CA1318371C - Hermetically sealed feedthroughs - Google Patents
Hermetically sealed feedthroughsInfo
- Publication number
- CA1318371C CA1318371C CA000601234A CA601234A CA1318371C CA 1318371 C CA1318371 C CA 1318371C CA 000601234 A CA000601234 A CA 000601234A CA 601234 A CA601234 A CA 601234A CA 1318371 C CA1318371 C CA 1318371C
- Authority
- CA
- Canada
- Prior art keywords
- ferrule
- port
- rim
- metal
- clearance
- 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
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B17/00—Insulators or insulating bodies characterised by their form
- H01B17/26—Lead-in insulators; Lead-through insulators
- H01B17/30—Sealing
- H01B17/303—Sealing of leads to lead-through insulators
- H01B17/305—Sealing of leads to lead-through insulators by embedding in glass or ceramic material
-
- 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
- Y10T403/00—Joints and connections
- Y10T403/21—Utilizing thermal characteristic, e.g., expansion or contraction, etc.
- Y10T403/217—Members having different coefficients of expansion
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Ceramic Engineering (AREA)
- Connector Housings Or Holding Contact Members (AREA)
- Connections Arranged To Contact A Plurality Of Conductors (AREA)
Abstract
HERMETICALLY SEALED FEEDTHROUGHS
Abstract of the Disclosure In the sealed feedthrough construction disclosed herein, a maximally compliant solder joint is provided between the low expansion ferrule of a glass insulated feedthrough connector and a bore in an enclosure bulkhead of a high expansion metal. The desired uniform radial thickness is established by providing a step on either the outer diameter of the ferrule or the inner diameter of the bore.
Abstract of the Disclosure In the sealed feedthrough construction disclosed herein, a maximally compliant solder joint is provided between the low expansion ferrule of a glass insulated feedthrough connector and a bore in an enclosure bulkhead of a high expansion metal. The desired uniform radial thickness is established by providing a step on either the outer diameter of the ferrule or the inner diameter of the bore.
Description
13~3~
1 Background of the Invention The present invention relates to hermetically sealed elelectrical feedthroughs and more particularly feedthroughs for use in an enclosure constructed of a high expansion metal such as aluminum.
Hermetically sealed electrical feedtlhrough~ are typically constructed by bonding a connector pin into ,a tubular ferrule or bushing using a glass-like insulating materi,al, the ferrule being constructe~ of a metal such as KOVAR having a coefficient of expansion which approximates that of the gla~sy insulating material. The ferrule is then soldered into a bore in the enclosure bulkhead, each of the parts being previously plated to facilitate soldering. Typically, minimal clearance is provided between the ferrule and the bore in the enclosure wall in order to maintain concentricity which is important in many electrical applications, particularly those involving radio frequency (r.f.) energy~ While such construction~ h~ve heretofore been reliably implemented where the enclosure is steel or other low expansion metal, extremely high rates of failure have been encountered when attempting to utilize the same constructional techniques in ~aking feedthroughs through an aluminum wall member, owing to the very high coefficient expansion of aluminum~
The present invention is predicated in substantial part upon a perception that most seal failures in aluminum enclosures are due, not to failures of the glass insulating material but, rather, to failures of the solder joint between the ferrule and the material of the bulkhead within which the ferrule is soldered. Soldering a minimal clearance joint between the ferrule and the bulkhead results in a very thin layer of solder.
While a thin layer of solder exhibits great strength in certain contexts and types o~ testing, it does not provicle for any * ~rrade Mark 13~3~
1 significant radial compliance in the context of the ferrule/bulkhead joint described above. Accordingly, when the feedthrough is subjected to temperature cycling, as is required in the testing of many military components, the solder joint is fatigued and fails. This tendency to failure is apparently exacerbated by the well known tendency of solder to creep under stress. Not only is the clearance in general too small to provide adequate radial compliance, but the thickness oE solder layer is typically non-uniform since no means is provided for centering the ferrule within the very small clearance of the bore.
Thus, the ferrule will typically be somewhat eccentric producing a solder thickness even thinner than the nominal radial clearance.
Summary of the_Present Invention In accordance with the practice of the present invention, a solder joint of substantial or maximally compliant thickness is formed between the ferrule of a feedthrough assembly and a bore in the enclosure bulkhead. The desired spacing for the solder joint is maintained by either a rim on the inner end of the ferrule or a step in the diameter of the bore at its inner end.
Accordingly, in one aspect the invention resides in the method of making a hermetically seated electrical feed~hrough connection into an enclosure bu]khead of a high expansion metal, said method comprising bonding a connector pin into a tubular ferrule using a glass-like insulating material, said ferrule being constructed of a metal having a coefficient of expansion which approximates that Oe sai.d insulatlng ma~erlal, satd eerrule heitlg oF
~3~7~
1 subs~antially uniform outer diameter over most of its length but having, a~ its inner end, a shallow rim having a heigh~ which is substantially equal to the thickness of a maximally compliant solder joint; boring a feedthrough port into an enclosure bulkhead of a high expansion metal, said port having a diameter over most of its length which will accept said rim with minimal clearancei inserting said ferrule int.o said port rim end first with said rim centering the remaining length of the ferrule within the bore with essential uniform clearance; and introducing molten solder into said uniform clearance space ~hereby to provide a seal having radial compliance to accommodate differential expansion between said ferrule and said h;gh expansion metal.
