Feinmetall Exhibit 2002
`FormFactor, Inc. v. Feinmetall, GmbH
`IPR2019-00082
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`Page 1 of 9
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`US. Patent
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`Feb. 28, 1978
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`Sheet 1 of 3
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`4,076,356
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`US. Patent
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`Feb. 28, 1978
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`Sheet 2 of3
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`4,076,356
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`FIG. 7
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`US. Patent
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`Feb. 28, 1978
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`Sheet 3 of 3
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`4,076,356
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`1
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`4,076,356
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`2
`ery. First and second terminals are included on opposite
`ends of the connector for receiving electrically conduc-
`tive elements. Intermediate the first and second termi-
`nals is a unitary compliant section for producing a
`nearly uniform radial pressure on the electrically con-
`ductive material on the periphery of the aperture upon
`insertion of the connector. Integral with the unitary
`compliant section are raised pressure members for en-
`gaging the conductive material about the aperture pe-
`riphery at a plurality of discrete radial points.
`Accordingly, it is one feature of the present invention
`that the raised pressure members penetrate the conduc-
`tive material about the aperture periphery to ensure a
`reliable connection.
`
`Another feature is that the raised pressure members
`displace portions of the conductive material thereby
`reducing the production of conductive slivers.
`Yet another feature of the present invention is that
`the unitary compliant section produces a nearly uniform
`radial pressure on the aperture periphery upon insertion
`of the connector into the aperture.
`A further feature is that engagement between the
`raised pressure members and the aperture periphery
`impede connector rotation as electrical connections are
`made to the first and second receiving terminals.-
`Still a further feature of the present invention is that
`the raised pressure members permit the passage of flux
`and solder between the compliant section and the con-
`ductive material on the aperture periphery.
`An even further feature is that the compliant section
`can be advantageously segmented into a plurality of
`semiseparable sections to permit axial stacking of a
`plurality of printed circuit boards wherein each section
`engages an individual board.
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`The aforementioned objects and features of the in- '
`vention, as well as other objects and features, will be
`better understood upon consideration of the following
`detailed description and appended claims taken in con-
`junction with the attached drawings of an illustrative
`embodiment in which:
`
`FIG. 1 is a perspective view of a connector having a
`single compliant central section;
`FIG. 2 illustrates the connector in engagement with a
`circuit board;
`FIG. 3 is a side view of an unformed connector;
`FIG. 4 is a cross-sectional view along section 4—4 of
`FIG. 3;
`FIG. 5 is a cross‘sectional view of the compliant
`section wherein the pressure ridges are raised semicir-
`cular beads;
`FIG. 6 is similar to FIG. 5 except the pressure ridges
`have a rectangular cross section;
`FIG. 7 is similar to FIG. 5 except the cross section
`has generally piecewise linear inner and outer surfaces;
`FIG. 8 is similar to FIG. 7 except the pressure ridges
`have a generally triangular-shaped cross section;
`FIG. 9 is a perspective view similar to FIG. 1 illus-
`trating the sectioning of the compliant portion to form
`semiseparate segments;
`FIG. 10 is a side View of an unformed connector
`shown in FIG. 9; and
`FIG. 11 illustrates stacking of two circuit boards with
`the connector illustrated in FIG. 9.
`
`INTERCONNECI‘ION PIN FOR MULTILAYER
`PRINTED CIRCUIT BOARDS
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`5
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`10
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`BACKGROUND OF THE INVENTION
`1. Field of the Invention
`This invention relates to electrical connectors and, in
`particular, to a connector for electrically interconnect-
`ing multiple conductive layers in a printed circuit board
`and a method for making such a connector.
`2. Description of the Prior Art
`Current objectives in circuit design include a de-
`crease in overall physical size with a concurrent in-
`crease in component density on a printed circuit board.
`To meet these objectives more and more circuit design- 15
`ers are utilizing multilayer printed circuit boards.
`One of the problems encountered in the use of multi-
`layered boards is the electrical interconnection of the
`various conductive layers within the board at appropri-
`ate points. Another problem is the interconnection of 20
`discrete components or connectors to the circuit board.
`A third problem relates to the effectiveness of the inter
`connection device in maintaining a reliable, gastight
`connection during the life of the circuit.
`Connectors which alleviate to some extent the first 25
`two problems have been disclosed in U.S. Pat. No.
