PCB module support system

A support apparatus is disclosed including a support structure for holding a printed circuit board module, a heat sink thermally coupled with the printed circuit board module, and a capture bar secured to the support structure. The support apparatus includes a holding member with extension members for securing the holding member to the main printed circuit board. The heat sink has a projection extending from one surface, and the capture bar frictionally engages with the projection. Standoffs are disposed between the main printed circuit board and a chassis surrounding the main printed circuit board. A method for cooling the printed circuit board module is also disclosed. The method comprises coupling the printed circuit board module with the holding member, and thermally coupling the heat sink with the printed circuit board module. The capture bar is coupled with the projection of the heat sink and is secured to the holding member. Standoffs are disposed under the main printed circuit board. The extension members of the holding member are secured to the main printed circuit board and to the chassis.

FIELD OF THE INVENTION 
The present invention relates generally to support structures. More 
particularly, it pertains to a support structure for internal components 
of electronic devices. 
BACKGROUND OF THE INVENTION 
Advances in semiconductor technology are creating increasing heat 
dissipation problems in electronic components and systems. Because 
electronic components have a relatively large amount of electrical current 
flow within an extremely small area, the components generate a relatively 
substantial amount of heat. In particular, microprocessors tend to 
generate a significant amount of heat. 
The effect of the heat generated is intensified by the close spacing of the 
components on printed circuit boards and the close spacing of printed 
circuit boards within electrical devices. Some printed circuit boards are 
vertically mounted to the main printed circuit board, thereby adding to 
the number of electronic components in a limited area. The amount of heat 
generated has increased as electronic components get smaller and more 
powerful. As a result, more heat is generated in a smaller, more confined 
area. Excessive heat in a small area degrades system performance and 
reliability since high temperatures can damage circuitry and adversely 
affect performance. Thus, heat dissipation methods and devices are 
critical in the electronics industry. 
A variety of well-known methods and devices for dissipating heat are 
available. These include various finned heat sinks which dissipate heat 
from the surfaces of metal fins. The finned heat sinks are attached to the 
electronic component to be cooled and are often used in computer systems 
with electric fans that drive air over the fins to enhance their cooling 
effect. 
For cooling a heat producing component, the heat sink is thermally coupled 
with the heat producing component. For vertically mounted printed circuit 
boards, this creates support problems. The heat sinks have been difficult 
to mount to a heat producing component due to the weight and size of the 
heat sink. 
One attempt at supporting and cooling a printed circuit board module is by 
Intel Corporation of Santa Clara, Calif. In this approach, as shown in 
FIG. 1, the printed circuit board module is supported by a plastic card 
holder that is attached to the main printed circuit board. A finned heat 
sink is secured to the printed circuit board module, in part, by screws 
through the heat sink to the module. A bracket, as shown in FIG. 2, is 
secured to the main printed circuit board and encompasses the bottom row 
of fins on the heat sink. One disadvantage with this approach is that the 
mass of the heat sink puts stress on the printed circuit board module and 
the main printed circuit board. 
Accordingly, what is needed is a better way to provide support for cooling 
devices for electronic components. What is further needed is a way to 
support the cooling devices without damaging surrounding components. 
SUMMARY OF THE INVENTION 
A support apparatus comprises a support structure for providing support to 
a heat producing component, a heat sink thermally coupled with the heat 
producing component, and a capture bar secured to the support structure. 
The support apparatus is secured to a main printed circuit board. The 
support apparatus includes a holding member with extension members for 
securing the holding member to the main printed circuit board. In one 
embodiment, the heat producing component is a printed circuit board 
module, having a processor mounted thereon. The holding member receives 
the printed circuit board module therein. The heat sink has a projection 
extending from one surface, and the capture bar frictionally engages with 
the projection. 
In one embodiment, the capture bar has a cutout therein. The cutout of the 
capture bar receives the projection of the heat sink therein. In another 
embodiment, the projection of the heat sink is a hook structure for 
engaging with the cutout. Alternatively, the hook structure of the heat 
sink forms an L-shape. 
