Figure 1: Device Floor Plan

...

Image Added

Product features

The NG-MEDIUM device (NX1H35AS) is a Radiation Hardened By Design Sram-based FPGA manufactured on STM C65 Space process with following resources.

Resources

Device architecture

...

Hereafter packaging options vs Quality assurance:

...

The NG-Medium is offered in either

• Ceramic Quad Flat Package 352pins / CQFP-352 referenced CQ352

• Ceramic Land Grid Array 625pins / CLGA-625 referenced LG625

...

• CQFP lead form can be flat or J-leaded. The NG-Medium CQFP-352 has flat leads.

• Lead counts are 352-pins, all connected to a non-conductive ceramic tie-bar.

• It is the maximum lead count for that technology, otherwise the body would be larger and coplanarity would not be controlled properly.

• Flat leads are gold plated with a 27,25mm length.

• Leads will need to be cut and formed later on, by the PCB Assembly contractor, Anchor_Hlk62561223_Hlk62561223 after or before degolding and tinning process (depends of PCB assembly vendor).

• Hereafter a standard specification for lead forming:

...

...

The NG-Medium is offered in

Plastic Ball Grid Array 625pins / PBGA-625 referenced FG625

...

By knowing the thermal resistance of a package, one can calculate the IC's junction temperature for a given power dissipation and its reference temperature.

Definitions:

• Θ_JA is the thermal resistance from junction to ambient, measured as °C/W. Ambient is regarded as thermal "ground." Θ_JA depends on the package, board, airflow, radiation, and system characteristics.

• Θ_JC is the thermal resistance from junction to case. Case is a specified point on the outside surface of the package. Θ_JC depends on the package materials (the lead frame, mold compound, die attach adhesive) and on the specific package design (die thickness, exposed pad, internal thermal vias, and thermal conductivity of the metals used).

• Θ_CA is thermal resistance from case to ambient. Θ_CA includes thermal resistances for all heat paths from outside the package to ambient.
  
  Given the above definitions, we see that:

• Θ_JA =Θ_JC+Θ_CA

• Θ_JB is thermal resistance from junction to board. Θ_JB quantifies the junction-to-board thermal path and is typically measured on the board adjacent to the package near pin 1 (< 1mm from the package edge). Θ_JB includes thermal resistance from two sources: from the IC's junction to a reference point on the package bottom, and through the board under the package.

...

Thermal calculations:

Junction temperature

T_J = T_A + (Θ_JA × P) where

TJ= Junction temperature

TA : Anbient temperature

P : Power dissipation (W)
T_J can also be calculated by using Ψ_JB or Ψ_JT values as.

T_J = T_B + (Ψ_JB × P) where
T_B = board temperature measured within 1mm of the package

T_J = T_T + (Ψ_JT × P) where
T_T = temperature measured at the center of the top of package.

Note: The maximum junction temperature of the NG-Medium is +125°C.

Maximum allowable Power Dissipation

P_max =(T_J-max -T_A)/Θ_JA
Maxim listings of maximum allowable power assume an ambient temperature of +70°C and a maximum allowable junction temperature of +125°C.

Thermal characterization and measurement conditions

...