࿖ዤᐁдॾੱЕၹ྅ᑕϡ̝߄ጼ
CHALLENGES FOR THE APPLICATION OF
LEAD-FREE SOLDERS ON BALL GRID ARRAY
PACKAGES
ఄ!ڌ!႔
*ૺ!͵!᎖
**ዑ!ځ!྿
†ͳ!ކ!౼
†Tung-Han Chuang Shih-Ying Chang Ming-Da Cheng Shiuan-Sheng Wang
*ି **౾̀ޢࡁտ †౾̀Ϡ
઼ϲέ៉̂ጯՄफ़ࡊጯᄃ̍ጯր̄ၹ྅၁រ室
*
Professor **Post-doctorate †Ph.D. candidate Department of Materials Science and Engineering, National Taiwan University, Taipei, Taiwan 10617, R.O.C.
Abstract
The adoption of Pb-free solders in lieu of Pb solders is an inevitable trend in the electronics industry. This study sums up the failure modes to which the ball grid array packaging process is susceptible when various Pb-free solders, such as Sn-3.5Ag, Sn-0.9Cu, Sn-58Bi, Sn-51In, Sn-20In-0.8Cu, Sn-20In-2.8Ag, Sn-4Ag-0.5Cu, Sn-3Ag- 0.5Cu and Sn-4Ag-5Cu, are employed. Examples of potential failure modes include: intermetallic embrittlement, gold embrittlement, void formation, Ag3Sn plate formation, pad lifting, Sn-Bi joint degradation caused by Pb contamination, fatigue-induced ductile/brittle transition, Ag thick film dissolution, and non-wetting due to precipitation. Keywords: electronic packaging, lead-free solders, BGA
package, failure analysis.
ၡ ࢋ
