CA1295426C - Process for obtaining electrical interconnect using a solderable mechanical fastener - Google Patents
Process for obtaining electrical interconnect using a solderable mechanical fastenerInfo
- Publication number
- CA1295426C CA1295426C CA000592015A CA592015A CA1295426C CA 1295426 C CA1295426 C CA 1295426C CA 000592015 A CA000592015 A CA 000592015A CA 592015 A CA592015 A CA 592015A CA 1295426 C CA1295426 C CA 1295426C
- Authority
- CA
- Canada
- Prior art keywords
- eyelet
- circuit board
- conductive layer
- printed circuit
- hole
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
- H01R12/00—Structural associations of a plurality of mutually-insulated electrical connecting elements, specially adapted for printed circuits, e.g. printed circuit boards [PCB], flat or ribbon cables, or like generally planar structures, e.g. terminal strips, terminal blocks; Coupling devices specially adapted for printed circuits, flat or ribbon cables, or like generally planar structures; Terminals specially adapted for contact with, or insertion into, printed circuits, flat or ribbon cables, or like generally planar structures
- H01R12/50—Fixed connections
- H01R12/51—Fixed connections for rigid printed circuits or like structures
- H01R12/52—Fixed connections for rigid printed circuits or like structures connecting to other rigid printed circuits or like structures
- H01R12/526—Fixed connections for rigid printed circuits or like structures connecting to other rigid printed circuits or like structures the printed circuits being on the same board
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K3/00—Apparatus or processes for manufacturing printed circuits
- H05K3/40—Forming printed elements for providing electric connections to or between printed circuits
- H05K3/4038—Through-connections; Vertical interconnect access [VIA] connections
- H05K3/4046—Through-connections; Vertical interconnect access [VIA] connections using auxiliary conductive elements, e.g. metallic spheres, eyelets, pieces of wire
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
- H05K2201/10—Details of components or other objects attached to or integrated in a printed circuit board
- H05K2201/10227—Other objects, e.g. metallic pieces
- H05K2201/10401—Eyelets, i.e. rings inserted into a hole through a circuit board
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K3/00—Apparatus or processes for manufacturing printed circuits
- H05K3/30—Assembling printed circuits with electric components, e.g. with resistor
- H05K3/32—Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits
- H05K3/34—Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits by soldering
- H05K3/3447—Lead-in-hole components
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49002—Electrical device making
- Y10T29/49117—Conductor or circuit manufacturing
- Y10T29/49124—On flat or curved insulated base, e.g., printed circuit, etc.
- Y10T29/49147—Assembling terminal to base
- Y10T29/49149—Assembling terminal to base by metal fusion bonding
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Printing Elements For Providing Electric Connections Between Printed Circuits (AREA)
- Combinations Of Printed Boards (AREA)
- Structures For Mounting Electric Components On Printed Circuit Boards (AREA)
- Structure Of Printed Boards (AREA)
Abstract
Abstract A method for providing an electrical connection (via) between the top and bottom of a printed circuit board (PCB) is presented. An eyelet extends through a hole in the PCB. The top Or the PCB has a first conductive layer.
Around the hole the first conductive layer is shaped such that a conductive pad is isolated from the rest of the first conductive layer, except that spokes of the first conductive layer extend from the conductive pad to the reset of the first conductive layer. The eyelet is crimped such that crimped fingers or tabs of the eyelet cause the eyelet to be mechanically retained in the hole. The tabs are curved so that the tabs do not lie flat upon the conductive pad. The bottom Or the PCB is then wave soldered so that a base of the eyelet is electrically coupled to a conductive layer on the bottom of the PCB and the tabs are electrically coupled to the conductive pad.
Around the hole the first conductive layer is shaped such that a conductive pad is isolated from the rest of the first conductive layer, except that spokes of the first conductive layer extend from the conductive pad to the reset of the first conductive layer. The eyelet is crimped such that crimped fingers or tabs of the eyelet cause the eyelet to be mechanically retained in the hole. The tabs are curved so that the tabs do not lie flat upon the conductive pad. The bottom Or the PCB is then wave soldered so that a base of the eyelet is electrically coupled to a conductive layer on the bottom of the PCB and the tabs are electrically coupled to the conductive pad.
Description
SOLDERABLE MECHANICAL FASTEN~R
Back~round The present lnvention ha~ to do with providing an electrical lnterconnect between the bottom and the top of a prlnted circuit board (PCB). Such a connection 19 called a via.