In a further aspect the invention resides in an enclosure bulkhead of a high expansion metal, a hermetically sealed electrical feedthrough connection comprising a tubular ferrule constructed of a metal having a coefficient of expansion which approximates tha-t of glass, said ferrule being of substantially uniform outer diameter over most of its length but having, at its inner end, a shallow rim having a height which is substantial.ly equal to the thickness of a maximally compliant solder joint; a connector pln concentric within said ferrule; a - 25 glass-like insulator bonded between sai.d pin and said ferrule; a feedthrough por-t in said enc].osure bulkheads, said port having a diameter over most of its length which will accept said rim with min;.mal cl.earance, said Eerrule bel.ng inser~ed into saifl port rim end first with saicl rim centering the remainlng length of the ~errule ~ithin the 13~3~
] bore with essential uniform clearance; and solder filling said uniform clearance space thereby to provide a seal having radial compliance to accommoclate differential expansion between said ferr~le and said high expansion metal.
Brief Description of the Draw_ngs Fig. 1 is a side view, in section, of a feedthrough assembly useful in making a feedthrough connection in accordance with the present invention;
Fig. 2 is a sectional view of a bore in an enclosure bulkhead adapted for receiving the assembly of Fig. l;
Fig. 3 is a sectional view showing the assembly of Fig. 1 inserted into the bore of Fig. 2, together with a solder preform ready for soldering;
Fig. 4 is a sectional view of the completed feedthrough connection made in accordance with the present invention;
-3b 13~7~
1 ~iq. 5 is a graph representing a theoretical variation of solder join~ radial elongation for changing solder joint thickness;
~ig. 6 is a sectional view of a completed feedthrough S oonnection of an alternative embodiment of the invention; and Fig. 7 is a sectional view of a multi-pin feedthrough connector constructed in accordance with the present invention.
Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.
~3~ 3)~
1 Description o~ the Preferred Embod_ments Referring now to Fig. 1, a connector pin 11 is bonded into a generally tubular ferrule 13 using a gla~s-like insulating ~aterial 15 which is fused to both the pin 11 and the ferrule 13.
The bonding techniques for forming the glass insulating annulus are well known and are not described in greater detail hereinafter. The ferrule 13 is constructed of a metal, typically KOYAR, having a coefficient of expansion which approximates that of the in~ulating glass 15. The nominal dia~eter of the ferrule lo will typically be in the order of 0.100 inches for r.f. (radio frequency) applications and in the order of 0.050 - 0.075 inches for d.c. and signal applications. Rather than having a uniform outer diameter, however, the ferrule 13 has, at its inner end, a rim 17 of increased diameter. Preferably, the heighk of the rim is in the order of 0.005 inches, this being a height which is substantially equal to the thickness of a ~a~imally compliant solder joint as described in greater detail hereinafter. The remainder of the ferrule 13 is of unifor~ outer diameter, this portion being indicated by reference character lB.
Fig. 2 illustrates an aluminum bulkhead or enclosure wall wbich is bored to receive the feedthrough assembly of Fig. 1. In this embodiment, the ferrule 13 fits within a portion of the bore which is of uniform diameter, this portion being indicated by reference character 23. Typically, this portion does not pass all the way through the bulkhead 21 but, rather, there is a smaller diameter portion of the bore, designated by re~erence character 25 through which the connector pin extends. There may also be a short intermediate diameter portion 27 as i~
conventional. As is conventional, the alu~inum bulkhead, or at least the bore ~urface 23, i~ plated 80 a~ to ~acilitate aolderlng thereto.
~3~P~
1 As may be seen in Fig. 3, the bore portion 23 rece;ves the ferrule 13 with minimal clearance a~ound the rim but with a substantial and well defined clearance around the remaining uniform diameter portion 18 of the ferrule. Clearance around the rim may, for example, be only OoOOl inches or lesst i.e. only sufficient clearance to provide easy assembly, whereas the radial clearance between the remaining por~ion of the ferrule and the bore p3rtion 23 is in the ordPr of 0.005 inches.
A ring-like annular solder preform 31 is placçd around the ferrule at the outer end of the gap between the ferrule and the bore portion 23. Upon heating~ e~g. in a temperature controlled oven as is conventional in the art, ~he solder preform 31 melts and the solder is drawnl by capillary action, into the space between the ferrule and the bore portion 23. As is understood, most applications will require a multiplicity of feedthroughs and use of preforms and oven soldering allows the soldering of all of the feedthrough~ to be completed in one process step.
In accordance with the understanding of the present inven~ion, it has been found that a solder joint thickness in the order of 0.005 inches provides a practioally max imally compliant ~older joint. A thinner solder i~int, e.g. less than 0,001 as was utilized by the prior art, doe~ not have adequate radial compliance and will likely fail under thermal cycling. On the other hand, significantly thicker clearances between the main portion 18 of the ferrule 13 and the bore 23, e.g. 0.010 inches, will not provide a suitable capillary action for yieldlng a uniform filling of solder into the radial gap.
With reference to Fig. 5, there is illu~trated a graph representing theoretical radial elongation of the solder jo.int versus radial thickness o~ the solder joint over a st~ndard range -h-~ 3~ ~3PJ~
1 o temperatures, i.e. minus 65 degrees C. to plu8 125 degrees C., as called for by certain military test ~pecifications. A nominal diameter for the ferrule of 0.100 inches is assumed. Below 0.001 inch radial clearance, the percent radial elongation rises rapidly. As indicated previously, such radial elongation will most likely cause failure of the solder joint in thermal cycling.
