Advanced Solder Paste Technology for Precision Electronics
Innovations in solder stainless steel solutions for multi-level packaging and high-reliability electronic components
The Critical Role of Interconnection Soldering
Interconnection solder joints provide both electrical and mechanical connections, serving as essential components in electronic devices. To effectively solder stainless steel and other materials, the right formulation is crucial for ensuring reliability and performance.
Solder paste, a new type of welding material, has been widely used in the packaging of surface mount components in recent years. This paste, which is essential when working to solder stainless steel components, consists of a homogeneous mixture of solder alloy powder and flux.
As a high-end welding material developed with the rapid advancement of SMT technology, solder paste provides the necessary solder for forming joints during reflow soldering, contains flux that promotes cleaning and surface wetting, and secures components in place before the solder melts. When working to solder stainless steel in electronic assemblies, the quality of this paste directly impacts overall performance.
The Importance of Solder Paste Quality
Reliability Factor
As a critical connection material in SMT, the quality of solder paste directly determines the reliability of surface mount devices. When attempting to solder stainless steel components, inferior paste formulations can lead to numerous defects that compromise performance.
Common Defects
Poor quality solder paste can cause defects such as solder balls, bridging, tombstoning, and non-wetting after reflow soldering. These issues are particularly problematic when trying to solder stainless steel, as they can seriously endanger the normal operation of electronic products.
Operational Impact
Electronic components with soldering defects often fail prematurely or perform unreliably. This is especially true when manufacturers attempt to solder stainless steel without the proper materials, leading to increased maintenance costs and potential safety hazards.
Quality Standards in Modern Electronics
With the rapid development of technology, electronic devices have become increasingly complex, placing higher demands on packaging technology. As multi-level packaging expands, printed circuit boards (PCBs) require multiple soldering processes, each presenting unique challenges when needing to solder stainless steel components alongside other materials.
The ability to consistently produce high-quality solder joints across multiple reflow cycles is becoming increasingly important in advanced electronic manufacturing, particularly when working with challenging materials like stainless steel.
Challenges in Modern Soldering
Advanced electronic packaging presents unique challenges that traditional soldering materials struggle to address
High Temperature Challenges
During secondary (or multiple) soldering processes, printed circuit boards (PCBs) reach relatively high temperatures, typically above 240℃. For conventional solder pastes with low melting points, this can cause already formed solder joints to re-melt, especially when trying to solder stainless steel components alongside other materials.
This re-melting phenomenon results in poor adhesion of previously soldered components, seriously affecting welding quality and reducing product performance. The problem is particularly pronounced when attempting to solder stainless steel in multi-step processes where temperature control becomes increasingly complex.
The inability to withstand subsequent high-temperature processes limits design flexibility and increases the risk of component failure in applications requiring multiple soldering steps.
Underfill Complications
For components with underfill protection, high temperatures during secondary (or multiple) soldering can cause molten solder to be drawn into small pores within the underfill material due to capillary action in the gaps.
This phenomenon creates potential short circuits and reliability issues in delicate electronic assemblies. When attempting to solder stainless steel components that have been underfilled, the risk of these complications increases due to the material's unique thermal properties.
The interaction between molten solder and underfill materials represents a significant challenge in advanced packaging, requiring specialized solutions when working with diverse materials including stainless steel.
Limitations of Current Solutions
Sintered Silver Paste
Current technology primarily uses sintered silver paste as a substitute for traditional solder paste. This material sinters at relatively low temperatures, creating connections between components and substrates that maintain reliability at high temperatures, even when used to solder stainless steel components.
High production costs due to silver as a precious metal
不利于重工或返修 Makes rework or repair of soldered devices difficult
Traditional Solder Paste
Traditional solder pastes offer lower costs and easier rework capabilities, making them preferable for many applications where the ability to solder stainless steel isn't a primary concern.
Low melting points fail in high-temperature service environments
Poor performance in multi-level packaging requiring multiple reflow cycles
Innovative Solder Paste Technology
Our specialized solder paste for multi-level packaging addresses the critical challenges in modern electronics manufacturing
The Technical Solution
Our invention provides a specialized solder paste for welding multi-level packaged SMT components. This innovative formulation solves the technical problem of creating a material that can solder stainless steel and other components with a low welding temperature while maintaining a high melting point in service environments.
