Created: 10/19/99 |
Resch, Cheryl Lynn (M.S. Mechanical Engineering)
Calculation and Measurment of Temperature Profiles of Electronic Printed Wiring Boards
The temperature characteristics of printed wiring boards (PWBs) are investigated and a computer program for calculating the PWB temperature profile and the temperatures of individual components is described.
Steiner Tree Oriented Placement
Presented is a new design methodology for the placement of components
on a printed wiring board (PWB). By simulating the connection and the
movement of a node in a tree in a placement step, an iso-distance error
graph (IDEG) which contains connection errors generated by replacing a
Steiner tree with its equivalent not-Steiner tree is developed and is
used to estimate how well a non-Steiner tree functions as a Steiner tree.
To reduce connection errors in the IDEG and pursue the computational
efficiency, a row-based tree family, in which the tree length is dependent
on the terminal coordinates of each row, is constructed. Based on the
analysis of the error distribution on the IDEG of a row-based tree and
practical tests, the row-based tree functions better than the minimum
spanning tree does and a minimum or nearly minimum total Steiner tree
length can be obtained by minimizing the total row-based tree length.