̄ၹ྅ଳϡ࿖ዤᐁࠎ˘Ξਫ਼ᔖ۞ॡᔌ๕Ăώ ͛ЕᓝЧ̙Тј̶࿖ዤᐁдॾੱЕၹ྅ᄦٙ൴ன ຫયᗟĂ̚࿖ዤᐁΒ߁ĈSn-3.5AgăSn-0.9CuăSn- 58Bi ă Sn-51In ă Sn-20In-0.8Cu ă Sn-20In-2.8Ag ă Sn-4Ag- 0.5CuăSn-3Ag-0.5CuăSn-4Ag-5CuඈЪܛĂᕩৼ̝ຫ၁ ּΒ߁Ĉ̬ܛᛳᕝăܛຫă߽͋ԛјăڕېAg3Snԛ јăዤါࣤᗓăണ࿖ౄјSn-BiତᕇК̼ăি౻ౄјؼّ ᖼຫăᅙݓቯ໘ྋᕝͽ̈́ژۏౄјዤᐁ̙ማᒅඈĄ ᙯᔣෟȆ ̄ၹ྅ă࿖ዤᐁăॾੱЕၹ྅ăᗼ̶ژĄ
1. ݈! ֏
็̄ၹ྅ֹϡᅚЪܛٕᜠᗈЪܛ͔ཙᄃО ה ྮ ڕ ซ Җ ྅ (assembly) Ă ͔ ཙ ଵ Е ѣ ಏ ᙝ (Single In-line Package, SIP) ă ᗕ ᙝ (Dual In-line Package, DIP) ٕ α ͞ ଵ Е (Quad Flat Package, QFP)Ă̚α͞ଵЕၹ྅੫၆ I/O ᇴᅮՐ̏ҖȈ ዶѐĂ҃༊ၹ྅ I/O ᇴٺ 300Ăֹϡ QFP ̝ତཙ ม̈ٺ 0.3mmĂயݡ̙։தᆐᆧĂጱϠயјώ ೩ĂЯᑕ҃Ϡ۞ߏͽዤᐁפܛᛳ͔ཙ۞ॾੱ Еၹ྅ (Ball Grid Array Package, BGA)ĂBGA Ϥٺଳ ϡࢬੱଵЕ (area array)ĂᐁତᕇมΞ಼̂ٸᆵĂ ࢫҲயݡ̙։தĂѩγ၆ٺТཙᇴၹ྅ĂBGA ͎̇ᒺ ̈Ăᄃ็͔ཙᓑତ۞ QFP ၹ྅࠹ͧĂΞ༼࠷ྮڕ ۩ม̂ࡗ 49%Ăّ͞ࢬΞഴ͌ 31% ੈཱིटᄃ 46% Ϲ̢ຏĂЯ҃ᒺൺੈཱིؼᏵ̂ࡗ 46%ĂѩγĂᐁ ۞ҋҖ၆Ҝ (self-alignment) Ϻѣӄٺᄦ։த۞ ೩ [1]Ą ϤٺॾੱЕၹ྅ߏӀϡዤᐁᄃОהྮڕ ᓑତĂၹ྅̰۞ͯăދሀቱăૄڕͽ̈́Оהྮڕ ඈ̙ТՄኳٙԛјሤᑕ˧ࢋӮϤዤᐁٚצĂЯѩ ᐁ ତ ᕇ ۞ Ξ ያ ޘ ՙ ؠ ॾ ੱ Е ၹ ྅ ۞ ֹ ϡ ု ĂᇆᜩЯ৵Β߁Ĉᐁј̶ᄃඕၹăᐁ͎̇ᄃ ԛېăᐁତᕇޘăᐁዤါԛё (Solder Mask Defined, SMD ٕ Non-Solder Mask Defined, NSMD) ᄃܑࢬந (surface finishes)ăᐁ̶Ҷ (Б႕ă̚δ ۩ٕม۩)ăᐁมăāዤᄃॡड़୧ІඈĂ ̚ᐁј̶Ϥٺ̄யຽܜ˳ͽֽͽ Sn-37Pb Ъܛࠎ Ăѣᙯ BGA ᐁତᕇΞያޘ۞࠹ᙯࡁտϺ̂ొ੫ ၆ѩ็В࿖ᐁЪܛ [2~8]ĄܕѐֽĂϤٺᒖܲຍᙊ۞೩چĂ̄யݡԼϡ ࿖ዤᐁ۞ײᓏ͟ৈႚ [9]Ăለ߷ВТξಞ̏ՙᛉҋ ̳̮ 2008 ѐ̮͡ 1 ͟Бࢬ༰ϡӣ࿖̄யݡĂ͟ ώೀछ̳̂Φ (HitachiăNECăSonyăToshiba ඈ) Ϻ ̏ ࢎ ؠ ܕ ഇ ྿ ז ഴ ͌ ࿖ ֹ ϡ ณ 50% ۞ ϫ ᇾ Ă Matsushita ̳Φϫ݈Տ࣎͡Ϡய࿅ 40,000 ֹ࣎ϡ ࿖ዤᐁ۞ਜ਼ҰЍჄ፟Ă֭ࢍٺܕഇԆБ࿖Ϥ̄ யݡ̚ᅁĂNokia ̈́ Toshiba ̳Φՙؠͽ Sn-Ag-Cu ࿖ዤᐁϡٺϠயቢ˯ [10]Ă1997 ѐΐो̂ Nortel ̳ΦϺϠயௐ˘̙ӣ࿖۞ॸ˯ݭྖĂྮڕ ІତЪֹϡ Sn0.7Cu ࿖ዤᐁ [11]Ă઼࡚ᔵѝд 1990 ѐಶ̏Ϥણᛉੰ೩९טؠ̍ຽயݡ༰ϡ࿖̝ڱ ΄ĂҭЯ߆થӀৈ࠹̢֎˧҃дϲڱ˯̪ซणĂ ҃дለ߷̈́͟ώ۞ᑅ˧˭Ăధк̳Φ (͍ՠ֘ᄦౄ ຽ̈́ܫ఼ੈຽ) Ϻڱཉְ֗γĂּт Motorola ̳ Φ̏ࢎ൴ण࿖யݡ۞ॡᄃ̍ү΄ĄѩγĂ ధкࢦࢋ̍ຽᖐт NEMIăEIA ̈́ IPC ˵д᎕ໂࡁ થтңЯᑕ࿖ዤᐁϲڱ఼࿅ޢ̝ᑝĂధкጯఙࡁ տ፟ၹ (NCMSăNISTă֧ঔ̂ጯඈ) ͽ̈́ధкዤᐁ ᄦౄ̳Φ (Alpha MetalsăAIMăKesterăIndium ඈ) Ӯ ̏Ըڦໂ͕̂˧ࡁ൴࿖ዤᐁĄ Яᑕॡሗ߹ĂॾੱЕၹ྅ֹϡ࿖ዤᐁ̏ߏ Ξᔖ۞ᔌ๕Ă҃னล߱࿖ዤᐁॾੱЕၹ྅ ̪ѣధкܨޞҹڇ۞યᗟĂώ͛έ̂Մफ़ր̄ၹ ྅၁រވ࠹ᙯࡁտٙ൴னЧ࿖ዤᐁЪܛᑕϡٺ ॾੱЕၹ྅۞ຫ၁ּઇ˘ᕩৼĂႷ۞Ăࢬ၆࿖ ዤᐁ۞߄ጼĂயጯࡁࠧᔘѣ˘߱࠹༊ᓞࡴ۞ྮࢋ֕Ą
2. ၁រ͞ڱ
ώ ၁ រ ֹ ϡ Sn-3.5Ag ă Sn-0.9Cu ă Sn-58Bi ă Sn-51In ă Sn-20In-0.8Cu ă Sn-20In-2.8Ag ă Sn-4Ag- 0.5CuăSn-3Ag-0.5CǘSn-4Ag-5CuዤᐁĄ၁រٙ̚ ֹϡ۞ॾੱЕၹ྅ૄڕࠎBTቱૄڕ̈́Al2O3 ૄڕĂቱၹ྅͎̇ࠎ 7 × 7 × 1mmĂ̰ѣۣ֭ͯ ދቱĂBTૄڕ˯ѣ 7 × 7 ࣎ੱЕ̶Ҷ۞ᅚዤါĂဦ 1 ࠎೀңඕၹᄃ͎̇Ăૄڕٺܑࢬ፵ඕ 7 × 7 ࣎ੱЕଵЕ۞ᅙݓቯዤါĄ BTૄڕ˯ᅚዤါ۞ܑࢬநࠎAu/NiᔠᆸĂݓ ޘ̶Ҿࠎ 0.7µm 10µmĂ̚Niᆸߏࠎ˞֨ͤᅚါ ᄃዤᐁ۞ԣిͅᑕĂAuᔠᆸߏࠎ˞ܑ֨ͤᆸউ̼֭ᆧ ΐᄃዤᐁ۞ማᒅّĄAl2O3ૄڕ˯̝ᅙݓቯዤါݓ ޘࠎ 20µmĄ ၁រ̶ҾЧ̙Тј̶ᐁങдૄڕዤါ˯ [12]Ăᐁ͎̇Ӯࠎۡश 0.4mmĂޢซҖਫ਼ዤĄ੫ ၆ Տ ˘ ̙ Т ј ̶ ۞ ዤ ᐁ ̶ Ҿ ଳ ϡ প ؠ ۞ ਫ਼ ዤ ѡ ቢĂޘ̂ࡗӮٺዤᐁႦᕇ 50°CĂਫ਼ዤᚤࠎ ဦ 1 ώࡁտቱॾੱЕၹ྅̝ೀңඕၹᄃ͎̇ Fig. 1 Geometry of BGA speciments used in this
study ̣߱Ӯડሤࢲ၆߹ёĄਫ਼ዤޢ۞ྏͯГٺ̙Тޘ ̈́ॡม˭ซҖॡड़நĂͽሀᑢၹ྅၁ᅫֹϡ̝ྻү ୧ІĂٙѣྏͯӮซҖၟࢬܛ࠹៍၅Ă֭ͽ SEMă EDXăEPMA ඈᆇጡ̶ژࠧࢬٙϠј̬ܛᛳ̼Ъۏ۞ ј̶ĄՏ࿖ዤᐁॾੱЕၹ྅ྏͯΩγซҖଯ ീྏĂͽෞҤତᕇ۞ૻޘĂొ̶ၹ྅ซҖજၗি౻ྏ រĄଯീྏ̈́ি౻ྏរӮֹϡ MTS-Tytron-250 ̈ఈྏរ፟ĂѩᆇጡΞͽд̈ 0.001N ఈ̈́ 0.1µm Ҝொ˭ซҖᐖၗ̈́જၗ፟ୠّኳീྏĄଯྏ រఢቑֶ JEDEC ᇾ (JESD22-B117)Ăྏរ̚ଯ ˥Җซిதࠎ 0.1mm/secĂޘࠎᐁۡश۞ 1/2Ăଯ ീྏޢ۞ᇹݡซҖᕝࢬ៍၅Ăͽଣຫ۞ݭၗ ᄃ፟நĄ
