Metals & alloys · Joining alloys
SAC305 lead-free solder
A widely used Sn–3.0Ag–0.5Cu lead-free solder balancing processability, joint strength and established electronics manufacturing practice.
Browse this family
More
01
Overview
- Material class
- Metals & alloys
- Category
- Joining alloys
- Family
- Solder & Joining Alloy
- Product forms
- Not specified
Composition
| Constituent | Min | Max | Typical | Note |
|---|---|---|---|---|
| Sn | 96.5 | |||
| Ag | 2.8 | 3.2 | 3 | |
| Cu | 0.4 | 0.6 | 0.5 |
02
Properties and conditions
Engineering properties
| Property | Value | Unit | Condition |
|---|---|---|---|
| Density | ~7.4 | g/cm³ | Representative; verify product form and condition |
| Solidus | ~217 | °C | Representative; verify product form and condition |
| Liquidus | ~220 | °C | Representative; verify product form and condition |
| Elastic modulus | ~45–55 | GPa | temperature dependent |
| Thermal conductivity | ~55–65 | W/m·K | Representative; verify product form and condition |
| CTE | ~21–24 | µm/m·K | Representative; verify product form and condition |
Conditions
Representative supplied condition
Condition not fully specified in the source record.
03
Processing and use
Processing
- Peak temperature, time above liquidus and cooling rate influence intermetallic structure.
- Board finish and component metallurgy affect joint reactions.
Applications
- Printed circuit assemblies
- Electronic component attachment
- Lead-free manufacturing
Selection considerations
- Thermal-cycling reliability is package and geometry dependent.
- Silver cost and drop/shock behaviour may motivate lower-Ag alternatives.
Open in an analysis tool
04
Standards and related materials
Standards and designations
| System | Designation | Note |
|---|---|---|
| JEDEC | J-STD-006 | electronic-grade solder alloy requirements |
| ISO | 9453 | soft solder alloy designations |
| IPC | J-STD-001 | assembly process requirements |
05
Sources and context
Sources
- NIST solder thermodynamic databaseExisting reference
- JEDEC J-STD-006Existing reference
- ASM International and public alloy designation referencesIdentity reference
Confirm the applicable specification, product form and condition before using values for design or procurement.
Supply and sustainability
Global commodity electronics solder with extensive paste, bar and wire availability.
Lead elimination is a major benefit; silver content and electronics recovery affect overall resource performance.
Strategic context
Established engineering material with documented processing–performance relationships.