Here is the abstract you requested from the DPC_2007_FlipChip technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|Thermal Management for FC on LTCC|
|Keywords: Flip Chip, Low Temperature Cofired Ceramics, Themal Managment|
|The request for smaller and higher integrated RF-modules for mobile applications are rising. One of many examples for this development is the PAiD-Moduls (Power Amplifier with integrated Duplexer) where a power amplifier is mounted together with a SAW-filter (Surface Acoustic Wave) on an LTCC (Low Temperature Cofired Ceramics) module. Since the power amplifier is producing heat, due to the power loss, a thermal management is required. In a wirebond solution the complete die is mounted with the backside on a heatsink. But in a flip chip mounted die, where the backside is facing up and there is no space for a backside heatsink, the complete heat must be transferred through the solderbumps and the underfill. In order to meet this requirement, the thermal management for the FC (Flip Chip) on the LTCC has to be better understood. Therefore a test design was developed and die size, LTCC-thickness, thermal vias, heatspreader and underfill were used as parameters. The test die has a heating resistor to simulate the power loss in the amplifier and a diode circuit. With the voltage drop over the diode, the die temperature can be calculated. The test die also contains a daisy chain which is used for reliability investigations during thermal cycling and high temperature storage. For more detailed understanding of the thermal management an FE-model (Finite Element) was used. The FE-model was calibrated, using the results of the experimental setup. The usage of FE-modeling will shorten the design phase of a project significantly.|
|Markus Noren, Development Engineer
Deutschlandsberg, Styria 8530,