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Claims  |
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What is claimed is:
1. A module for mounting in an expansion slot of a mother board of a
computer, said module comprising:
a primary board including an interface portion for engaging with the
expansion slot, said primary board having a first side and a second side;
an auxiliary board mounted to said first side of said primary board in a
spaced relationship such that an air path is defined between said boards;
a second auxiliary board mounted to said second side of said primary board
in a spaced relationship such that an air path is defined between said
boards;
a plurality of surface mount connectors for mounting said auxiliary board
to said primary board;
an additional plurality of surface mount connectors for mounting said
second auxiliary board to said primary board;
a trace on said auxiliary board for electrically connecting said auxiliary
board to said primary board; and
a second trace on said second auxiliary board for electrically connecting
said second auxiliary board to said primary board;
wherein said surface mount connectors and said additional surface mount
connectors each include a male surface mount connector and a corresponding
female surface mount connector; and
wherein said male connector mates with said female connector.
2. The module of claim 1 wherein said trace is substantially equal in
length to said second trace.
3. The module of claim 1 wherein said plurality of surface mount connectors
and said additional plurality of surface mount connectors include
electrically conductive contacts for functioning as electrical connectors
between said auxiliary boards and said primary board.
4. The module of claim 1 wherein said surface mount connectors and said
additional surface mount connectors are connected to said traces.
5. The module of claim 1 wherein said interface portion is configured to be
compatible with an industry standard memory module expansion slot.
6. The module of claim 1 wherein said male connectors being directly
attached to said first side and said second side of said primary board,
and said female connectors being directly attached to a side of said
auxiliary boards.
7. The module of claim 1 wherein each side of said primary board includes
five said male connectors arranged in a first row and a second row,
wherein said first row being adjacent to a top edge of said primary board
and said second board being adjacent to a bottom edge of said primary
board.
8. The module of claim 7 further comprising:
a plurality of chips mounted to said auxiliary boards, said plurality of
chips including memory chips;
one end of said trace connecting to at least one of said plurality of chips
and the other end of said trace connecting to at least one of said
plurality of surface mount connectors;
one end of said second trace connecting to at least one of said additional
plurality of chips and the other end of said second trace connecting to at
least one of said plurality of additional surface mount connectors and to
at least one of said plurality of surface mount connectors and said second
trace connecting to at least one of said plurality of chips; and
a plurality of additional chips mounted to said primary boards.
9. The module of claim 1 further comprising a fastening pin securing said
primary board and said auxiliary boards together, wherein said fastening
pin fits into apertures formed in each of said primary board and said
auxiliary boards.
10. A computer comprising:
a mother board including an expansion slot; and
a memory module including:
a primary board including a plurality of integrated circuit chips, and an
interface portion configured to be engaged with said expansion slot;
a pair of auxiliary boards mounted to respective sides of said primary
board in a spaced relationship such that an air path is defined between
each of said auxiliary boards and said primary board;
a plurality of additional integrated circuit chips connected to said
auxiliary boards;
a plurality of surface mount connectors for mounting said auxiliary boards
to said primary board, each of said surface mount connectors including a
male surface mount connector and a matching female surface mount
connector, wherein said male connector mates with said female connector
with a friction fit; and
a trace for each said auxiliary board electrically connecting each said
auxiliary board to said primary board.
11. The computer of claim 10 wherein said expansion slot is configured as a
168-pin dual in-line memory module (DIMM) connector.
12. The computer of claim 10 wherein each said trace of said auxiliary
boards have substantially equal lengths.
13. The computer of claim 12 further including a fastening pin securing
said primary board and said auxiliary boards together, wherein said
fastening pin fits into apertures formed in each of said primary board and
said auxiliary boards.
14. A method for increasing memory capacity of a computer, comprising:
(a) providing a computer including a mother board with an expansion slot;
(b) providing a memory module including:
a primary board including an interface portion configured to engage with
the expansion slot of the computer, a plurality of chips including memory
chips, and a trace connecting the interface portion with at least one of
the chips;
an auxiliary board attached to the primary board in a spaced relationship
such that an air path is defined between the boards, the auxiliary board
including a plurality of chips including memory chips;
a plurality of surface mount connectors for mechanically and electrically
connecting the auxiliary board to the primary board wherein each of the
surface mount connectors includes a male surface mount connector and a
corresponding female surface mount connector, the male connector and the
female connector mate to form a friction fit, and the male connector being
attached to the primary board and the female connector attached to the
auxiliary board;
a trace on the auxiliary board connecting the surface mount connectors with
at least one of the chips; and
(c) inserting the interface portion of the memory module into the expansion
slot of the computer.
15. The method of claim 14 wherein the expansion slot is a 168-pin dual
in-line memory module (DIMM) expansion slot, and the primary board has at
least 200 megabytes of memory capacity.
16. The method of claim 14 further comprising:
(d) arranging the surface mount connectors in a first row adjacent to a top
edge of the primary board and auxiliary board; and
(e) arranging the surface mount connectors in a second row adjacent to a
bottom edge of the primary board and auxiliary board.
17. The method of claim 14 further comprising mechanically attaching the
primary board and auxiliary board together by inserting a fastening pin
through a hole in each of the primary board and auxiliary board.
18. A module for mounting in an expansion slot of a mother board of a
computer, said module comprising:
a primary board comprising:
an interface portion for engaging with the expansion slot;
a plurality of chips mounted thereon; and
a trace connecting said interface portion to at least one of said plurality
of chips;
an auxiliary board mounted to said primary board in a spaced relationship
such that an air path is defined between said boards;
a plurality of fasteners for mounting said auxiliary board to said primary
board; and
a trace for electrically connecting said auxiliary board to said primary
board;
wherein said trace of said primary board has a length substantially equal
to said trace connecting said auxiliary board with said primary board.
19. A module as claimed in claim 18 wherein said primary board has a first
side and a second side, said auxiliary board being mounted on said first
side of said primary board;
said module further comprising:
a second auxiliary board mounted on said second side of said primary board
in a spaced relationship such that an air path is defined between said
boards; and
a second trace for electrically connecting said second auxiliary board to
said primary board;
said plurality of fasteners including fasteners for mounting said second
auxiliary board to said primary board.
20. A module as claimed in claim 19 wherein said plurality of fasteners
include conductive fasteners for functioning as electrical connectors
between said auxiliary boards and said primary board.
21. A module as claimed in claim 20 wherein said conductive fasteners are
connected to said traces.
22. A module as claimed in claim 18 wherein said interface portion is
configured to be compatible with an industry standard memory module
expansion slot.
23. A module as claimed in claim 22 further comprising a plurality of chips
mounted to said boards, said plurality of chips including memory chips.
24. A module as claimed in claim 18 wherein each of said boards has a top
edge and a bottom;
said interface portion being disposed along the bottom edge of said primary
board.
25. A module as claimed in claim 24 wherein said air path is substantially
open along the top edges of said boards.
26. A computer comprising:
a mother board including an expansion slot;
a memory module including:
a primary board including:
an interface portion configured to be engaged with said expansion slot;
a plurality of chips mounted thereon; and
a trace connecting said interface portion with at least one of said
plurality of chips;
a pair of auxiliary boards mounted to respective sides of said primary
board in a spaced relationship such that an air path is defined between
each of said auxiliary boards and said primary board;
a plurality of fasteners for mounting said auxiliary boards to said primary
board; and
a pair of traces each for electrically connecting one of said auxiliary
boards to said primary board;
wherein said trace of said primary board has a length substantially equal
to the length of said pair of traces.
27. A computer as claimed in claim 26 wherein said expansion slot is
configured as a 168-pin dual in-line memory module (DIMM) connector.
28. A computer as claimed in claims 26 wherein said memory module has a
thickness defined from an outer edge of one said auxiliary board to an
outer edge of the other said auxiliary board of less than about 0.5 inch
and a height defined from the bottom edge to the top edge of said primary
board of less than about 1.5 inches.
29. A module for mounting in an expansion slot of a mother board of a
computer, said module comprising:
a primary board having an interface portion engaging with the expansion
slot;
an auxiliary board mounted to said primary board in a spaced relationship
such that an air path is defined between said boards; and
a plurality of surface mount connectors for mounting said auxiliary board
to said primary board;
each of said surface mount connectors having a male surface mount connector
and a matching female surface mount connector;
wherein said male surface mount connector mates with said matching female
surface mount connector.
