Detachable MEMS package top cover
A MEMS chip package is provided with a removable cover to allow non-destructive testing. The MEMS package has a container (with walls and a bottom) and a cover. The cover has a glass pane, and is secured to the MEMS package with an elastomeric gasket mounted between the walls of the MEMS package and the cover. A number of attachment mechanisms secure the cover to the MEMS package.
1. A micro-electromechanical system (MEMS) apparatus for beam steering in a Light Detection and Ranging (LiDAR) system of an autonomous vehicle, the apparatus comprising:
a laser diode emitting a laser beam;
a photodetector positioned to detect a reflection of the laser beam;
a MEMS mirror positioned to scan the laser beam across an environment;
a MEMS package enclosing one of the laser diode, photodetector and MEMS mirror, the MEMS package comprising:
a MEMS container having a bottom and four walls;
a metal cover with a glass pane in a central portion of the metal cover;
an elastomeric gasket attached to a bottom perimeter of the metal cover;
a slot in the top of the four walls of the MEMS container, the slot having an inverse of the shape of the elastomeric gasket;
a plurality of tabs attached to the walls of the MEMS container, each tab having a lip extending over the cover at a height requiring compression of the gasket to engage the cover under the lip, thereby maintaining downward pressure on the cover by the lips;
wherein the tabs have a slot on an inward surface underneath the lips, engaging an edge of the cover to secure the cover in place, and a controller configured to control the MEMS mirror to scan the environment.
2. The apparatus of claim 1 further comprising:
an inert gas sealed inside the MEMS container and metal cover.
3. The apparatus of claim 1 further comprising a glue or epoxy fastening the elastomeric gasket to the bottom perimeter of the metal cover.
4. The apparatus of claim 1 wherein the elastomeric gasket is rounded in cross-section, and the slot in the top of the four walls of the MEMS container has a rounded bottom.
5. An apparatus comprising:
a MEMS structure;
a MEMS package enclosing the MEMS structure, the MEMS package comprising:
a MEMS container having a bottom and walls;
a cover with a glass pane;
an elastomeric gasket mounted between the walls of the MEMS container and the cover;
a plurality of attachment mechanisms for removably attaching the cover to the MEMS container; and
a slot in the top of the walls of the MEMS container shaped to engage the gasket.
6. The apparatus of claim 5 wherein the gasket has a curved cross-section, and the slot is curved to match the shape of the gasket.
7. An apparatus comprising:
a MEMS structure;
a MEMS package enclosing the MEMS structure, the MEMS package comprising:
a MEMS container having a bottom and walls;
a cover with a glass pane;
an elastomeric gasket mounted between the walls of the MEMS container and the cover; and
a plurality of attachment mechanisms for removably attaching the cover to the MEMS container;
wherein the attachment mechanisms comprise tabs having lips which extend over the cover.
8. The apparatus of claim 7 wherein the tabs further include slots beneath the lips for engaging the cover.
9. The apparatus of claim 7 wherein the tabs are integrally formed with the MEMS container walls.
10. An apparatus comprising:
a MEMS structure;
a MEMS package enclosing the MEMS structure, the MEMS package comprising:
a MEMS container having a bottom and walls;
a cover with a glass pane;
an elastomeric gasket mounted between the walls of the MEMS container and the cover; and
a plurality of attachment mechanisms for removably attaching the cover to the MEMS container;
wherein the elastomeric gasket is silicon rubber that is overmolded on the cover.
11. An apparatus comprising:
a MEMS structure;
a MEMS package enclosing the MEMS structure, the MEMS package comprising:
a MEMS container having a bottom and walls;
a cover with a glass pane;
an elastomeric gasket mounted between the walls of the MEMS container and the cover;
a plurality of attachment mechanisms for removably attaching the cover to the MEMS container; and
an inert gas sealed inside the MEMS container and metal cover.
12. The apparatus of claim 11 wherein the inert gas is nitrogen or helium.
13. An apparatus comprising:
a MEMS structure;
a MEMS package enclosing the MEMS structure, the MEMS package comprising:
a MEMS container having a bottom and walls;
a cover with a glass pane;
an elastomeric gasket mounted between the walls of the MEMS container and the cover;
a plurality of attachment mechanisms for removably attaching the cover to the MEMS container; and
a glue or epoxy fastening the elastomeric gasket to the bottom perimeter of the cover.