There are various method~ for providing an electrical connection between the bottom and top Or a PCB in the prior art. For in~tance, plated througb holes provide an efrective via; however, thi-~ method Or providing via~ i3 relatively expensive. Similarly the insertion of a wire ~umper through two hole~ in a PCB and soldering the wire to the board on both the top and bottom sldes is an errective but expensive method Or providing vla. The wire Jumper lnsertion method requires hand ~oldering Or the PCB and i~
thererore co~tly and time consuming.
Eyelet~ have been used in the prlor art. For lnstance metal eyelets may be ~waget lnto a hole ln a PCB.
Sometimes a ¢omponent lead 19 lnserted through the eyelet berore soldering. For a conventlonal eyelet the top slde Or the PC8 mu~t be soldered ln a separate operatlon lf a reliable connectlon through the PCB 19 deslred.
Slmilarly, commercially available "~older-through"
eyelets, that 19 special eyelet~ which utllize capillary actlon to carry molten solder rrom the bottom slde Or a PCB
to the top slde, allow the solderlng of both ~ides of an ': ~
: , . :
' ~29$~
eyelet in a single operation. Component leads are inserted through these eyelets before soldering. The eyelet serves the purpo~e Or strengthenlng the mechanical connection Or the component to the PCB.
The ma~or drawback Or using eyelet3 ror vias in the prior art ha3 been the inabllity to provide a reliable electrical Jolnt. Thermal expanslon due to temperature cycling orten causea ~oints to crack resultlng in electrical failure.
SummarY Or the Invention In accordance with the preferred embodiment of the present in~ention a method for providing vlas between the top and bottom of a two-layered printed circuit board (PCB) is presented. An eyelet extends through a hole in the PC3. The top Or the PCB ha~ a rlrat conductive layer.
Around the hole the rirst contuctive layer l~ 3haped such that a conductlve pad ia thermally isolated rrom the rest Or the rirat conductive layer, except that spokes Or the-rirst conductive layer extend rrom the conductive pad to the rest Or the rirst conductive layer. The thermal iaolation Or the ¢onductive pads alds in heat retention during 301dering. The eyelet i9 crimped such that crimped rlngers or tabs Or the eyelet ¢ause the eyelet to be mechanically retained in the hole. The tabs are curved so that the tabs do not lie ~lat upon the conductiYe pad. The bottom Or the PCB is then wave soldered 90 that a base Or the eyelet is electrically coupled to a second conductlve `~ 12954'~i layer on the bottom of the PCB and the tabs are electrically coupled to the conductive pad on the first conductive layer.
Various other aspects of this invention are as follows:
A method for providing an electrical connection between a bottom and a top of a printed circuit board, the method comprising the steps of:
(a) isolating a first portion of conductive layer on top of the printed circuit board and around a hole in the printed circuit board, so that when soldering, heat may be conserved in the first portion;
(b) inserting an eyelet through the hole:
(c) crimping the eyelet so that tabs of the eyelet cause the eyelet to be mechanically retained in the hole and so capillary solder paths to the copper pad are formed; and (d) wave soldering the bottom of the printed circuit board.
A method for providing an electrical connection between a bottom and a top of a printed circuit board, the method comprising the steps of:
(a) creating a hole in the printed circuit board;
(b) inserting an eyelet through the hole;
(c) crimping the eyelet so that tabs of the eyelet cause the eyelet to be mechanically retained in the hole, so that the tabs are curved and so that the tabs do not lie flat upon the first portion of the conductive layer; and (d) wave soldering the bottom of the printed circuit board.
An electrical connector which provides electrical coupling between a bottom and a top of a printed circuit 1'~9~26 3a board, the printed circuit board having a first conductive layer on top of the printed circuit board, a second conductive layer on bottom of the printed circuit board and a hole which extends to the bottom of the printed circuit board to the top of the printed circuit board, the electrical connector comprising:
a first portion of the first conductive layer coupled to the rest of the first conductive layer through a plurality of conductive spokes, wherein the first~portion surrounds the hole;
a hollow eyelet having a middle region positioned substantially within the hole in the printed circuit board, t~e middle region having a hollow section extending the~.length of the hole in the printed circuit board, a base, coupled to the middle region and extending out the bottom of the printed circuit board, the base being shaped in such a way that it does not fit into the hole, and a plurality of tabs coupled to the middle region and extending out the top of the printed circuit board, the tabs extending from the middle region and curving such that a first section of each tab extends upward in a direction out of the hole, a second section of each tab extends in a direction parallel to the top of the printed circuit board, and a third section of each tab extends downward toward the first portion of the first conductive layer; and, solder placed around the hollow eyelet and the printed circuit board such that the solder provides an electro-mechanical connection between the base of the first hollow eyelet and the second conductive layer of the printed circuit board, the solder fills the hollow section of the middle region of the hollow eyelet, the solder ~25~ 6 -3b-provides an electro-mechanical connection between each of the tabs and the first portion of the first conductive layer, and the solder fills regions between the second section of each tab and the first portion of the first conductive layer.
Brief Descri~tion of the Drawinqs Figure 1 shows an eyelet used as a mechanical fastener in accordance with the preferred embodiment of the present invention.
Figure 2 shows a portion of a printed circuit board in accordance with the preferred embodiment of the present invention.
Figure 3 shows a cross-sectional view of the eyelet shown in Figure 1, placed in the circuit board shown in Figure 2.
Figure 4 is another view of the eyelet shown in Figure 1, placed in the circuit board shown in Figure 2.
Figure 5 is a cross-sectional view of the eyelet shown in Figure 1 after it has been soldered in place in the circuit board shown in Figure 2.
Description of the Preferred Embodiment Figure 1 shows an eyelet 10 used to make electrical connection between the top and the bottom of a printed circuit board (PCB). Eyelet 10 is a hollow mechanical fastener made of copper with nickel flash and plated with tin-lead. Eyelet 10 has been pre-scored, that is, grooves 11 are placed in eyelet 10 for easy separation upon crimping. Eyelets, such as eyelet 10 are available commercially, for instance, from Mark Eyelet and Stamping ... .
4 i2~S~26 Inc. 63 Wakelee Road, Wolcot, Connecticut 06716. Diameter 12 Or eyelet 10 l~ 1.52 millimeters. Diameter 13 of eyelet 10 iq 2.41 millimeterq. Len6th 14 Or eyelet 10 i~ 2.87 millimeterq. Length 15 Or eyelet 10 19 2.24 milllmeters.
In Figure 2 ls shown a portion Or a printed circuit board (PC8) 21. PCB 21 should be made out Or material with a low thermal coerricient Or expansion, e.~., epoxy glass material. For instance. Norplex, having a place Or business at 1300 Norplex Drive, La Cross, ~isconsin 64601, sells a copper clad epoxy base laminate printed circuit board material which is called CEM 3 tProduct Number NP525).
Placed on top Or PCB 21 is a copper layer 23. Throu~h PCB 21 is a hole 25 and a hole 27. Hole 25 and hole 27 are ~or eyelets such a~ eyelet 10. The diameter Or hole 25 and hole 27 i 1.ô5 mm. Copper }ayer 23 has boen removed ln portlonJ to eXpOJe an ln~ulatod layer 22. The removal Or copper layer 23 ha~ lert a copper pad 24 around hole 25 and a copper pad 26 around hole 27. Out~ide dlameter Or copper pad 24 and copper pad 26 i9 3.2 mm.
Copper pad 24 and copper pad 26 are coupled to the remalnder Or copper layer 23 through spokes. For in~tance, copper pad 24 19 connected to the remainder Or copper layer 23 throu~h a spoke 28a, a spoke 28b~ a spoke 28c and a spoke 28d. Spokes 28a, 28b, 28c and 28d are part Or copper layer 23. Each are approximately 0.3 mm wlde and extend a .
5 1~:9~;~26 distance Or 0.5 mm rrom copper pad 24 to the rest Or copper layer 23.
Copper pad 24 and copper pad 26 are thermally isolated rrom the rest Or copper layer 23 ln order to con~erve heat to the area where eyeletq are soldered.
Figure 3 shows eyelet 10 placed through hole 25 Or PCB
21. Arter bein~ placed through hole 25, eyelet 10 has been crimped to mechanically rasten eyelet 10 within hole 25.
Tabs 31, 32, 33, 34, 35 and 36 provide mechanlcal and electrical connection between copper pad 24 and eyelet 10.
Tabs 34, 35 and 36 and copper pad 24 are shown in Figure 4.
Eyelet 10 is not crimped flat, but is rolled. Ir eyelet 10 is crimped too flat, solder will 3tay on tabs 31, 32, 33, 34, 35 and 36, and not ~low onto copper pad 24.
Addltionally, the ahape Or the Jpace between each o~ tabs 31-36 needs to be ~uch as to provide capillary rlow or ~older out onto ¢opper pad 24. Further, eyelet 10 is crimped to that under itJ own weight~ eyelet 10 is able to move slightly in and out Or hole 25 without ralling out, and Jllghtly horizontally, back and ~orth acros~ copper pad 24. The maxlmum vertical mo~ement and the maximum horlzontal movement is approximately 0.25 millimeters.