The heat sink is coupled with the heat producing component by engaging the 
projection of the heat sink with the capture bar. In addition, the heat 
sink is secured directly to the heat producing component with retaining 
members, such as screws or rivets. In one embodiment, thermal grease is 
disposed between the heat sink and the heat producing component. 
In another embodiment, at least one standoff is disposed between the main 
printed circuit board and a chassis surrounding the main printed circuit 
board. The standoffs are located proximate to the support structure and 
elevate the main printed circuit board from the chassis, while 
simultaneously supporting the weight of the heat sink and the printed 
circuit board module. The standoffs, in one embodiment, are plastic discs. 
In another embodiment of the present invention, a method for cooling the 
printed circuit board is provided. The method comprises coupling the 
printed circuit board module with the holding member, and thermally 
coupling the heat sink with the printed circuit board module. The capture 
bar is coupled with the projection of the heat sink and is secured to the 
holding member. Standoffs are disposed under the main printed circuit 
board. The extension members of the holding member are secured to the main 
printed circuit board and to the chassis. 
The support apparatus beneficially provides support to the heat sink and 
the printed circuit board module by securing them to the computer chassis. 
The printed circuit board module is isolated from the weight of the heat 
sink. In addition, the support apparatus alleviates stress to the main 
printed circuit board from the weight of the heat sink. 
These and other embodiments, aspects, advantages, and features of the 
present invention will be set forth in part in the description which 
follows, and in part will become apparent to those skilled in the art by 
reference to the following description of the invention and referenced 
drawings or by practice of the invention. The aspects, advantages, and 
features of the invention are realized and attained by means of the 
instrumentalities, procedures, and combinations particularly pointed out 
in the appended claims.

DESCRIPTION OF THE EMBODIMENTS 
In the following detailed description, reference is made to the 
accompanying drawings which form a part hereof, and in which is shown by 
way of illustration specific embodiments in which the invention may be 
practiced. These embodiments are described in sufficient detail to enable 
those skilled in the art to practice the invention, and it is to be 
understood that other embodiments may be utilized and that structural 
changes may be made without departing from the spirit and scope of the 
present invention. Therefore, the following detailed description is not to 
be taken in a limiting sense, and the scope of the present invention is 
defined by the appended claims. 
A support system 10 is shown in FIG. 3. The computer system 10 includes a 
main printed circuit board 30, which includes a memory (not shown). In one 
embodiment, the processor is mounted on a secondary printed circuit board 
enclosed in a case, which collectively form a printed circuit board module 
100. The main printed circuit board 30 has a first surface 32 and a second 
surface 34. A chassis 20 encompasses the main printed circuit board 30, 
which provides support and protection to the electronic components 
therein. Mounting apertures 36 are provided within the main printed 
circuit board 30. 
The printed circuit board module 100 is disposed generally perpendicular to 
the main printed circuit board 30. The printed circuit board module 100 is 
shown in FIG. 4. The printed circuit board module 100 includes a secondary 
printed circuit board 105 having a processor 106 disposed thereon. 
Secondary printed circuit board 105 is shown in a broken away view. A 
mounting plate 104 is connected with the secondary printed circuit board. 
The mounting plate 104 is fabricated from metal for facilitating heat 
transfer to the heat sink 120. The mounting plate 104 has a plurality of 
apertures 102 for securing the printed circuit board module 100 to the 
heat sink 120. A holding member 50 is provided for securing the printed 
circuit board module 100 to the main printed circuit board 30. 
FIG. 5 illustrates a detailed view of the holding member 50. The holding 
member 50 is fabricated from plastic material. The holding member 50 can 
be formed by injection molding or other plastic formed methods known in 
the art. Alternatively, the holding member 50 can be fabricated from other 
materials, including metals. In one embodiment, the holding member 50 is 
generally U-shaped. Forming the U-shape, two side members 54 extend away 
from a base member 60. The base member 60 has a cutout 62 for receiving a 
printed circuit board module connector 110 (FIG. 3) therethrough. Each of 
the side members 54 have a channel 55 formed therein. The channel 55 of 
each side member 54 is sized and dimensioned to slidably receive the 
printed circuit board module 100 therein. The printed circuit board module 
100 has sides comprising suitably dimensioned structures for mating with 
the channels 55. The side members 54 of the holding member 50 each have a 
first surface 56. In one embodiment, the first surface 56 is parallel to 
the base member 60. Disposed within the first surface 56 of each side 
member 54 is a side member aperture 57. The first surface 56 mates with a 
capture bar 70, which will be further described below. 
