Disk drive head suspension components having microstructured surfaces and a method for making the components. One embodiment of the method includes depositing a layer of photoimageable polymer having an associated set of process parameters including a minimum resolution and exposing the photoimageable polymer through a photomask having a microstructure-producing region with features below the minimum resolution for the photoimageable polymer. The exposed photoimageable polymer is developed to produce a layer of polymer having a thickness and a microstructured surface region with depressions that are less than the thickness of the polymer. In one embodiment the photomask has a microstructure-producing region with features sized and spaced between about 1 m and 10 m. Microstructured surfaces on structures such as flying leads, flying termination pads, cover coat layers and at insulating layer-trace interfaces and insulating layer-cover coat interfaces can be manufactured.

A method of assembly a dual stage actuated suspension includes either applying an adhesive to a microactuator motor and then B-staging the adhesive, or applying an adhesive that has already been B-staged such as in film adhesive form to the microactuator then assembling the microactuator into a suspension and then finishing the adhesive cure. The adhesive can be applied to bulk piezoelectric material, with the adhesive being B-staged either before or after it is applied to the bulk piezoelectric material, and the piezoelectric material then singulated into a number of individual piezoelectric microactuators. The method allows greater control over how much adhesive is used, and greater control over spread of that adhesive and control over potential contamination, than traditional liquid epoxy dispense methods.

According to one embodiment, a magnetic disk device includes a first magnetic disk, a second magnetic disk, a first actuator with a first head which reads/writes data from/to the first magnetic disk, a second actuator with a second head which reads/writes data from/to the second magnetic disk, the second actuator operated independently from the first actuator, a first controller configured to retracts the first actuator at a first time, and a second controller configured to retract the second actuator at a second time which is shifted from the first time by a certain period of time.

A spindle motor includes a base plate in which a through hole is formed, a stator core that is provided inside the base plate and is wound with a coil, and a circuit board that is provided outside the base plate and to which a conducting wire of the coil drawn out to outside through the through hole is connected, wherein the through hole includes an inner opening that opens inward of the base plate, an outer opening that opens outward of the base plate, and an intermediate portion having a cylindrical shape that is provided between the inner opening and the outer opening, an enlarged opening is formed to be connected to the outer opening, the enlarged opening is offset to extend toward a side where the circuit board is not present, and the through hole is sealed with a sealing material.

A PZT microactuator such as for a hard disk drive has a restraining layer bonded on its side that is opposite the side on which the PZT is mounted. The restraining layer comprises a stiff and resilient material such as stainless steel. The restraining layer can cover most or all of the top of the PZT, with an electrical connection being made to the PZT where it is not covered by the restraining layer. The restraining layer reduces bending of the PZT as mounted and hence increases effective stroke length, or reverses the sign of the bending which increases the effective stroke length of the PZT even further. The restraining layer can be one or more active layers of PZT material that act in the opposite direction as the main PZT layer. The restraining layer(s) may be thinner than the main PZT layer.

A spindle motor includes a base plate in which a through hole is formed, a stator core that is provided inside the base plate and is wound with a coil, and a circuit board that is provided outside the base plate and to which a conducting wire of the coil drawn out to outside through the through hole is connected, wherein the through hole includes an inner opening that opens inward of the base plate, an outer opening that opens outward of the base plate, and an intermediate portion having a cylindrical shape that is provided between the inner opening and the outer opening, an enlarged opening is formed to be connected to the outer opening, the enlarged opening is offset to extend toward a side where the circuit board is not present, and the through hole is sealed with a sealing material.

A PZT microactuator such as for a hard disk drive has a restraining layer bonded on its side that is opposite the side on which the PZT is mounted. The restraining layer comprises a stiff and resilient material such as stainless steel. The restraining layer can cover most or all of the top of the PZT, with an electrical connection being made to the PZT where it is not covered by the restraining layer. The restraining layer reduces bending of the PZT as mounted and hence increases effective stroke length, or reverses the sign of the bending which increases the effective stroke length of the PZT even further. The restraining layer can be one or more active layers of PZT material that act in the opposite direction as the main PZT layer. The restraining layer(s) may be thinner than the main PZT layer.

A piezoelectric actuator assembly is described. The assembly including a first layer including a top and a bottom surfaces. The assembly including a second layer having a top and a bottom surfaces, the bottom surface of the second layer is disposed over the top surface of the first layer. The assembly including a third layer having a top and a bottom surfaces, the bottom surface of the third layer is disposed over the top surface of the second layer. The assembly includes a first electrode, a second electrode, a third electrode, and a fourth electrode. The third electrode is configured to be shorter than the second electrode such that the active PZT length of the second layer and the third layer is shorter than the active PZT length of the first layer.

According to one embodiment, a wiring board unit includes a reinforcing board, a flexible printed circuit board includes a joint portion including a first plane and a second plane and attached on the reinforcing board, a relay unit extending from the first plane, a plurality of connection pad groups located on one of the first plane and the second plane and a first IC chip mounted on the first plane, and the joint portion is bent on a boundary between the first plane and the second plane.

A magnetic recording medium substrate is provided in which a NiP type plating film is formed on a surface of an aluminum alloy substrate that includes Si in a range of 9.5 mass % or more and 11.0 mass % or less, Mn in a rage of 0.45 mass % or more and 0.90 mass % or less, Zn in a range of 0.32 mass % or more and 0.38 mass % or less, Sr in a range of 0.01 mass % or more and 0.05 mass % or less. In the alloy structure of the aluminum alloy substrate, an average particle diameter of Si particles is 2 m or less, the film thickness of the NiP type plating film is 7 m or more. An outer diameter of the magnetic recording medium substrate is 53 mm or more, the thickness is 0.9 mm or less, and the Young's modulus is 79 GPa or more.