Technical Data
Solder Preforms provide a precisely defined amount of solder volume on a pre-printed pad. They are offered in various sizes and are RoHS compliant. The alloy of the solder material is SAC305 - Sn96.5Ag3Cu0.5. The corresponding tolerances to the component thickness can be taken from the following table:
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0.025mm to 0.050mm
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±0.0076mm
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0.050mm to 0.254mm
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±0.0127mm
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0.254mm to 0.508mm
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±0.0254mm
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0.508mm to 1.27mm
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±0.0635mm
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More than 1.27mm
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±5%
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An example of use
Exposed pads are often used to achieve heat dissipation in so-called BTCs (bottom terminated components). However, voids can occur during the reflow process, sometimes even with a proportion of 50% or more. An exposed pad with critical voids can look like this:
Trying to solve the voiding problem by adding more solder paste can lead to lifting of the component and problems soldering the side pins. Also, more solder paste inevitably leads to more flux/air bubbles on the exposed pad because it gets trapped and can't flow off.
To solve the problem, you can use preforms, for example. In simple words, you put more pure solder into the solder joint. The improved results by using preforms would be as follows:
Voiding has been reduced significantly. By using preforms the assembly process can get safer and more reproducible.
Advantages
- Improved thermo-mechanical stress on the solder joint
- Solder preforms are very uniform in shape, each has the exact same volume of solder
- Reduction of the repair effort
- Different sizes and shapes are available
Packaging
1. Bulk packaging
2. Stacked packaging
3. Chip box packaging
4. Tape and reel packaging (Reel Size 7” & 13”)
Ideal for machine placement
Thanks to tape and reel packaging, the preforms can be conveniently loaded by machine without the use of special Equipment.
Customized Manufacturing
Other designs and alloys are possible on request. For example cubic solder preforms.
For questions or inquiries about developments, please feel free to contact us.
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