Helium Hard Disk Drive Manufacture.
The ambient air in standard hard disk drive enclosures adversely affects read/write performance and produces vibrations in operation that hinder efficiency. Filling a hard drive enclosure with lower density helium reduces vibrations, decreases read write head drag and facilitates precision tracking. Helium however has a tendency to leak through adhesive substances and any cavities normally found in aluminium die cast base plates. Ensuring that the helium gas stays sealed inside the hard disk drive assembly for the shelve life of the product presents a difficult challenge in manufacture.
Mass production of Hard Disk Drives with zero defects, that can be sealed for 5 years without leaking any helium is essential. In order to ensure that the helium does not leak through the 1-2 mm thin base plate, every parameter of the casting process—the shape of each part of the metal moulding is optimized based on Computer Aided analysis of the flow of molten aluminium during casting.
The adhesive used to seal the Hard Disk Drives is another important factor in preventing helium leakage. After making sure that the adhesive is applied thickly, the individual components are joined together under very high pressure in order to maximize resistance to leakage.
Adhesive with a low out-gassing rate is chosen to avoid contamination caused by gases other than helium. The HDD components go through repeated baking procedures—removing gas in advance—during every step of the manufacturing process in order to minimize out-gassing from the adhesive and resin etc. The spindle motor fluid dynamic bearing uses a specialized oil with a low rate of evaporation and high resistance to external moisture.
The availability of helium-filled hard disk drive products is a result of numerous developments enabling thinner disks, greater number of disks and greater storage capacity. Advancements that result in much lower electricity power consumption.