Design Guidelines: Vias (thru & filled)

Our Solid Copper Filled Vias are qualified for use in Space Applications. Filled Via Qualification Report

Solid Copper Vias versus Solid Gold Vias

  • Cost effective - 10-20% less cost than comparable Gold
  • Thermal conductivity 33% greater than Gold
  • Lead time 20% sooner than Gold
  • Facilitized for prototype through high volume production quantities
  • Can withstand up to +300°C processing temperatures

Via and/or Wrapped Connections

In any circuit medium, vias are a great advantage to the designer.  However, the tendency to overpopulate ground areas is a temptation obvious in many designs.  Critical to hard substrate manufacturing is the careful consideration of via quantity and location.  While aiding the performance of the design, poorly placed vias can degrade yield due to reduced durability of the substrate in manufacturing. Our CAD services can optimize your design for your electrical need balanced with manufacturing enhancements.  One method of enhancing a design which has developed into a significant advantage to designers is the use of the filled via. Knowles Precision Devices uses the industry preferred solid Cu and Au process as opposed to the less-desirable glass/metal paste method used by other companies.

Plated Through Vs Filled Vias

Feature DC
Resistance
Inductance RF
Resistance
Filled Vias
1 mΩ
78pH
4 mΩ
Plate Vias
4 mΩ
81pH
14 mΩ
Data based on a 0.020" diameter via in a
0.025" thick Alumina substrate

 

Plated Through Via Vs Substrate Thickness

Substrate
Thickness
Substrate
Material
Preferred Via
Diameter
Allowable Via
Diameter
Via Spacing
Cntr.-Cntr. Cntr.-Edge
.005"
Al2O3
.005"
.003" - .005"
.027"
.023"
.010"
Al2O3,AIN
.010"
.006" - .010"
.030"
.025"
.015"
Al2O3,AIN
.015"
.008" - .015"
.035"
.027"
.020"
Al2O3,AIN
.020"
.010" - .020"
.040"
.030"
.025"
Al2O3,AIN
.025"
.012" - .025"
.045"
.033"
.040"
Al2O3,AIN
.032"
.024" - .040"
.060"
.040"
.050"
Al2O3,AIN
.040" - .050"
.025" - .050"
.070"
.045"
 

Filled Via Vs Substrate Thickness

Substrate
Thickness
Substrate
Material
Ideal Via
Diameter
Via Spacing
Cntr.-Cntr. Cntr.-Edge Fill
.010"
Al2O3
.008"
.028"
.020"
Cu,Au
.015"
Al2O3
.012"
.034"
.020"
Cu,Au
.020"
Al2O3,AIN
.016"
.032"
.020"
Cu,Au
.025"
Al2O3,AIN
.020"
.040"
.025"
Cu,Au


Via Application Data

Filled Via Conductivity
Parameter Valve
Copper 99.9%
393 W/M°C
Gold 99.9%
300 W/M°C
Filled Via Planarity
+0/-.0003"