Typically, the crimping iq done ~o that a maximum torque Or 250 ~ram~ per millimeter is required to rotate eyelet 10 ln hole 25.
Figure 4 ~hows a bird'~ eye view Or eyelet 10 placed through hole 25. As can be seen tabs 31-36 are shown 6 1295~
makinB meohanioal electrical contact with copper pad 24. A
hole 41 through eyelet 10 allows solder to ~low from the bottom of PCB 21, over and between tabs 31-36 onto copper pad 24.
Figure 5 shows a cross-section vlew through the middle Or hole 25 arter eyelet 10 has been ~oldered lnto place by solder 51. Wave solderlng i9 used to solder eyelet 10. A
flux that 19 not an organlc acid rlux 19 used ln wave solderlng ln order to aa~ure that the soldered Jolnt 19 later not subJect to corroslon. The wave soldering i~ done on the bottom Or PCB 21. Solder masks are used to cover portions Or the bottom Or PCB 21 which are not to be soldered. The solder 19 heated to approximately 4?0 deBrees Fahrenhelt. The top Or PCB 21 i9 heated to about 220 degrees Fahrenheit. Solder wave helght should be no less than one thlrd the thlckneas Or PCB 21 ln order to insure that ~olter will rlow through hole 41 of eyelet 10, over and between tabs 31-36 onto ¢opper pad 24. As can be seen from Figure 5, an area 52 under tab 31 and an area 53 under tab 34 ha~ received ~older, making a well soldered Jolnt. If the Joint is not well-soldered, as PCB 21 cools rollowlng the solderlng, thermal contraction Or the thlckness Or PCB 21 wlll cause the soldered Joint to crack.
.. ..
Back~round The present lnvention ha~ to do with providing an electrical lnterconnect between the bottom and the top of a prlnted circuit board (PCB). Such a connection 19 called a via.
There are various method~ for providing an electrical connection between the bottom and top Or a PCB in the prior art. For in~tance, plated througb holes provide an efrective via; however, thi-~ method Or providing via~ i3 relatively expensive. Similarly the insertion of a wire ~umper through two hole~ in a PCB and soldering the wire to the board on both the top and bottom sldes is an errective but expensive method Or providing vla. The wire Jumper lnsertion method requires hand ~oldering Or the PCB and i~
thererore co~tly and time consuming.
Eyelet~ have been used in the prlor art. For lnstance metal eyelets may be ~waget lnto a hole ln a PCB.
Sometimes a ¢omponent lead 19 lnserted through the eyelet berore soldering. For a conventlonal eyelet the top slde Or the PC8 mu~t be soldered ln a separate operatlon lf a reliable connectlon through the PCB 19 deslred.
Slmilarly, commercially available "~older-through"
eyelets, that 19 special eyelet~ which utllize capillary actlon to carry molten solder rrom the bottom slde Or a PCB
to the top slde, allow the solderlng of both ~ides of an ': ~
: , . :
' ~29$~
eyelet in a single operation. Component leads are inserted through these eyelets before soldering. The eyelet serves the purpo~e Or strengthenlng the mechanical connection Or the component to the PCB.
The ma~or drawback Or using eyelet3 ror vias in the prior art ha3 been the inabllity to provide a reliable electrical Jolnt. Thermal expanslon due to temperature cycling orten causea ~oints to crack resultlng in electrical failure.
SummarY Or the Invention In accordance with the preferred embodiment of the present in~ention a method for providing vlas between the top and bottom of a two-layered printed circuit board (PCB) is presented. An eyelet extends through a hole in the PC3. The top Or the PCB ha~ a rlrat conductive layer.
Around the hole the rirst contuctive layer l~ 3haped such that a conductlve pad ia thermally isolated rrom the rest Or the rirat conductive layer, except that spokes Or the-rirst conductive layer extend rrom the conductive pad to the rest Or the rirst conductive layer. The thermal iaolation Or the ¢onductive pads alds in heat retention during 301dering. The eyelet i9 crimped such that crimped rlngers or tabs Or the eyelet ¢ause the eyelet to be mechanically retained in the hole. The tabs are curved so that the tabs do not lie ~lat upon the conductiYe pad. The bottom Or the PCB is then wave soldered 90 that a base Or the eyelet is electrically coupled to a second conductlve `~ 12954'~i layer on the bottom of the PCB and the tabs are electrically coupled to the conductive pad on the first conductive layer.
