Encapsulated miniature hard disc drive
View Patent ↗The present invention is directed to a miniature hard disc drive having a metal base plate, an actuator assembly wherein the actuator assembly comprises a plurality of bearings, a shaft, and a housing; a spindle motor assembly comprising a stator with conductors, a shaft, a plurality of bearings, and a rotor; and a monolithic body of phase change material unitizing said actuator assembly housing and stator to the base plate. Methods of developing and constructing the hard disc drive are also disclosed.
1. A miniature hard disc drive comprising:
a) a base having:
i) a metal base plate; and
ii) a monolithic body of injection molded thermoplastic material molded onto one or more surfaces of the metal base plate comprising body features, the base plate being generally rectangular and the body features on the base plate including sidewalls along at least two opposite sides of the base plate, wherein each of the two sidewalls include a longitudinal groove in the outside surface of the sidewall, wherein said thermoplastic material provides a vibration dampening in the range of 20–15,000 Hz of at least 2 decibels when compared to an all-metal base;
b) an actuator assembly;
c) a spindle motor; and
d) a cover mounted to said base.
2. The miniature hard disc drive of claim 1 wherein the cover comprises a printed circuit board.
3. The miniature hard disc drive of claim 1 wherein the cover is overmolded with a monolithic body of phase change material.
4. The miniature hard disc drive of claim 1 further comprising magnetic storage media having data tracks wherein the data tracks are spaced to have at least 10,000 tracks/inch.
5. The miniature hard disc drive of claim 1 having improved shock resistance if dropped compared to a hard disc drive with an all metal base.
6. The miniature hard disc drive of claim 1 wherein the thermoplastic material has a coefficient of linear thermal expansion of less than 2×10 −5 in/in/° F. throughout the range of 0–250° F.
7. The miniature hard disc drive of claim 1 wherein the base has extractable particles greater than 0.5 micrometers in size of less than ten thousand particles per milliliter.
8. The miniature hard disc drive of claim 1 wherein the cover is located on the base using details formed in the monolithic body of thermoplastic material.
9. The miniature hard disc drive of claim 1 wherein the cover is secured to the base by a form selected from the group consisting of heat staking, sonic welding and gluing.
10. The miniature hard disc drive of claim 1 wherein the thermoplastic material has a coefficient of linear thermal expansion of less than 1.5×10 −5 in/in/° F. throughout the range of 0–250° F.
11. The miniature hard disc drive of claim 1 wherein the thermoplastic material has a coefficient of linear thermal expansion of between about 0.8×10 −5 in/in/° F. and about 1.3×10 −5 in/in/° F. throughout the range of 0–250° F.
12. A portable consumer electronics device having a miniature hard disc drive, the miniature hard disc drive comprising:
a) a base having:
i) a metal base plate; and
ii) a monolithic body of injection molded thermoplastic material molded onto one or more surfaces of the metal base plate comprising body features, the base plate being generally rectangular and the body features on the base plate including sidewalls along at least two opposite sides of the base plate, wherein said thermoplastic material provides a vibration dampening in the range of 20–15,000 Hz of at least 2 decibels when compared to an all-metal base;
b) an actuator assembly;
c) a spindle motor; and
d) a cover mounted to said base.
13. The portable consumer electronics device of claim 12 wherein the device comprises a cellular phone.
14. The portable consumer electronics device of claim 12 wherein the thermoplastic material is injection molded onto the metal plate to form the base of the miniature hard disc drive, and wherein the consumer electronics device has a longer battery life than one using a miniature hard disc drive with a metal base plate that does not have thermoplastic material injection molded onto the base plate.
15. The portable consumer electronics device of claim 12 wherein the thermoplastic material is injection molded onto the metal plate to form the base of the miniature hard disc drive, and wherein the consumer electronics device has an improved shock resistance compared to one using a miniature hard disc drive with a metal base plate that does not have thermoplastic material injection molded onto the base plate.