CA1088811A - Method of and means of desoldering - Google Patents
Method of and means of desolderingInfo
- Publication number
- CA1088811A CA1088811A CA289,374A CA289374A CA1088811A CA 1088811 A CA1088811 A CA 1088811A CA 289374 A CA289374 A CA 289374A CA 1088811 A CA1088811 A CA 1088811A
- Authority
- CA
- Canada
- Prior art keywords
- braid
- length
- joint
- circuit
- solder
- 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
Links
Landscapes
- Connections Effected By Soldering, Adhesion, Or Permanent Deformation (AREA)
Abstract
Abstract of the Disclosure In desoldering soldered joints, an electrically conductive wick or braid, used to absorb molten solder from the joint, is connected to a ground conductor of the circuit of which the joint forms a part, thus pre-venting possible damage to voltage-sensitive circuit components, for example PET's. A solder-absorbent conductive wick is provided with connecting means for connection either directly or through an intermediate conductor with a ground conductor of a circuit in which a joint is to be desoldered by the aid of the wick.
Connection to the circuit conductor may be by way of a first electrical connector portion mating with a second connector portion on a circuit board carrying the circuit.
The first connector portion may be mounted on a jig or locating fixture arranged to receive the circuit board.
The wick may be wound on a spool and have its end electrically connected to a contact member of an electrical connector portion mounted on the spool and connected to the circuit by way of a wire having appropriate connector portions at its ends.
Connection to the circuit conductor may be by way of a first electrical connector portion mating with a second connector portion on a circuit board carrying the circuit.
The first connector portion may be mounted on a jig or locating fixture arranged to receive the circuit board.
The wick may be wound on a spool and have its end electrically connected to a contact member of an electrical connector portion mounted on the spool and connected to the circuit by way of a wire having appropriate connector portions at its ends.
Description
Back~rouIId ol` tlle inventior-Field of the Irlven-tion _ This invention relates to an improved method of desoldering, that is of removing solder from joints by which electronic componen-ts are electrically connected in a circuit.
Description of the Prior Art Rnown methods of desoldering using ~uction to remove the solder a~ter this has been melted b~ the application of a heated tip to the joint, either by using a soldering iron having at its tip a channel connected to a suction source, or by using a normal soldering iron and manually operated suction device employing a resilient bulb, are found to give rise at the site of the desoldering application to electrostatic charges which m2y cause damage to sensitive electronic components, such as ~ield-effect transistors.
A similar difficulty may arise when using a metal wick or braid for removing molten solder from elcctronic circuit joints to be unsoldered, because the operative performing the unsoldering operation usually holds the braid in his ~ingers and an electrostatic potential applied to the joint from the soldering device or even ~rom the person of the operator b~ way of the wiclc or braid may be sufficient to cause damage to sensitive electronic components.
.' ~
. . . , , ~ . -............ - . - -Summclry of th~_~nvention It icl an object o~ the in~ention to provide an improved desolderin$ method in which dama~e to voltage-sensitive components is prevented.
It is a further object of the invention to provide an improved desoldering method which prevents the inadvertent application of undesirable potential to an electric circuit containing a joint to be desol~ered.
It is another object of the invention to provide de~oldering apparatus facilitating the safe desoldering of joints in electric circuits.
It is a specific object of the present in~ention to provide a method of ~esoldexing a soldered joint in an electronic circuit which comprises placing in ;~
electrical contact with the joint a metal wick or braid which i~ electrically connected to a grounded portion of the electronic circuit and heating the solder of the joint to its melting point.
It will be understood that the presence o~ the earthed metal wick or braid in electrical contact with the joint will prevent an~ potential different from earth potential from appearing at the joint and will thu~
ensure that deleterious potentials cannot be applied to sen~itive component~ in the circuit.
In one manner of carrying out the invention a length o~ metal desoldering wick is provided at one end ~
with a spring clip or other means convenient to establish an electrical connection between the wick and an earthed .
portion of an electronic circuit includins a joint ~o be desoldered. The connecting means i~ applied to th~
circuit to produc~ the required connection of thc wick to the ear~hed circuit portion and the other end of the S braid is applied $o the joint to be soldered before the solder i9 melted, thus preven$ing the appearance of undesired electrical potentials upon the conductors of the jointO
In an alternative manner of carr~ing out the invention a solder-absorbent wick is provided at one end with a means convenient for the connectlon o~ an electrically conductive wire and is ¢onnected to an earthed portion of an electronic circuit by means of a wire connec*ed to an appropriate circuit conductor i5 and to the ~ick before being used as above described in unsoldering a joint in the circuit.