3. ඕڍᄃኢ
ტ Ъ Ч ̙ Т ј ̶ ࿖ ዤ ᐁ ॾ ੱ Е ၹ ྅ ၁ រĂΞᕩৼ˭Еຫ९ּĈ3.1 ̬ܛᛳᕝ
Sn-20In-0.8Cu Ъܛ̝୵࠹ቢޘ̶Ҿࠎ 163°C ᄃ 187°CĂѩ࿖ዤᐁࢋ۞ᐹᕇࠎႦᕇତܕ็ ۞В࿖ᐁЪܛĂϺӈ੫၆В Sn-0.9Cu ࿖ዤᐁ۞ ႦᕇયᗟΐͽԼචĂIn ۞ΐੵ˞ࢫҲႦᕇĂՀΞ ೩Ъܛ۞ԩሕតّ̈́֨ͤܛன෪۞൴ϠĄ ဦ 2(a) ࠎѩ Sn-20In-0.8Cu ࿖ዤᐁਫ਼ዤޢĂ Гགྷ 115°C ॡड़ந 1,000 ̈ॡ̝ܛ࠹ᖐĂዤᐁᄃ ૄڕ˯۞ Au/Ni ᔠᆸͅᑕĂٺࠧࢬАޢԛј(a) 界面介金屬型態
(b) 推球試驗斷面組織
ဦ 2 Sn-20In-0.8Cu ዤ ᐁ ॾ ੱ Е ၹ ྅ ᄦ གྷ
115°C ॡ ड़ 1,000h ޢ ̝ ຫ ९ ּ Ĉ (IM1:
Cu6(Sn,In)5 + Ni3(Sn,In)4; IM2: Ni3 (Sn,In)2)
Fig. 2 Sn-20In-0.8Cu solder joint in BGA pack- aging after aging at 115°C for 1,000 hours, (a) morphology of the intermetallic compounds; (b) fractography after ball shear test
ࠎCu6(Sn,In)5ᄃNi3(Sn,In)4ЪјĂIM2 ̬ܛᛳј
ࠎNi3(Sn,In)2ĄଯྏរពனّᕝĂତᕇૻޘϤ ਫ਼ዤېၗ۞ 4.5NࢫҌ 3.2NĂᕝҜཉϺϤࣧАࡍ࿅ ዤᐁ̰ొᖼೱࠎڻIM2 ̬ܛᛳᆸĂᙋ၁ࠧࢬ̬ܛᛳ ᕝࠎତᕇૻޘК̼۞ჹЯ [13]Ą
3.2 ܛຫ
В Sn-0.9Cu Ъܛࠎ˘ໂజ࠻р۞࿖ዤᐁĂ࡚ ઼઼छ̄ᄦౄםົ (NEMI) ܕޙᛉਫ਼ዤ (reflow) ᄦଳϡ Sn-3.9Ag-0.6Cu ЪܛĂگዤ (wave soldering) ᄦଳϡВ Sn-0.9Cu ЪܛĄѩ࿖ዤᐁႦᕇ྿ 227°CĂࠎࢋᕇĂҭЯѣྵָ۞ତЪૻޘ ᄃҲຆ۞јώĂ҃צזຽࠧࢦෛĄ ੫၆࿖ዤᐁਫ਼ዤᄦٙซҖ̝ࡁտĂဦ 3(a) ព ϯSn-0.9Cuዤᐁਫ਼ዤޢĂዤါ˯۞ᔠAuᆸԆБᏉˢዤ ᐁ̚Ă֭ԛјफᑎې(Au,Ni)Sn4̬ܛᛳ̼ЪۏĂ҃д ତᕇࠧࢬԛј(Cu,Ni,Au)6Sn5̬ܛᛳᆸĂѩॡଯ (Au, Ni)Sn4 IM1(Cu, Au, Ni)6Sn5
IM2
Ni
(a) 迴銲後
(b) 150°C 時效 300 小時
ဦ 3 Sn-0.9Cu ዤᐁॾੱЕၹ྅ຫ९ּ Fig. 3 Morphology of the Sn-0.9Cu solder joint of
