Method and apparatus for reducing solder pad size in an electrical lead suspension (ELS) to decrease signal path capacitive discontinuities
View Patent ↗An apparatus and method for reducing solder pad size in an electrical lead suspension (ELS) to decrease signal path capacitive discontinuities. The method provides a base-metal layer for the ELS. A dielectric layer above the base-metal layer is also provided. A signal conductive layer is provided above dielectric layer. The signal conductive layer carries at least one solder pad portion, wherein both a size of the solder pad portion and an amount of solder applied to the solder pad portion are reduced such that the solder pad to a ground, and solder on the solder pad to adjacent solder on adjacent pads, capacitance are reduced providing low signal reflection losses and a decrease in cross-talk.
1. A method for reducing solder pad size in an electrical lead suspension (ELS) to decrease signal pat capacitive discontinuities comprising:
providing a base-metal layer for the ELS;
providing a dielectric layer above the base-metal layer; and
providing a signal conductive layer above the dielectric layer, said signal conductive layer comprising at least one solder pad portion.
2. The method of claim 1 wherein said solder comprises leaded, unleaded or any other form of solder material.
3. The method of claim 1 wherein said signal-conductor layer is comprised of copper.
4. The method of claim 1 wherein said dielectric layer of said ELS is comprised of polyimide.
5. The method of claim 1 wherein said base-metal layer of said ELS is comprised of stainless steel.
6. The method of claim 1 wherein the size of said solder pad portion is reduced to approximately 200 microns by approximately 475 microns.
7. An electrical lead suspension (ELS) having a reduced solder pad size to decrease signal path capacitive discontinuities comprising:
a base-metal layer for the ELS;
a dielectric layer above the base-metal layer; and
a signal conductive layer above the dielectric layer, said signal conductive layer comprising:
at least one solder pad portion above a portion of said dielectric layer.
8. The ELS of claim 7 wherein said solder comprises leaded, unleaded or any other form of solder material.
9. The ELS of claim 7 wherein said signal-conductor layer is comprised of copper.
10. The ELS of claim 7 wherein said dielectric layer of said ELS is polyimide.
11. The ELS of claim 7 wherein said base-metal layer of said ELS is stainless steel.
12. The ELS of claim 7 wherein the size of said solder pad portion is reduced to approximately 200 microns by approximately 475 microns.
13. A hard disk drive comprising:
a housing;
a disk pack mounted to the housing and having a plurality of disks that are rotatable relative to the housing, the disk pack defining an axis of rotation and a radial direction relative to the axis, and the disk pack having a downstream side wherein air flows away from the disks, and an upstream side wherein air flows toward the disk;
an actuator mounted to the housing and being movable relative to the disk pack, the actuator having a plurality of heads for reading data from and writing data to the disks; and
an electrical lead suspension, said electrical lead suspension (ELS) having a reduced solder pad size to decrease signal path capacitive discontinuities comprising:
a base-metal layer for the ELS;
a dielectric layer above the base-metal layer; and
a signal conductive layer above the dielectric layer, said signal conductive layer comprising:
at least one solder pad portion above a portion of said dielectric layer.
14. The hard disk drive of claim 13 wherein said solder comprises leaded, unleaded or any other form of solder material.
15. The hard disk drive of claim 13 wherein said signal-conductor layer is comprised of copper.
16. The bard disk drive of claim 13 wherein said dielectric layer of said ELS is polyimide.
17. The hard disk drive of claim 13 wherein said base-metal layer of said ELS is stainless steel.
18. The hard disk drive of claim 13 wherein die size of said ELS is reduced to approximately 200 microns by approximately 475 microns.
19. An electrical lead suspension (ELS) having a reduced solder pad size to decrease signal path capacitive discontinuities comprising:
a means for providing a base-metal layer for the ELS;
a means for providing a dielectric layer above the base-metal layer; and
a means for providing a signal conductive layer above the dielectric layer, said signal conductive layer comprising at least one solder pad portion.
20. The ELS of claim 19 wherein the size of said solder pad portion is reduced to approximately 200 microns by approximately 475 microns.