QFN 贴装服务

柔性与刚柔结合 PCB 的 QFN 贴装服务

空洞控制、锡膏纪律和可放行报告

ISO 9001|ISO 13485|IATF 16949
Engineering review before quotationPrototype through volume productionTest report and traceability support
柔性与刚柔结合 PCB 的 QFN 贴装服务

摘要

QFN 贴装是针对 quad flat no-lead 封装的 SMT 工艺,焊点位于器件边缘下方,普通目检无法完整判断。

Gerber, BOM, centroid, stencil notes, X-ray criteria, MOQ, and sample timing are reviewed before quotation.

Capability includes 0.4 mm QFN/LGA, 01005 passives, 100% 3D SPI, AOI, and X-ray review.

IPC-A-610, IPC-A-620, UL-758, and IATF 16949 stay mapped to workmanship and traceability needs.

QFN 贴装服务 for RFQ-stage supplier decisions

在 RFQ 阶段,OEM 采购工程师需要确认的不是能不能贴 QFN,而是锡膏窗口、回流曲线和 X-ray 证据是否可追溯。 QFN 贴装是针对 quad flat no-lead 封装的 SMT 工艺,焊点位于器件边缘下方,普通目检无法完整判断。 LGA 贴装是相关的平面焊盘工艺,同样依赖共面性和受控锡膏体积。 X-ray 检查是一种无损检测,用于查看隐藏焊点、散热焊盘覆盖率和空洞分布。 FlexiPCB keeps the technical baseline identical across markets: 0.4 mm QFN/LGA, 01005, 100% 3D SPI, AOI, X-ray, IPC-A-610, IPC-A-620, UL-758, IATF 16949, ISO 9001, 5 business days for samples, and 10-15 business days for typical production after approval.

中国大陆: 0.4 mm QFN/LGA capability is reviewed against flex, rigid-flex, and FR-4 assembly areas before quotation.
采购团队应提供 Gerber, BOM, centroid, QFN datasheet, stencil notes, MOQ, and sample timing so engineering can price the real risk.
您将收到 DFM 反馈 on aperture reduction, window-pane thermal pads, via-in-pad, stencil thickness, and local step-down needs.
100% 3D SPI before placement, AOI after reflow, and X-ray review for hidden QFN/LGA joints remain part of the release path.
样品会随检测证据一起放行: 5 business days typical for samples after complete RFQ and material approval; 10-15 business days typical for production after approval.
The case bank evidence stays unchanged: "multi-PO program", "split PIs", "same-day payment confirmation", and "early delivery warning issued".

QFN Assembly Capability Table

Package typesQFN, DFN, LGA, MLF, exposed-pad ICs, mixed SMT
Minimum QFN/LGA pitch0.4 mm after DFM approval
Minimum passive size01005 (0.4 mm x 0.2 mm)
Stencil controlLaser-cut stainless, aperture reduction, window-pane thermal pads, step stencil when needed
Paste inspection100% 3D SPI before placement
Reflow optionsLead-free SAC305 or leaded Sn63/Pb37 by project requirement
InspectionAOI plus X-ray for QFN/LGA hidden joints and voiding review
SubstratesFlex PCB, rigid-flex, FR-4, stiffened FPC, cable-integrated PCB assemblies
MOQ1-10 pcs engineering samples; pilot and production by BOM review
Sample lead time5 business days typical after complete RFQ and material approval
Production lead time10-15 business days typical after sample approval and material release
Standards referencedIPC-A-610, IPC-A-620, UL-758, IATF 16949, ISO 9001

Where QFN assembly reduces release risk

Robotics controller boards

中国大陆: for compact controllers, the Singapore robotics case shows why schedule visibility matters. The recorded controls were "multi-PO program", "split PIs", "same-day payment confirmation", and "early delivery warning issued".

Industrial machinery PCBAs

The South Africa industrial case moved harness and PCBA sourcing into one program through IC STM32F105RBT6 sourcing, PCB/PCBA manufacturing integration, and Multi-category supply consolidation.

Automotive and EV modules

Sensor boards and accessory controllers often combine QFN devices, pigtails, and connector tails; IPC-A-610, IPC-A-620, UL-758, and IATF 16949 are reviewed before release.

Medical and compact IoT electronics

Small battery-powered products use QFN packages to save area, but they need controlled paste volume, thermal-pad voiding review, and inspection documentation before enclosure integration.