In one sense, it may be understood that the thin ~older joint does not have sufficient radial compliance to acco~modate the differential expansion which occurs between the ferrule and the high expansion bulkhead. On the other hand, over a range of radial thickness from about 0.003 to 0.007 inches, the percent radial elongation has dropped to a relatively low level, i.e.
about two to five percent. This is a level which can be tolerated by the solder joint wi~hout significant failure rates.
As indicated previously, a significantly thicker solder joint ~e.g. 0.010 inches) is disadvantageous as a practical matter since such a large gap will not provide suitable capillary action for yielding a uniform filling of solder into the radial gap ~.
Thus, a ~older joint thickness between 0.003 and 0.007, i.e. in the order of 0.005 inches, may be considered to provide a practically maximally compliant solder joint.
As indicated previously, centering of the ferrule feedthrough assembly can be provided either by a ri~ on ~he ferrule or a shoulder in the bore in the high expansion bulkhead.
Fig. 6 illustrates the alternative arrangement. With reference to Fig. 6, the feedthrough assembly illustrated there employs a ferrule 41 having an outer diameter which is constant. Ferrule 41 fits within a bore in an aluminum bulkhead 43, tbe major portion of the bore being of con~tant diameter provlding ,a radial clearance of about 0.005 inche~. Thls portion i~ indicat~d by referewe character 45. At the inner end of the bore, however, 1 3 ~
1 there i8 a step providing a section of reduced diameter, designated by reference character 47. This reduced diameter portion provides minimum clearance of the outer diameter of the ferrule and thus centers the ferrule within the lar~er diameter portion 45 of the bore. Again, the radial clearance is preferably in the order of 0.005 inches so as to provide a practically maximally compliant solder joint.
Many applications, particularly coaxial connectors coupling microwave r.f. enerqy into or out of the enclosure, will require the feedthroughs to be individually positioned in the enclosure. In which case, the methods oE construction ju~t described are usable directly on the enclosure walls or bulkheads. In other applications, however, it may be appropriate to implement a multi-pin connector, eOg. for the introduction of control signals and power lines, etc. In such a case, an aluminum connector body may in effect constitute the bulkhead into which a multiplicity of feedthrough pins are inserted in accordance with the procedures described above. Such a construction is illustrated in Fig. 70 As ~ay be seen, an aluminum connector body 51 is provided wi~h a plurality of bores 53 for receiving eedthrough assemblies 55 of the type illustrated in Fig. 1. Again the rims on the ferrules of the feedthrough assemblies are sized to provide a solder joint thickness in the order of 0.005 inches. The aluminum connector body 51 may then be soldered a corresponding opening in an aluminum enclosure without any particular diEficulties, since the connector and the enclosure will have substantially ~atching coefficients of expansion.
In view of the foregoing, it may be seen that ~everal objects of the present invention are achieved and oth~r advan~ageou~ results have been attained.
~3~3~
1 As ~arious chanses could be made in the above constructions without departing from the scope of the invention, it should be understood that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
1 Background of the Invention The present invention relates to hermetically sealed elelectrical feedthroughs and more particularly feedthroughs for use in an enclosure constructed of a high expansion metal such as aluminum.
Hermetically sealed electrical feedtlhrough~ are typically constructed by bonding a connector pin into ,a tubular ferrule or bushing using a glass-like insulating materi,al, the ferrule being constructe~ of a metal such as KOVAR having a coefficient of expansion which approximates that of the gla~sy insulating material. The ferrule is then soldered into a bore in the enclosure bulkhead, each of the parts being previously plated to facilitate soldering. Typically, minimal clearance is provided between the ferrule and the bore in the enclosure wall in order to maintain concentricity which is important in many electrical applications, particularly those involving radio frequency (r.f.) energy~ While such construction~ h~ve heretofore been reliably implemented where the enclosure is steel or other low expansion metal, extremely high rates of failure have been encountered when attempting to utilize the same constructional techniques in ~aking feedthroughs through an aluminum wall member, owing to the very high coefficient expansion of aluminum~
The present invention is predicated in substantial part upon a perception that most seal failures in aluminum enclosures are due, not to failures of the glass insulating material but, rather, to failures of the solder joint between the ferrule and the material of the bulkhead within which the ferrule is soldered. Soldering a minimal clearance joint between the ferrule and the bulkhead results in a very thin layer of solder.
While a thin layer of solder exhibits great strength in certain contexts and types o~ testing, it does not provicle for any * ~rrade Mark 13~3~
1 significant radial compliance in the context of the ferrule/bulkhead joint described above. Accordingly, when the feedthrough is subjected to temperature cycling, as is required in the testing of many military components, the solder joint is fatigued and fails. This tendency to failure is apparently exacerbated by the well known tendency of solder to creep under stress. Not only is the clearance in general too small to provide adequate radial compliance, but the thickness oE solder layer is typically non-uniform since no means is provided for centering the ferrule within the very small clearance of the bore.
Thus, the ferrule will typically be somewhat eccentric producing a solder thickness even thinner than the nominal radial clearance.
Summary of the_Present Invention In accordance with the practice of the present invention, a solder joint of substantial or maximally compliant thickness is formed between the ferrule of a feedthrough assembly and a bore in the enclosure bulkhead. The desired spacing for the solder joint is maintained by either a rim on the inner end of the ferrule or a step in the diameter of the bore at its inner end.