Various other aspects of this invention are as follows:
A method for providing an electrical connection between a bottom and a top of a printed circuit board, the method comprising the steps of:
(a) isolating a first portion of conductive layer on top of the printed circuit board and around a hole in the printed circuit board, so that when soldering, heat may be conserved in the first portion;
(b) inserting an eyelet through the hole:
(c) crimping the eyelet so that tabs of the eyelet cause the eyelet to be mechanically retained in the hole and so capillary solder paths to the copper pad are formed; and (d) wave soldering the bottom of the printed circuit board.
A method for providing an electrical connection between a bottom and a top of a printed circuit board, the method comprising the steps of:
(a) creating a hole in the printed circuit board;
(b) inserting an eyelet through the hole;
(c) crimping the eyelet so that tabs of the eyelet cause the eyelet to be mechanically retained in the hole, so that the tabs are curved and so that the tabs do not lie flat upon the first portion of the conductive layer; and (d) wave soldering the bottom of the printed circuit board.
An electrical connector which provides electrical coupling between a bottom and a top of a printed circuit 1'~9~26 3a board, the printed circuit board having a first conductive layer on top of the printed circuit board, a second conductive layer on bottom of the printed circuit board and a hole which extends to the bottom of the printed circuit board to the top of the printed circuit board, the electrical connector comprising:
a first portion of the first conductive layer coupled to the rest of the first conductive layer through a plurality of conductive spokes, wherein the first~portion surrounds the hole;
a hollow eyelet having a middle region positioned substantially within the hole in the printed circuit board, t~e middle region having a hollow section extending the~.length of the hole in the printed circuit board, a base, coupled to the middle region and extending out the bottom of the printed circuit board, the base being shaped in such a way that it does not fit into the hole, and a plurality of tabs coupled to the middle region and extending out the top of the printed circuit board, the tabs extending from the middle region and curving such that a first section of each tab extends upward in a direction out of the hole, a second section of each tab extends in a direction parallel to the top of the printed circuit board, and a third section of each tab extends downward toward the first portion of the first conductive layer; and, solder placed around the hollow eyelet and the printed circuit board such that the solder provides an electro-mechanical connection between the base of the first hollow eyelet and the second conductive layer of the printed circuit board, the solder fills the hollow section of the middle region of the hollow eyelet, the solder ~25~ 6 -3b-provides an electro-mechanical connection between each of the tabs and the first portion of the first conductive layer, and the solder fills regions between the second section of each tab and the first portion of the first conductive layer.
Brief Descri~tion of the Drawinqs Figure 1 shows an eyelet used as a mechanical fastener in accordance with the preferred embodiment of the present invention.
Figure 2 shows a portion of a printed circuit board in accordance with the preferred embodiment of the present invention.
Figure 3 shows a cross-sectional view of the eyelet shown in Figure 1, placed in the circuit board shown in Figure 2.
Figure 4 is another view of the eyelet shown in Figure 1, placed in the circuit board shown in Figure 2.
Figure 5 is a cross-sectional view of the eyelet shown in Figure 1 after it has been soldered in place in the circuit board shown in Figure 2.
Description of the Preferred Embodiment Figure 1 shows an eyelet 10 used to make electrical connection between the top and the bottom of a printed circuit board (PCB). Eyelet 10 is a hollow mechanical fastener made of copper with nickel flash and plated with tin-lead. Eyelet 10 has been pre-scored, that is, grooves 11 are placed in eyelet 10 for easy separation upon crimping. Eyelets, such as eyelet 10 are available commercially, for instance, from Mark Eyelet and Stamping ... .
4 i2~S~26 Inc. 63 Wakelee Road, Wolcot, Connecticut 06716. Diameter 12 Or eyelet 10 l~ 1.52 millimeters. Diameter 13 of eyelet 10 iq 2.41 millimeterq. Len6th 14 Or eyelet 10 i~ 2.87 millimeterq. Length 15 Or eyelet 10 19 2.24 milllmeters.
In Figure 2 ls shown a portion Or a printed circuit board (PC8) 21. PCB 21 should be made out Or material with a low thermal coerricient Or expansion, e.~., epoxy glass material. For instance. Norplex, having a place Or business at 1300 Norplex Drive, La Cross, ~isconsin 64601, sells a copper clad epoxy base laminate printed circuit board material which is called CEM 3 tProduct Number NP525).
Placed on top Or PCB 21 is a copper layer 23. Throu~h PCB 21 is a hole 25 and a hole 27. Hole 25 and hole 27 are ~or eyelets such a~ eyelet 10. The diameter Or hole 25 and hole 27 i 1.ô5 mm. Copper }ayer 23 has boen removed ln portlonJ to eXpOJe an ln~ulatod layer 22. The removal Or copper layer 23 ha~ lert a copper pad 24 around hole 25 and a copper pad 26 around hole 27. Out~ide dlameter Or copper pad 24 and copper pad 26 i9 3.2 mm.