30. The module of claim 29 wherein said primary board has a first side and
a second side, said auxiliary board being mounted on said first side of
said primary board, said module further comprising:
a second auxiliary board mounted on said second side of said primary board
in a spaced relationship such that an air path is defined between said
boards; and
an additional plurality of surface mount connectors for mounting said
second auxiliary board to said primary board.
31. The module of claim 30 wherein said male connectors being directly
attached to said first side and said second side of said primary board,
and said female connectors being directly attached to a side of said
auxiliary boards.
32. The module of claim 31 further comprising
a plurality of chips mounted to said auxiliary boards, said plurality of
chips including memory chips; and
A plurality of additional chips mounted to said primary board.
33. The module of claim 29 wherein said interface portion is configured to
be compatible with an industry standard memory module expansion slot.
34. The module of claim 29 further comprising a fastening pin securing said
primary board and said auxiliary board together, wherein said fastening
pin fits into apertures formed in each of said primary board and said
auxiliary board.
35. A method of forming a memory module comprising:
(a) providing a primary board;
(b) attaching a plurality of chips on the primary board;
(c) providing an auxiliary board;
(d) attaching a plurality of chips on the auxiliary board;
(e) mechanically and electrically connecting the auxiliary board to the
primary board in a spaced relationship such that an air path is defined
between the auxiliary board and the primary board;
(f) mounting a plurality of surface mount connectors to the auxiliary board
and the primary board to perform step (e), each of the surface mount
connectors having a male surface mount connector and a matching female
surface mount connector, and the male surface mount connector mating with
the matching female surface mount connector to form a friction fit.
36. The method of claim 35 further comprising:
(g) arranging the surface mount connectors in a first row adjacent a top
edge of the primary board and the auxiliary board; and
(h) arranging the surface mount connectors in a second row adjacent to a
bottom edge of the primary board and the auxiliary board.
37. The method of claim 35 further comprising:
(g) mechanically attaching the primary board to the auxiliary board by
inserting a fastening pin through a hole in each of the primary board and
the auxiliary board.
38. A module for mounting in an expansion slot of a mother board of a
computer, said module comprising:
a primary board comprising:
an interface portion engageable with the expansion slot;
a first plurality of chips disposed on said primary board; and
a first trace connecting said interface portion to at least one of said
first plurality of chips;
an auxiliary board mounted to said primary board in a spaced relationship
such that an air path is defined between said boards, said auxiliary board
comprising:
a second plurality of chips disposed on said auxiliary board; and
a second trace connecting at least one of said second plurality of chips to
said primary board;
wherein said first trace has a length substantially equal to said second
trace; and
a plurality of fasteners for mounting said auxiliary board to said primary
board.
39. The module of claim 38 wherein said plurality of fasteners are surface
mount connectors, each of said surface mount connectors having a male
surface mount connector and a matching female surface mount connector,
said male surface mount connector mating with said matching female surface
mount connector to form a friction fit, said male surface mount connector
attachable to one of said primary board and said auxiliary board, and said
matching female surface mount connector attachable to the other one of
said primary board and said auxiliary board.
40. The module of claim 39 wherein said primary board has a first side and
a second side, said auxiliary board mountable to said first side of said
primary board, and said module further comprising:
a second auxiliary board mountable to said second side of said primary
board in a spaced relationship such that an air path is defined between
said secondary auxiliary board and said primary board;
a third trace for electrically connecting said second auxiliary board to
said primary board;
wherein said first trace has a length substantially equal to said third
trace; and
another plurality of fasteners for mounting said second auxiliary board to
said primary board.
41. The module of claim 38 wherein said plurality of fasteners are
connected to said first trace and said second trace.
42. The module of claim 38 wherein said interface portion is configured to
be compatible with an industry standard memory module expansion slot.
43. The module of claim 38 where said plurality of chips are memory chips. |
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Claims |
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Description |
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FIELD OF THE INVENTION
The present invention is directed to computer memory boards and, more
particularly, to expansion modules for mounting in an expansion slot of a
mother board of a computer.