`3,400,358 issued to H. P. Byrnes et al on Sept. 3, 1968;
`U.S. Pat. No. 3,783,433 issued to H. N. Kurtz et al on
`Jan. 1, 1974; and U.S. Pat. No. 3,907,400 issued to R. K.
`Dennis on Sept. 23, 1975. However, none of these con- 30
`nectors adequately solves the third problem. In particu-
`lar, insertion of any of these types of connectors into a
`plated-through hole in the multilayer board, especially
`where the plating is covered by oxides or other contam-
`inants, does not ensure a reliable connection.
`In some circuit applications it may be desirable to
`axially stack a number of multilayer boards atop one
`another to further increase the packaging density. Fab-
`rication of a single multilayer board with an equivalent
`number of layers is often provided by cost and reliabil- 40
`ity considerations. Consequently, stacking is utilized.
`While the concept of stacking is known, as evidenced
`by U.S. Pat.vNo. 3,893,233 issued to D. W. Glover on
`July 8, 1975, the reliability problem set out previously is
`not alleviated.
`'
`Accordingly, it is one object of the present invention
`to configure a connector which advantageously ensures
`a reliable connection to oxide coated or contaminated
`conductive platings.
`Another object is to diminish the production of con- 50
`ductive slivers during connector insertion.
`A further object of the present invention is to provide
`a connector which produces a nearly uniform radial
`pressure on conductive material on the periphery of a
`plated-through hole upon insertion of the connector.
`Yet another object is to reduce the possibility of con-
`nector rotation during wire-wrapping operations.
`Still a further object of the present invention is to
`facilitate axial stacking of a plurality of printed circuit
`boards with each board engaging a semiseparate seg- 60
`ment of a connector.
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`SUMMARY OF THE INVENTION
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`The foregoing and other objects of the invention are
`realized in an illustrative embodiment of a connector for 65
`electrically interconnecting multiple conductive layers
`in a printed circuit board having at least one aperture
`with electrically conductive material about its periph-
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`3
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`DETAILED DESCRIPTION
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`4,076,356
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`An interconnection pin 100, illustrated in FIG. 1,
`includes a compliant section 101 and a pair of terminals
`102 and 103 integral therewith and extending outwardly
`in opposite directions. Terminals 102 and 103 are elon-
`gated members having a generally rectangular cross
`section. This cross section advantageously permits elec-
`trically conductive elements to be connected to termi-
`nals 102 and 103 by techniques such as wire wrapping
`for example. Generally tetrahedron-shaped tips 104 and
`105 at the ends of terminals 102 and 103, respectively,
`facilitate insertion of pin 100 into an aperture 107 in a
`circuit board 108, as shown in FIG. 2.
`Compliant section 101 includes a generally rectangu-
`lar-shaped central portion 109, as shown in its unformed
`state in FIG. 3, which is integrally coupled to terminals
`102 and 103 by tapered cross sections 110 and 111,
`respectively. Tapered cross section 110 decreases in
`width from central portion 109 to terminal 103. Corre-
`spondingly,
`tapered cross section 111 decreases in
`width from central portion 109 to terminal 102. Central
`portion 109 has a nonuniform thickness between an
`inner surface 112 and an outer surface 113 as shown in
`FIG. 4. This nonuniform thickness varies from a mini-
`mum near tips, 114 and 115 to a maximum in central
`region 116.
`.
`In its formed state, compliant section 101 has a gener-
`ally cuplike-shaped cross section, as illustrated in FIGS.
`5 through 8, which lies in a plane perpendicular to a
`plane containing an axis of symmetry of pin 100. The
`diameter of the cuplike-shaped cross section is slightly
`larger than the diameter of aperture 107 and is substan-
`tially larger than a width dimension of a side face 106 of
`terminal 102 as shown in FIG. 1. With the thickness and
`cross sectional dimensions as described, compliant sec-
`tion 101 produces a nearly uniform radial pressure on
`conductive material 118 about the periphery of aperture
`107, as shown in FIG. 2, when pm 100 is brought into
`engagement with circuit board 108.
`Along outer edge 133 of central portion 109 and
`integral
`therewith are a plurality of raised pressure
`ridges 120. Pressure ridges 120 are generally parallel
`with an axis of symmetry of pin 100, as shown in FIG.