This advanced paste replaces currently used sintered silver paste, reducing production costs while facilitating easier rework and repair of soldered devices. The ability to effectively solder stainless steel while maintaining compatibility with other materials represents a significant advancement in electronic manufacturing.
By combining carefully selected alloys and additives, our solder paste delivers superior performance in multi-level packaging applications where traditional materials fail to meet requirements.
Formulation Composition
Tin Alloy Powder
A mixture of one or two of the following: tin-silver alloy powder, tin-antimony alloy powder, tin-copper alloy powder, and tin-lead alloy powder.
By mass percentage:
- Tin: 2% ~ 96%
- Lead: 1% ~ 92%
- Silver: 0.6% ~ 4%
- Copper: 0.05% ~ 0.8%
- Antimony: 10% ~ 25%
Nanometal Powder
One or more mixtures of copper powder, lead powder, titanium powder, cobalt powder, and gold powder. This component is crucial for creating a paste that can effectively solder stainless steel.
By mass percentage:
- Copper: 2% ~ 60%
- Lead: 0.5% ~ 15%
- Titanium: 0.1% ~ 5%
- Cobalt: 0.1% ~ 5%
- Gold: 0.1% ~ 10%
Rare Earth Alloy Powder
Precisely formulated rare earth alloys that enhance the overall performance and reliability of the solder paste, particularly when used to solder stainless steel components.
By mass percentage:
- Rare earth alloy powder: 0.01% ~ 2%
- Nanometal powder: 98% ~ 99.9%
Flux Paste
A precisely balanced mixture of active ingredients that facilitate the soldering process, ensuring proper wetting and adhesion, especially important when working to solder stainless steel.
By mass percentage:
- Hydrogenated rosin: 3% ~ 8%
- Diethylene glycol monohexyl ether: 1% ~ 6%
- Succinic acid: 0.1% ~ 0.8%
- Methylbenzotriazole: 0.03% ~ 0.1%
- Citric acid: 0.01% ~ 0.2%
Advanced Manufacturing Process
Our proprietary manufacturing process ensures consistent quality and performance in every batch
Step 1: Prepare Tin Alloy Powder
This stage involves creating various tin-based alloys that form the foundation of our solder paste. Each alloy is carefully formulated to contribute specific properties when used to solder stainless steel and other materials.
- Melting raw materials in medium-frequency or vacuum furnaces
- Controlled cooling in stainless steel containers
- Precise mixing with tin powder at 200-300℃
- Addition of potassium metal powder at 150-180℃
- Atomization and classification into seven particle sizes
Step 2: Prepare Nanometal Powder
The production of high-quality nanometal powders is critical for creating a paste that can effectively solder stainless steel. These tiny particles enhance the material's properties and enable reliable bonding to various surfaces.
- Melting of copper, lead, titanium, cobalt, and/or gold
- Processing through nanometer powder forming equipment
- Precise centrifugal classification and screening
- Particle size control between 2~100nm
Steps 3 & 4: Rare Earth Alloy & Flux Preparation
These critical components enhance the solder paste's ability to form strong, reliable bonds, particularly when working to solder stainless steel. The flux ensures proper wetting and cleaning of surfaces.
- Rare earth alloy processing and classification
- Controlled melting of hydrogenated rosin at 120-140℃
- Precise addition of diethylene glycol monohexyl ether
- Temperature-controlled addition of active ingredients
Step 5: Final Mixing & Packaging
The final stage combines all components under precise conditions to create the finished solder paste. This careful blending ensures the material can consistently solder stainless steel and other components in demanding applications.
- Sequential addition of all components to automatic planetary mixer
- Thorough mixing under vacuum conditions
- Precise packaging into appropriate containers
- Storage at controlled temperature (2~10℃) to maintain freshness
Applications & Benefits
Our specialized solder paste delivers exceptional performance in demanding electronic manufacturing environments
Semiconductor Packaging
Ideal for advanced semiconductor packaging where multiple reflow cycles are required. The paste's ability to maintain integrity through subsequent high-temperature processes makes it perfect for complex assemblies that include stainless steel components.