The base member 60 further comprises at least one extension member 52, 
which extends generally transverse to the base member 60. In one 
embodiment, the holding member 50 includes four extension members 52 which 
are disposed on two opposite sides of the base member 60. Each extension 
member 52 is generally square shaped, although other shapes are 
contemplated. Each extension member 52 has an aperture 58 disposed 
therein. The extension member 52 provides additional support to the 
printed circuit board module 100, and is used for physically attaching the 
holding member 50 to the main printed circuit board 30. In one embodiment, 
the extension members 52 are sized and spaced to distribute weight over a 
portion of the main printed circuit board 30. 
For cooling the printed circuit board module 100, a heat sink 120, as 
illustrated in FIG. 6, is provided. The heat sink 120 has a plurality of 
fins 126 extending from a mounting surface 134. In one embodiment, the 
heat sink 120 includes a means for directing an air flow, such as a fan, 
over the fins 126. The heat sink is extruded from aluminum material. 
Alternatively, the heat sink 120 can be formed in other heat dissipating 
shapes, and from other thermally conductive materials, such as copper. For 
connecting the heat sink 120 to a heat source to be cooled, the mounting 
surface 134 has at least one aperture 132 disposed therein. In one 
embodiment, four apertures 132 are disposed within the mounting surface 
134. The apertures 132 are sized to receive retaining members 
therethrough. The apertures 132 align with apertures 102 in the printed 
circuit board module 100 to facilitate additional support for mounting of 
the heat sink 120 to the printed circuit board module 100. 
Extending from the mounting surface 134 of the heat sink 120 is a mounting 
ridge 130. The mounting ridge 130 extends in an opposite direction to the 
fins 126. In one embodiment, the mounting ridge 130 is a flat plate, which 
extends across the entire surface of the mounting surface 134. 
Alternatively, the mounting ridge 130 can extend across only a portion of 
the mounting surface 134, or the ridge 130 can extend on multiple 
surfaces. In another embodiment, the mounting ridge 130 forms a hook 
structure. The mounting ridge 130 has a first portion 136 which extends 
generally transverse to the mounting surface 134. A second portion 138 
extends from the first portion 136. The second portion 138 is generally 
parallel to the mounting surface 134, thereby forming a hook structure. 
The mounting ridge 130 can be formed in other shapes for creating a hook 
structure, such as a curved shape, without departing from the scope of the 
present invention. 
The heat sink 120 is coupled with the printed circuit board module 100 and 
provides heat dissipation of heat generated by the printed circuit board 
module 100. Thermal grease 122 is disposed between the mounting surface 
134 of the heat sink 120 and the printed circuit board module 100 for 
facilitating a thermal path away from the printed circuit board module 
100. Alternatively, thermal cement or other equivalents can be disposed 
between the heat sink 120 and the printed circuit board module 100. The 
heat sink 120 provides for additional heat dissipation from the printed 
circuit board module 100 since the mounting surface 134 substantially 
covers the mounting plate 104 of the printed circuit board module 100. 
A capture bar 70 is illustrated in FIG. 7. Secured to first surface 56 of 
the holding member 50, the capture bar 70 couples the heat sink to the 
holding member 50. The capture bar 70 extends from a first end 72 to a 
second end 74. The first and second ends 72, 74 each have an aperture 76 
disposed therein. The apertures 76 align with apertures 57 when the 
capture bar 70 is secured to the holding member 50 with screws or other 
attachment members. The capture bar 70 also has a cut out 80 therein. The 
cut out 80 is sized to receive the mounting ridge 130 of the heat sink 120 
therein when the capture bar 70 is coupled to the holding member 50. 
