Method of making small gaps for small electrical/mechanical devices
AssigneeBall Semiconductor, Inc.
InventorRisaku Toda
Life of this patent
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Abstract
A method and system for making small gaps in a MEMS device is disclosed. The MEMS device is first made with a sacrificial layer where the gap is to reside. The device can then be assembled, including forming a protective coat surrounding the device. Once the protective coat is formed, small holes in the protective coat can be made to expose the sacrificial layer to an external environment. The holes can be formed using laser ablation. After the small holes have been made, an etchant can then be applied through the holes to remove the sacrificial layer.
Claims13
A method for making a gap in a small electro/mechanical device, the method comprising the steps of:
- making the device with a sacrificial layer where the gap is to reside;
- assembling the device, including forming a protective coat surrounding the device;
- forming one or more small holes in the protective coat that expose the sacrificial layer to an external environment;
- and
- applying an etchant through the small holes to remove the sacrificial layer;
- wherein the step of applying the etchant is performed after the protective coat has been formed.
A method for making a MEMS device, comprising the steps of:
- applying a first metal layer on a substrate;
- forming a sacrificial layer on the first metal layer;
- applying a second metal layer on the sacrificial layer, the second metal layer having a portion removed therefrom;
- performing assembly;
- forming a protective coat on the second metal layer;
- forming a small hole extending through the protective coat, through the portion, and to the sacrificial layer;
- and
- applying an etchant through the small hole to remove the sacrificial layer;
- wherein the step of applying the etchant is performed after the step of assembling.
Dependencies are inferred from the claim text.