Copper pad 24 and copper pad 26 are coupled to the remalnder Or copper layer 23 through spokes. For in~tance, copper pad 24 19 connected to the remainder Or copper layer 23 throu~h a spoke 28a, a spoke 28b~ a spoke 28c and a spoke 28d. Spokes 28a, 28b, 28c and 28d are part Or copper layer 23. Each are approximately 0.3 mm wlde and extend a .
5 1~:9~;~26 distance Or 0.5 mm rrom copper pad 24 to the rest Or copper layer 23.
Copper pad 24 and copper pad 26 are thermally isolated rrom the rest Or copper layer 23 ln order to con~erve heat to the area where eyeletq are soldered.
Figure 3 shows eyelet 10 placed through hole 25 Or PCB
21. Arter bein~ placed through hole 25, eyelet 10 has been crimped to mechanically rasten eyelet 10 within hole 25.
Tabs 31, 32, 33, 34, 35 and 36 provide mechanlcal and electrical connection between copper pad 24 and eyelet 10.
Tabs 34, 35 and 36 and copper pad 24 are shown in Figure 4.
Eyelet 10 is not crimped flat, but is rolled. Ir eyelet 10 is crimped too flat, solder will 3tay on tabs 31, 32, 33, 34, 35 and 36, and not ~low onto copper pad 24.
Addltionally, the ahape Or the Jpace between each o~ tabs 31-36 needs to be ~uch as to provide capillary rlow or ~older out onto ¢opper pad 24. Further, eyelet 10 is crimped to that under itJ own weight~ eyelet 10 is able to move slightly in and out Or hole 25 without ralling out, and Jllghtly horizontally, back and ~orth acros~ copper pad 24. The maxlmum vertical mo~ement and the maximum horlzontal movement is approximately 0.25 millimeters.
Typically, the crimping iq done ~o that a maximum torque Or 250 ~ram~ per millimeter is required to rotate eyelet 10 ln hole 25.
Figure 4 ~hows a bird'~ eye view Or eyelet 10 placed through hole 25. As can be seen tabs 31-36 are shown 6 1295~
makinB meohanioal electrical contact with copper pad 24. A
hole 41 through eyelet 10 allows solder to ~low from the bottom of PCB 21, over and between tabs 31-36 onto copper pad 24.
Figure 5 shows a cross-section vlew through the middle Or hole 25 arter eyelet 10 has been ~oldered lnto place by solder 51. Wave solderlng i9 used to solder eyelet 10. A
flux that 19 not an organlc acid rlux 19 used ln wave solderlng ln order to aa~ure that the soldered Jolnt 19 later not subJect to corroslon. The wave soldering i~ done on the bottom Or PCB 21. Solder masks are used to cover portions Or the bottom Or PCB 21 which are not to be soldered. The solder 19 heated to approximately 4?0 deBrees Fahrenhelt. The top Or PCB 21 i9 heated to about 220 degrees Fahrenheit. Solder wave helght should be no less than one thlrd the thlckneas Or PCB 21 ln order to insure that ~olter will rlow through hole 41 of eyelet 10, over and between tabs 31-36 onto ¢opper pad 24. As can be seen from Figure 5, an area 52 under tab 31 and an area 53 under tab 34 ha~ received ~older, making a well soldered Jolnt. If the Joint is not well-soldered, as PCB 21 cools rollowlng the solderlng, thermal contraction Or the thlckness Or PCB 21 wlll cause the soldered Joint to crack.
.. ..
Claims (9)
1. A method for providing an electrical connection between a bottom and a top Or a printed circuit board, the method comprising the steps or:
(a) isolating a first portion of conductive layer on top of the printed circuit board and around a hole in the printed circuit board, so that when soldering, heat may be conserved in the first portion;
(b) inserting an eyelet through the hole;
(c) crimping the eyelet so that tabs of the eyelet cause the eyelet to be mechanically retained in the hole and so capillary solder paths to the copper pad are formed.
(d) wave soldering the bottom of the printed circuit board.
(a) isolating a first portion of conductive layer on top of the printed circuit board and around a hole in the printed circuit board, so that when soldering, heat may be conserved in the first portion;
(b) inserting an eyelet through the hole;
(c) crimping the eyelet so that tabs of the eyelet cause the eyelet to be mechanically retained in the hole and so capillary solder paths to the copper pad are formed.
(d) wave soldering the bottom of the printed circuit board.