When a supply of desoldering wick is carried on a plastics spool or reel, as is often the case, it i~ convenient to provide on the spool a portion o~ an electrical connector, to which portion the inner end of the wick is electrically connected. A ~lexible electrical conductor provided at one end with a connector portion matable with that on the spool, and at it~
other end with a spring clip or other means convenient for establi~hing electrical connection to a grounded portion o~ a circuit containing a joint to ba desoldered.
I~, as is sometimes the case, an oparator i~
re~uired to deal with electronic circuits carried in a jig or other locating fixture, it will often be convenient ~or the eleotrical connection of the wick to the circuit to be affccted by way o~ a connectins mea~ provided on the jig or fixtur~ to recci~e ~lectr:ic~l connecting means provid~d on the clectronic circuit.
Brief Description of the Drawing Figure i illustrates the operatioll of unsoldering a joint in an electronic circuit by the method of the invention;
Figure 2 illustrates improved means for performing the ~ethod of Figure 1; and Figure 3 illustrates a modification of the mean~ shown in Figure 2.
Description of the Preferred Embodiment~
15 In Figure 1 there is shown a fragment 10 of a printed circuit board 11 carrying an electronic circuit.
The circuit conductors lia on that face of the board that i8 shown as uppermost in the dra~ing. Four such conductors are shown at 12, 13, 14 and 15. An electronic component beneath the board has wire ends 16, 17, 18 that extend ~pwardly through holes in the board and are connected to conductors lZ-14 by soldered joints 19-21. Conductor 15 o~ the printed circuit board 11 is a grounded conductor as is indicated by sround symbol 22 and is electrically connected to a contact member 23 that extends beyond the edge 24 of the board 11.
To desolder joint 19 in accordance with the invention one end of a length of solder-absorbent wick or braid 25 is electrically connected to grounded 5 - -~
' ~3~
cond~ctor 15 of circuit board il. This m~y be effected most conveniently by providing wick 25 wi-th a spring clip 26 su.itable to grip con-tact member 23 or some other accessible portion of a grounded conductor of the circuit. Alternatively, wick 25 may be provided with an electrical connector portion matable with a circuit board connector so as to establish the required connection. The free end 26A is applied to joint 19, thus ensuring that this joint is held at ground potential and the solder of the joint is then melted by the application of a soldering iron 27 or in other known manner.
Figure 2 shows an alternati~e arrangement o~
desoldering wick convenient for carrying out the in~ention.
15 ~ A length of metal wick or braid ~ is pro~ided at one end with an electrical connector portion 37. A flexible electrical conductor 38 is provided at one end with an electrical connector portio~ 39 matable with connector portion 37 to establish electrical connection between wick 36 and conductor 38. At the other end of ~lexible conduotor 38 is provided an electrical connector portion ~0 matable with a grounded conductor o~ the electronic circuit o~ which a joint is to be desoldered.
When desoldering operations are required to be carried out on a plurality of similar structural units ~or example, printed circuit boards, such as 41 ~t will o~ten be convenient to arrange that connector portion 40 is secured to a ii8 or locating ~ixture 42 sultable to receive one of the structural units, so that the necessary connection of wick 36 *o a grounded alrFuit ~A
~' .
', ~ ' ' ` .
'' ' . . ` ' ' conductor is necessarily establishcd by the act of inserting the structural unit in the iiS or fixture.
Figure 3 shows a modification of the arrange-ment o~ desoldering wick shown in Figure 2. It is known to provide desoldering ~ick on a plastics spool.
In the arrangement shown in Figure 3, a plastics spool 43 carrying a length o~ desolderins wick 36 i~
provided with an electrical connector portion 37 to which the inner end of wick 36 is connected~ As for the arrangement of Figure 2, connector 37 will be used to establish electrical connection between the desoldering wick 36 and a grounded conductor o~ an electronic circuit be~ore the wick is used to desolder a joint in th0 circuit~
Description of the Prior Art Rnown methods of desoldering using ~uction to remove the solder a~ter this has been melted b~ the application of a heated tip to the joint, either by using a soldering iron having at its tip a channel connected to a suction source, or by using a normal soldering iron and manually operated suction device employing a resilient bulb, are found to give rise at the site of the desoldering application to electrostatic charges which m2y cause damage to sensitive electronic components, such as ~ield-effect transistors.
A similar difficulty may arise when using a metal wick or braid for removing molten solder from elcctronic circuit joints to be unsoldered, because the operative performing the unsoldering operation usually holds the braid in his ~ingers and an electrostatic potential applied to the joint from the soldering device or even ~rom the person of the operator b~ way of the wiclc or braid may be sufficient to cause damage to sensitive electronic components.
.' ~
. . . , , ~ . -............ - . - -Summclry of th~_~nvention It icl an object o~ the in~ention to provide an improved desolderin$ method in which dama~e to voltage-sensitive components is prevented.
