US20020057986A1 - Solders - Google Patents
Solders Download PDFInfo
- Publication number
- US20020057986A1 US20020057986A1 US09/932,059 US93205901A US2002057986A1 US 20020057986 A1 US20020057986 A1 US 20020057986A1 US 93205901 A US93205901 A US 93205901A US 2002057986 A1 US2002057986 A1 US 2002057986A1
- Authority
- US
- United States
- Prior art keywords
- solder
- lead
- solders
- tin
- present
- 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.)
- Abandoned
Links
- 229910000679 solder Inorganic materials 0.000 title claims abstract description 153
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 claims abstract description 26
- 229910052718 tin Inorganic materials 0.000 claims abstract description 24
- 229910052709 silver Inorganic materials 0.000 claims abstract description 22
- 239000004332 silver Substances 0.000 claims abstract description 22
- 229910052797 bismuth Inorganic materials 0.000 claims abstract description 21
- JCXGWMGPZLAOME-UHFFFAOYSA-N bismuth atom Chemical compound [Bi] JCXGWMGPZLAOME-UHFFFAOYSA-N 0.000 claims abstract description 21
- 229910052738 indium Inorganic materials 0.000 claims abstract description 21
- APFVFJFRJDLVQX-UHFFFAOYSA-N indium atom Chemical compound [In] APFVFJFRJDLVQX-UHFFFAOYSA-N 0.000 claims abstract description 21
- 238000000034 method Methods 0.000 claims description 29
- 238000005476 soldering Methods 0.000 claims description 23
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 claims description 21
- 238000012360 testing method Methods 0.000 description 23
- 238000009736 wetting Methods 0.000 description 23
- 238000000576 coating method Methods 0.000 description 12
- 230000008569 process Effects 0.000 description 8
- 230000004907 flux Effects 0.000 description 5
- 238000011109 contamination Methods 0.000 description 4
- 230000000704 physical effect Effects 0.000 description 4
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 3
- 229910045601 alloy Inorganic materials 0.000 description 3
- 239000000956 alloy Substances 0.000 description 3
- 229910052802 copper Inorganic materials 0.000 description 3
- 239000010949 copper Substances 0.000 description 3
- 238000007654 immersion Methods 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 229910000978 Pb alloy Inorganic materials 0.000 description 2
- 229910001128 Sn alloy Inorganic materials 0.000 description 2
- 238000004140 cleaning Methods 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- 230000006978 adaptation Effects 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 239000000356 contaminant Substances 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 239000010931 gold Substances 0.000 description 1
- BHEPBYXIRTUNPN-UHFFFAOYSA-N hydridophosphorus(.) (triplet) Chemical compound [PH] BHEPBYXIRTUNPN-UHFFFAOYSA-N 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- 239000011135 tin Substances 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
- B23K35/22—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by the composition or nature of the material
- B23K35/24—Selection of soldering or welding materials proper
- B23K35/26—Selection of soldering or welding materials proper with the principal constituent melting at less than 400 degrees C
- B23K35/262—Sn as the principal constituent
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C13/00—Alloys based on tin
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C13/00—Alloys based on tin
- C22C13/02—Alloys based on tin with antimony or bismuth as the next major constituent
Definitions
- THIS INVENTION relates to solders, and in particular to solders which are substantially lead-free.
- solders contain lead as a major constituent thereof. Such solders often have desirable physical properties, and the use of lead-containing solders is widespread among several industries, including those concerned with the production of printed circuit boards.
- one aspect of the present invention provides a solder comprising: between 87.2% and 89.5% tin; between 4.0% and 4.8% bismuth; between 3.5% and 4.5% indium; and between 3.0% and 3.5% silver.
- the solder is a substantially lead-free solder.
- the solder is a lead-free solder.
- the solder comprises 88.3% tin, 4.5% bismuth, 4.0% indium and 3.2% silver.
- Another aspect of the present invention provides a method of preparing a solder, comprising the step of mixing tin, bismuth, indium and silver such that: the proportion of tin in the solder is between 87.2% and 89.5%; the proportion of bismuth in the solder is between 4.0% and 4.8%; the proportion of indium in the solder is between 3.5% and 4.5%; and the proportion of silver in the solder is between 3.0% and 3.5%.
- the method comprises the addition of substantially no lead to the solder.
- the method comprises the addition of no lead to the solder.
- the method comprises the step of mixing tin, bismuth, indium and silver such that: the proportion of tin in the solder is 88.3%; the proportion of bismuth in the solder is 4.5%; the proportion of indium in the solder is 4.0%; and the proportion of silver in the solder is 3.2%.
- a further aspect of the present invention provides a method of soldering, comprising the step of using a solder comprising: between 87.2% and 89.5% tin; between 4.0% and 4.8% bismuth; between 3.5% and 4.5% indium; and between 3.0% and 3.5% silver.
- the method comprises the step of using a solder comprising: 88.3% tin; 4.5% bismuth; 4.0% indium; and 3.2% silver
- the method comprises the step of wave-soldering.
- FIG. 1 shows a table of wetting times, in seconds, for a plurality of different solders, at a variety of temperatures
- FIG. 2 shows a graph representing the data expressed in the table of FIG. 1;
- FIG. 3 shows a table of maximum wetting force, for a plurality of different solders, at a variety of temperatures
- FIG. 4 shows a graph representing the data expressed in the table of FIG. 3;
- FIG. 5 shows a table of wetting times, for a solder embodying the present invention and a prior art solder, when the solders are applied to various coatings;
- FIG. 6 presents the experimental conditions of an experiment involving use of a solder embodying the present invention in a wave-soldering machine
- FIGS. 7 and 8 show the results of the experiment of FIG. 6.
- solder composed of a lead-free alloy comprising between 87.2% and 89.5% tin, between 4.0 and 4.8% bismuth, between 3.5% and 4.5% indium and between 3.0% and 3.5% silver possesses significantly improved properties when compared with conventional lead-free solders.
- a solder embodies the present invention. Indeed, the properties of solders embodying the present invention are comparable to conventional leaded solders with regard to wettability, fluidity, compatibility with existing component coatings and drossing.
- the first test concerned the wettability of a solder embodying the present invention, as compared to a number of existing lead-free solders and a conventional leaded solder (comprising 63% tin and 37% lead).
- the solder of the present invention employed in the first test comprised 88.3% tin, 4.5% bismuth, 4.0% indium and 3.2% silver.
- a first aspect of the first test comprised the measurement of the wetting time, based on the ANSI/J Std-003 standard, for the solders under consideration at a variety of temperatures ranging from 235° C. to 265° C.
- a specimen of copper was immersed in a quantity of each molten solder.
- a sensitive force measuring device was connected to the copper specimen, and arranged so that vertical forces on the specimen could be measured and recorded.
- the second factor is a force acting on the specimen due to the change in contact angle between the surface of the solder and the surface of the specimen.
- the wetting time in each particular case was defined as the time taken for the wetting force acting on the specimen to be equal to zero.
- the solder embodying the present invention exhibited a wetting time, at each of the temperatures, that was comparable to that displayed by the conventional leaded solder.
- the solder embodying the present invention exhibited a wetting time, at all but one of the temperatures considered, that was lower than that displayed by the any of the existing lead-free solders.
- the wetting time is a measure of the rapidity with which a solder adheres to a substrate, and clearly a low wetting time is a desirable property for a solder.
- the solder embodying the present invention performed better overall in the first aspect of the first test than any of the existing lead-free solders.
- a second aspect of the first test comprised the measurement of the maximum wetting force at 2.0 seconds after immersion of the specimen in the respective solders.
- the wetting force is, as described above, the adhesive force between the solder and the specimen.
- the wetting force provides a useful indication of the strength with which a solder binds to a substrate, and a high wetting force is a desirable property for a solder.
- solder embodying the present invention exhibits very similar properties, with regard to wettability, than the existing lead-free solders studied. Clearly, this similarity in physical properties renders the solder embodying the present invention far more suitable for use as a replacement for the conventional leaded solder than any of the existing lead-free solders.
- a second test concerned the compatibility of the solder of the present invention with existing component coatings.
- Components on, for example, printed circuit boards may have coatings of various materials, and it is important that a solder to be used in conjunction with such components adheres readily to the coatings thereof.
- solder embodying the present invention is suitable for use as a direct replacement for conventional leaded solders, with regard to compatibility with existing component coatings.
- a third test was concerned with the suitability for use of the solder of the present invention in a wave-soldering machine.
- a circuit board is held just above the surface of a quantity of molten solder.
- a wave is then caused to propagate across the surface of the molten solder, of sufficient amplitude that the crest of the wave comes into contact with the surface of the circuit board.
- the wave is as wide as the circuit board (or the portions thereof that require soldering), and as the wave propagates across the surface of the molten solder all parts of the downward-facing surface of the circuit board are contacted with molten solder.
- This method of application of solder to a circuit board entails a greatly reduced risk of solder coming into contact with the upward-facing surface of the circuit board, compared to a method where the circuit board is dipped directly into molten solder.
- solder embodying the present invention having a composition of 88.3% tin, 4.5% bismuth, 4.0% indium and 3.2% silver was put to use in a conventional wave-soldering machine. No alteration of the machine was made to accommodate the use of the solder. The wave-soldering machine was then used to solder circuit boards, in the same way as for a conventional solder comprising a tin/lead alloy.
- the wave-soldering machine was used at four different pot temperatures, namely 235° C., 245° C., 255° C. and 265° C. These temperatures are all within the range of temperatures that would normally be used when using the wave-soldering machine with a conventional leaded solder.
- the conveyor speed i.e. the speed at which the circuit boards were moved over the surface of the pot
- Each of these conveyor speeds was within the normal range of conveyor speeds that would normally be used when using the wave-soldering machine with a conventional leaded solder.
- the third test was carried out in a normal air environment.
- a lead-free flux was developed for use in the process, the lead-free flux being a RMA 13% solid content flux.
- the level of contamination in the pot and the alloy composition of the pot were measured and recorded.
- the dross in the pot was removed and weighed to determine the amount of dross produced by the wave-soldering process.
- the present invention provides a lead-free solder that is more suitable for use as a direct replacement for conventional leaded solders than previously-proposed lead-free solders, due to the comparable characteristics of wettability, fluidity, compatibility with existing component coatings and drossing exhibited by the solder of the present invention.
- An advantage of this suitability is that the need for manufacturers to replace existing machinery, processes or component coatings to accommodate use of a lead-free solder can be lessened or eliminated by employing the solder of the present invention. It will be clear that, as a result, the process of converting to use of a lead-free solder may be rendered far simpler and more economically viable for many manufacturers.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Electric Connection Of Electric Components To Printed Circuits (AREA)
- Adhesives Or Adhesive Processes (AREA)
- Conductive Materials (AREA)
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| SG200006841-1 | 2000-11-16 | ||
| SG2000068411 | 2000-11-16 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US20020057986A1 true US20020057986A1 (en) | 2002-05-16 |
Family
ID=71993755
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US09/932,059 Abandoned US20020057986A1 (en) | 2000-11-16 | 2001-08-17 | Solders |
Country Status (5)
| Country | Link |
|---|---|
| US (1) | US20020057986A1 (zh) |
| JP (1) | JP2002153991A (zh) |
| CN (1) | CN1354065A (zh) |
| HK (1) | HK1045824A1 (zh) |
| MY (1) | MY134159A (zh) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20090055454A1 (en) * | 2007-08-24 | 2009-02-26 | International Business Machines Corporation | Half Width Counting Leading Zero Circuit |
| US20100230152A1 (en) * | 2009-03-16 | 2010-09-16 | Fujitsu Limited | Method of soldering electronic component, and electronic component |
| US20110192536A1 (en) * | 2009-01-08 | 2011-08-11 | Fujitsu Limited | Joining method and reflow apparatus |
| CN105215569A (zh) * | 2015-10-30 | 2016-01-06 | 苏州优诺电子材料科技有限公司 | 一种无铅焊料合金 |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7654471B2 (en) | 2008-01-23 | 2010-02-02 | Bruce Johnson | Waterfall apparatus |
| CN104870673B (zh) * | 2012-12-18 | 2016-07-06 | 千住金属工业株式会社 | 无铅软钎料合金 |
| KR102339805B1 (ko) * | 2014-02-21 | 2021-12-15 | 덴카 주식회사 | 세라믹스 회로 기판 |
| CN108672979B (zh) * | 2018-06-06 | 2020-02-14 | 上海莜玮汽车零部件有限公司 | 一种无铅焊料合金及其应用、玻璃组件 |
-
2001
- 2001-05-29 MY MYPI20012542 patent/MY134159A/en unknown
- 2001-06-22 CN CN01122037A patent/CN1354065A/zh active Pending
- 2001-06-29 JP JP2001199220A patent/JP2002153991A/ja active Pending
- 2001-08-17 US US09/932,059 patent/US20020057986A1/en not_active Abandoned
-
2002
- 2002-10-15 HK HK02107460.4A patent/HK1045824A1/zh unknown
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20090055454A1 (en) * | 2007-08-24 | 2009-02-26 | International Business Machines Corporation | Half Width Counting Leading Zero Circuit |
| US20110192536A1 (en) * | 2009-01-08 | 2011-08-11 | Fujitsu Limited | Joining method and reflow apparatus |
| US8434658B2 (en) * | 2009-01-08 | 2013-05-07 | Fujitsu Limited | Joining method and reflow apparatus |
| US20100230152A1 (en) * | 2009-03-16 | 2010-09-16 | Fujitsu Limited | Method of soldering electronic component, and electronic component |
| CN105215569A (zh) * | 2015-10-30 | 2016-01-06 | 苏州优诺电子材料科技有限公司 | 一种无铅焊料合金 |
Also Published As
| Publication number | Publication date |
|---|---|
| HK1045824A1 (zh) | 2002-12-13 |
| CN1354065A (zh) | 2002-06-19 |
| MY134159A (en) | 2007-11-30 |
| JP2002153991A (ja) | 2002-05-28 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| AS | Assignment |
Owner name: QUANTUM CHEMICAL TECHNOLOGIES (SINGAPORE) PTE LTD. Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:CHEW, KAI HWA;PAN, WEI CHIH;REEL/FRAME:012264/0981 Effective date: 20011022 |
|
| STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |