differences are located, and why new delivery arrangements require reconfirmation.
Read ArticleHigh-frequency material substitution requires comparison of Dk, loss, copper foil, and dielectric thickness under identical frequencies and methods, plus manufacturing-compatibility checks. This article adds material-comparison fields, propagation/loss sensitivity examples, and a staged verification process. It explains when geometry, prototypes, or approvals must change, avoiding definitions of equivalent material based on one typical parameter.
Read ArticleHeavy-copper PCB RFQs should distinguish base copper, finished copper, and plating requirements by layer before confirming via arrays, terminals, and cooling. This article adds copper-weight unit examples, an outer-layer plating definition table, current-path breakdowns, and acceptance records. It explains why 3OZ or 4OZ cannot directly establish system current or replace hole-wall copper and local thermal verification.
Read ArticleHDI structure and low-volume material preparation involve two separate decisions: define via layer pairs and build-up layers, then assess how material availability and substitutions affect validation.
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