2. A method as in Claim 1 wherein step (a) comprises the substep:
(a1) removing sections of the conductive layer around the first portion of the conductive layer, so that the first portion or the conductive layer is coupled to the rest of the conductive layer through a plurality of spokes.
(a1) removing sections of the conductive layer around the first portion of the conductive layer, so that the first portion or the conductive layer is coupled to the rest of the conductive layer through a plurality of spokes.
3. A method as in Claim 1 wherein in step (c) the eyelet is crimped such that the tabs are curved and the tabs do not lie flat upon the first portion of the conductive layer.
4. A method as in Claim 3 wherein in step (c) the eyelet is crimped with such a tension that under its own weight, the eyelet is able to move slightly in and out of the hole, and the eyelet is able to move slightly in a horizontal motion across the first portion of the conductive layer.
5. A method as in Claim 4 wherein the eyelet is able to move a maximum of 0.25 millimeters across the first portion of the conductive layer and a maximum of 0.25 millimeters vertically in and out of the hole.
6. A method for providing an electrical connection between a bottom and a top of a printed circuit board, the method comprising the steps of:
(a) creating a hole in the printed circuit board;
(b) inserting an eyelet through the hole;
(c) crimping the eyelet so that tabs of the eyelet cause the eyelet to be mechanically retained in the hole, so that the tabs are curved and so that the tabs do not lie flat upon the first portion of the conductive layer.
(d) wave soldering the bottom of the printed circuit board.
(a) creating a hole in the printed circuit board;
(b) inserting an eyelet through the hole;
(c) crimping the eyelet so that tabs of the eyelet cause the eyelet to be mechanically retained in the hole, so that the tabs are curved and so that the tabs do not lie flat upon the first portion of the conductive layer.
(d) wave soldering the bottom of the printed circuit board.
7. A method as in Claim 6 wherein in step (c) the eyelet is crimped with such a tension that under its own weight, the eyelet is able to make slight vertical motion in and out of the hole, and the eyelet is able to move slightly in a horizontal motion across the first portion of the conductive layer.
8. A method as in Claim 7 wherein the eyelet is able to move a maximum of 0.25 millimeters across the first portion of the conductive layer and a maximum of 0.25 millimeters vertically, in and out of the hole..
9. An electrical connector which provides electrical coupling between a bottom and a top of a printed circuit board, the printed circuit board having a first conductive layer on top of the printed circuit board, a second conductive layer on bottom of the printed circuit board and a hole which extends to the bottom of the printed circuit board to the top of the printed circuit board, the electrical connector comprising:
a first portion of the first conductive layer coupled to the rest of the first conductive layer through a plurality of conductive spokes, wherein the first portion surrounds the hole;
a hollow eyelet having a middle region positioned substantially within the hole in the printed circuit board, the middle region having a hollow section extending the length of the hole in the printed circuit board, a base, coupled to the middle region and extending out the bottom of the printed circuit board, the base being shaped in such a way that it does not fit into the hole, and a plurality of tabs coupled to the middle region and extending out the top of the printed circuit board, the tabs extending from the middle region and curving such that a first section of each tab extends upward in a direction out of the hole, a second section of each tab extends in a direction parallel to the top of the printed circuit board, and a third section of each tab extends downward toward the first portion of the first conductive layer; and, solder placed around the hollow eyelet and the printed circuit board such that the solder provides an electro-mechanical connection Between the base of the first hollow eyelet and the second conductive layer of the printed circuit board, the solder rills the hollow section of the middle region of the hollow eyelet, the solder provides an electro-mechanical connection between each of the tabs and the first portion of the first conductive layer, and the solder fills regions between the second section of each tab and the first portion of the first conductive layer.
a first portion of the first conductive layer coupled to the rest of the first conductive layer through a plurality of conductive spokes, wherein the first portion surrounds the hole;
a hollow eyelet having a middle region positioned substantially within the hole in the printed circuit board, the middle region having a hollow section extending the length of the hole in the printed circuit board, a base, coupled to the middle region and extending out the bottom of the printed circuit board, the base being shaped in such a way that it does not fit into the hole, and a plurality of tabs coupled to the middle region and extending out the top of the printed circuit board, the tabs extending from the middle region and curving such that a first section of each tab extends upward in a direction out of the hole, a second section of each tab extends in a direction parallel to the top of the printed circuit board, and a third section of each tab extends downward toward the first portion of the first conductive layer; and, solder placed around the hollow eyelet and the printed circuit board such that the solder provides an electro-mechanical connection Between the base of the first hollow eyelet and the second conductive layer of the printed circuit board, the solder rills the hollow section of the middle region of the hollow eyelet, the solder provides an electro-mechanical connection between each of the tabs and the first portion of the first conductive layer, and the solder fills regions between the second section of each tab and the first portion of the first conductive layer.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US160,390 | 1980-06-17 | ||
| US07/160,390 US4881906A (en) | 1988-02-25 | 1988-02-25 | Method for obtaining electrical interconnect using a solderable mechanical fastener |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1295426C true CA1295426C (en) | 1992-02-04 |
Family
ID=22576695
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000592015A Expired - Lifetime CA1295426C (en) | 1988-02-25 | 1989-02-24 | Process for obtaining electrical interconnect using a solderable mechanical fastener |
Country Status (5)
| Country | Link |
|---|---|
| US (1) | US4881906A (en) |
| EP (1) | EP0331818B1 (en) |
| JP (1) | JPH01253988A (en) |
| CA (1) | CA1295426C (en) |
| DE (1) | DE3881378T2 (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0437087A (en) * | 1990-05-31 | 1992-02-07 | Toshiba Corp | Printed-wiring board device, eyelet therefor and mounting thereof |
| JP2748768B2 (en) * | 1992-03-19 | 1998-05-13 | 株式会社日立製作所 | Thin film multilayer wiring board and method of manufacturing the same |
| JPH10500248A (en) * | 1994-05-10 | 1998-01-06 | バーグ・テクノロジー・インコーポレーテッド | Multiple hooks holddown |
| DE19900639C1 (en) * | 1999-01-11 | 2000-06-08 | Siemens Ag | Electrical contacting connector e.g. for installing in control device for transmission on engine of motor vehicle |
| DE10017774B4 (en) * | 2000-04-10 | 2005-03-10 | Epcos Ag | Mounting plate, mounting arrangement with the mounting plate and use of the mounting plate |
| US6617520B1 (en) | 2000-08-30 | 2003-09-09 | Heatron, Inc. | Circuit board |
| US9860975B2 (en) * | 2014-01-30 | 2018-01-02 | Hewlett Packard Enterprise Development Lp | Thermal relief pad |
| CN108337817A (en) * | 2017-01-20 | 2018-07-27 | 台达电子工业股份有限公司 | Electronic device and connection method |
| DE102017205360B3 (en) * | 2017-03-29 | 2018-07-19 | Te Connectivity Germany Gmbh | Electrical contact element and method for producing a brazed, electrically conductive connection with a mating contact by means of a pressed solder body made of brazing material |
| CN108966505A (en) * | 2018-08-28 | 2018-12-07 | 郑州云海信息技术有限公司 | The method of pcb board installation via hole |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3103547A (en) * | 1963-09-10 | ansley | ||
| US2756485A (en) * | 1950-08-28 | 1956-07-31 | Abramson Moe | Process of assembling electrical circuits |
| US3061911A (en) * | 1958-01-31 | 1962-11-06 | Xerox Corp | Method of making printed circuits |
| US3621116A (en) * | 1969-12-29 | 1971-11-16 | Bertram C Adams | Printed circuit board |
| US3601750A (en) * | 1970-02-09 | 1971-08-24 | Berg Electronics Inc | Circuit board connector |
| FR2184437A2 (en) * | 1972-05-17 | 1973-12-28 | Delaye Raymond | |
| FR2205799B1 (en) * | 1972-11-07 | 1975-11-28 | Delaye Raymond | |
| US3825999A (en) * | 1972-12-26 | 1974-07-30 | United Wiring And Mfg Co Inc | Method of connecting electrical component |
| US4181385A (en) * | 1978-03-30 | 1980-01-01 | Motorola, Inc. | Low profile socket for circuit board with gas vents for fixed position soldering |
| JPS5724775U (en) * | 1980-07-17 | 1982-02-08 |
-
1988
- 1988-02-25 US US07/160,390 patent/US4881906A/en not_active Expired - Lifetime
- 1988-12-30 DE DE88121895T patent/DE3881378T2/en not_active Expired - Fee Related
- 1988-12-30 EP EP88121895A patent/EP0331818B1/en not_active Expired - Lifetime
-
1989
- 1989-02-23 JP JP1045076A patent/JPH01253988A/en active Pending
- 1989-02-24 CA CA000592015A patent/CA1295426C/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH01253988A (en) | 1989-10-11 |
| EP0331818B1 (en) | 1993-05-26 |
| DE3881378D1 (en) | 1993-07-01 |
| US4881906A (en) | 1989-11-21 |
| DE3881378T2 (en) | 1994-01-13 |
| EP0331818A1 (en) | 1989-09-13 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |