Top cover having a patterned gasket fixing region, disk drive apparatus, and method of manufacturing top cover
A top cover for use in a disk drive apparatus includes a plate made of a metal and a gasket fixed to the plate. The gasket is made of an elastomer. A surface of the plate includes a fixing region to which the gasket is closely adhered. The fixing region includes a plurality of ridges and in plan view a plurality of filamentous projections extending from each of the plurality of ridges. The plurality of ridges are arranged in the fixing region to increase a surface area of the fixing region. The plurality of ridges and the plurality of filamentous projections extending from each ridge are distributed over the fixing region.
1. A top cover for use in a disk drive apparatus, the top cover comprising:
a plate made of a metal; and
a gasket made of an elastomer, and fixed to the plate; wherein
a surface of the plate includes a fixing region to which the gasket is fixed; and
in plan view, the fixing region includes a plurality of ridges and a plurality of filamentous projections extending from each of the plurality of ridges.
2. The top cover according to claim 1 , wherein at least one of the plurality of ridges is annular or substantially annular in shape.
3. The top cover according to claim 1 , wherein at least some of the plurality of ridges overlap with one another.
4. The top cover according to claim 1 , wherein
the plurality of ridges included in the fixing region include a first row of ridges overlap with one another; and
the first row extends in a first direction.
5. The top cover according to claim 4 , wherein
the plurality of ridges included in the fixing region further include a second row of ridges overlap with one another;
the second row extends in a second direction different from the first direction; and
the first row and the second row cross each other.
6. The top cover according to claim 4 , wherein the fixing region has a width greater than that of the gasket.
7. The top cover according to claim 4 , wherein the fixing region has a width smaller than that of the gasket.
8. The top cover according to claim 1 , wherein
the top cover is square, substantially square, rectangular or substantially rectangular;
the gasket extends along an outer edge of the top cover;
the gasket includes:
a body portion with a uniform or substantially uniform width; and
a projecting portion projecting from a side surface of the body portion toward an outer circumference of the plate along the surface of the plate; and
each of the body portion and the projecting portion is in contact with the fixing region.
9. The top cover according to claim 8 , wherein
the gasket includes a gate mark; and
the gate mark is located in the projecting portion.
10. The top cover according to claim 1 , wherein the fixing region includes:
a first rugged portion in which a distribution density of the ridges is a first density; and
a second rugged portion in which the distribution density of the ridges is a second density greater than the first density.
11. A disk drive apparatus comprising:
a base plate including a bottom portion and a wall portion extends upward from an outer circumferential portion of the bottom portion, and surrounds the bottom portion;
the top cover of claim 1 arranged to close an upper side of the base plate to define a case together with the base plate;
a spindle motor; and
an access portion configured to perform at least one of reading and writing of information from or to a disk supported by the spindle motor; wherein
the gasket is in contact with an upper end portion of the wall portion; and
a rotating portion of the spindle motor and the access portion are accommodated in an interior of the case defined by the base plate and the top cover.
12. A disk drive apparatus comprising:
a base plate including a bottom portion and a wall portion extending upward from an outer circumferential portion of the bottom portion, and surrounding the bottom portion;
a top cover made of a metal, and arranged to close an upper side of the base plate to define a case together with the base plate;
a gasket made of an elastomer, fixed to an upper end surface of the wall portion, and in contact with a lower surface of the top cover;
a spindle motor; and
an access portion configured to perform at least one of reading and writing of information from or to a disk supported by the spindle motor; wherein
a rotating portion of the spindle motor and the access portion are accommodated in an interior of the case defined by the base plate and the top cover;
the base plate includes, in the upper end surface of the wall portion, a fixing region to which the gasket is fixed; and
in plan view, the fixing region includes a plurality of ridges and a plurality of filamentous projections extending from each of the plurality of ridges.
13. The base plate of the disk drive apparatus of claim 12 , wherein at least one of the ridges is annular or substantially annular in shape.
14. The base plate of the disk drive apparatus of claim 12 , wherein at least some of the plurality of ridges overlap with one another.
15. The base plate of the disk drive apparatus of claim 12 , wherein
the plurality of ridges included in the fixing region include a first row of ridges overlap with one another; and
the first row extends in a first direction.
16. The base plate according to claim 15 , wherein
the plurality of ridges included in the fixing region further include a second row of ridges overlap with one another;
the second row extends in a second direction different from the first direction; and
the first row and the second row cross each other.
17. The base plate according to claim 15 , wherein the fixing region has a width greater than that of the gasket.
18. The base plate according to claim 15 , wherein the fixing region has a width smaller than that of the gasket.
19. The disk drive apparatus according to claim 12 , wherein
the gasket includes:
a body portion with a uniform or substantially uniform width; and
a projecting portion projecting from a side surface of the body portion toward an outer circumference of the wall portion along an upper surface of the wall portion; and
each of the body portion and the projecting portion is in contact with the fixing region.
20. The disk drive apparatus according to claim 19 , wherein
the gasket includes a gate mark; and
the gate mark is located in the projecting portion.
21. The disk drive apparatus according to claim 12 , wherein the fixing region includes:
a first rugged portion in which a distribution density of the plurality of ridges is a first density; and
a second rugged portion in which the distribution density of the plurality of ridges is a second density greater than the first density.
22. A method of manufacturing a top cover for use in a disk drive apparatus, the method comprising the steps of:
a) defining, in a surface of a plate, a fixing region including a plurality of ridges and, in plan view, a plurality of filamentous projections extending from each of the plurality of ridges;
b) cleaning the plate after step a); and
c) injection-molding a gasket on the plate after step b); wherein in step c), the gasket is fixed to the fixing region.