DocumentCode :
854506
Title :
Precision passive mechanical alignment of wafers
Author :
Slocum, Alexander H. ; Weber, Alexis C.
Author_Institution :
Dept. of Mech. Eng., Massachusetts Inst. of Technol., Cambridge, MA, USA
Volume :
12
Issue :
6
fYear :
2003
Firstpage :
826
Lastpage :
834
Abstract :
A passive mechanical wafer alignment technique, capable of micron and better alignment accuracy, was developed, fabricated and tested. This technique is based on the principle of elastic averaging: It uses mating pyramid (convex) and groove (concave) elements, which have been previously patterned on the wafers, to passively align wafers to each other as they are stacked. The concave and convex elements were micro machined on 4-in (100) silicon wafers using wet anisotropic (KOH) etching and deep reactive ion etching. Submicron repeatability and accuracy on the order of one micron were shown through testing. Repeatability and accuracy were also measured as a function of the number of engaged elements. Submicrometer repeatability was achieved with as little as eight mating elements. Potential applications of this technique are precision alignment for bonding of multiwafer MEMS devices and three-dimensional (3-D) interconnect integrated circuits (ICs), as well as one-step alignment for simultaneous bonding of multiple wafer stacks. Future work will focus on minimizing the size of the elements.
Keywords :
etching; micromachining; silicon; sputter etching; wafer bonding; LEGO blocks; concave elements; convex elements; deep reactive ion etching; elastic averaging; groove elements; kinematic coupling; mating pyramid; micromachined; multiple wafer stacks; multiwafer MEMS devices; one-step alignment; passive mechanical wafer alignment; precision passive wafer alignment; submicron repeatability; wafer bonding; wet anisotropic etching; Assembly; Instruments; Integrated circuit interconnections; Kinematics; Microelectromechanical devices; Silicon; Sockets; Testing; Wafer bonding; Wet etching;
fLanguage :
English
Journal_Title :
Microelectromechanical Systems, Journal of
Publisher :
ieee
ISSN :
1057-7157
Type :
jour
DOI :
10.1109/JMEMS.2003.820289
Filename :
1257360
Link To Document :
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