What files do you need to evaluate a PCBA project?

Send Gerber files (RS-274X or ODB++), a BOM with manufacturer part numbers, the pick-and-place (centroid) file and an assembly drawing. If you need functional testing, add the test specification, firmware and any test fixture requirements so FCT can be planned before production.

Do you support low-volume prototypes as well as mass production?

Yes. The same SMT lines handle engineering prototypes, pilot runs and volume production. Small batches carry a higher unit cost because stencil, line setup and component reel minimums are spread across fewer boards; our engineers advise on panelization and alternate parts to reduce that cost.

How do you control PCBA quality?

Quality is controlled in a closed loop: incoming material inspection, 3D SPI after solder paste printing, AOI after reflow, X-ray inspection for BGA and hidden joints, and functional testing before packing. Workmanship follows IPC-A-610 Class 2 by default, with Class 3 available on request, and the process targets a first-pass yield of 98.5% or higher.

Can you source the electronic components for us?

Yes. We offer full turnkey service where we procure all components through long-term supply partners, partial turnkey where you consign critical parts, and consignment assembly where you supply all materials.

Can overseas buyers audit the factory before ordering?

Yes. Buyers can schedule an on-site audit at our Shenzhen facility or a live video audit covering material storage, SMT lines, inspection stations and traceability records.

Custom Lead Free Pcba Assembly Service & Supplier

Precision Engineering Portfolio

Featured Lead-Free Electronics Assemblies

Engineered for extreme thermal cycling resistance, zero lead cross-contamination, and strict international compliance standards.

Technical Metallurgy & Reliability

Engineering Integrity in Lead-Free Soldering Processes

Transitioning from conventional eutectic tin-lead (Sn63Pb37) to lead-free alloys requires deep metallurgical mastery to resolve higher melting thresholds, tin whisker risks, and brittle intermetallic compound (IMC) formation.

SAC305 & SAC0307 Alloy Dynamics

Lead-free alloys like SAC305 (Sn96.5/Ag3.0/Cu0.5) possess a liquidus temperature of ~217°C, demanding peak reflow zones between 235°C and 245°C. We maintain rigorous delta-T control under ±3°C across multi-layer high-Tg FR4 substrates to prevent delamination and localized warping.

Nitrogen (N2) atmosphere reflow ovens (<500 ppm O2)
Surface finish compatibility: ENIG, OSP, Immersion Silver

Intermetallic (IMC) Layer Control

Excessive thermal exposure results in thick, fragile Cu6Sn5 and Cu3Sn intermetallic layers at the solder-substrate interface. Our specialized 10-zone reflow profiles optimize the Time Above Liquidus (TAL) between 45–75 seconds, sustaining shear strength and dampening fatigue cracks under shock loads.

Controlled IMC layer thickness between 1.5µm to 3.5µm
Zero head-in-pillow (HiP) defects on fine-pitch 0.4mm BGAs

Tin Whisker & Void Mitigation

Tin whiskers present long-term short-circuit vulnerabilities in mission-critical applications. By maintaining controlled trace amounts of dopants (Nickel/Bismuth), stringent conformal coating, and vacuum reflow soldering, we suppress void rates inside BGA solder balls to under 10% (exceeding IPC Class 3 standard of 25%).

3D X-Ray Computed Tomography (AXI) validation
Conformal coating via automated selective spray platforms

Soldering Characteristic	Conventional Sn63Pb37 Solder	Lead-Free SAC305 (Shenzhen Aozite Standard)	Quality & Life Impact
Melting Point	183°C (Eutectic)	217°C - 220°C	Requires elevated component heat resistance (MSL handling).
Surface Tension & Wetting	Extremely fast wetting (0.2s - 0.5s)	Slower wetting speed, higher wetting contact angle	Demands nitrogen purging & high-activity lead-free fluxes.
Solder Joint Appearance	Bright, smooth, and mirror-like	Slightly dull, satin crystalline surface grain	Requires dedicated 3D AOI optical algorithms for true inspection.
Environmental Safety	Contains Toxic Heavy Metals (Banned in EU/US)	100% RoHS 3, REACH SVHC, WEEE Compliant	Mandatory for global customs clearance, consumer & industrial access.

Compliance & Risk Mitigation

Localized Regulatory Support & Global Compliance Assurance

Supplying PCBA assemblies to the European Union, North America, Japan, and Australia demands end-to-end audit defense, verifiable certifications, and complete material accountability.

RoHS 3, REACH SVHC & Prop 65

Every incoming batch of raw components, laminates, and solder paste undergoes documented spectroscopic verification. We offer ICP analytical test reports, Full Material Disclosures (FMD), and signed declarations to ensure tariff and customs safety across transatlantic checkpoints.

X-Ray Fluorescence (XRF) screening on passive arrivals
Halogen-Free (IEC 61249-2-21) fabrication on demand

Traceability from Wafer to Shipment

Our intelligent Manufacturing Execution System (MES) maps every serial number to reel part numbers, feeder slots, solder paste lots, reflow temperature profiles, and inspection outcomes. We safeguard clients against batch recertifications and localize audit trails.