Enables reliable interconnections in multi-chip modules and system-in-package designs where traditional materials fail during secondary soldering operations.
Automotive Electronics
Perfect for automotive electronic systems that operate in extreme temperature environments. Our solder paste provides the reliability needed in under-hood applications and other harsh conditions where the ability to solder stainless steel components is essential.
Withstands thermal cycling and vibration while maintaining electrical and mechanical integrity in critical safety systems.
Aerospace & Defense
Meets the stringent requirements of aerospace and defense applications where failure is not an option. The paste's ability to perform in extreme environments and maintain connections through multiple thermal cycles makes it ideal for these critical systems.
Provides the high reliability needed in avionics, satellite systems, and military electronics where temperature extremes are common.
Key Performance Advantages
High-Temperature Service
Maintains integrity in service environments above 300℃, far exceeding the capabilities of conventional solder pastes when used to solder stainless steel and other high-performance materials.
Cost-Effective
Significantly lower production costs compared to sintered silver paste alternatives while providing superior performance when needing to solder stainless steel components.
Rework Capability
Enables easier rework and repair of soldered devices compared to sintered silver paste, reducing manufacturing costs and improving yield rates.
Multi-Level Compatibility
Perfectly suited for multi-level packaging requiring multiple soldering steps, maintaining joint integrity through each subsequent thermal cycle.
Technical Implementations
Practical formulations demonstrating our solder paste technology in action
Example 1: Tin-Silver Base Formulation
Alloy Composition
- 30g tin metal + 70g silver metal, melted at 1100-1200℃ in medium-frequency furnace
- Alloy mixed with 1000g tin powder at 200-300℃ for 60 minutes
- 8g potassium metal powder added at 150-180℃, stirred for 60 minutes
- 25g copper + 0.8g lead as nanometal component
- 0.15g rare earth alloy powder
Flux Composition
- 40g hydrogenated rosin melted at 120-140℃
- 16g diethylene glycol monohexyl ether added and mixed
- 1.5g succinic acid + 5g methylbenzotriazole added at 80-110℃
- 1.5g citric acid added at 40-50℃
- All components mixed under vacuum and stored at 2-10℃
Example 2: Tin-Copper Base Formulation
Alloy Composition
- 10g tin metal + 100g copper metal, melted at 1100-1200℃ in medium-frequency furnace
- Alloy mixed with 1000g tin powder at 200-300℃ for 60 minutes
- 9g potassium metal powder added at 150-180℃, stirred for 60 minutes
- 25g copper + 0.4g silver as nanometal component
- 0.2g rare earth alloy powder
Flux Composition
- 50g hydrogenated rosin melted at 120-140℃
- 16g diethylene glycol monohexyl ether added and mixed
- 2g succinic acid + 9g methylbenzotriazole added at 80-110℃
- 1.8g citric acid added at 40-50℃
- All components mixed under vacuum and stored at 2-10℃
Example 3: Tin-Antimony-Lead Formulation
Alloy Composition
- 10g tin + 100g antimony, melted at 650-800℃ in vacuum furnace
- 63g tin + 37g lead, melted at 1300-1400℃ in medium-frequency furnace
- Alloys mixed with 1000g tin powder at 200-300℃ for 60 minutes
- 12g potassium metal powder added at 150-180℃, stirred for 60 minutes
- 0.4g titanium + 0.4g cobalt + 0.4g silver as nanometal component
Flux Composition
- 80g hydrogenated rosin melted at 120-140℃
- 20g diethylene glycol monohexyl ether added and mixed
- 2g succinic acid + 10g methylbenzotriazole added at 80-110℃
- 3g citric acid added at 40-50℃
- All components mixed under vacuum and stored at 2-10℃
Revolutionizing Electronic Manufacturing
Our specialized solder paste represents a significant advancement in materials technology for electronic manufacturing. By addressing the critical challenges of high-temperature service and multi-level packaging, this innovative solution provides superior performance while remaining cost-effective and practical for real-world applications.
The ability to reliably solder stainless steel and other challenging materials in complex assemblies opens new possibilities for electronic design and manufacturing, enabling more robust, reliable, and cost-effective products across industries.
Learn more