 |
 |
Aluminum Heat Sink Soldering
Superior Flux offers Aluminum Solder Paste and flux solutions for direct soldering of aluminum heat sinks. Superior Flux's technology eliminates the need for costly plating operations in heat sink fabrication.
Please review our selection of aluminum soldering Video Links.
| Superior Flux Number |
Description | Rec. Base Metals |
Rec. Solders |
Rec. Temp Ranges | MSDS | Spec. Sheet |
| AL26-Series | Aluminum Solder Paste |
Aluminum to: Aluminum, Copper and Brass | 99.3Sn/0.7Cu; SN100C; 96.5Sn/3.5Ag; 99Sn/1Ag | Dependent upon alloy |  |
 |
| AL261-143-75 | Aluminum Solder Paste – Low Temp |
Aluminum to: Aluminum, Copper and Brass – for Heat Sink Applications | Proprietary low-temp solder | Capable of soldering under 200°C | |
|
| No. 1260 | Honey Consistency Soldering Flux | Aluminum to: Aluminum, Copper and Brass | Tin-Zinc: 91Sn/9Zn, 80Sn/20Zn 70Sn/30Zn, Tin-based alloys | 177-288°C 350-550°F |
|
|
| No. 1261 | Liquid Aluminum Soldering Flux – Dip Soldering Aluminum Magnet Wire |
Aluminum to: Aluminum, Copper and Brass | Tin-Zinc: 91Sn/9Zn, 80Sn/20Zn 70Sn/30Zn, Tin-based alloys | 177-288°C 350-550°F |
|
|
| No. 1265 | Aluminum Soldering Flux - Dispensable | Aluminum to: Aluminum, Copper and Brass | Tin-Zinc: 91Sn/9Zn, 80Sn/20Zn 70Sn/30Zn, Tin-based alloys | 177-288°C 350-550°F |
|
|
All aluminum soldering pastes RoHS Compliant.
Please review the following papers on aluminum soldering:
Direct Aluminum Solder Paste (IMAP Thermal Management Workshop - Palo Alto, CA, 2011)
Soldering Aluminum (SME International Brazing & Soldering Conference - Orlando, FL, 2009)
Heat sinks are often made of aluminum. Rather than directly soldering the aluminum heat fins to their aluminum or copper base, the components are typically tin-plated. This plating step is not only costly, but it involves hazardous chemicals. Our heat sink soldering technologies offers the opportunity to bypass plating and directly solder the aluminum components of the heat sink. Our aluminum solder paste can be applied in the same way that traditional solder paste is applied. Its residues do, however, need to be cleaned after soldering.
One primary consideration that has to be made when soldering aluminum is the aluminum alloy that is being soldered:
| Aluminum Alloy | Solderability | Best Solder Alloy | Solderable via Solderpaste | Can be tinned with SN100C |
| 1100, 1145, 1050, 3003 | Great | 91Sn/9Zn; 96.5Sn/3.5Ag; 80Sn/20Zn 70Sn/30Zn, Tin-based alloys | Yes | Yes |
| 1350, some 8000 series | Good | 99.3Sn/0.7Cu; SN100C; 96.5Sn/3.5Ag; | Yes | Yes |
| 6061, 6063, 5050 | Poor to not solderable | 91Sn/9Zn; SN100c | No | Yes |
| 4000, 7000, 2000 series | Very poor | None | No | Unlikely |
The following are options available for Heat Sink Soldering.
Superior AL26-Series Aluminum Solder Paste combines aluminum flux and solder powder to create an all-in-one aluminum soldering solution. Available alloys include 99.3Sn/0.7Cu, 96.5Sn/3.5Ag, 99Sn/1Ag, SAC-305 and SN100C. This aluminum solder paste can be used for joining aluminum to aluminum, copper and brass and is ideal for applications where precision dispensing is required. This solder paste can also be used for Heat Sink applications where copper piping is not built into the aluminum heat sink device. (See AL261-143-75 for heat sink applications where copper piping is built into the aluminum heat sink). Superior AL26-Series flux residues are water soluble and must be washed off after soldering. Our aluminum solder paste has excellent soldering characteristics for copper and nickel-plated aluminum surfaces. The aluminum solder paste creates a true inter-metallic bond between the solder and aluminum substrate.
Superior AL26-143-75 is blended with a proprietary solder alloy that is specifically formulated for the direct soldering of heat sinks. It solders at temperatures under 200°C, thus protecting copper piping built into the heat sink. Most importantly, Superior AL26-143-75 allows for direct Aluminum-to-Aluminum or Aluminum-to-Copper soldering in heat sink fabrication, thus negating the need for plating in heat sink applications. Eliminating plating not only translates into greatly reduced costs, but eliminates the associated hazardous chemicals from the work environment. Post-solder residues are water-soluble and should be cleaned post soldering.
Superior No. 1260 is a general purpose aluminum soldering flux that has a honey-like consistency and color. It is high activity, organic based and chloride-free. No. 1260 is formulated for soldering Aluminum-to-Aluminum, Aluminum-to-Copper, Aluminum-to-Brass, and Aluminum-to-plated terminals. No. 1260 is effectively used with solder foil in heat sink applications. Post-solder residues are water-soluble and should be cleaned post soldering. Superior No. 1260 can also be utilized in joining Aluminum to difficult-to-solder metals like stainless steel, kovar or nickel.
Superior No. 1261 Aluminum Tinning Flux offers the effectiveness of No. 1260 in a liquid form. In addition to being effective for heat sink applications, it is ideal for tinning and soldering of aluminum wires, cable connectors and for dip soldering aluminum magnet wire. Post-solder residues are water-soluble and should be cleaned post soldering.
Superior No. 1265 Aluminum Paste Flux was formulated for applications where the adhesiveness of a paste form is required. No. 1265 can be precision dispensed and spread. In heat sink applications, it can be used in tandem with preformed solder foil. Once applied, the Aluminum Paste Flux adheres to the desired location without spreading or dripping. Post-solder residues are water-soluble and should be cleaned post soldering.