Here is the abstract you requested from the Passives_2007 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.
|Resistance Behavior & Reliability of Embedded Resistor According to Temperature and Humidity|
|Keywords: embedded resistor, carbon paste, memory module|
|This Paper is the content of a developing Embedded Resistor instead of a discrete resistor in memory module. The embedded resistor can solve the smt area limit of the high speed , high density memory module, is being raised up a epochal solution to reduce customer's mechanical damage claims of component. It is electrically as good as discrete resistor about TCR, power dissipation. In order to design and make a test resistor, it was used TU-15-8 series of ASAHI CHEMICAL to trim by laser. We have tested the reliability of memory module level ; Thermal Cycling (-25'C to 125'C, 1000 Cycles), THB(85'C/85%,1.8V, 504Hrs), Thermal shock (288C / 10sec), ect , and measured a behavior of resistance change by reflow number of times, by time, by pcb vendor. The initial resistance of before reflow is ¡¾1%, but it is changed to -3% after exposing a smt reflow ; max 245'C, 2 times. When it expose in high temperature, a distance of carbon particle in the carbon paste is closer and closer. Increasing conductivity of resistance, the sheet resistance is lower and lower. To solve this problem, We have optimized the curing process parameter of embedded resistor, the change rate of sheet resistance keeps ¡¾1% as a result of optimization . Nowadays the long-term reliability test is progressing.|
|Hyung Mo Hwang, Engineer
Asan-City, Chungcheongnam-Do 336-711,