JPS6235472A - High-density impedance control connector - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to high density impedance control connectors, and more particularly to high density impedance control connectors.

A high-density connector that can be used to couple multiple modules (daughter boards) to a bank plane (motherboard), each electrical connection of which has controlled impedance and minimal crosstalk.

(Prior Art and Problems to be Solved by the Invention) In the prior art, there has been considerable discussion regarding the use of flat cable systems containing flat or round wires for handling high speed signals such as high speed digital pulses. . The advantage of a flat cable is that it is possible to provide a conductive layer on one or both sides of the cable, the conductive layer being grounded. - When using a single conductive layer on the sides,
A microstrip is formed. If conductive layers are used on both sides, a strip line is formed. A paper discussing the mathematical theory and properties of the flat cable mentioned above was published in December 1970 in N.E.H.
Electrical and Transmission Characteristics Tests in Flat Cables by Bossi, Dennis F. Presented at the 19th International Wire and Cable Symposium held at Atlantic C1ty, s e y 3+1
sting Electric-cal And Tra
nsmission Properties In F
See Lam Cable).

P and J published on October 12, 1971, in which a strip line is formed using a ground plate on the top and bottom surfaces of a flat cable formed using multiple flat conductors.
, Thomas U.S. Patent No. 3,612,74.
Seen in 4. A second flat cable in the form of a microstrip is C6J, published on April 3, 1984.
, Anderson U.S. Patent No. 4,441,0
88.

The Anderson patent teaches reducing the amount of crosstalk by adjusting the amount of dielectric material between the flat conductor and the ground plane to be proportional to the amount of dielectric material overlying the flat conductor.

The advantages of utilizing flat cables will become apparent upon consideration of the explanations provided in the references cited above. That is, the dimensions of the cable can be varied to select or control the impedance and reduce the amount of crosstalk. This idea was incorporated into early connectors in which a dielectric sheet of elastic material was surrounded on one side by a ground plate and on the other side by a conductive strip. The distance between the conductive strip and the elastic ground plane was said to achieve impedance matching characteristics. P issued September 10, 1968
See U.S. Pat.

Later connectors that shielded the internal electrical contacts to allow high-frequency signals to pass through the connector and used stripline construction were published in the IBM Technical Disclosure Bulletin (I
BM Technical Disclosure Bu
lletin), Volume 10, No. 3, August 1, 1967
As shown on pages 203-204. This connector is not intended to be a high density connector as contemplated in the present invention.

Furthermore, it is well known in the prior art to use connectors with multiple contacts attached directly to the motherboard. These contacts couple with conductive elements on the motherboard and have spring fingers that touch conductive elements on the daughterboard to electrically connect the daughterboard and the motherboard. 19
H, E, Hen5c published on March 21, 1972
In one of the aforementioned connectors, shown in U.S. Pat. Impedance matching of the microstrip circuit is performed by connecting the terminal to the ground of the microstrip circuit. In this configuration, the signal carrying contacts are surrounded by ground connections to provide impedance control and matching. However, this configuration is very expensive and is not suitable for high density connector systems.

Furthermore, in 1978, two connector systems were developed in which round wires were bent 90 degrees to form contacts and inserted into the motherboard.
R8V issued on January 24, Hutchiso
U.S. Patent Nos. 4.070.084 and 198 for n.
No. 4,232,929 to F. Zobawa, issued Nov. 11, 2003. The first patent describes a means of controlling impedance by embedding conductive elements in a dielectric layer using a microstrip configuration. Ground plate on one side of the flexible dielectric material.

An alternative configuration with a conductive element on the other side is also shown. The second patent discusses reducing the amount of crosstalk by providing an intermediate ground plate between the contacts. Both of these configurations suffer from bulk and inability to form high density connectors.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a high density connector capable of providing constant impedance and low crosstalk.

A further object of the present invention is to provide a high density connector that provides impedance control regardless of the length of the contacts by using a stripline configuration within the connector.

Another object is to provide a high density connector that is easily reconfigurable to accommodate different sized printed circuit boards and different mounting configurations.

Yet another object is to provide an arrangement for an electrical connector that is easily replaceable and repairable.

Yet another object of the present invention is to provide a high density impedance control connector that is economical, flexible, and scalable.