`3. Upon insertion of pin 100 into aperture 107, pressure
`ridges 120 engage conductive material 118 at a plurality
`of discrete radial points. As this engagement
`takes
`place, pressure ridges 120 break up any oxides formed
`on conductive material 118 and displace portions of this
`material thereby reducing the production of conductive
`slivers as pin 100 is further inserted into aperture 107.
`Pressure ridges 120 further permit passage of flux and
`solder between compliant section 101 and the periphery
`of conductive material 118 about the periphery of aper-
`ture 107. It should be noted also that pressure ridges 120
`impede the rotation of pins 100 as a wire-wrapped con-
`nection is made with terminals 102 and 103.
`In one embodiment of pin 100, compliant section 101
`has a generally crescent-shaped cross section, as shown
`in FIG. 5, the thickness of which is smallest near tips
`114 and 115 and largest at a midpoint between the two
`tips. The pressure ridges 120 in this embodiment are
`comprised of projections having a single, generally
`semicircular face 121. In another embodiment, shown in
`FIG. 6, pressure ridges 120 may be advantageously
`comprised of generally rectangular projections having
`first, second, and third faces 122, 123 and 124, respec-
`tively, first and third faces 122 and 124 being spaced
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`apart and generally parallel with one another, while
`second face 123 is generally perpendicular to first and
`third faces 122 and 124.
`Further embodiments of compliant section 101 are
`shown in FIGS. 7 and 8. In these embodiments the
`cuplike-shaped cross section has generally polygonal~
`shaped inner and outer surfaces 112 and 113. Pressure
`ridges 120 for these two embodiments are formed by
`first and second faces 126 and 127 oriented at an angle
`between 90° and 150" with respect to one another.
`In applications where it is desirable to stack circuit
`boards 108 atop one another, pin 100 has its compliant
`section 101 segmented into a plurality of semiseparate
`sections 130 and 131, for example, as shown in FIGS. 9
`and 10. Each section engages a separate circuit board
`108 in an axially aligned stack of such boards as illus-
`trated in FIG. 11. Segmentation of compliant section
`101 into the plurality of semiseparate sections 130 and
`131 is effected by one or more pairs of oppositely di-
`rected notches 132. Notches 132 extend from edges 133
`and 134 of central portion 109 to intermediate points
`135 and 136, respectively. Notches 132 are oriented at
`an angle between 30° and 90° with respect to the axis of
`symmetry of pin 100.
`Pressure ridges 120 on sections 130 and 131, in these
`embodiments of pin 100 are radially offset from one
`another. This radial offset of pressure ridges 120 ensures
`that sections 130 and 131 will engage virgin conductive
`material 118 in aperture 107 as pin 100 passes through
`circuit boards 108 in an axial stack of boards. Conse-
`
`quently, all the advantages attributed to pressure ridges
`120 resulting from their engagement with conductive
`material 118 at the periphery of aperture 107 in a single
`circuit board 108 are equally applicable to any addi-
`tional boards 108 when a stack of such boards are to be
`interconnected.
`A number of methods for fabricating a connector as
`described above may be advantageously utilized. One
`such method includes the steps of stamping a sheet of
`electrically conductive material to form first and second
`elongated terminals 102 and 103 with generally rectan-
`gular-shaped central portion 109 intermediate terminals
`102 and 103. Central portion 109 is then swaged to
`produce a nonuniform thickness wherein the thickness
`along outer edges 133 and 134 of the central portion 109
`is less than the thickness through central region 116.
`Central portion 109 is then coined to produce the
`plurality of generally parallel pressure ridges 120. It
`should be noted that pressure ridges 120 produced by
`this operation are to be generally parallel with an axis of
`symmetry which passes through terminals 102 and 103
`of pin 100. At the end of these three steps pin 100 has a
`shape as illustrated in either FIG. 3 or FIG. 10, depend-
`ing upon whether pin 100 is to be used for a single board
`application or the stacking of two or more boards 108.
`Central portion 109 is then cupped to impart the gener-
`ally cuplike-shaped cross section to compliant section
`101 when the latter is viewed in a plane generally per-
`pendicular to the axis of symmetry of pin 100. Finally,
`the distant ends of terminals 102 and 103 are coined to
`produce the generally tetrahedron-shaped tips 104 and
`105 used to facilitate insertion of pin 100 into aperture
`107 of circuit board 108.
