PZT structure for microactuator suspension
Publication Date: 2014-Jun-24
The IP.com Prior Art Database
Disclosed is a PZT(piezoelectric actuator) that has internal electrode structure solving ion migration issue. Even in high temperature and high humidity condition, new internal electrode structure can solve ion migration issue and can have enough stroke.
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When a PZT is driven by a voltage in high temperature and high humidity condition, there is a problem that an ion migration occurs between an internal electrode and a suspension pad by conductive adhesive containing Ag.
In prior art, there is a resin coating on side surface of PZT to avoid the ion migration.
But the resin coating cannot avoid the ion migration completely.
There are other approaches as shortened internal electrode, or narrow internal electrode in all length to avoid exposing electrode to the side surface. But it decreases the stroke due to decrease of the active area of PZT.
This invention can solve the problem by
The tip of the lower electric potential internal electrode has narrower width for the PZT that is attached to microactuator suspension.
By this structure, the decrease of the active area can be minimized and can increase the distance between the internal electrode and the conductive adhesive on the suspension pad. It can improve the reliability.
Figure 1 shows the structure of microactuator suspension and PZT.
PZT is attached to the flexure pad by conductive adhesive, and covered by epoxy resin. The tip of the internal electrode is narrow and not exposed to the side surface. The distance between conductive adhesive and internal electrode is larger than the prior art. PZT
Figure 2 shows example of manufacturing process of PZT.
Internal electrode is printed on a PZT sheet. The narrow shape of the tip of the internal electrode is printed....