In accomplishing these and other objectives, a separate wafer of dielectric material having a plurality of conductive elements thereon is provided. A single ground plane element is mounted on the wafer for coupling to electrical ground. Separated wafer.

A base plate, stacked in parallel and attached by two wafers, surrounds a plurality of conductive elements attached by a single separate wafer. This arrangement creates a stripline configuration for multiple conductive elements, which controls the impedance of the conductive elements.

Embodiments There are several embodiments that incorporate the original idea of the present invention. These embodiments will be described in detail below based on the accompanying drawings.

FIG. 1 is a side view of an alternative embodiment of a high density connector according to the present invention.

FIG. 2 is an end view of FIG. 1.

FIG. 3 is a bottom view of FIG. 1.

FIG. 4 is an exploded perspective view of the connector shown in FIGS. 1-3.

FIG. 5 is a cross-sectional view of a high-density connector that attaches four daughterboards to one motherboard.

FIG. 6 shows a typical arrangement for conductive pads that may be used on a motherboard or daughterboard mounted with the connectors shown in FIGS. 1-5.

FIG. 7 is a perspective view of an isolation wafer used in one preferred embodiment of the present invention.

FIG. 8 is a cross-sectional view taken along line 8-8 in FIG. 7.

FIG. 9 is a cross-sectional view of a high-density connector using the wafers shown in FIGS. 7 and 8.

10 is a curved view of the second side of the wafer shown in FIG. 9. FIG.

FIG. 11 is a side view similar to FIG. 1.

1 is a preferred embodiment of a high density connector incorporating features of the present invention.

FIG. 12 is an end view of FIG. 11.

FIG. 13 is a bottom view of the connector shown in FIG. 11.

14 is a perspective view of the insulating housing receiving the separated wafers of FIG. 7; FIG.

FIG. 15 is a partial view of a conductive pad that may be used on a printed circuit board with attached connectors as shown in FIGS. 7-14.

FIG. 16 is a cross-sectional view taken along line 16-16 in FIG. 9.

FIG. 17 is a cross-sectional view taken along line 17-17 in FIG. 9.

FIG. 18 shows a curve of maximum crosstalk in percentage versus pitch to height ratio (P/H) of the connector.

FIG. 19 is a schematic diagram similar to FIG. 12.

Figure 3 illustrates a connector configuration that allows printed circuit boards to be attached in a parallel-column configuration.

FIG. 20 is a schematic diagram similar to FIG. 19.

Figure 3 shows a connector mounting configuration that allows printed circuit boards to be mounted in parallel.

FIG. 21 shows a schematic configuration of the plurality of conductive elements shown in the connectors of FIGS. 7 to 14.

FIG. 22 is a schematic diagram similar to FIG. 21.

Another example is shown.

1-5 illustrate one embodiment of a high-density connector 10, with FIG. 1 being a side view showing various parts of the connector, including a separated wafer 12; In this alternative embodiment, it has a plurality of signal carrying contact elements 14, with a single ground plane element 16 mounted near the aforementioned elements. Each separated wafer 12 is arranged in a parallel stack, with a ground plate element 16 placed between the two separated wafers 12 and the other separated wafer, as best shown in FIG. In this configuration, one individual contact element 14 is contained within the insulating dielectric material of wafer 12 and is surrounded on each side by a ground plane 16 to create a stripline arrangement for each contact element 14.

In the embodiment shown in FIGS. 1 to 5.

Each contact element 14 is fabricated with a 90 degree change in orientation (FIG. 5), and each end of said contact element terminates in a pair of spring wiping fingers 18. Similarly, each plate element 16 is provided with four spring wiping fingers 19 (FIG. 4). The spring fingers 18 and 19 are bent to the right by a certain angle in FIGS. 1, 2, and 4, and the fingers 18 come out from the concave surface 2o of each wafer 12 and bend to the right. Make it possible.

As shown in FIGS. 1 and 3, the rightward deflection of springs 18 and 19 interrupts adjacent spring fingers without interfering with them.

These fingers can fit in parallel stacks of wafers 12 in high density. At the rightmost end of each stack is a spacer 22 followed by a mounting bracket 24.

The ground plate element 16 and the spacer 22 include a recess 23,
It has a shape similar to that of the wafer 12. Now, what is the purpose of the spacer 22 and its recess 23?