`Another method which may be utilized to fabricate
`pin 100 entails the extrusion of central portion 109 pro-
`duced by the stamping operation to impart to it the
`generally cuplike—shaped cross section. In the extrusion
`operation the cuplike-shaped cross section is given a
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`5
`nonuniform thickness and pressure ridges 120 are
`formed directly on outer surface 113 of compliant sec—
`tion 101. The extrusion step in this method of fabrica-
`tion replaces the swaging, coining, and cupping opera—
`tions of the previously described method. As with the
`first method, the distant ends of terminals 102 and 103
`are coined to produce the tetrahedron-shaped tips 104
`and 105.
`
`Still another method of fabricating pin 100 employs
`the stamping operation of the first two methods. How-
`eVer, in this method of fabrication, swaging is utilized to
`prodUce the nonuniform thickness of the pressure ridges
`120. The swaged central portion 109 is then formed to
`impart the generally cuplike-shaped cross section. As
`before, the tetrahedron-shaped tips 104 and 105 are
`produced by coining the distant ends of terminals 102
`and 103.
`In all cases, it is to be understood that the above-
`described embodiments are illustrative of but a small
`
`number of many possible specific embodiments which
`can represent applications of the principles of the inven-
`tion. Thus, numerous and various other embodiments
`can readily be devised in accordance with these princi-
`ples by those skilled in the art without departing from
`the ‘spirit and scope of the invention.
`What is claimed is:
`1. A connector for electrically interconnecting multi-
`ple conductive layers in a circuit board having at least
`one aperture therein with electrically conductive mate—
`rial about its periphery including
`first and second means for receiving electrically con-
`ductive elements,
`unitary compliant means, intermediate said first and
`second means and gradually increasing in cross-
`sectional thickness from a first end point to a mid-
`point and thereafter gradually decreasing in cross—
`sectional thickness from said midpoint to a second
`end point, for producing a nearly uniform radial
`pressure on said electrically conductive material on
`the periphery of said aperture upon the insertion of
`said connector into said aperture,
`means,
`integral with and abruptly increasing the
`cross-sectional thickness of an intermediate region
`along the length of said unitary compliant means at
`a plurality of discrete radial points, for engaging
`said conductive material about said aperture pe-
`riphery at said plurality of discrete radial points,
`means, integral with said unitary compliant means,
`for segmenting said compliant means into a plural-
`ity of semiseparate segments, each of said segments
`engageable with a separate circuit board in an axi—
`ally assigned stack of such boards, and
`said engaging means on each of said segments are
`radially offset from one another.
`2. The connector in accordance with claim 1 wherein
`each of said first and second means includes
`
`an elongated member having a generally rectangular
`cross section, and
`a generally tetrahedron-shaped tip at an end point of
`said elongated member for facilitating insertion of
`said connector into said aperture.
`3. The connector in accordance with claim 2 wherein
`said engaging means, integral with said unitary com-
`pliant means, break up any oxides formed on said
`electrically conductive material on said aperture
`periphery and displace portions of said conductive
`material thereby reducing the production of con-
`ductive slivers as said connector is inserted into
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`4,076,356
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`6
`said aperture, permit passage of flux and solder
`between said compliant means and said electrically
`conductive material on said aperture periphery,
`and impede rotation of said connector as a wire-
`wrapped connection is made with said elongated
`member.
`4. The connector in accordance with claim 2 wherein
`said unitary compliant means includes
`a central section having a diameter slightly larger
`than a diameter of said aperture and substantially
`larger than a width dimension of a side face of said
`elongated member, said central section having a
`generally cuplike-shaped cross section lying in a
`plane perpendicular to a plane containing an axis of
`symmetry of said connector, said cuplike-shaped
`cross section having a nonuniform thickness be-
`tween an inner surface and an outer surface, and
`first and second spaced apart end sections having
`tapered cross sections coupling said central section
`to said first and second means.
`5. The connector in accordance with claim 4 wherein
`said segmenting means includes
`at least one pair of oppositely directed notches ex-
`tending from end points of said cuplike-shaped
`cross section to intermediate points in said unitary
`compliant means, said notches oriented at a prede-
`termined angle with respect to said axis of symme-
`try of said connector.
`6. The connector in accordance with claim 4 wherein
`said cuplike-shaped cross section has a generally po-
`lygonal-shaped outer surface.
`7. The connector in accordance with claim 1 wherein
`said engaging means comprises
`a ridge having first and second face oriented at an
`angle between 90 degrees and 150 degrees with
`respect to one another.
