Surface Mountable Packages

Leadless Ceramic SMT Packages and Chip Carriers with PCTF® for a Direct PCB Mount
Commercial Quasi-Hermetic SMT Package Fully Hermetic SMT Package

Leadless SMT packages and chip carriers design concept is based on creating an interconnect pattern on a ceramic substrate   with PCTF® (Plated Copper on Thick Film Technology) for multiple or single die applications. Essential features of this package   design are solid plugged via holes and wraparounds (castellations) which are described below.



 Solid Metal Vias provide hermetic, high thermal and electrical conductivity connections.

  • Plugged  vias withstand gross leak test requirements common for commercial  and industrial applications.
  • For more demanding applications, plugged vias are fabricated to meet  full MIL STD  hermeticity requirements and pass fine leak test to 10-8 atm  cc/sec.


Ceramic thickness Plugged Via Holes
.010” – .025” .007” – .020”
.025” – .040” .009” – .030”
.040” + Consult Factory

 Wraparounds (Castellations) provide cost effective, reliable  SMT leadless connection  for a direct PCB mounting in a wide   ceramic size range, to a  1×1” ceramic substrate and larger. Standard Dimensions for Solid Plugged Via and Plated Castellation   are listed below.

Ceramic Thickness – A

Castellation Width – B

Castellation Depth – C

Metallization Width – D



















Plated Through Hole

Solid Plugged Via

Plated Castellation

Plated Copper Through Holes  ensure a higher current carrying  capacity, low loss RF signal and  ground interconnections.

Solid plugged via holes are fully  hermetic, withstand gross and fine leak  test (10-8 atm cc/s).
Plugged via holes provide excellent  thermal and electrical signal and ground  interconnections.

Plated Castellations /  Wraparound provide for a  reliable direct PCB attach / for  SMT chip carriers and packages.


Efficient Thermal Management

Plugged vias with High thermal conductivity of  200 W/°CxM  create an effective heat transfer path with a low thermal   resistance.


    • Via fill  material thermal conductivity is actually better than  200 W/°C xM.
    • Typical .008”-.012” plugged via in .015″ – .020” thick alumina ceramic will create a thermal pass with a thermal resistance of ~ 35-40de
    • °C/W per via depending on Cu plating thickness, substrate thickness and plugged via hole diameter.
    • A single die of 3mm x 3mm (.120”x.120”) dissipating 5 W has 20 plugged vias underneath the chip. Approximately,   the total  effective thermal resistance  θ of  0.020” thick alumina under the die is 2°C/W. Therefore,  the   temperature rise should not exceed  more than:  ∆T=10° C max  (from  the back of a die to the  back of the   package).


Hermeticity of a package is achieved by ensuring the hermeticity of both  plugged via holes and hermetic sealing of  ring frame to ceramic substrate.

1. Ring Frame Landing Area Width

Due to the  necessity to ensure a proper solder fillet form the inner and outer sides of the ring frame the minimum dimensions   required for solder fillets are listed below:

  1. Standard:  Minimum X.=.010” from each side
  2. Premium: Minimum X’=.008” from each side

Following the above mentioned rule the landing area for the Ring Frame is calculated as follows:

Add Ring Frame Wall Thickness
Add Fillet width on both sides (2X or 2X’)


Min Width of the Ring Frame landing area

2. Plugged Via Metalization Diameter

To ensure the hermeticity a minimum  annular ring around the circumference of the plugged via hole should be as listed below:

  1. Standard:  .010” from each side Minimum
  2. Premium: .008” from each side Minimum

Following the above mentioned rule the annular ring dimensions for the plugged via hole must be calculated as follows:

Nominal diameter of the drilled hole


10% of the ceramic thickness


Annular ring width * 2


Min Diameter of the Annular Ring

Notes: More information is available

  1. For packages Sizes and availability consult factory
  2. For Reliability Testing report consult factory
  3. Packages operate in a broad frequency range. Consult factory for the details