It will be appreciated that the purpose is to provide an area into which the spring fingers 18 and 19 can flex when the connector 10 is mated on the printed circuit board.

Mounting bracket 24 on the opposite side of the weber stack
Once added, the assembly is complete.

It is easiest to understand by looking at Figure 4, but wafer 12. Ground plate element 16. Spacers 22 and mounting brackets 24 are assembled into a stack that can be formed to any desired length using a repeated series of parts. These parts have a plurality of openings, including small openings 25 . and a large opening 27 through which the support axle rod 28 passes. Connector 10 is thus stacked with mounting bracket 24 on the left end of the stack, followed by base plate element 16° wafer 12. Then, the base plate element 16 and the shaft rods 26 and 28 are stacked until a predetermined number of wafers and base plate elements are passed through them. It should be noted here that the number of ground plate elements 16 is one more than the number of wafers 12. Then continue the stack with spacer 22,
The spacer 22 is the spring finger 1 for the contact 14.
8 and a recess 23 into which the spring finger 19 for the base plate 16 is inserted. Next element to add to the stack.

This is a second mounting bracket 24. In the embodiment shown in FIGS. 1-3, the stack is typically 12 inches by 172 inches by 172 inches in size. The support shaft rod 28 is.

Screws 30 are threaded into each end, passing through the blind holes in bracket 24 and into the ends of internally threaded axles 28 to hold the 12-inch stack in place and maintain its desired configuration.

In the high-density connector 10 shown in FIGS. 1 to 5, there are four contact elements 14 and their corresponding spring fingers 18 are mounted between two spring fingers 19 associated with the base plate element 16. . This ensures electrical isolation of the four contacts 14.

Now refer to FIG. The figure shows the connector 10, with each bracket 24 having four locating pins 32 extending from two adjacent sides. Attached to the first side is a backplane or motherboard 34 in which locating pins 32 fit into openings 36 in board 34.

A module or daughterboard 38 is mounted at a right angle or 90 degree angle to the motherboard 34, and the daughterboard also has openings 36 for receiving locating pins 32.
There is. Motherboard 34 and daughterboard 38 are attached to connector 10 and retained by suitable fastening means, such as screws 40. As shown on the right side of Figure 5, screw 4
0 passes through boards 34 and 38 and into threaded holes in mounting bracket 34. Further down the stack of connectors 10, contact elements 14 are housed within the wafer 12, as shown on the left side of FIG. The spring fingers 18 of the contact element 14 are pressed against the motherboard 34 and the daughterboard 38 in the recess 20 and make an electrical connection therebetween.

To make the electrical connection, the spring fingers 18 are
Contact a suitable pad 42 as shown in FIG. 6 attached to daughter board 38.

Each individual pad 42 has an opening 44 to make an electrical connection to the opposite side of the daughterboard where it completes the connection with an electrical conductor (not shown). Spring fingers 19 on ground plate element 16 contact a pair of conductive strips 46 on either side of pad 42 .

In the alternative embodiment shown in FIGS. 1-5, the connector 10 includes five brackets 24 and four spacers 22.
．． 204 wafers12. and 208 main plates 14
Consists of a stack of . The reader should note that in the illustrated embodiment, there are four sub-stacks of wafers 12, and therefore there is an additional ground plane 16 in each sub-stack.

You'll remember that there are four additional baseplates across the stack. The configuration shown is.

There are 816 signal contacts made by spring fingers 18 and 416 ground contacts made by fingers 19.

One preferred embodiment of the invention is shown in FIGS. 7-14. As best seen in FIGS. 7 and 8, the 1-separation dielectric wafer 52.

A suitable insulating material 1, for example molded from polysulfone, with individual conductive contact elements 5 on one side as shown in FIG.
4 are attached, and a single ground plate element 56 is attached to the other side as shown in FIG. Each individual signal contact 54 is fabricated with a 90 degree arc and terminates in a spring wiping finger 58 at each end. 9 and 10, spring fingers 58 are shown in a fully compressed state as if pressed against a printed circuit board, such as board 34 or 38. The ground plate element 56 also includes a plurality of spring fingers 59,
The spring fingers 59 have an arrangement interval that is equal to the contact element 5.
4. Coinciding with each individual spring finger 58 from 4.