`8. The connector in accordance with claim 1 wherein
`said engaging means comprises
`a projection having first, second, and third faces, said
`first and third faces being spaced apart and gener-
`ally parallel with one another and said second face
`is generally perpendicular to said first and third
`faces.
`9. The connector in accordance with claim 1 wherein
`said engaging means comprises
`a projection having a single generally semicircular
`face.
`10. A connector for electrically interconnecting mul-
`tiple conductive layers in a circuit board having at least
`one aperture therein with electrically conductive mate-
`rial about its periphery comprising
`first and second end portions for receiving electri-
`cally conductive elements,
`a compliant portion intermediate Said first and second
`end portions, said compliant portion having a gen-
`erally cuplike-shaped cross section lying in a plane
`perpendicular to a plane containing an axis of sym-
`metry of said connector, said cuplike—shaped cross
`section having a gradually increasing cross-sec-
`tional thickness from a first end point to a midpoint
`and thereafter having a gradually decreasing cross-
`sectional thickness from said midpoint to a second
`end point, said compliant portion further including
`at least one pair of oppositely directed notches
`extending from end points of said cuplike-shaped
`cross section to intermediate points in said compli-
`ant portion, said notches oriented at a predeter-
`mined angle with respect to said axis of symmetry
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`7
`of said connector and separating said compliant
`portion into at
`least two semiseparate segments
`each of which is engageable with a separate circuit
`board in an axially aligned stack of such boards,
`and
`
`a plurality of generally parallel pressure ridges on an
`outer surface of an intermediate region along the
`length of said compliant portion, said pressure
`ridges abruptly increasing the cross-sectional thick-
`ness of said compliant portion at a plurality of dis-
`crete radial points, for engaging said conductive
`material about said aperture periphery at said plu-
`rality of discrete radial points, said pressure ridges
`being generally parallel with an axis of symmetry
`of said connector.
`11. The connector in accordance with claim 10
`wherein each of said first and second end portions in-
`cludes
`
`an elongated member having a generally rectangular
`cross section, and
`a generally tetrahedron-shaped tip at an end point of
`said elongated member for facilitating insertion of
`said connector into said aperture.
`12. The connector in accordance with claim 11
`wherein said compliant portion includes
`a central section having a diameter slightly larger
`than a diameter of said aperture and substantially
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`8
`larger than a width dimension of a side face of said
`elongated member, and
`first and second spaced apart end sections having
`tapered cross sections coupling said central section
`to said first and second end portions.
`13. The connector in accordance with claim 10
`wherein
`
`said pressure ridges on each of said semiseparate
`segments are radially offset from one another.
`14. The connector in accordance with claim 10
`wherein said pressure ridges include
`projections having first and second faces oriented at
`an angle between 90° and 150" with respect to one
`another.
`.
`15. The connector in accordance with claim 10
`wherein said pressure ridges include
`projections having first, second, and third faces, said
`first and third faces being spaced apart and gener-
`ally parallel with one another and said second face
`is generally perpendicular to said first and third
`faces.
`16. The connector in accordance with claim 10
`wherein said pressure ridges include
`projections having a single generally semicircular
`face.
`17. The connector in accordance with claim 10
`wherein
`
`said cuplike-shaped cross section has a generally po-
`lygonal-shaped outer surface.
`*
`It
`i
`I!
`#
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`UNITED STATES PATENT AND TRADEMARK OFFICE
`
`CERTIFICATE OF CORRECTION
`
`PKENTNO.
`
`:
`
`4,076,356
`
`DATED
`
`: February 28, 1978
`
`INVENTOHS): Peter J. Tamburro
`
`[SEAL]
`
`It is certified that error appears in the above—identified patent and that said Letters Patent
`mehembyconededasshownbmow:
`
`line 40, "provided" should read ——prohibited--.
`Column 1,
`Column 2,
`line 20, "produces" should read -—provides——.
`Column 4,
`line 28, between "will" and "engage“ insert
`——each-—;
`line 31, between "advantages" and "attributed"
`insert --previously-—.
`
`gigncd and Scaled this
`
`Twentieth Day of
`
`June 1978
`
`RUTH C. MASON
`
`DONALD W. BANNER
`
`Arresting Oflicer
`
`Commissioner of Patents and Trademarks
`
`_
`
`r t l I l
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