Device for measuring a gram load
View Patent ↗A gram load measurement assembly is configured to measure the gram load of a head stack assembly (HSA) of a disk drive being manufactured using the HSA's suspension tabs, thereby avoiding contact with the Air Bearing Surface (ABS) of the HSA's sliders when checking the gram load forces after the installation of the Head Gimbal Assembly (HGA) installation on the actuator assembly.
1. A device for measuring a gram load, comprising:
a disk drive actuator clamping assembly configured to clamp down on and hold captive an actuator assembly of a disk drive, the actuator assembly comprising a plurality of head gimbal assemblies (HGA), wherein each of the plurality of HGAs comprises a slider and a suspension tab disposed away from the slider at a distal free end of the HGA;
a disk simulator assembly comprising a separately-disposed bearing surface corresponding to each slider of a first set of HGAs on the actuator assembly;
a load cell assembly configured to generate an output related to a force exerted by a suspension tab on the disk simulator assembly; and
a head spreader assembly configured to spread the sliders of the first set of HGAs such that suspension tabs of the spread sliders face a respective one of the bearing surfaces of the disk simulator assembly at a predetermined non-zero distance therefrom, the head spreader assembly being configured to selectively release a HGA such that the suspension tab thereof contacts and bears against its corresponding bearing surface to thereby enable the load cell assembly to measure the force and to generate the output.
2. The device of claim 1 , wherein the disk simulator assembly and the head spreader assembly are configured such that respective air bearing surfaces (ABS) of the sliders of the first set of HGAs do not contact the bearing surfaces of the disk simulator assembly.
3. The device of claim 1 , wherein the disk simulator assembly is configured to be modular and swappable, to conform to different actuator assemblies.
4. The device of claim 1 , further comprising a base assembly configured to house the load cell assembly and a top tooling assembly comprising the disk drive actuator clamping assembly, the disk simulator assembly and the head spreader assembly.
5. The device of claim 4 , wherein the top tooling assembly is configured to removably couple to the base assembly.
6. The device of claim 1 , wherein the head spreader assembly is configured to be pneumatically-actuated.
7. The device of claim 1 , wherein the head spreader assembly is configured to interdigitate at least some of the suspension tabs within openings in the disk simulator assembly that define the bearing surfaces.
8. The device of claim 1 , wherein the head spreader assembly comprises an individually-actuable head spreader tab for each slider of the first set of HGAs, each head spreader tab being configured to contact a corresponding HGA away from the slider thereof.