In a preferred embodiment, contact element 54 and ground plane element 56 may be fabricated from beryllium copper or other suitable alloy.

Dielectric wafer 52 is formed into a hexagonal shape having first and second generally planar surfaces 60 and 62 (FIG. 7).

First surface 60 includes a plurality of grooves 64 into which arcuate contact elements 54 fit, eight grooves being shown in the preferred embodiment of FIG. The two perpendicular edges of surface 60 are removed along these edges to a depth equal to the depth of groove 64 to form recess 66. These recesses 66 are connected to spring fingers 58
provides space for the spring fingers 58 to move when pressed against the printed circuit board. The second side 62 of wafer 52 includes a single recess 68 that receives ground plate element 56 . The recesses 68 extend to the two edges of the hexagonal wafer 52 at 90 degrees to each other so that the spring fingers 59 of the ground plate element 56 are exposed to the opposing fingers 58 of the printed circuit board. Make it.

A comparison of contact 58 in FIG. 9 and contact 59 in FIG. 10 shows that ground plate contact 58 is wider than the other contact 58. This shape allows the narrow spring fingers 58 of the signal carrying contacts 54 to be better shielded by an individual spring finger 59, reducing crosstalk between the fingers 58.

Please refer to FIGS. 11 to 13. It can be seen that separated wafers 52 with contacts 54 and ground planes 56 in place can be stacked in parallel to form high density connectors 50. Groove 64 is formed sufficiently deep within surface 60 of wafer 52 (
Thus, one wafer can be stacked on top of the other without contacting the contact elements 54 with the adjacent base plate 56. However, in the preferred embodiment,
A slotted housing 72 is used to house the 1-separation wafer 52. The housing 72 in FIG. 14 has a cross section of 6
It is rectangular and molded from a suitable insulating material such as polysulfone.

It has a plurality of slots 74 that are open along two end faces that are perpendicular to each other. Slot 74 is for wafer 52
．． The contact element 54 and the ground plate 56 are housed therein. Housing 72 thus forms a first housing for mounting a plurality of wafers 52. Housing 72 is then inserted into elongated opening 76 in second housing 78 . first housing 72 to elongated opening 76
can be inserted by removing the top of the housing 78. However, in the preferred embodiment,
Remove the pie-shaped part 79. spring finger 58
and 59 to avoid damaging the housing 7.
2 into the opening 76 by turning it slightly. By rotating the housing 72, the housing 72 can be fully inserted into the slot 76 so that there is clearance between the contacts 58 and 59 at the left-hand opening of the slot 76. Once the housing 72 is securely in place within the housing slot 76, the wedge member 79 can be returned to its original position and held in place by suitable fastening means 1, such as screws (not shown). can. The second housing 78 includes locating pins 80 and threaded openings 81 for aligning and attaching the connector 50 to appropriate printed circuit boards 82 and 84, as shown in FIG.
Fix with screws 85.

As shown in FIGS. 11 and 13, the stack of wafers 52 has a base plate 56 at the leftmost end of the slot 76 adjacent the housing 72. As shown in FIGS. The base plate is attached to a wafer 52, and a contact element 54 is attached to the next side of this wafer. This alternating stack continues until the rightmost end of slot 76, where the last wafer 52 contains only ground plate 56. In this way, the slot 76 can accommodate 101 wafers 52, and the slot 76 can accommodate 101 wafers 52 therein.
There are 101 sets of contact elements 54 and 101 sets of ground plate elements 56. This configuration is.

A total of 1608 spring finger contacts 54 and 56 are installed. In FIGS. 11 and 13, spring fingers 54 and 56 are shown schematically as mere dots.

A printed circuit board or motherboard 82 is connected to the connector 50.
When pressed against the housing 78 of the contact element 54, the spring finger 58 of the contact element 54 slides over the pad (Fig. 15).
, are electrically connected to the board 82. Similarly, the ground plate element 5
The spring finger 59 of 6 is connected to the conductive strip 88
It completes the stripline circuit formed by the contact element 54 and the ground plane element 56 sliding over and surrounding it.