It is a further object of the invention to provide an improved desoldering method which prevents the inadvertent application of undesirable potential to an electric circuit containing a joint to be desol~ered.
It is another object of the invention to provide de~oldering apparatus facilitating the safe desoldering of joints in electric circuits.
It is a specific object of the present in~ention to provide a method of ~esoldexing a soldered joint in an electronic circuit which comprises placing in ;~
electrical contact with the joint a metal wick or braid which i~ electrically connected to a grounded portion of the electronic circuit and heating the solder of the joint to its melting point.
It will be understood that the presence o~ the earthed metal wick or braid in electrical contact with the joint will prevent an~ potential different from earth potential from appearing at the joint and will thu~
ensure that deleterious potentials cannot be applied to sen~itive component~ in the circuit.
In one manner of carrying out the invention a length o~ metal desoldering wick is provided at one end ~
with a spring clip or other means convenient to establish an electrical connection between the wick and an earthed .
portion of an electronic circuit includins a joint ~o be desoldered. The connecting means i~ applied to th~
circuit to produc~ the required connection of thc wick to the ear~hed circuit portion and the other end of the S braid is applied $o the joint to be soldered before the solder i9 melted, thus preven$ing the appearance of undesired electrical potentials upon the conductors of the jointO
In an alternative manner of carr~ing out the invention a solder-absorbent wick is provided at one end with a means convenient for the connectlon o~ an electrically conductive wire and is ¢onnected to an earthed portion of an electronic circuit by means of a wire connec*ed to an appropriate circuit conductor i5 and to the ~ick before being used as above described in unsoldering a joint in the circuit.
When a supply of desoldering wick is carried on a plastics spool or reel, as is often the case, it i~ convenient to provide on the spool a portion o~ an electrical connector, to which portion the inner end of the wick is electrically connected. A ~lexible electrical conductor provided at one end with a connector portion matable with that on the spool, and at it~
other end with a spring clip or other means convenient for establi~hing electrical connection to a grounded portion o~ a circuit containing a joint to ba desoldered.
I~, as is sometimes the case, an oparator i~
re~uired to deal with electronic circuits carried in a jig or other locating fixture, it will often be convenient ~or the eleotrical connection of the wick to the circuit to be affccted by way o~ a connectins mea~ provided on the jig or fixtur~ to recci~e ~lectr:ic~l connecting means provid~d on the clectronic circuit.
Brief Description of the Drawing Figure i illustrates the operatioll of unsoldering a joint in an electronic circuit by the method of the invention;
Figure 2 illustrates improved means for performing the ~ethod of Figure 1; and Figure 3 illustrates a modification of the mean~ shown in Figure 2.
Description of the Preferred Embodiment~
15 In Figure 1 there is shown a fragment 10 of a printed circuit board 11 carrying an electronic circuit.
The circuit conductors lia on that face of the board that i8 shown as uppermost in the dra~ing. Four such conductors are shown at 12, 13, 14 and 15. An electronic component beneath the board has wire ends 16, 17, 18 that extend ~pwardly through holes in the board and are connected to conductors lZ-14 by soldered joints 19-21. Conductor 15 o~ the printed circuit board 11 is a grounded conductor as is indicated by sround symbol 22 and is electrically connected to a contact member 23 that extends beyond the edge 24 of the board 11.
To desolder joint 19 in accordance with the invention one end of a length of solder-absorbent wick or braid 25 is electrically connected to grounded 5 - -~
' ~3~
cond~ctor 15 of circuit board il. This m~y be effected most conveniently by providing wick 25 wi-th a spring clip 26 su.itable to grip con-tact member 23 or some other accessible portion of a grounded conductor of the circuit. Alternatively, wick 25 may be provided with an electrical connector portion matable with a circuit board connector so as to establish the required connection. The free end 26A is applied to joint 19, thus ensuring that this joint is held at ground potential and the solder of the joint is then melted by the application of a soldering iron 27 or in other known manner.
Figure 2 shows an alternati~e arrangement o~
desoldering wick convenient for carrying out the in~ention.
15 ~ A length of metal wick or braid ~ is pro~ided at one end with an electrical connector portion 37. A flexible electrical conductor 38 is provided at one end with an electrical connector portio~ 39 matable with connector portion 37 to establish electrical connection between wick 36 and conductor 38. At the other end of ~lexible conduotor 38 is provided an electrical connector portion ~0 matable with a grounded conductor o~ the electronic circuit o~ which a joint is to be desoldered.
When desoldering operations are required to be carried out on a plurality of similar structural units ~or example, printed circuit boards, such as 41 ~t will o~ten be convenient to arrange that connector portion 40 is secured to a ii8 or locating ~ixture 42 sultable to receive one of the structural units, so that the necessary connection of wick 36 *o a grounded alrFuit ~A
~' .
', ~ ' ' ` .
'' ' . . ` ' ' conductor is necessarily establishcd by the act of inserting the structural unit in the iiS or fixture.
Figure 3 shows a modification of the arrange-ment o~ desoldering wick shown in Figure 2. It is known to provide desoldering ~ick on a plastics spool.
In the arrangement shown in Figure 3, a plastics spool 43 carrying a length o~ desolderins wick 36 i~
provided with an electrical connector portion 37 to which the inner end of wick 36 is connected~ As for the arrangement of Figure 2, connector 37 will be used to establish electrical connection between the desoldering wick 36 and a grounded conductor o~ an electronic circuit be~ore the wick is used to desolder a joint in th0 circuit~
Claims (8)
1. Apparatus for desoldering a soldered joint between two electrically conductive components of a circuit, comprising (a) a length of conductive solder-absorbent braid, said length of braid being free at one end for direct engagement with the soldered joint; and (b) ground connection means connected with the other end of said length of braid for connecting said braid with ground, whereby when the soldered joint is heated to melt the solder thereof, the melted solder is removed from the joint by absorption by said one braid length end, and any potential difference appearing across the joint is reduced to ground potential via the length of braid.
2. Apparatus as defined in claim 1, wherein said ground connection means comprises a spring clip.
3. Apparatus as defined in claim 1, wherein said ground connection means includes separable connector means.
4. Apparatus as defined in claim 3, and further including spool means upon which said length of braid is wound, said separable connector means including a pair of connector elements one of which is mounted on said spool means.
5. Desoldering apparatus for removing the solder from a soldered joint between two electrical components of a circuit mounted on a structural unit, said circuit including a ground conductor, comprising (a) jig means for supporting the structural unit;
(b) first connector means (40) connected with said jig means for electrical engagement with the ground conductor of the circuit;
(c) a flexible conductor (38) connected at one end with said first connector means;
(d) a length of conductive solder-absorbent braid (36), said length of braid being free at one end for direct engagement with the soldered joint; and (e) second connector means (37, 39) for connecting the other ends of said flexible conductor and said braid, respectively, whereby when the soldered joint is heated to melt the solder thereof, the melted solder is removed from the joint by absorption by said one braid length end, and and potential difference appearing across the joint is reduced to ground potential via said braid length, said second connector means, said flexible conductor, and said first connector means.
(b) first connector means (40) connected with said jig means for electrical engagement with the ground conductor of the circuit;
(c) a flexible conductor (38) connected at one end with said first connector means;
(d) a length of conductive solder-absorbent braid (36), said length of braid being free at one end for direct engagement with the soldered joint; and (e) second connector means (37, 39) for connecting the other ends of said flexible conductor and said braid, respectively, whereby when the soldered joint is heated to melt the solder thereof, the melted solder is removed from the joint by absorption by said one braid length end, and and potential difference appearing across the joint is reduced to ground potential via said braid length, said second connector means, said flexible conductor, and said first connector means.
6. A method for desoldering a soldered joint between two electrical components of a circuit, which comprises the steps of (a) connecting one end of a length of conductive solder-absorbing braid with ground;
(b) placing the other end of said length of braid in engagement with the joint; and (c) heating the joint to melt the solder thereof, whereby the solder is removed by the capillary action of the wick, and the potential difference across the joint is reduced to ground potential via the length of braid.
(b) placing the other end of said length of braid in engagement with the joint; and (c) heating the joint to melt the solder thereof, whereby the solder is removed by the capillary action of the wick, and the potential difference across the joint is reduced to ground potential via the length of braid.
7. The method as defined in claim 6, wherein.
the circuit includes a ground conductor, and further wherein the connecting step includes connecting the said one end of the braid length with the ground conductor by a conductive spring clip.
the circuit includes a ground conductor, and further wherein the connecting step includes connecting the said one end of the braid length with the ground conductor by a conductive spring clip.
8. The method as defined in claim 7, wherein the circuit is arranged on a circuit board and includes a ground conductor, and further including the preliminary step of mounting the circuit board in a jig, said ground connecting step including the steps of mounting one end of a flexible conductor on said jig in electrical engagement with the ground conductor, and electrically connecting the other ends of said flexible conductor and said length of braid, respectively.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA289,374A CA1088811A (en) | 1977-10-24 | 1977-10-24 | Method of and means of desoldering |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA289,374A CA1088811A (en) | 1977-10-24 | 1977-10-24 | Method of and means of desoldering |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1088811A true CA1088811A (en) | 1980-11-04 |
Family
ID=4109842
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA289,374A Expired CA1088811A (en) | 1977-10-24 | 1977-10-24 | Method of and means of desoldering |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1088811A (en) |
-
1977
- 1977-10-24 CA CA289,374A patent/CA1088811A/en not_active Expired
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |