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LeskerBond™ Services
Offering NanoBond® & NanoFoil® technologies from RNT
Our LeskerBond™ service offers in-air room temperature target bonding of dissimilar materials using Reactive NanoTechnologies Inc. (RNT) NanoFoil®. Our service offers superior bonding of targets to backing plates with different coefficients of thermal expansion --- reducing or eliminating target cracking or debonding during deposition.
Illustration of process
Close-up of foil and solder in-situ
The Lesker Advantage
RNT's NanoBond® process offers:
- Strong metallic bonds (3000-4000psi typical)
- Ideal for bonding dissimilar materials; especially ceramics to metals
- Reduced strain and deflection compared to conventional techniques
- Better bond line thickness control
- Use of high temperature solders enables high sputter rates
- In-air room temperature process
- Controlled local heat source reduces stress to target assembly
The Technology
The LeskerBond™ services offer the patented NanoBond® process technology and patented NanoFoil® under license from RNT. NanoFoil® consists of hundreds of alternating nanoscale layers of elements, such as aluminum and nickel. Once activated, the inter-mixing of the metal layers leads to heat generation within the foil. This heat source is then used to melt adjoining layers of solder to bond components together without having to heat the entire assembly past the melting point of the solder.
The Process
The appropriate solder is selected based on wetting characteristics of the target assembly and the application. The sputter target and backing plate surfaces are prepared with the solder and the NanoFoil® is placed between the two materials. Depending on the size of the target assembly, the foil can be a singular piece or a tiled array. Once the pieces are correctly aligned, pressure (50- 350psi) is applied to the assembly. An electrical impulse is then applied to the assembly which incites the reaction in the foil. This reactive, localized heat source instantaneously reflows the solder which bonds the target assembly. The bond is considered stress free since the target and backing plate, with different CTEs, do not heat up to any great extent during the bonding process.
Download LeskerBond™ Process Animation Movie
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| Format: QuickTime Length: 1:37 min File size: 474 kB |
Format: Windows Media Length: 1:37 min File size: 14.7 MB |
Format: Flash Player Length: 1:37 min File size: 449 kB |
Performance Data
Summary of sputtering trials (all targets bonded to copper backing plates)
| Target Material | Power Mode | Bond Type | Max. Power without Failure (W) |
Power Density (W/cm3) |
| Indium Tin Oxide | DC | InSn-Reflow | 200 | 4.4 |
| Indium Tin Oxide | DC | Elastomer | 300 | 6.6 |
| Indium Tin Oxide | DC | NanoBond® | 400 | 8.8 |
| Alumina | RF | Elastomer | 300 | 6.6 |
| Alumina | RF | NanoBond® | 400* | 8.8* |
| Boron Carbide | DC | In Reflow | 2000 | 2 |
| Boron Carbide | DC | NanoBond® | 4000* | 4* |
* Conservative values, not run to failure.
FEA Stress Modeling
The strain energy of a NanoBond® joint is 1/8 that of a conventional bond joint and deflection is an order of magnitude less.
NanoBond has a maximum y deflection of 0.04mm whereas conventional bonding has a maximum y deflection of 0.7mm for materials with CTEs of 6 and 17
Alumina (3 inch diameter) targets after sputtering trials. Conventional bond (left) versus NanoBond (right).
NanoFoil® and NanoBond® are registered trademarks of RNT (Reactive NanoTechnologies Inc.)
All images, including "foil spark", courtesy of RNT.