As shown in FIG. 16, the cross-section of the stripline connection formed by the ground plane elements 56 on both sides of the contact element 54 is formed by parallel ground planes 56 equidistant from the contact 54. The main plate 56 is separated by a distance rb and has a width ry.
,, the contact element 54 having a thickness "t" is connected to the base plate 56 by rH,
There is a distance of Finally, the contacts 54 are arranged at intervals of Pj. The impedance ZO of each contact 54 can be expressed by the following equation.

Z□=60 1n 4b e, 0.67(0,8y + t)In the formula,
b = height.

t = Thickness of conductor.

W = Width of conductor.

er = Relative dielectric constant of insulating material.

In = natural logarithm.

From the above equation, it can be seen that there are four values that can be adjusted to tune and control the impedance of the connector. They are.

These are the dielectric constant of the insulating material forming the wafer 52, the width and thickness of the contact 54, and the height between the ground Fi 56 and the contact 54. By adjusting one or all of these values, the impedance of each contact element 54 can be set to a constant value 9, for example 60 ohms, regardless of the length of the contact element.

Crosstalk within connector 50 is achieved through spring fingers 59 that are thicker than spring fingers 58 for each contact 54.
can be reduced by using for each plate 56. This configuration is shown in FIG. Crosstalk can be reduced by adjusting the ratio of the distances between two adjacent contact elements 54, or the pitch "Pj, in proportion to the height 'HJ of the contacts 54 above the ground plane 56.

The relationship between the crosstalk reduction expressed as a percentage and the pitch to height ratio (P/)I) is shown in FIG.

By adjusting the pitch of the contact elements 54 or adjusting the equidistant placement of these contacts from the ground plane 56, crosstalk can be significantly reduced, as shown by the curves in FIG.

A preferred embodiment is as shown in FIG.

Although the daughter board 84 is mounted at right angles to the motherboard 82, the connector 50 and its housing 78 are modified so that the contacts 54 extend in a 180 degree arc to connect the two boards 82, as shown in FIG. and 8
4 can also be in a parallel-column configuration. Additionally, the connector 50 and its housing 78 may be modified to provide a linear configuration of the contacts, with the two boards 82 and 84 parallel, one on top of the other, as shown in FIG. You can also do it. The preferred embodiment also shows that spring fingers 58 from contact element 54 are mounted in alternating rows with fingers 59 from ground plate element 56. Such a configuration is schematically shown in FIG. However, in some embodiments, it may be desirable to have the spring fingers 58 adjacent and parallel and separated by a pair of ground plate elements 56. This configuration is used in the 22nd
As shown in the figure. This configuration can be easily achieved by the present invention.

Upon consideration of the above specification and accompanying drawings.

Other modifications of the invention will be apparent to those skilled in the art. Accordingly, the invention is limited only by the scope of the appended claims.

[Brief explanation of drawings]

1 is a side view of an alternative embodiment of a high density connector according to the present invention; FIG. 2 is an end view of FIG. 1; FIG. 3 is a bottom view of FIG. 1; and FIG. An exploded perspective view of the connector illustrated in FIGS. 1 to 3;
Figure 5 is a cross-sectional view of a high-density connector with four daughter boards attached to one motherboard, and Figure 6 is a cross-sectional view of a high-density connector with four daughter boards attached to one motherboard.
FIG. 7 shows a typical arrangement for conductive pads that may be used on a motherboard or daughterboard fitted with the connectors shown in FIGS. 5-5. A perspective view of a dielectric isolation wafer used in one preferred embodiment of the present invention, FIG.
A cross-sectional view along FIG. FIGS. 7 and 8 are cross-sectional views of high-density connectors using the wafers shown in FIGS. 7 and 8, FIG. 10 is a cross-sectional view of the second side of the wafer shown in FIG. 12 is an end view of FIG. 11, and FIG. 13 is a bottom view of the connector shown in FIG. 11, illustrating a preferred embodiment of the high density connector with features; Figure 14 shows
FIG. 15 is a partial view of a conductive pad that may be used on a printed circuit board with attached connectors as shown in FIGS. 7-14; Figure 16 is the straight line 16-16 in Figure 9.
17 is a cross-sectional view taken along line 17-17 in FIG.
18 shows the curve of the maximum crosstalk in percentage and the ratio of pitch to height (P/H) of the connector; FIG. 19 shows the curve of the printed circuit board parallel to - The first diagram shows the configuration of connectors that can be installed in a row configuration.
20 is a schematic diagram similar to FIG. 19 showing a connector mounting configuration in which printed circuit boards can be mounted in parallel; FIG. 21 is a schematic diagram similar to FIG.
FIG. 22, which is a diagram showing a schematic configuration of a plurality of conductive elements shown in the connector shown in FIG. 4, is a schematic diagram similar to FIG. 21 showing another embodiment. 10... High-density connector, 12... Separated wafer,
14... Contact element, 16... Ground plate element, 18.19
...Spring finger, 22...Spacer, 2
4...Mounting bracket, 26...Axle rod, 28
...Support shaft rod, 52...Separated dielectric wafer, 54.
...Conductive contact element, 56... Ground plate element, 58.59.
... Spring finger, 72 ... Housing, 7
4...Slot. lftg, γ ゝnoseehaΦ θ Nail, introduction 3Itg, If P/H smutllt13.21

Claims (1)

[Claims] (1) A plurality of separate insulating wafers, a plurality of first conductive elements for transmitting electrical signals attached to each wafer so as to be protected, and a plurality of first conductive elements attached to each wafer so as to be protected; a single second conductive element for electrical grounding, the plurality of separated wafers being mounted in a stack, with each single second conductive element attached by each wafer within the stack; A controlled impedance high-density electrical connector characterized in that elements are attached to opposite sides of the first plurality of conductive elements to form a stripline connection in a high-density stack. (2), wherein said wafer is dielectric, said plurality of first electrically conductive elements are mounted with each wafer, and said single second electrically conductive element is mounted adjacent to each wafer; High-density electrical connectors in item 1 of the range. (3) said wafer is dielectric, each having a first and second side, said plurality of first conductive elements being attached to said first side of said wafer; said single second conductive element on said second conductive element of said wafer;
A high-density electrical connector according to claim 1 attached to the surface of the claim 1. (4) said wafer has a plurality of grooves on said first side, said first conductive elements being mounted therein; and said wafer has a plurality of grooves on said second side; 4. The high density electrical connector of claim 3 having a single recess within which said second conductive element is mounted. (5) having a first insulating housing with a plurality of slots therein, each slot housing said wafer and said first and second conductive elements to form an elongated stack; A high density electrical connector according to claim 1. (6) a second housing having a line-elongated opening therein to house the first insulating housing, and the second housing housing the first printed circuit board; 2. The high density electrical connector of claim 1, further comprising means for attaching to a second printed circuit board. (7) the high-density electrical connector of claim 6, wherein said second housing mounts said first printed circuit board and said second printed circuit board at a 90 degree angle to each other; . (8) The high density electrical connector of claim 6, wherein said second housing mounts said first printed circuit board and said second printed circuit board parallel to each other. (9) the high-density electrical connector of claim 6, wherein said second housing mounts said first printed circuit board and said second printed circuit board parallel to each other and in the same plane; . 10. The high-density electrical connector of claim 1 having axial rod means extending through said wafer and retaining said wafer and said first and second conductive elements in said stack. (11), first and second with conductive pads on the surface
a printed circuit board, said first and second electrically conductive elements each having spring means for contacting said electrically conductive pads, mounting bracket means and spacer means, said wafer mounted on said wafer; 2. The high density electrical connector of claim 1, wherein the stack of first and second conductive elements includes mounting bracket means and spacer means as described above. (2) said stack is in turn arranged with a selected number of second wafers, one on top of the other, with mounting bracket means, spacer means, and a selected number of wafers having said first conductive elements mounted thereon; electrically conductive elements, and mounting bracket means, in said stack having one more second electrically conductive element than said wafers, and including axle means for holding said stack in said stack in said stack; A high density electrical connector according to claim 11. (13) wherein said mounting bracket means mounts said first and second printed circuit boards to each other at a desired angle, said spring means contacting said conductive pads. High density electrical connector. (14), first and second with conductive pads on the surface
a printed circuit board, each of said first and second electrically conductive elements having spring means for contacting said electrically conductive pad, said spring means on said first electrically conductive element being , having a narrower width than said spring means on said second conductive element to reduce crosstalk between said first element.