Accordingly, in one aspect the invention resides in the method of making a hermetically seated electrical feed~hrough connection into an enclosure bu]khead of a high expansion metal, said method comprising bonding a connector pin into a tubular ferrule using a glass-like insulating material, said ferrule being constructed of a metal having a coefficient of expansion which approximates that Oe sai.d insulatlng ma~erlal, satd eerrule heitlg oF
~3~7~
1 subs~antially uniform outer diameter over most of its length but having, a~ its inner end, a shallow rim having a heigh~ which is substantially equal to the thickness of a maximally compliant solder joint; boring a feedthrough port into an enclosure bulkhead of a high expansion metal, said port having a diameter over most of its length which will accept said rim with minimal clearancei inserting said ferrule int.o said port rim end first with said rim centering the remaining length of the ferrule within the bore with essential uniform clearance; and introducing molten solder into said uniform clearance space ~hereby to provide a seal having radial compliance to accommodate differential expansion between said ferrule and said h;gh expansion metal.
In a further aspect the invention resides in an enclosure bulkhead of a high expansion metal, a hermetically sealed electrical feedthrough connection comprising a tubular ferrule constructed of a metal having a coefficient of expansion which approximates tha-t of glass, said ferrule being of substantially uniform outer diameter over most of its length but having, at its inner end, a shallow rim having a height which is substantial.ly equal to the thickness of a maximally compliant solder joint; a connector pln concentric within said ferrule; a - 25 glass-like insulator bonded between sai.d pin and said ferrule; a feedthrough por-t in said enc].osure bulkheads, said port having a diameter over most of its length which will accept said rim with min;.mal cl.earance, said Eerrule bel.ng inser~ed into saifl port rim end first with saicl rim centering the remainlng length of the ~errule ~ithin the 13~3~
] bore with essential uniform clearance; and solder filling said uniform clearance space thereby to provide a seal having radial compliance to accommoclate differential expansion between said ferr~le and said high expansion metal.
Brief Description of the Draw_ngs Fig. 1 is a side view, in section, of a feedthrough assembly useful in making a feedthrough connection in accordance with the present invention;
Fig. 2 is a sectional view of a bore in an enclosure bulkhead adapted for receiving the assembly of Fig. l;
Fig. 3 is a sectional view showing the assembly of Fig. 1 inserted into the bore of Fig. 2, together with a solder preform ready for soldering;
Fig. 4 is a sectional view of the completed feedthrough connection made in accordance with the present invention;
-3b 13~7~
1 ~iq. 5 is a graph representing a theoretical variation of solder join~ radial elongation for changing solder joint thickness;
~ig. 6 is a sectional view of a completed feedthrough S oonnection of an alternative embodiment of the invention; and Fig. 7 is a sectional view of a multi-pin feedthrough connector constructed in accordance with the present invention.
Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.
~3~ 3)~
1 Description o~ the Preferred Embod_ments Referring now to Fig. 1, a connector pin 11 is bonded into a generally tubular ferrule 13 using a gla~s-like insulating ~aterial 15 which is fused to both the pin 11 and the ferrule 13.
The bonding techniques for forming the glass insulating annulus are well known and are not described in greater detail hereinafter. The ferrule 13 is constructed of a metal, typically KOYAR, having a coefficient of expansion which approximates that of the in~ulating glass 15. The nominal dia~eter of the ferrule lo will typically be in the order of 0.100 inches for r.f. (radio frequency) applications and in the order of 0.050 - 0.075 inches for d.c. and signal applications. Rather than having a uniform outer diameter, however, the ferrule 13 has, at its inner end, a rim 17 of increased diameter. Preferably, the heighk of the rim is in the order of 0.005 inches, this being a height which is substantially equal to the thickness of a ~a~imally compliant solder joint as described in greater detail hereinafter. The remainder of the ferrule 13 is of unifor~ outer diameter, this portion being indicated by reference character lB.
Fig. 2 illustrates an aluminum bulkhead or enclosure wall wbich is bored to receive the feedthrough assembly of Fig. 1. In this embodiment, the ferrule 13 fits within a portion of the bore which is of uniform diameter, this portion being indicated by reference character 23. Typically, this portion does not pass all the way through the bulkhead 21 but, rather, there is a smaller diameter portion of the bore, designated by re~erence character 25 through which the connector pin extends. There may also be a short intermediate diameter portion 27 as i~
conventional. As is conventional, the alu~inum bulkhead, or at least the bore ~urface 23, i~ plated 80 a~ to ~acilitate aolderlng thereto.
~3~P~
1 As may be seen in Fig. 3, the bore portion 23 rece;ves the ferrule 13 with minimal clearance a~ound the rim but with a substantial and well defined clearance around the remaining uniform diameter portion 18 of the ferrule. Clearance around the rim may, for example, be only OoOOl inches or lesst i.e. only sufficient clearance to provide easy assembly, whereas the radial clearance between the remaining por~ion of the ferrule and the bore p3rtion 23 is in the ordPr of 0.005 inches.
A ring-like annular solder preform 31 is placçd around the ferrule at the outer end of the gap between the ferrule and the bore portion 23. Upon heating~ e~g. in a temperature controlled oven as is conventional in the art, ~he solder preform 31 melts and the solder is drawnl by capillary action, into the space between the ferrule and the bore portion 23. As is understood, most applications will require a multiplicity of feedthroughs and use of preforms and oven soldering allows the soldering of all of the feedthrough~ to be completed in one process step.