BACKGROUND OF THE INVENTION
It is well known that in the electronics industry, particularly the
personal computer industry, that the trend is to design products which are
smaller, lighter, and more compact while maintaining or increasing power,
speed, and memory capacity. In recent years, the computer industry has
experienced the advent of the lap-top computer, the notebook computer, and
now the palm-top computer. Although these computers are amazingly compact
and lightweight, they are still incredibly powerful and fast. They are
capable of running software applications that only in the recent past were
able to be run on desk-top computers with large amounts of memory.
Personal computers (including desk-top, lap-top, notebook, and palm-top
computers) include a mother board for controlling the operation of the
computer. Personal computers are sold with a specified amount of memory,
for example, 1.2 gigabytes (GB) of storage memory on a hard drive and 64
megabytes (MB) of random access memory (RAM). Many users upgrade the RAM
of their computers. Accordingly, motherboards typically include
standardized expansion slots in which a memory card may be inserted. The
expansion slots may also receive cards for upgrading a particular function
of the computer, such as cards for sounds, video, and graphics.
A dual in-line memory module (DIMM) connector is a standard industry
connector for receiving a memory module. And in accordance with the
"smaller-is-better" trend in the computer industry, many mother boards are
equipped with only two DIMM connectors. As such, in order to install a
larger amount of memory in only two DIMM connectors, higher density memory
modules have been developed.
One conventional technique for increasing the storage capacity of a memory
module is to double the height of the module. To do so, two rows of memory
chips are mounted on the memory module, essentially doubling the capacity
of the module. However, there are two primary disadvantages of such a
configuration. One disadvantage is the double height. The housing of the
computer and the area around the mother board both need to be sufficiently
large in order to accommodate this doubled size of the expansion, which
runs contrary to the small-is-better design principle. Another
disadvantage lies in different trace lengths. A trace is the electrical
conductor which connects the chips to the edge connector or interface
portion of the module. In the double-row configuration, one row of chips
has one trace length, and the other row of chips has another trace length.
The trace of the further row of chips is essentially twice as long as the
closer row of chips from the edge connector. Accordingly, a signal
traveling to the further rows of chips take about twice as long to arrive
as the signal traveling to the closer row of chips. This arrangement
requires the signal delay to be eliminated, which may be done by
synchronizing the signals, which is difficult and expensive to accomplish.
Alternatively, the trace of the closer row of chips may be physically
doubled in length so that the signals arrive at the two rows at about the
same time. Either solution results in a module which is limited in speed
by the double-length trace.
Another conventional technique for increasing storage capacity of a memory
module is to configure the double-height arrangement discussed above with
a foldable portion such as an integral flex conductor. The module may then
be folded in half, thereby reducing the height essentially by two.
However, this foldable configuration still suffers from the drawback of
the varying trace lengths. An additional drawback is created by the folded
arrangement in that vertical air circulation is restricted. The components
of the module produce heat, and under normal convection the heated air
would rise and be drawn out of the computer by a fan. However, the folded
portion of the module retains heat between the folded sections, which may
cause the module to function improperly and errant.
Accordingly, in view of the foregoing, it is an object of the present
invention to provide an expansion module which overcomes the disadvantages
and drawbacks associated with conventional expansion modules.
It is another object of the present invention to provide a memory module
which maximizes memory per unit volume of space which the memory module
occupies.
It is yet another object of the invention to provide a high-density memory
module which operates at the highest speed possible.
It is yet another object of the invention to provide a multiple-layer
memory module with a minimized trace length.
It is yet another object of the present invention to provide a
multiple-layer memory module with substantially equal trace lengths
between layers.
It is a further object of the present invention to provide a multiple-layer
memory module having boards that can be readily connected and disconnected
from each other.
SUMMARY OF THE INVENTION
These and other objects are achieved by the apparatus of the present
invention which provides a module for insertion into an expansion slot on
a motherboard of a computer. Exemplary module maximizes the speed at which
the module operates, maximizes chip density per expansion slot, and
minimizes trace length. Although capable of performing all types of
functions typical of expansion modules, the module of the present
invention is particularly suitable for expanding the memory of a computer,
either a desk-top, lap-top, notebook, or palm-top computer.
