• Silver-Coated Particle Selection Guide

Hart Materials offers a choice of no fewer than 68 silver-coated particles, 32 with various glass substrates and a further 36 with non-glass substrates.

Given the wide choice of particles available, the following information provides a guide as to which type of particle might give optimum performance in different circumstances. Please click a section below to expand:

Low silver content

The particles with the highest silver coating content obviously give the highest level of conductivity, but at the expense of weight and cost.

See particles with low silver content below:

TYPE GRADE SILVER CONTENT (%) PARTICLE SIZE (µm) AVG. DENSITY (g/cc)
Solid Glass S 2429 S 4 89 2.6
  S 3000 S 4 41 2.6
Glass Microspheres TP50 S06 6 50 2.6
Glass Fibre SF82 TF8 8  130 x (15)* 2.6
Glass Granules SG100 P6 6  100 2.6
Aluminium SA100 P05 5 100 2.8
Nickel SN40 P08 8  31 9.0
Silicon Carbide SSI C85 P06 6  83 3.3
  SSI C160 P04 4  160 3.3

* Figure in ( ) is the fibre diameter in microns

Large particle size

In terms of size, smaller particles are used in products that need to fill narrow gaps, whereas the larger particles offer the advantage of a lower volume percentage of filler to achieve the required conductivity levels.

See products with large particle sizes below:

TYPE GRADE SILVER CONTENT (%) PARTICLE SIZE (µm) AVG. DENSITY (g/cc)
Solid Glass Spheres S 2429 S 4 89 2.6
Microspheres TP100 S02 2 100  2.5
Glass Granules SG75 P12 12  75 2.7
  SG100P6 6 100 2.6
Copper Spheres SC80 S08 8 70 9.2
  SC120 S04 4 105 9.0
Hollow Ceramic Spheres AG-SL150 16-TRD 16 85 0.9
  AG-SL150 30-TRD 30 85 1.1
Silicon Carbode Particles SSI C160 P04 4 160 3.3

Small particle size

Sub-10 micron particles are useful in conductive adhesives where narrow bond-line (Z-plane) thickness is required, and in conductive pastes for fine line screen printing.

Low density

Hollow spheres, particularly the larger ones, obviously have much lower density than solid spheres. This results in significant weight savings, a highly important factor in the aerospace industry.

See hollow sphere particles:

Thin coatings

The flake and fibre products are more suitable for use in coating systems where it is only necessary to deposit a thin layer of conductive material.

Robust metallic substrates

Silver-coated metallic substrate products are very robust. Ideal for applications where high shear mixing may be part of the manufacturing process, or high pressure is applied to the final articles, for example, silicone gaskets into which the particles have been incorporated.

See particles with metal substrates:

High conductivity

Copper substrate particles have the advantage of the high conductivity of the substrate material.

High conductivity with lower density

Aluminium substrate particles similarly have high inherent conductivity but at much lower density than copper. They also create minimal galvanic corrosion when in contact with aluminium surfaces.

Ferromagnetic properties

Nickel-based particles are extremely robust and also show ferromagnetic properties that give enhanced electronic shielding.

Magnetic properties with less environmental impact

Ferrite-based products offer similar magnetic properties to nickel-based products, but without the potential environmental concerns of nickel.

See particles with miscellaneous substrates:

Low weight with high strength

Ceramic hollow spheres offer the weight reduction benefits of hollow glass, but are available in larger sizes than glass hollow spheres and also have a higher crush strength.

Non-conductive/low density applications

In non-conductive applications, such as Particle Image Velocimetry (PIV), low particle density combined with the relatively large particle size of either hollow silver-coated glass or ceramic spheres, provides ideal material for this technology.

For further advice from our technical team, please contact us.

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