In accordance with the understanding of the present inven~ion, it has been found that a solder joint thickness in the order of 0.005 inches provides a practioally max imally compliant ~older joint. A thinner solder i~int, e.g. less than 0,001 as was utilized by the prior art, doe~ not have adequate radial compliance and will likely fail under thermal cycling. On the other hand, significantly thicker clearances between the main portion 18 of the ferrule 13 and the bore 23, e.g. 0.010 inches, will not provide a suitable capillary action for yieldlng a uniform filling of solder into the radial gap.
With reference to Fig. 5, there is illu~trated a graph representing theoretical radial elongation of the solder jo.int versus radial thickness o~ the solder joint over a st~ndard range -h-~ 3~ ~3PJ~
1 o temperatures, i.e. minus 65 degrees C. to plu8 125 degrees C., as called for by certain military test ~pecifications. A nominal diameter for the ferrule of 0.100 inches is assumed. Below 0.001 inch radial clearance, the percent radial elongation rises rapidly. As indicated previously, such radial elongation will most likely cause failure of the solder joint in thermal cycling.
In one sense, it may be understood that the thin ~older joint does not have sufficient radial compliance to acco~modate the differential expansion which occurs between the ferrule and the high expansion bulkhead. On the other hand, over a range of radial thickness from about 0.003 to 0.007 inches, the percent radial elongation has dropped to a relatively low level, i.e.
about two to five percent. This is a level which can be tolerated by the solder joint wi~hout significant failure rates.
As indicated previously, a significantly thicker solder joint ~e.g. 0.010 inches) is disadvantageous as a practical matter since such a large gap will not provide suitable capillary action for yielding a uniform filling of solder into the radial gap ~.
Thus, a ~older joint thickness between 0.003 and 0.007, i.e. in the order of 0.005 inches, may be considered to provide a practically maximally compliant solder joint.
As indicated previously, centering of the ferrule feedthrough assembly can be provided either by a ri~ on ~he ferrule or a shoulder in the bore in the high expansion bulkhead.
Fig. 6 illustrates the alternative arrangement. With reference to Fig. 6, the feedthrough assembly illustrated there employs a ferrule 41 having an outer diameter which is constant. Ferrule 41 fits within a bore in an aluminum bulkhead 43, tbe major portion of the bore being of con~tant diameter provlding ,a radial clearance of about 0.005 inche~. Thls portion i~ indicat~d by referewe character 45. At the inner end of the bore, however, 1 3 ~
1 there i8 a step providing a section of reduced diameter, designated by reference character 47. This reduced diameter portion provides minimum clearance of the outer diameter of the ferrule and thus centers the ferrule within the lar~er diameter portion 45 of the bore. Again, the radial clearance is preferably in the order of 0.005 inches so as to provide a practically maximally compliant solder joint.
Many applications, particularly coaxial connectors coupling microwave r.f. enerqy into or out of the enclosure, will require the feedthroughs to be individually positioned in the enclosure. In which case, the methods oE construction ju~t described are usable directly on the enclosure walls or bulkheads. In other applications, however, it may be appropriate to implement a multi-pin connector, eOg. for the introduction of control signals and power lines, etc. In such a case, an aluminum connector body may in effect constitute the bulkhead into which a multiplicity of feedthrough pins are inserted in accordance with the procedures described above. Such a construction is illustrated in Fig. 70 As ~ay be seen, an aluminum connector body 51 is provided wi~h a plurality of bores 53 for receiving eedthrough assemblies 55 of the type illustrated in Fig. 1. Again the rims on the ferrules of the feedthrough assemblies are sized to provide a solder joint thickness in the order of 0.005 inches. The aluminum connector body 51 may then be soldered a corresponding opening in an aluminum enclosure without any particular diEficulties, since the connector and the enclosure will have substantially ~atching coefficients of expansion.
In view of the foregoing, it may be seen that ~everal objects of the present invention are achieved and oth~r advan~ageou~ results have been attained.
~3~3~
1 As ~arious chanses could be made in the above constructions without departing from the scope of the invention, it should be understood that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
Claims (12)
1. The method of making a hermetically sealed electrical feedthrough connection into an enclosure bulkhead of a high expansion metal, said method comprising:
bonding a connector pin into a tubular ferrule using a glass-like insulating material, said ferrule being constructed of a metal having a coefficient of expansion which approximates that of said insulating material, said ferrule being of substantially uniform outer diameter over most of its length but having, at its inner end, a shallow rim having a height which is substantially equal to the thickness of a maximally compliant solder joint;
boring a feedthrough port into an enclosure bulkhead of a high expansion metal, said port having a diameter over most of its length which will accept said rim with minimal clearance;
inserting said ferrule into said port rim end first with said rim centering the remaining length of the ferrule within the bore with essential uniform clearance; and introducing molten solder into said uniform clearance space thereby to provide a seal having radial compliance to accommodate differential expansion between said ferrule and said high expansion metal.
bonding a connector pin into a tubular ferrule using a glass-like insulating material, said ferrule being constructed of a metal having a coefficient of expansion which approximates that of said insulating material, said ferrule being of substantially uniform outer diameter over most of its length but having, at its inner end, a shallow rim having a height which is substantially equal to the thickness of a maximally compliant solder joint;
boring a feedthrough port into an enclosure bulkhead of a high expansion metal, said port having a diameter over most of its length which will accept said rim with minimal clearance;
inserting said ferrule into said port rim end first with said rim centering the remaining length of the ferrule within the bore with essential uniform clearance; and introducing molten solder into said uniform clearance space thereby to provide a seal having radial compliance to accommodate differential expansion between said ferrule and said high expansion metal.
2. The method as set forth in claim 1 wherein the height of said rim is in the order of 0.005 inch.
3. The method as set forth in claim 1 wherein said substantially uniform outer diameter is in the order of 0.100 inch and the height of said rim is in the order of 0.005 inch.
4. The method as set forth in claim 3 wherein said high expansion metal is aluminum and said port is plated to facilitate soldering.
5. The method of making a hermetically sealed electrical feedthrough connection into an enclosure bulkhead of a high expansion metal, said method comprising:
bonding a connector pin into a tubular ferrule using a glass-like insulating material, said ferrule being constructed of a metal having a coefficient of expansion which approximates that of said insulating material, said ferrule being of substantially uniform outer diameter over its length;
boring a feedthrough port into an enclosure bulkhead of a high expansion metal, said port having a diameter over most of its length which will accept said ferrule with clearance which is substantially equal to the thickness of a maximally compliant solder joint and having, at the inner end of said port, a portion of reduced diameter which will receive one end of said ferrule with minimal clearance;
inserting said ferrule into said port with said portion of reduced diameter centering the remaining length of the ferrule within the bore with essential uniform clearance; and introducing molten solder into said uniform clearance space thereby to provide a seal having radial compliance to accommodate differential expansion between said ferrule and said high expansion metal.
bonding a connector pin into a tubular ferrule using a glass-like insulating material, said ferrule being constructed of a metal having a coefficient of expansion which approximates that of said insulating material, said ferrule being of substantially uniform outer diameter over its length;
boring a feedthrough port into an enclosure bulkhead of a high expansion metal, said port having a diameter over most of its length which will accept said ferrule with clearance which is substantially equal to the thickness of a maximally compliant solder joint and having, at the inner end of said port, a portion of reduced diameter which will receive one end of said ferrule with minimal clearance;
inserting said ferrule into said port with said portion of reduced diameter centering the remaining length of the ferrule within the bore with essential uniform clearance; and introducing molten solder into said uniform clearance space thereby to provide a seal having radial compliance to accommodate differential expansion between said ferrule and said high expansion metal.
6. The method as set forth in claim 5 wherein the reduction in diameter of the port at its inner end is in the order of 0.005 inch.
7. The method as set forth in claim 5 wherein the nominal diameter of said port is in the order of 0.100 inch and the reduction in diameter is in the order of 0.005 inch.
8. The method as set forth in claim 7 wherein said high expansion metal is aluminum and said port is plated to facilitate soldering.
9. In an enclosure bulkhead of a high expansion metal, a hermetically sealed electrical feedthrough connection comprising:
a tubular ferrule constructed of a metal having a coefficient of expansion which approximates that of glass, said ferrule being of substantially uniform outer diameter over most of its length but having, at its inner end, a shallow rim having a height which is substantially equal to the thickness of a maximally compliant solder joint;
a connector pin concentric within said ferrule;
a glass-like insulator bonded between said pin and said ferrule;
a feedthrough port in said enclosure bulkhead, said port having a diameter over most of its length which will accept said rim with minimal clearance, said ferrule being inserted into said port rim end first with said rim centering the remaining length of the ferrule within the bore with essential uniform clearance; and solder filling said uniform clearance space thereby to provide a seal having radial compliance to accommodate differential expansion between said ferrule and said high expansion metal.
a tubular ferrule constructed of a metal having a coefficient of expansion which approximates that of glass, said ferrule being of substantially uniform outer diameter over most of its length but having, at its inner end, a shallow rim having a height which is substantially equal to the thickness of a maximally compliant solder joint;
a connector pin concentric within said ferrule;
a glass-like insulator bonded between said pin and said ferrule;
a feedthrough port in said enclosure bulkhead, said port having a diameter over most of its length which will accept said rim with minimal clearance, said ferrule being inserted into said port rim end first with said rim centering the remaining length of the ferrule within the bore with essential uniform clearance; and solder filling said uniform clearance space thereby to provide a seal having radial compliance to accommodate differential expansion between said ferrule and said high expansion metal.
10. The feedthrough connection as set forth in claim 9 wherein the height of said rim is in the order of 0.005 inch.
11. In an enclosure bulkhead of a high expansion metal, a hermetically sealed electrical feedthrough connection comprising:
a tubular ferrule constructed of a metal having a coefficient of expansion which approximates that of glass, said ferrule being of substantially uniform outer diameter over its length;
a connector pin concentric within said ferrule;
a glass-like insulator bonded between said pin and said ferrule;
a feedthrough port in said enclosure bulkhead, said port having a diameter over most of its length which will accept said ferrule with clearance which is substantially equal to the thickness of a maximally compliant solder joint and having, at the inner end of said port, a portion of reduced diameter which will receive said ferrule with minimal clearance, said ferrule being inserted into said port with said portion of reduced diameter centering the remaining length of the ferrule within the bore with essential uniform clearance; and solder filling said uniform clearance space thereby to provide a seal having radial compliance to accommodate differential expansion between said ferrule and said high expansion metal.
a tubular ferrule constructed of a metal having a coefficient of expansion which approximates that of glass, said ferrule being of substantially uniform outer diameter over its length;
a connector pin concentric within said ferrule;
a glass-like insulator bonded between said pin and said ferrule;
a feedthrough port in said enclosure bulkhead, said port having a diameter over most of its length which will accept said ferrule with clearance which is substantially equal to the thickness of a maximally compliant solder joint and having, at the inner end of said port, a portion of reduced diameter which will receive said ferrule with minimal clearance, said ferrule being inserted into said port with said portion of reduced diameter centering the remaining length of the ferrule within the bore with essential uniform clearance; and solder filling said uniform clearance space thereby to provide a seal having radial compliance to accommodate differential expansion between said ferrule and said high expansion metal.
12. The feedthrough connection as set forth in claim 11 wherein the reduction in diameter of the port at its inner end is in the order of 0.005 inch.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US07/135,602 US4841101A (en) | 1987-12-21 | 1987-12-21 | Hermetically sealed feedthroughs and methods of making same |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1318371C true CA1318371C (en) | 1993-05-25 |
Family
ID=22468800
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000601234A Expired - Lifetime CA1318371C (en) | 1987-12-21 | 1989-05-31 | Hermetically sealed feedthroughs |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US4841101A (en) |
| CA (1) | CA1318371C (en) |
Families Citing this family (48)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4915719A (en) * | 1988-09-30 | 1990-04-10 | Honeywell Inc. | Method of producing a hermetic glass to metal seal without metal oxidation |
| US5015207A (en) * | 1989-12-28 | 1991-05-14 | Isotronics, Inc. | Multi-path feed-thru lead and method for formation thereof |
| US5223672A (en) * | 1990-06-11 | 1993-06-29 | Trw Inc. | Hermetically sealed aluminum package for hybrid microcircuits |
| FR2669254B1 (en) * | 1990-11-16 | 1995-01-06 | Egide Sa | METHOD OF BRAZING AN ELEMENT CROSS-SECTION TO A WALL, JUNCTION ASSEMBLY FOR IMPLEMENTING A HOUSING FOR AN ELECTRONIC COMPONENT. |
| DE69218122T2 (en) * | 1991-11-27 | 1997-06-19 | Fujitsu Ltd | Arrangement for a coaxial line |
| US5308925A (en) * | 1992-06-26 | 1994-05-03 | Emerson Electric Co. | Conductive pin assembly for a machine housing |
| WO1994003037A1 (en) * | 1992-07-27 | 1994-02-03 | Pacific Coast Technologies | Sealable electronics packages and methods of producing and sealing such packages |
| US5563562A (en) * | 1995-03-24 | 1996-10-08 | Itt Industries, Inc. | RF feed-through connector |
| BR9608062A (en) * | 1995-04-28 | 1999-11-30 | Rosemount Inc | Mounting set for a pressure sensor on a pressure transmitter, and, process for connecting a pressure transmitter holder. |
| US6139336A (en) * | 1996-11-14 | 2000-10-31 | Berg Technology, Inc. | High density connector having a ball type of contact surface |
| US6261872B1 (en) | 1997-09-18 | 2001-07-17 | Trw Inc. | Method of producing an advanced RF electronic package |
| US5936494A (en) * | 1998-03-20 | 1999-08-10 | Special Hermetic Products, Inc. | Waveguide window |
| US6111198A (en) * | 1998-06-15 | 2000-08-29 | Olin Aegis | Duplex feedthrough and method therefor |
| US6433276B1 (en) * | 2001-03-14 | 2002-08-13 | John Bellora | Surface mount feedthrough |
| US6762909B2 (en) | 2002-08-02 | 2004-07-13 | Hitachi Global Storage Technologies Netherlands B.V. | Magnetic recording disk drive with self-limiting wearable contact pad air-bearing slider in hermetically sealed environment |
| US6918617B2 (en) * | 2003-03-20 | 2005-07-19 | Thaddeus E. Nordquist | Self-centering soldered feed-through |
| US6899545B2 (en) * | 2003-10-16 | 2005-05-31 | Special Hermetic Products, Inc. | Coupling and method for producing a hermetic seal |
| US6903268B2 (en) * | 2003-10-29 | 2005-06-07 | Medtronic, Inc. | Implantable device feedthrough assembly |
| US7168979B2 (en) * | 2004-08-05 | 2007-01-30 | Agilent Technologies, Inc. | Microwave connector |
| JP4812288B2 (en) * | 2004-11-22 | 2011-11-09 | 京セラ株式会社 | Fuel reformer storage container and fuel reformer |
| US20060160415A1 (en) * | 2005-01-20 | 2006-07-20 | Pollock John A | Coupling and method for producing a hermetic seal |
| US8027739B2 (en) | 2007-09-13 | 2011-09-27 | Cardiac Pacemakers, Inc. | Medical device having a glass coating and method therefor |
| GB0721556D0 (en) * | 2007-11-02 | 2007-12-12 | Siemens Magnet Technology Ltd | Current leadthrough for cryostat |
| EP2278666A4 (en) * | 2008-05-15 | 2014-04-02 | Sumitomo Wiring Systems | Water stop structure for wire harness |
| DE102009008673B3 (en) * | 2009-02-12 | 2010-08-19 | Schott Ag | Punched feedthrough element with soldered contact pin |
| DE202010007043U1 (en) | 2010-04-15 | 2010-09-30 | Micro-Epsilon Messtechnik Gmbh & Co. Kg | sensor |
| US11462789B2 (en) | 2011-02-18 | 2022-10-04 | Schott Ag | Base body for feeding through of a conductor, and a housing component of a housing, in particular a battery housing comprising said base body |
| US10224521B2 (en) | 2011-02-18 | 2019-03-05 | Schott Ag | Feed-through |
| WO2018114392A2 (en) | 2016-12-20 | 2018-06-28 | Schott Ag | Main part for the leadthrough of a conductor and housing part of a housing, in particular of a battery housing comprising said main part |
| CN109956682B (en) | 2011-02-18 | 2022-05-17 | 肖特公开股份有限公司 | Solder glass, insulating sleeve and device comprising insulating sleeve |
| KR101853160B1 (en) | 2011-06-10 | 2018-06-04 | 쇼오트 아게 | Feedthrough |
| WO2014143179A1 (en) | 2013-03-15 | 2014-09-18 | Emerson Electric Co. | High-pressure hermetic terminal |
| US9208929B2 (en) | 2013-09-20 | 2015-12-08 | Schott Corporation | GTMS connector for oil and gas market |
| GB2534757A (en) * | 2013-10-01 | 2016-08-03 | Onesubsea Ip Uk Ltd | Electrical conductor and method of fabricating the same |
| US9138821B2 (en) * | 2014-01-17 | 2015-09-22 | Medtronic, Inc. | Methods for simultaneously brazing a ferrule and lead pins |
| US20170203380A1 (en) * | 2016-01-20 | 2017-07-20 | Indium Corporation | Capillary block |
| US11894322B2 (en) | 2018-05-29 | 2024-02-06 | Analog Devices, Inc. | Launch structures for radio frequency integrated device packages |
| JP7231339B2 (en) * | 2018-06-01 | 2023-03-01 | ショット日本株式会社 | airtight terminal |
| US11424196B2 (en) | 2018-06-01 | 2022-08-23 | Analog Devices, Inc. | Matching circuit for integrated circuit die |
| KR20210092810A (en) | 2018-11-23 | 2021-07-26 | 쇼오트 아게 | Electrical Feedthrough Glass-to-Metal Electrodes |
| DE102018220118A1 (en) | 2018-11-23 | 2020-05-28 | Schott Ag | execution |
| US11417615B2 (en) | 2018-11-27 | 2022-08-16 | Analog Devices, Inc. | Transition circuitry for integrated circuit die |
| US11350537B2 (en) * | 2019-05-21 | 2022-05-31 | Analog Devices, Inc. | Electrical feedthrough assembly |
| US11224754B2 (en) | 2019-05-23 | 2022-01-18 | Medtronic, Inc. | Feedthrough assembly with feature for controlling component position |
| DE102020107224A1 (en) | 2020-03-17 | 2021-09-23 | Schott Ag | Electrical facility |
| TW202228344A (en) * | 2020-09-30 | 2022-07-16 | 美商康寧光纖通信射頻有限責任公司 | Rf connectors with dispensable and formable insulative materials and related methods |
| DE202021103495U1 (en) | 2021-06-30 | 2022-10-07 | Schott Ag | Electrical device, in particular microbattery |
| US11744021B2 (en) | 2022-01-21 | 2023-08-29 | Analog Devices, Inc. | Electronic assembly |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB697420A (en) * | 1951-08-03 | 1953-09-23 | Longford Engineering Company L | Means for making electrical connections through partitions |
| US3119052A (en) * | 1959-11-24 | 1964-01-21 | Nippon Electric Co | Enclosures for semi-conductor electronic elements |
-
1987
- 1987-12-21 US US07/135,602 patent/US4841101A/en not_active Expired - Lifetime
-
1989
- 1989-05-31 CA CA000601234A patent/CA1318371C/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| US4841101A (en) | 1989-06-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1318371C (en) | Hermetically sealed feedthroughs | |
| US4545637A (en) | Plug connector and method for connecting same | |
| US4174145A (en) | High pressure electrical insulated feed thru connector | |
| JPH0461450B2 (en) | ||
| CA1121630A (en) | Fiber optic connector assembly | |
| US4135781A (en) | Optical fiber termination | |
| US4172212A (en) | Submarine housing for submarine cable system repeater components or the like | |
| US3685005A (en) | Hermetically sealed connector | |
| US4088381A (en) | Interconnector | |
| JP3899017B2 (en) | Method for hermetically sealing a fiber optic light guide in a metal feedthrough sleeve with glass solder and hermetic feedthrough apparatus manufactured thereby | |
| US4593970A (en) | Fiber optic feedthrough module, and method of making same | |
| CA2000711A1 (en) | Optical fiber composite insulator and method of producing the same | |
| US6821145B1 (en) | Hermetically sealed connector and methods of providing the same | |
| US5170142A (en) | Radio frequency feedthrough seal and method | |
| US5033808A (en) | Quick disconnect fiber optic feedthrough for well borehole usage | |
| EP0112379B1 (en) | Fabrication of optical connectors | |
| US5521996A (en) | Electrical and fiber-optic connector | |
| US20060154521A1 (en) | Method for sealing partition bushing connector coaxial contacts, adapted coaxial contact and resulting connector | |
| US6474879B1 (en) | Post assembly metallization of a device to form hermetic seal | |
| US6407504B1 (en) | High pressure discharge lamp having composite electrode | |
| US4062612A (en) | Electrical feedthrough devices | |
| US4136442A (en) | Interconnector | |
| US6469599B1 (en) | Assembly for the pressure-tight separation of a first waveguide from a second waveguide and method of producing such an assembly | |
| US4689440A (en) | Gas pressurizable coaxial cables and cable termination fitting assemblies | |
| US5013110A (en) | Optical fibre end piece for an optical fibre |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed | ||
| MKEC | Expiry (correction) |
Effective date: 20121205 |