RDL & Bump Wafer — Redistribution Layer & Wafer-Level Services

0.4–5μm L/SRDL Design Rules

1–8 LayersStack Height

10–500μmBump Pitch

200mm, 300mmWafer Diameter

Overview

RDL bump wafers are a core technology in advanced packaging, enabling high-density interconnects through redistribution layers (RDL) and under-bump metallization (UBM). GINECHIP offers a full range of RDL and bumping services — including fine-line RDL, copper pillar bumps, solder bumps, and micro-bump technology — supporting 2.5D/3D package integration.

We deliver industry-leading quality and precision, with every RDL and bumping process performed in an ISO Class 5 cleanroom.

RDL Technology Tiers

Standard RDL

Entry-level redistribution layer for cost-sensitive fan-out and flip-chip packages, balancing routing density with high fab yield and fast cycle time.

L/S: 5/5μmCu thickness: 5–8μmVia: 20–30μm diaPI dielectric: 5–8μm thickLayers: 1–3Bump pitch: 300–500μm

Fine-Pitch RDL

Multi-layer fine-line RDL using BCB or advanced polyimide dielectrics for denser routing in 2.5D interposers and high-I/O fan-out packages.

L/S: 2/2μmCu thickness: 3–5μmVia: 10–15μm diaBCB or advanced PI dielectricLayers: 2–5Bump pitch: 130–300μm

Advanced Damascene RDL

Sub-micron damascene copper RDL with CVD SiO₂ dielectric and TaN/Ta barrier, built for the highest interconnect density in 2.5D/3D and chiplet integration.

L/S: 0.4/0.4μmCu thickness: 1–3μmVia: 5–10μm diaSiO₂ dielectric (CVD)Layers: 2–8Damascene Cu + TaN/Ta barrier

Bumping Technology Options

Wafer bumping creates interconnect structures on semiconductor wafers for flip-chip assembly. Our comprehensive bumping platform supports multiple materials, pitches, and aspect ratios across 100mm to 300mm wafers.

Solder Bump

Wafer-level solder bumping in SAC305, SAC405, or SnPb alloys with Ti/Cu or TiW/Cu UBM, ideal for standard flip-chip BGA assembly.

Alloys: SAC305, SAC405, SnPbPitch: 130–400μmHeight: 50–100μmUBM: Ti/Cu or TiW/CuReflow: wafer-level

Copper Pillar Bump

High-aspect-ratio copper pillars with SnAg solder caps for finer pitch and lower electrical resistance than conventional solder bumps.

Pillar height: 20–80μmSolder cap: 10–25μm SnAgPitch: 40–130μmNi barrier optionAR: 2:1–5:1

Micro Bump

Sub-55μm pitch Cu/Ni/SnAg micro bumps for 2.5D/3D stacking, hybrid bonding, and the tightest interconnect requirements in HBM and chiplet designs.

Pitch: 10–55μmDiameter: 5–25μmCu/Ni/SnAg stackHybrid bonding compatibleMass reflow or TCB

Bonding Process Flow

Wafer Cleaning & Prep

Incoming wafers undergo particle and organic contaminant removal to establish a clean surface for dielectric coating.

Dielectric Coating & Cure

Polyimide or BCB dielectric is spin-coated and thermally cured to form the insulating base layer for RDL routing.

RDL Photolithography

Photoresist patterning defines the RDL trace geometry, exposed and developed to the target line/space design rule.

Cu Seed Sputtering

A thin copper seed layer is sputter-deposited across the wafer to enable subsequent electroplating.

Cu Electroplating

Copper is electroplated into the patterned traces and vias to build the conductive RDL routing.

UBM Deposition

Under-bump metallization is deposited to provide adhesion, diffusion barrier, and solderable surfaces at each bump site.

Bump Plating & Placement

Solder, copper pillar, or micro bump structures are plated or placed at each UBM site per the selected bump technology.

Reflow & Final Inspection

Bumps are reflowed to final shape, then verified by AOI, cross-section sampling, and electrical continuity testing before release.

Key Applications

Fan-Out Wafer-Level Packaging

RDL and bump layers form the backbone of FOWLP, enabling thinner, smaller packages without a substrate.

2.5D/3D IC Integration

Fine-pitch RDL and micro bumps connect interposers and stacked die for high-bandwidth, low-latency system integration.

Flip-Chip BGA Assembly

Solder and copper pillar bumps provide the direct chip-to-substrate connections used in standard flip-chip ball grid array packages.

HPC & AI Accelerators

High-density RDL routing and micro bump interconnects support the massive I/O counts required by AI and HPC compute dies.

5G & RF Modules

Low-loss RDL routing and precision bump placement meet the electrical performance demands of 5G front-end and RF modules.

Mobile SoC Packaging

Compact fan-out and fine-pitch bump solutions deliver the thin-profile, high-I/O packaging mobile application processors require.

Integrated Passive Devices

Integrated Passive Devices fabricated in the RDL layers provide capacitors, inductors, and resistors directly on the wafer surface. IPD integration reduces component count, minimizes parasitics, and improves electrical performance for RF and power management applications.

Quality Assurance & Metrology

Our quality management system is certified to ISO 9001:2015 with additional compliance to SEMI standards, RoHS, REACH, and Conflict Minerals regulations. Each shipment includes a certificate of conformance with lot traceability back to the original ingot.

Ready to Get Started?

Contact our engineering team to discuss your specific requirements and receive a detailed quotation within 24 hours.

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ISO 9001 Certified GDS Support AOI Inspection JEDEC Standard

RDL Bump Wafer