According to one aspect of the invention, an exemplary module includes a
primary board with an interface portion for engaging with the expansion
slot. The interface portion may be configured to engage with a
conventional 168-pin dual in-line memory module (DIMM) connector, for
example. At least one but preferably two auxiliary boards are mounted to
respective sides of the primary board. The auxiliary boards are mounted
with fasteners in a spaced relationship which defines an air path between
each of the auxiliary boards and the primary board. Each of the auxiliary
boards has a trace for electrically connecting the board to the primary
board.
One of the advantages of the invention is that the air spaces allow air to
circulate between the boards. Each of the boards may have a plurality of
chips mounted thereon which generate heat when operating. In addition, the
computer in which the module is inserted is a closed environment with many
electronic components which also generate heat. As temperature increases,
the speed of a chip decreases because of increased resistance. However, in
accordance with the present invention, air is able to freely circulate
between the boards, thereby either cooling the chips or at least providing
adequate ventilation to prevent the ambient temperature from increasing
undesirably.
Another aspect of the present invention focuses on the traces. In addition
to the traces of the auxiliary board or boards, the primary board has a
trace connecting the interface portion with any number of the chips that
may be mounted thereon. The traces of the auxiliary boards have
substantially the same length, which is only slightly longer than that of
the trace of the primary board.
In contrast to conventional double-height arrangement in which one of the
traces is essentially twice as long as the other trace, the traces of the
module of the present invention are substantially the same length. This
feature of equal trace length advantageously eliminates the need for
synchronizing signals to different rows of chips. In addition, by way of
example only, the module of the invention reduces trace length on average
by about 20% to 50% over conventional arrangements or some other value
consistent with operational parameters. The reduction in trace length
results in a much faster operating module.
Another aspect of the present invention focuses on surface mount
connectors, which are a specific type of fastener, that enable the
auxiliary boards to be securely mounted to respective sides of the primary
boards. One of the advantages of the surface mount connectors is the ease
in which the auxiliary boards can be mounted and dismounted from the
primary board, thus, reducing the time and costs of assembly. In addition,
electrical failure verification and failure analysis can be readily
performed by easily separating the auxiliary boards from the primary board
and interfacing the individual boards with test equipment via the surface
mount connectors.
Other aspects, features, and advantages of the present invention will
become apparent to those persons having ordinary skill in the art to which
the present invention pertains from the following description taken in
conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an exemplary embodiment of an expansion
module of the present invention, particularly illustrating the expansion
module mounted in an expansion slot of a mother board of a computer;
FIG. 2 is a perspective view of an exemplary expansion module of the
present invention, illustrating a multiple-layer, parallel-plane
configuration of boards;
FIG. 3A is a side view of an auxiliary board of an expansion module of the
invention, illustrating a plurality of chips mounted on a first side of
the board;
FIG. 3B is a view similar to that of FIG. 3A, illustrating a plurality of
chips mounted on a second side of the board;
FIG. 4 is a side view of a board of an exemplary expansion module of the
invention, particularly highlighting a masked wiring arrangement of the
board;
FIG. 5 is a cross-sectional view of an expansion module of the invention,
particularly illustrating minimized trace lengths of auxiliary boards and
a primary board of the module;
FIG. 6 is a cross-sectional view of an exemplary module of the invention,
particularly illustrating open air paths defined between boards in a
spaced relationship; and
FIG. 7 is an exploded perspective view of an alternative embodiment of an
expansion module of the present invention, illustrating a plurality of
surface mount connectors;
FIG. 8 is an exploded cross-sectional view of the expansion module
illustrated in FIG. 7;
FIG. 9A is a side view of a primary board of the expansion module
illustrated in FIG. 7, illustrating a plurality of chips and surface mount
connectors mounted on a first side of the primary board;
FIG. 9B is a view similar to that of FIG. 9A, illustrating a plurality of
chips and surface mount connectors mounted on a second side of the primary
board;
FIG. 10A is a side view of an auxiliary board of the expansion module
illustrated in FIG. 7, illustrating a plurality of chips mounted on a
