Circuit connection pad design for improved electrical robustness using conductive epoxy

Patent metadata

Field	Value
Publication number	US-9679593-B2
Application number	US-201514860921-A
Country	US
Kind code	B2
Filing date	Sep 22, 2015
Priority date	Sep 22, 2014
Publication date	Jun 13, 2017
Grant date	Jun 13, 2017

Abstract

Disk drives including head suspensions within dual stage actuation systems have improved electrical connectivity between electrical connection pads from flexible circuits as are applied to head suspension assemblies with piezoelectric microactuators as also provided to head suspension assemblies. A more robust electrical connection provides for better control of microactuator actuation for fine movements and positioning of magnetic read/write heads relative to disk data tracks as part of dual stage actuated suspension systems. Electrical connections utilize conductive epoxy for physically and electrically connecting electrically conductive trace connection pads with one or more surfaces of piezoelectric microactuators. Electrical connections include better conductivity by utilizing plural surface portions of electrical connection pads. The result is a more robust and predictable performance for high data resolution within disk drives.

First claim

What is claimed is:

1. A head suspension for supporting a head within a disk drive, the head suspension comprising:
a load beam including a base portion for connection to an actuator for moving the load beam relative to a disk and a flexure for connection with a head and to permit movement of the head for orientation thereof relative to a surface of the disk;
a microactuator operatively provided and coupled to the load beam for providing fine movements of the load beam relative to the disk, the microactuator including a surface for connection with an electrical source to effect fine movement of the load beam;
a flexible circuit provided to extend along the load beam and comprising a plurality of electrical traces along an insulator layer, at least one trace including a connection pad positioned to extend over the surface connection of the microactuator for connection with a controllable power source for selective actuation of the microactuator, wherein the connection pad comprises a conductive first surface that is accessible by an opening within the insulator layer, an oppositely facing conductive second surface, and at least an edge portion between the first and second surfaces, and the connection pad is adhered to the surface connection of the microactuator solely and without further structural interconnection by a conductive adhesive that is adhered to the surface connection of the microactuator and to the first and second conductive surfaces and the edge portion of the connection pad so as to encapsulate the edge portion and at least adjacent edges of the first and second conductive surfaces with conductive adhesive for providing electrical conduction between the connection pad and the surface of the microactuator and also to solely physically connect the connection pad to the surface of the microactuator.

2. The head suspension of claim 1 , wherein the flexible circuit further comprises a stainless steel support layer on the opposite side of the insulator layer than the electrical traces, wherein the stainless steel support layer also includes an opening to provide accessibility to the connection pad.

3. The head suspension of claim 2 , wherein the connection pad is offset from the at least one trace so as to be at least partially positioned within the opening of the insulator layer.

4. The head suspension of claim 3 , wherein the connection pad includes an opening provided through the connection pad that defines the edge portion that is adhered with the conductive adhesive.

5. The head suspension of claim 4 , wherein the connection pad includes plural openings defining plural edge portions with the plural edge portions and a portion of the second surface of the connection pad between the openings being adhered with the conductive adhesive.

6. The head suspension of claim 5 , wherein the plural openings of the connection pad are symmetrically arranged.

7. The head suspension of claim 3 , wherein the connection pad comprises an arm portion that extends from the connection pad and provides the edge portion that is adhered with the conductive adhesive along with portions of the first and second surfaces of the connection pad adjacent to the edge portion.

8. A flexible circuit to be provided onto at least one surface of a head suspension and for providing data signals and a power supply to a microactuator of the head suspension, the flexible circuit comprising:
a plurality of electrical traces provided to extend along an insulator layer, at least one trace for connection with a controllable power source for selective actuation of a microactuator the at least one trace including a connection pad positioned for extension over a surface connection of the microactuator, wherein the connection pad comprises a conductive first surface that is accessible by an opening within the insulator layer, an oppositely facing conductive second surface, and at least an edge portion between the first and second surfaces so that the connection pad can be adhered to the surface connection of the microactuator solely and without further structural interconnection by a conductive adhesive with the conductive adhesive to be adhered to the surface connection of the microactuator and to the first and second conductive surfaces and the edge portion of the connection pad so as to encapsulate the edge portion and at least adjacent edges of the first and second conductive surfaces with conductive adhesive for providing electrical conduction between the connection pad and the surface of the microactuator and also to solely physically connect the connection pad to the surface of the microactuator.

Assignees

• Seagate Technology Llc

Inventors

• Berscheit Gary
• Brandts Jackson

Classifications

• G11B5/483

  Piezoelectric devices between head and arm, e.g. for fine adjustment · CPC title

• G11B5/486

  with provision for mounting or arranging electrical conducting means or circuits on or along the arm assembly · CPC title

• G11B5/4833

  Structure of the arm assembly, e.g. load beams, flexures, parts of the arm adapted for controlling vertical force on the head (G11B5/484 takes precedence) · CPC title

• G11B5/4846 Primary

  Constructional details of the electrical connection between arm and support · CPC title