Electricity: electrical systems and devices – Housing or mounting assemblies with diverse electrical... – For electronic systems and devices
Reexamination Certificate
2002-05-10
2003-08-05
Thompson, Gregory (Department: 2835)
Electricity: electrical systems and devices
Housing or mounting assemblies with diverse electrical...
For electronic systems and devices
C165S080200, C165S185000, C360S097020, C361S708000, C361S719000, C361S715000
Reexamination Certificate
active
06603659
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a heat dissipator for an optical writing and/or reproducing apparatus, and more particularly, the present invention relates to a heat dissipator for an optical writing and/or reproducing apparatus, which is constructed to properly dissipate heat generated in a heat generating element, especially, a drive IC (integrated circuit) while the optical writing and/or reproducing apparatus is driven.
2. Description of the Related Art
Generally, in an optical writing and/or reproducing apparatus such as a disk drive, a great amount of heat is generated during operation. In an optical writing and/or reproducing apparatus, heat generating parts include a loading motor for producing power needed to load and eject an optical disk, a spindle motor for rotating the optical disk, an optical pick-up for writing and/or reproducing data on and/or from the optical disk, a step motor for driving the optical pick-up, and elements installed on a circuit board for controlling operation of the optical writing and/or reproducing apparatus.
If generated heat is not properly dissipated out of the optical writing and/or reproducing apparatus, not only the corresponding heat generating source but also surrounding parts can be adversely affected by the heat, and thereby, an operational error can be caused in the optical writing and/or reproducing apparatus.
Specifically, among the elements installed on the circuit board for controlling operation of the optical writing and/or reproducing apparatus, a drive IC for controlling driving of the motors generates a substantial amount of heat when compared to the other elements.
FIG. 1
is a cross-sectional view illustrating a conventional heat dissipator for an optical writing and/or reproducing apparatus.
Referring to
FIG. 1
, an optical writing and/or reproducing apparatus includes a main base
30
, and a circuit board
40
positioned below the main base
30
. Elements for controlling operation of the optical writing and/or reproducing apparatus are installed on the circuit board
40
. A spindle motor, a loading motor and a step motor (not shown) are installed on the main base
30
.
Among the elements installed on the circuit board
40
, since a drive IC
42
continuously controls driving of the motors, it consumes a large amount of power and thereby generates a substantial amount of heat when compared to the other elements. For this reason, the drive IC
42
is installed on a lower surface
40
b
of the circuit board
40
so as not to adversely influence, by heat, surrounding elements including an RF (radio frequency) IC and a DSP (digital signal processor) IC which are installed on an upper surface
40
a
of the circuit board
40
. At this time, the drive IC
40
is installed in a manner such that outer leads
43
externally formed thereon are bonded to the lower surface
40
b
of the circuit board
40
.
Hereafter, the conventional heat dissipator for dissipating heat generated in the drive IC
42
will be described in detail.
The heat dissipator includes a lower cabinet
51
b
which is positioned to face the lower surface
40
b
of the circuit board
40
and a heat dissipating conduction member
54
which is interposed between the lower cabinet
51
b
and a molding section
42
a
of the drive IC
42
. The lower cabinet
51
b
delimits an outer contour of the optical writing and/or reproducing apparatus and is made of a metallic material. The heat conduction member
54
functions to dissipate or conduct the heat generated in the drive IC
42
. Over a region where the lower cabinet
51
b
faces the molding section
42
a
of the drive IC
42
, the lower cabinet
51
b
is formed with an upward protrusion
51
c
which projects toward the drive IC
42
to allow the heat dissipating conduction member
54
to be brought into close contact with the molding section
42
a
of the drive IC
42
.
At this time, the heat conduction member
54
is not brought into contact with the outer leads
43
which serve to connect the drive IC
42
to the circuit board
40
.
Concretely speaking, between the drive IC
42
installed on the lower surface
40
b
of the circuit board
40
and the lower cabinet
51
b
facing the drive IC
42
, there is interposed the heat conduction member
54
in a manner such that it is brought into close contact with the molding section
42
a
of the drive IC
42
. As a consequence, heat generated in the molding section
42
a
of the drive IC
42
is transmitted through the heat conduction member
54
to the lower cabinet
51
b
to be dissipated to the outside.
However, the conventional heat dissipator constructed as mentioned above suffers from defects as described below.
While heat generated inside the drive IC
42
is first conducted to a molding material, that is, the molding section
42
a
serving as an encapsulant, and then transmitted to the lower cabinet
51
b
, in actual fact, since a considerable portion of the heat generated inside the drive IC
42
is conducted to the outer leads
43
made of a metallic material, the outer leads
43
have a higher temperature than the molding material. Resultingly, as heat of the outer leads
43
is transmitted to a circuit pattern formed on the circuit board
40
, the circuit pattern is likely to be thermally damaged.
Also, because the heat conduction member
54
is installed over the region which faces only a lower surface of the molding section
42
a
of the drive IC
42
, heat of side surfaces of the drive IC
42
and heat of the outer leads
43
cannot be properly conducted to the heat dissipating conduction member
54
. Therefore, heat as a whole, generated in the entire drive IC
42
, cannot be properly transmitted to the lower cabinet
51
b.
The reason for this is that only heat of the lower surface of the molding section
42
a
of the drive IC
42
is conducted to the heat conduction member
54
to be dissipated to the outside, and heat of the side surfaces of the drive IC
42
and heat of the outer leads
43
are dissipated to the outside only by convection through air.
SUMMARY OF THE INVENTION
Accordingly, the present invention has been made in an effort to solve the problems occurring in the related art, and an object of the present invention is to provide a heat dissipator for an optical writing and/or reproducing apparatus, which is constructed to properly dissipate heat generated in the optical writing and/or reproducing apparatus, thereby improving operational reliability of the optical writing and/or reproducing apparatus.
According to one aspect of the present invention, there is provided a heat dissipator for an optical writing and/or reproducing apparatus, comprising: a main base having mounted thereto a plurality of parts including at least one motor for optical writing and/or reproduction; a circuit board positioned below the main base and having installed thereon elements for controlling the parts; a heat generating element formed with a plurality of leads which are connected to a circuit pattern of the circuit board; a heat conduction member brought into contact with at least the leads, for receiving heat generated in the heat generating element; and a cabinet brought into contact with the heat conduction member and formed with an element accommodating section and/or a pair of protrusions which are shaped to be functionally associated with an outer surface of the heat generating element to ensure that the heat conduction member is brought into close contact with the leads of the heat generating element.
According to another aspect of the present invention, there is provided a heat dissipator for an optical writing and/or reproducing apparatus, comprising: a heat generating element installed on a circuit board and having a molding section which is formed with a plurality of leads connected to a circuit pattern of the circuit board; a cabinet formed with a pair of protrusions which project toward the heat generating element to allow a portion of heat generated in the heat generating element, which por
Kim Tae Hyoung
Kim Tae Sung
Park Kyung Hawn
Park Un Gyu
Hitachi-LG Data Storage Korea Inc.
Thompson Gregory
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