Laser-etched 2D DataMatrix board-level serialization
Archived records retrievable up to 10 years

IPC-A-610 Class 2 & Class 3 Workmanship

Assembly operators and QA inspectors are certified IPC specialists. Whether producing standard commercial consumer electronics or high-uptime industrial automation boards, we adhere strictly to the acceptance criteria of IPC-A-610 and J-STD-001.

Comprehensive barrel fill checks on plated through-holes
Controlled ionic contamination levels <1.56 µg/cm² NaCl eq.

Shenzhen Industrial Cluster Advantage

Unrivaled Turnkey Supply Chain Velocity in Shenzhen

Positioned at the core of the Greater Bay Area, Shenzhen Aozite leverages a 1-hour radius ecosystem for fast component kitting, localized rapid prototyping, and scalable mass production runs.

Same-Day Sourcing

Direct authorized partnerships with top global and tier-1 domestic semiconductor distributors enable immediate replacement for lead-time-choked parts.

24H Rapid Stencil Turn

Laser stencils with nanocoating and multi-layer bare PCBs turned around within 24–48 hours, shrinking prototype iterations by weeks compared to Western lines.

Economies of Scale

Aggregated BOM procurement drives cost efficiencies 25%–40% higher than European or North American domestic EMS providers without compromising component authenticity.

Export Logistics Integration

Daily direct consolidation routes to HKIA and Shenzhen Shekou ports ensure fast transit via DHL, FedEx air cargo, and reliable sea freight forwarding.

8

High-Speed SMT Lines

1.2M+

Placements per Day

≥98.5%

Target First-Pass Yield

100+

Countries Exported To

Global Demand Sectors

Fulfilling Modern Corporate Procurement Imperatives

Hardware innovators and international brands require reliable contract manufacturing that balances low Total Cost of Ownership (TCO) with rock-solid durability and design protection.

Automotive & EV Subsystems

High thermal cycling resistance is critical in under-the-hood microcontrollers, Battery Management Systems (BMS), and telematics. We implement high-melting-point SAC305/Innolot alloys tailored to endure vibration and severe temperature extremes from -40°C to +125°C.

Class II & III Medical Devices

From patient monitoring consoles to diagnostic telemetry systems, medical electronics demand stable solder joints, low-residue fluxes, and zero electrochemical migration. Our ISO 13485-aligned cleanroom lines ensure pristine assembly surfaces.

Smart IoT & Industrial Gateways

IoT edges pack compact BGAs, fine 01005 passives, and complex RF modules into small form factors. Lead-free reflow with selective soldering shields sensitive wireless antennas while achieving flawless mechanical strength on high-load terminals.

The Future of Surface-Mount Tech

Emerging Trends in Lead-Free PCBA Manufacturing

Staying ahead of component densification, decarbonization demands, and ultra-miniaturized electronic hardware.

Low-Temperature Soldering (LTS)

To cut energy consumption and minimize thermal stress on warpage-prone ultra-thin chip substrates, Bi-Sn (bismuth-tin) low-temperature alloys melting around 138°C–170°C are expanding into modern SMT pipelines, reducing factory carbon footprints by up to 25%.

AI-Powered SMT Vision Inspection

Machine-learning-trained 3D AOI systems now differentiate harmless cosmetic paste irregularities from genuine micro-voids, bridge defects, and solder balling, raising first-pass yields while eliminating inspection bottlenecks.

Enhanced Conformal Nano-Coatings

Lead-free alloys present narrower corrosion margins against harsh humid environments. Micro-thin plasma and moisture-barrier nanocoatings are rapidly replacing thick liquid silicones to achieve IP67/IP68 water ingress resistance on compact wearables.

Engineering & Procurement FAQ

Frequently Asked Questions: Lead-Free PCBA

Detailed answers to vital technical and procurement questions asked by hardware engineers, supply chain managers, and OEM decision-makers.

How does Aozite avoid cross-contamination between leaded and lead-free runs?

We maintain dedicated SMT lines, discrete wave soldering pots, and isolated feeder storage strictly reserved for lead-free SAC305 assembly. Equipment, squeegees, stencils, and maintenance tools are color-coded and segregated to guarantee zero cross-contamination under RoHS compliance.

What surface finishes are recommended for lead-free PCBA?

Electroless Nickel Immersion Gold (ENIG) is optimal for fine-pitch BGA and planar coplanarity. Lead-Free HASL is economical for less complex boards, while Organic Solderability Preservatives (OSP) and Immersion Silver (Ag) deliver pristine coplanar pads for high-frequency RF applications.

Can you assist with component obsolescence and lead-free drop-in alternates?

Yes. Our veteran engineering team conducts comprehensive BOM scrub reviews, identifying legacy or lead-bearing parts, advising on form-fit-function (FFF) pin-compatible lead-free replacements, and generating revised Gerber stencil designs without delaying development schedules.

What documentation accompanies every delivered lead-free production lot?

Each shipment includes an IPC-A-610 Certificate of Conformance (CoC), 3D AOI and X-ray test reports, RoHS 3 & REACH declarations, reflow thermal logging curves, solder paste lot numbers, and full functional circuit test (FCT) sign-off logs.

OEM / ODM Product Catalog