Electrical connectors – Preformed panel circuit arrangement – e.g. – pcb – icm – dip,... – With provision to conduct electricity from panel circuit to...
Reexamination Certificate
2002-07-31
2004-04-06
Abrams, Neil (Department: 2839)
Electrical connectors
Preformed panel circuit arrangement, e.g., pcb, icm, dip,...
With provision to conduct electricity from panel circuit to...
Reexamination Certificate
active
06716038
ABSTRACT:
This invention relates to electrically connecting printed circuit boards and other similar substrates in a vertical or z-axis direction to form a three-dimensional circuit module by using z-axis interconnectors, preferably of the type known as twist pins. More particularly, the present invention relates to a new and improved electrical connection in which one or more bulges of the interconnector establish electrical contact with and between the substrates without fully inserting the bulge into a plated through hole or via in at least one of the substrates, thereby simplifying the assembly, connection and disconnection of the substrates in the three-dimensional circuit module.
BACKGROUND OF THE INVENTION
A variety of techniques have been developed for electrically connecting printed circuit boards, circuit components, substrates and/or other circuit elements into three-dimensional circuit modules. The propriety of using any one technique over another technique depends on the given situation and application for the module. Generally, the preferred technique in any situation is the one that enables the fastest, least-expensive and easiest assembly of the module in a manner which is consistent with the best use and longevity of the module. Additional considerations include the ease with which the module can be disassembled and reassembled, such as for troubleshooting or repair purposes.
To form a three-dimensional circuit module, usually a plurality of printed circuit boards, or substrates, are stacked vertically above one another. Vertical electrical connections between the stacked printed circuit boards are established by using z-axis interconnectors. Z-axis interconnectors extend vertically in the direction of the z-axis between the printed circuit boards which are oriented generally in a horizontal plane in the x-axis and y-axis directions. The z-axis interconnectors typically contact and extend through plated through holes or “vias” formed in each of the printed circuit boards. The electronic components and integrated circuits of each printed circuit board are connected to the vias by conductor traces formed on the surface of or within each printed circuit board. In this manner, the components of the printed circuit boards are connected to the components of one or more of the vertically stacked circuit boards, thereby creating a three-dimensional matrix of electrical connections, rather than limiting the electrical connections only to those elements on each circuit board. Consequently, a three-dimensional module of electrical connections and components is formed.
There are many benefits to three-dimensional circuit modules. One significant benefit is that a relatively large amount of electrical functionality can be obtained in a relatively small space or volume. This benefit maximizes the amount of electronic functionality for a given amount of space or reduces the amount of space required to obtain a given amount of electronic functionality.
To create the three-dimensional module, the vias are formed in each of the individual printed circuit boards at the same x-axis and y-axis locations, so that when the printed circuit boards are stacked in the three-dimensional module, the vias of the printed circuit boards are aligned vertically in the z-axis direction. The z-axis interconnectors are then inserted vertically through the aligned vias to establish the electrical contact and connection between the vertically separated circuit boards. Since the vias are connected to the electronic components on each circuit board by the traces, those components are also electrically interconnected in a three-dimensional manner.
A number of different types of z-axis interconnectors have been proposed. One particularly advantageous type of z-axis interconnector is known as a “twist pin.” Twist pin z-axis interconnectors are described in U.S. Pat. Nos. 5,014,419, 5,064,192, and 5,112,232, all of which are assigned to the assignee hereof, as well as other prior art patents. General techniques for fabricating twist pins are described in these three patents, as well as in U.S. patent applications for a “High-Speed, High-Capacity Twist Pin Connector Fabricating Machine and Method,” Ser. No. 09/782,987; a “Wire Feed Mechanism and Method Used for Fabricating Electrical Connectors,” Ser. No. 09/782,991; a “Rotational Grip Twist Machine and Method for Fabricating Bulges of Twisted Wire Electrical Connectors,” Ser. No. 09/782,888; and a “Pneumatic Inductor and Method of Electrical Connector Delivery and Organization,” Ser. No. 09/780,981, all of which are assigned to the assignee hereof. The use of z-axis interconnectors to create three-dimensional modules from printed circuit boards is described in U.S. Pat. No. 5,045,975, also assigned to the assignee hereof.
An example of a prior art twist pin
50
is shown in
FIGS. 1 and 2
. The twist pin
50
is formed from a length of wire
52
which has been formed conventionally by helically coiling a number of outer strands
54
around a center core strand
56
in a planetary manner. At selected, spaced-apart segments along the length of the wire
52
, an expanded bulge
58
is formed by untwisting the outer strands
54
in a reverse or anti-helical direction. As a result of untwisting the strands
54
in the anti-helical direction, the space consumed by the outer strands
54
increases, causing the outer strands
54
to bend, expand and diverge outward from the center strand
56
at the axis of the twist pin. The outer strands
54
expand outward from the regularly twisted wire
52
in a pair of generally frustroconically-shaped expanding portions
57
which meet at a maximum-diameter or maximum-width portion
59
. At the maximum-width portion
59
, the diameter for the bulge
58
is larger than the diameter of the regular stranded wire
52
. The laterally outward extent of the maximum-width portion
59
of the bulge
58
is exemplified in
FIG. 3
, compared to FIG.
2
.
The twist pin
50
has mechanical characteristics to maintain the shape of the wire in the expanded configuration, to allow the outer strands
54
to diverge outward in the expanding portions
57
to the maximum-width portion
59
at each bulge
58
when untwisted, and to cause the strands
54
at the maximum-width portion
59
to compress radially inward toward the center strand
56
when the bulge is inserted into a via of the printed circuit board. The radial compression of the outer strands
54
toward the center strand
56
at the bulge applies resilient radial contact force against a side wall of a via to establish the electrical connection of the twist pin to the via of the printed circuit board and to resist longitudinal movement of the twist pin relative to the printed circuit board.
The bulges
58
are positioned at selected predetermined distances along the length of the wire
52
to contact the vias
60
in printed circuit boards
62
of a three-dimensional module
64
, as shown in FIG.
4
. Contact of the bulges
58
with the vias
60
is established by pulling the twist pin
50
through an aligned vertical column of vias
60
in the module
64
while the printed circuit boards
62
are held in position. The resiliency of the outer strands
54
of the wire
52
at the bulges
58
, when compressed radially inward by insertion into the somewhat smaller via
58
, press against an inner surface of a sidewall
66
of each via
60
, and thereby establish the electrical connection between the twist pin
50
and the via
60
, as shown in FIG.
5
.
To insert the twist pins
50
into the vertically aligned vias
60
of the module
64
with the bulges
58
contacting the inner surfaces
66
of the vias
60
, a leader
68
of the regularly-coiled strands
54
and
56
extends at one end of the twist pin
50
. The strands
54
and
56
at a terminal end
70
of the leader
68
have been welded or fused together to form a rounded end configuration
70
to facilitate insertion of the twist pin
50
through the column of vertically aligned vias. The leader
68
is of sufficient length to extend
Abrams Neil
Dinh Phuong
Ley John R.
Medallion Technology, LLC
LandOfFree
Z-axis connection of multiple substrates by partial... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Z-axis connection of multiple substrates by partial..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Z-axis connection of multiple substrates by partial... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3221314