first side of the auxiliary board;
FIG. 10B is a view similar to that of FIG. 10A, illustrating a plurality of
chips and surface mount connectors mounted on a second side of the
auxiliary board;
FIG. 11A is a side view of the primary board of the expansion module shown
in FIG. 7, particularly highlighting a masked wiring arrangement of the
first side of the primary board;
FIG. 11B is a view similar to that of FIG. 11A, illustrating a masked
wiring arrangement on the second side of the primary board;
FIG. 12A is a side view of the auxiliary board of the expansion module
shown in FIG. 7, particularly highlighting a masked wiring arrangement of
the first side of the auxiliary board;
FIG. 12B is a view similar to that of FIG. 12A, illustrating a masked
wiring arrangement on the second side of the auxiliary board;
FIG. 13A is a top view of a male surface mount connector of the expansion
module illustrated in FIG. 7;
FIG. 13B is a top view of a female surface mount connector of the expansion
module illustrated in FIG. 7;
FIG. 14 is a cross-sectional view of the expansion module illustrated in
FIG. 7, particularly illustrating minimized trace lengths of auxiliary
boards of the module; and
FIG. 15 is a cross-sectional view of an expansion module illustrated in
FIG. 7, particularly illustrating open air paths defined between boards in
a spaced relationship.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
Referring to the drawings in more detail, in FIG. 1 an exemplary embodiment
of a high-density, stacked parallel-plane module 50 and 150 of the present
invention is illustrated. Exemplary module 50 and 150 is installable in a
mother board 52 of a computer 54. As known in the art, mother board 52
includes a main board 56 with a microprocessor 58 mounted thereon. Mother
board 52 may include a plurality of additional semiconductor chips and
electronic components operatively associated with microprocessor 58, which
additional chips and components are not shown in the drawings for clarity.
Also not shown in the drawings are components and peripheral devices which
may be configured with computer 52, including a monitor, input devices
such as a keyboard and/or a mouse, network connections, output devices
such as a printer, and so on.
Mother board 52 also includes at least one, but in general a plurality of
expansion slots 60a-1 in communication with microprocessor 58. Expansion
slots 60a-1 may respectively receive add-on modules for performing
particular functions. For example, a memory module may be inserted into
one of the expansion slots 60 to increase the amount of memory of computer
54. The expansion slots 60 are also known in the art as connectors. A
168-pin dual in-line memory module (DIMM) connector is an example of a
standard expansion slot or connector commonly used in industry today. As
computers become increasingly small and compact, particularly portable
computers such as lap-top computers and now palm-top computers, many
mother boards for desk-top computers are equipped with as few as two
168-pin DIMM connectors. As a referencing convention for this description,
expansion slots (or connectors) are referenced generally by numeral 60,
with each particular expansion slot referenced specifically by alpha
suffix a, b, . . . l, respectively. This referencing convention will be
utilized throughout this description for the expansion slots as well as
for other plural elements of the present invention.
Referencing FIG. 2, exemplary module 50 of the present invention includes a
primary board 62 and at least one auxiliary board 64. As exemplified in
the embodiment shown in FIG. 2, exemplary module 50 includes a pair of
auxiliary boards 64a and 64b. Upon reading this description, those skilled
in the art will appreciate that module 50 of the invention may include a
plurality of auxiliary boards 64a-m. Auxiliary boards 64 are mounted to
primary board 62 with fasteners 66. As illustrated, auxiliary boards 64a
and 64b are configured in a substantially spaced and parallel-plane
relationship with respect to primary board 62, with one of the auxiliary
boards 64 being mounted on a first side of primary board 62 and the other
auxiliary board 64 being mounted on a second side of primary board 62.
Such as relationship has a number of advantages, including ventilation,
high density, reduced trace length, ease of manufacturing, which
advantages will be discussed in more detail below. Exemplary boards 62 and
64 may be generally configured as printed circuit boards (PCBs) or printed
wiring boards (PWBs), as known in the art. In addition to mechanically
mounting auxiliary boards 64 to primary board 62, a number of fasteners 66
or each may also be conductive and serve as electrical connections, which
will also be discussed in more detail below.
With additional reference to FIGS. 3A and 3B, each board 62 and 64 may
include a plurality of chips 68a-n mounted on each side thereof. Each chip
68 may perform a particular function. For example, each chip 68 may be a
memory chip so that exemplary module 50 is a high-density me | | |