A standoff 150 is illustrated in FIG. 8. The standoff 150 is generally 
disc-shaped and has a bore 152 disposed therethrough. The bore 152 is 
aligned with a radial axis of the standoff 150. The bore 152 is sized to 
receive a retaining member, such as a screw, therein. The standoff 150 is 
fabricated from plastic, although other materials are suitable for use 
with the present invention. As shown in FIG. 3, the standoff 150 is 
disposed between the main printed circuit board 30 and the chassis 20. 
Disposing the standoff 150 adjacent to the printed circuit board module 
100 and between the main printed circuit board 30 and the chassis 20 
provides additional support to the printed circuit board module 100 and 
the heat sink 120 via the holding member 50. The standoff 150 also 
alleviates stress from the main printed circuit board 30 since the holding 
member 50 can be secured to the chassis 20 without flexing the main 
printed circuit board 30. 
The printed circuit board module 100 is disposed within the channels 55 of 
the holding member 50. The mounting ridge 130 of the heat sink 120 is 
placed on the printed circuit board module 100 such that the mounting 
surface 134 abuts the mounting plate 104 of the printed circuit board 
module 100. Retaining members, such as screws, are disposed through the 
apertures 132 on the heat sink and into the apertures 102 on the printed 
circuit board module. The capture bar 70 is disposed over the mounting 
ridge 130 of the heat sink 120, where the mounting ridge 130 is received 
by cut out 80 of the capture bar 70. The capture bar 70 is secured to the 
holding member 50 by retaining members 78, such as screws, inserted into 
aperture 76 of the capture bar 70 and side member apertures 57 of the 
holding member 50. 
The holding member 50 is coupled with the first surface 32 of the main 
printed circuit board 30. The base member 60 is placed adjacent to the 
first surface 32 where the apertures 58 of the extension members 52 align 
with the mounting apertures 36 of the main printed circuit board 30. The 
bore 152 of the standoff 150 is aligned with the mounting apertures 36, 
and a retaining member 151, such as a screw, secures the holding member 50 
with the main printed circuit board 30 and the chassis 20. Advantageously, 
the holding member 50, capture bar 70, and the standoff 150 relieve stress 
that would otherwise be placed directly on the printed circuit board 
module 100 or the main printed circuit board 30. 
In one embodiment of the present invention, a method is provided for 
mounting a cooling apparatus to the printed circuit board module with less 
stress. The method comprises the steps of coupling the printed circuit 
board module 100 with the holding member 50, placing the heat sink 120 
adjacent to the processor module and disposing thermal grease 
therebetween. The capture bar 70 is coupled with the mounting ridge of the 
heat sink 120 and is secured to the holding member 50 with screws. The 
standoffs 150 are disposed under the main printed circuit board 30, where 
the radial axis 154 of the standoffs 150 are aligned with the radial axis 
of each aperture 58 of the extension members 52. The extension member 52 
are secured to the main printed circuit board 30 and to the chassis 20. To 
secure the holding member 50 to the chassis 20, a retaining member, such 
as a screw, is inserted through the aperture 58 of the extension member 
52, through the mounting aperture 36 of the main printed circuit board 30, 
through the bore 152 of the standoff 150 to connect with the chassis 20. 
The support system 10 advantageously provides increased heat dissipation 
and increased support to the printed circuit board module. The support 
apparatus provides support to the heat sink and the printed circuit board 
module by securing them to the computer chassis. The mounting ridge 
provides increased thermal coupling between the heat sink and the printed 
circuit board module, which allows increased heat dissipation. In 
addition, the support apparatus alleviates stress to the main printed 
circuit board from the weight of the heat sink. 
It is to be understood that the above description is intended to be 
illustrative, and not restrictive. Many other embodiments will be apparent 
to those of skill in the art upon reviewing the above description. The 
scope of the invention should, therefore, be determined with reference to 
the appended claims, along with the full scope of equivalents to which 
such claims are entitled.