QFN Assembly Workflow

1

RFQ file review

采购团队应提供 Gerber, drill, stackup, centroid, assembly drawing, QFN datasheet, quantity forecast, and required inspection records. The review separates real QFN risk from missing-file assumptions.

2

Stencil and paste DFM

您将收到 DFM 反馈 for perimeter pads, exposed thermal pad, aperture reduction, window-pane design, paste-release ratio, and step stencil options before sample build.

3

Component and MSL control

QFN/LGA sourcing, date code, approved alternates, moisture sensitivity level, baking notes, and distributor preference are checked so reflow risk does not start at incoming material.

4

3D SPI, placement, reflow

Every paste print is checked by 3D SPI before placement. Reflow is set around flex thickness, stiffener mass, copper balance, and thermal pad load rather than copied from a generic FR-4 profile.

5

AOI, X-ray, release

样品会随检测证据一起放行. AOI checks visible solder and polarity; X-ray reviews hidden joints and voiding; the report package supports procurement, quality, and engineering sign-off.

Why buyers in 中国大陆 use FlexiPCB for QFN assembly

QFN risk is visible before build

您将收到 DFM 反馈 before samples are started, so solder-mask clearance, exposed-pad size, via-in-pad, orientation, and stencil thickness are not discovered after failure.

Hidden joints get evidence

QFN solder joints cannot be fully judged visually. 3D SPI and X-ray review make acceptance evidence-based for 中国大陆 RFQ teams.

PCB and harness interfaces stay aligned

When pigtails or cable exits are included, IPC-A-620 and UL-758 concerns are reviewed together with IPC-A-610 solder workmanship.

Procurement communication is case-backed

The case bank records "multi-PO program", "split PIs", "same-day payment confirmation", and "early delivery warning issued" as real order controls.

Send This With Your RFQ

A complete package lets engineering price the QFN risk instead of guessing it.

采购团队应提供 Gerber, drill, stackup, assembly drawing, centroid, and panel constraints.

采购团队应提供 BOM with QFN/LGA datasheets, approved alternates, MSL class, and sourcing preference.

采购团队应提供 stencil file if available, or paste-layer notes for aperture reduction and thermal pad targets.

采购团队应提供 X-ray acceptance criteria, voiding expectation, test requirement, and sample approval process.

采购团队应提供 MOQ, annual forecast, target sample date, production release date, and shipment split plan.

What You Get Back

The response is built for procurement, quality, and engineering review.

您将收到 DFM 反馈 on QFN footprint, exposed pad, via-in-pad, stencil thickness, and paste-window design.

Quotation with MOQ, sample lead time, production lead time, tooling, and component sourcing risks for 中国大陆.

Inspection plan covering 3D SPI, AOI, X-ray review, electrical test, and report format.

Standards map for IPC-A-610, IPC-A-620, UL-758, IATF 16949, and ISO 9001 documentation needs.

Production release checklist for BOM revision, lot traceability, packaging, and split-delivery control.

What is QFN assembly?

QFN 贴装是针对 quad flat no-lead 封装的 SMT 工艺,焊点位于器件边缘下方,普通目检无法完整判断。 Paste control, reflow profile, and X-ray review matter more than visual inspection alone.

Can FlexiPCB assemble QFN packages on flex PCB?

Yes. We support QFN and LGA packages on flex and rigid-flex boards when footprint, stiffener support, bend-zone distance, and reflow profile pass DFM review.

What should we send to get a useful quote?

Send Gerber, BOM, centroid, assembly drawing, QFN datasheets, stencil or paste notes, quantity forecast, sample target, and X-ray or voiding acceptance criteria.

Standards and Public References

Public references provide standards context; customer drawings and purchase specifications control production acceptance.

Factory Engineering Note

Written for global OEM procurement teams evaluating QFN assembly suppliers at RFQ stage.

Hommer Zhao

FlexiPCB manufacturing and sourcing specialist

Hommer Zhao has supported flexible PCB, PCBA, and cable-integrated builds for OEM procurement teams since 2008. For QFN assembly programs, the engineering review focuses on hidden-joint inspection, paste-window control, component sourcing, sample timing, and production release documentation.

Factory KPI

5 business day typical samples after complete RFQ and material approval

Production KPI

10-15 business day typical production lead time after sample approval

Case evidence

multi-PO program; split PIs; same-day payment confirmation; early delivery warning issued

Standards

IPC-A-610, IPC-A-620, UL-758, IATF 16949, ISO 9001

QFN Assembly on Flex PCBs

Paste inspection, fine-pitch placement, reflow profiling, and hidden-joint review for compact PCBAs

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