Current Carrying Capacity Testing in 1998
JUNO Visit with Daughter!
PO Box 2892
Centennial, CO 80161 US
Chapter 16, Current Carrying Capacity in Printed Circuits, Printed Circuits Handbook, Clyde Coombs Jr., Rev 6, McGraw Hill Publishing (2009).
Chapter 16, Current Carrying Capacity in Printed Circuits, Printed Circuits Handbook, Clyde Coombs Jr., Rev 7, McGraw Hill Publishing (2016).
Thermal Management LLC is a single person LLC formed on December 4, 2014.
IPC Volunteer Work
Improving the knowledge of current flow in conductors from a PCB thermal management perspective from 1999 to 2016.
IPC-2152, task group 1-10b chairman from 1999 to 2016.
Since 1954, the focus of current carrying capacity in printed circuits has only been on the steady state temperature rise in traces of a specific geometry that is not representative of a broader term of conductors, especially in today’s technology. Conductor temperature rise, as a result of applied current, in vias, mirco-vias, wagon wheels, and variations of those, not to mention the transient aspects of high current pulses and high current in general have not been tested and documented.
The existing standard does not address these areas. The temperature rise of a conductor, when current is applied, is dependent on many things. One of those things is the presence of copper planes (there are no copper planes in a standard test vehicle) which exist in most printed circuit board designs. Copper plane layers spread the localized heat in a trace when current is applied to it. The influence of copper planes is complex, as the temperature rise of a conductor near a plane is a function of the size and geometry of the plane, as well as the distance from the trace to the plane.
An industry survey was performed in 2012 and used to focus future testing to support IPC-2152, Standard for Determining Current Carrying Capacity in Printed Board Design.
Proposed Future Testing
The following list covers the main areas of conductor variations that require test data. The test data allows a base point for corporations to use as a design guide and a data point to compare with computer model results of thermal analysis simulations. The focus of each testing phase is to determine the temperature rise of a conductor when current is applied. The following list falls into three different categories that will require special elements written for the proposal. The three categories are rigid and flex designs, small geometries (vias, microvias, wagon wheels, embedded resistors) and the last is high current pulses or time dependent current applications.
· Conductors in Rigid Boards
· Conductors in Flex Boards
· Parallel Conductor Rule
· Wagon Wheels (Thermal Reliefs)
· Printed Conductors (materials other than copper)
· Embedded Resistors
· High Current
· High Current Pulses (Transient Temperature Rise)
· Power Dissipation in Conductors
· Dielectric Thermal Properties (thermal conductivity x, y, z, specific heat, density)
· Electrical Resistivity – IPC-TM-650 184.108.40.206a
NASA InSight Spacecraft Electronics (Thermal Design and Analysis)
NASA Osiris-REx Spacecraft Elecronics (Thermal Design and Analysis)
NASA Orion Electronics (Thermal Analysis)
NASA Orion ECLSS (System Analysis)
NASA JUNO Spacecraft (System Thermal Analysis and Test)
NASA Phoenix Spacecraft and Lander (Mission Operations Support)
NASA Stardust Electronics (Thermal Design and Analysis)
NASA Mars Reconnaissance Orbiter Electronics (Thermal Design and Analysis)
NASA Space Station Passive Thermal Control (Thermal Design and Analysis)
Thermal Management LLC
IPC-2152 Release (2009)