the BGA package after (a) reflow; (b) aging at 150°C for 300 hours ૻޘ྿ 8.4NĄ҃ޢᜈд 150°Cॡड़ந 300h ޢĂࣧАҜٺዤᐁ̰ొ۞ (Au,Ni)Sn4̬ܛᛳົаזࠧ ࢬĂֹࣧАࠧࢬ̝̬ܛᛳᆸ̰Auӣณ೩˘ࢺ (ဦ 3(b))ĂѩॡซҖଯྏរΞ൴னᕝҜཉڻࠧࢬ ۞̬ܛᛳᆸĂତᕇૻޘϺ಼̂ࢫҲҌ 5.1N [14]Ą
3.3 ߽͋ԛј
Sn-20In-2.8Ag тТ Sn-20In-0.8Cu Ъܛ˵ߏࠎ˞ ࢫҲВ Sn-3.5Ag ЪܛႦᕇ҃ΐ In ̮৵Ă୵ ࠹ቢޘ̶Ҿࠎ 175°C ᄃ 187°CĂѩ࿖ዤᐁጾѣໂ ָ۞ؼणّᄃԩሕតّĄ ҃Ăώࡁտ൴னSn-20In-2.8AgॾੱЕၹ྅གྷ ਫ਼ዤޢĂГซҖ 100°Cॡड़ந 700 ̈ॡ (ဦ 4)Ăᐁ ତᕇ̰ొᄃࠧࢬӮனځព۞߽͋Ăѩ߽͋۞ԛј ᄃ̬ܛᛳ̼Ъۏјܜ࠹ᙯᓑĂඕڍጱᐁᕝڻ ࠧࢬ൴ϠĄѩSn-20In-2.8Agዤᐁд 150°C̙Тॡมซ Җॡड़நޢĂ߽͋ԛјՀΐᚑࢦ (ဦ 5)Ă༊ॡड़ॡม ܜ྿ 1,000 ̈ॡĂᐁೀͼតј۩͕ඕၹ(ဦ 5(e))Ăଯ ྏរૻޘϺϤਫ਼ዤېၗ۞ 5.1NࢫҌ 3.5N [15]ĄAuIn2
(a) ࠧࢬ̬ܛᛳ̈́ෘᓀݭၗ (b) ଯྏរᕝࢬᖐ
ဦ 4 Sn-20In-2.8Ag ዤᐁॾੱЕၹ྅ᄦགྷ 100°C ॡड़ 700h ޢ̝ຫ९ּ
Fig. 4 Sn-20In-2.8Ag solder joint in BGA packaging after aging at 100°C for 700 hours: (a) morphology of the intermetallic compounds and cracks; (b) fractography after ball shear tests
(a) 100h (b) 300h
(c) 500h (d) 700h (e) 1000h ဦ 5 Sn-20In-2.8Ag ዤᐁॾੱЕၹ྅གྷ 150°C ̙Тॡมॡड़ޢ̝߽͋ԛјຫ९ּ
Fig. 5 Voids formation for Sn-20In-2.8Ag solder joint in BGA packaging after aging at 150: (a) 100 h; (b) 300 h; (d) 500 h; (d) 700 h; (e) 1,000 h
3.4 ڕېAg
3Sn̬ܛᛳԛј
В Sn-Ag-Cu րЕЪܛߏజෛࠎѣ፟ົଳϡ ۞࿖ዤᐁĂႦᕇࡗд 216 ~ 218°C ̝มĂѣ։ р۞፟ୠّኳĂͷᄃૄՄѣޝр۞ማᒅّĄ ˘ਠଐڶĂSn-Ag-Cuዤᐁ̰ొົҶᔺې Ag3Sn̬ܛᛳ࠹ĂࢋԷႊژૻ̼ड़ᑕĂ҃ώࡁ տ൴ன˘ј̶ࠎSn-4Ag-0.5Cu۞ॾੱЕၹ྅ਫ਼ዤ ޢĂᐁ̰ొົϠј̂ڕې۞Ag3Sn̬ܛᛳ[16] (ဦ 6(a) ဦ 6(b))Ăޢᜈ۞જၗি౻ྏរពϯෘᓀࢋ ൴ϠٺAg3SnڕᄃዤᐁૄՄ۞۞ࠧࢬćѩγĂܜ୧ ڕېAg3Sn̬ܛᛳ۞хдϺົԛјᗝγ۞ྮాඕĂ ౄјّ۞ԼតĄ Ω˘ј̶ࠎSn-3Ag-0.5Cu۞࿖ዤᐁॾੱЕ ၹ྅ਫ਼ዤޢ̝ܛ࠹ᖐពϯᐁ̰ొ̙֭ົயϠڕ ېAg3Sn̬ܛᛳ(ဦ 6(c) ဦ 6(d))ĂϤѩᙋ၁ΞᖣϤ አፋዤᐁЪܛ̰AgӣณҲٺ 3wt%ĂͽԺͤѣच۞ڕ ېAg3SnϠјĄ3.5 ॡड़ዤါࣤᗓ
ВSn-3.5AgЪܛ˵ߏ࠹༊జ࠻р۞࿖ዤᐁĂ Ϥٺ̰ొAg3Snژ࠹۞ૻ̼үϡĂѩዤᐁѣໂ ָ۞፟ୠૻޘᄃԩሕតّĂ221°C۞Ⴆᕇజ̳ᄮߏ ѩЪܛפ็Sn-37Pbዤᐁ۞ᅪᘣĂ҃၁រពϯ дॾੱЕၹ྅۞ᑕϡ˯ĂSn-3.5Ag۞યᗟֲ̙ٺ ࿖ዤᐁĈ݈Sn-0.9CuዤᐁॾੱЕၹ྅۞ܛ ຫன෪Тᇹ൴ϠдSn-3.5AgЪܛ [17] (ဦ 7)Ă݈ Sn-4Ag-0.5Cu۞̂ڕېAg3Sn̬ܛᛳ༊˵хдٺ Sn-3.5AgॾੱЕၹ྅[17] (ဦ 8)Ă҃༊ܛᄃAg3Sn ڕ ې ̬ ܛ ᛳ Т ॡ ன д ᐁ ᄃ ዤ ါ ࠧ ࢬ ॡ ( ဦ 9(a))Ăӈֹߏڀෳ۞BTૄڕ˵дዤါડાԛјᚑࢦય ᗟ (ဦ 9(b))ĂඕԊߏጱଯྏរॡ൴Ϡዤါࣤᗓ (ဦ 9(c))ĂᐁତᕇૻޘϺϤ 8.9N಼̂ࢫҌ 2.9N[17]Ą3.6 ണ࿖ౄј Sn-Bi ዤᐁତᕇК̼
В Sn-58Bi ዤᐁጾѣ։р۞፟ୠૻޘᄃԩি౻ ّĂႦᕇࠎ 138°CĂᆊॾҲຆĂࠎ࠹༊ѣሕ˧۞Ҳ ࿖ዤᐁĂҭߏд̄யຽԆБซˢ࿖ዤᐁᄦ ݈۞࿅ഭॡഇĂొ̶న౯̮̈́ІΞਕ̪ണณ࿖Ă ֱณ࿖˘όˢ Sn-Bi ࿖ዤᐁ̰Ăԛјˬ̮ ̬ܛᛳ࠹ (Bi-30Pb-8Sn)Ăѩˬ̮̬ܛᛳ࠹۞Ⴆᕇ่ ࠎ 97°CĂдֹϡ˯ౄјତᕇ۞К̼Ąဦ 10 ࠎ Sn-58Bi ΐ̙Т࿖ӣณ̝ DSC ̶ژඕڍĂд 97°C хдѣ˘ӛሤपĂࠎ݈ Bi-30Pb-8Sn Ҳ̬ܛᛳ࠹ ۞ϠјͅᑕĂᐌ࿖ӣณ۞೩Ăѩӛሤपᆧ̂Ăព ϯѩˬ̮ Bi-30Pb-8Sn ̬ܛᛳ۞Ϡјณᐌ࿖ӣณ۞Ag3Sn Ag3Sn (a) (b)
(c) (d)
ဦ 6 (a)ă(b)ĈSn-4Ag-0.5Cu ዤᐁॾੱЕၹ྅ਫ਼ዤޢԛјڕېAg3Sn̬ܛᛳć(c)ă(d)Ĉͧྵ Sn-3Ag-0.5Cu
ዤᐁѩன෪
(c), (d): compared with Sn-3Ag-0.5Cu showing the solder without the phenomenon
ဦ 7 Sn-3.5Ag ዤᐁॾੱЕၹ྅གྷ 175°C ॡड़
1,000 h ޢ۞ຫ९ּ
Fig. 7 Morphology of the Sn-3.5Ag solder joint of the BGA package after aging at 175°C for 1,000 h
ဦ 8 Sn-3.5Ag ዤ ᐁ ॾ ੱ Е ၹ ྅ གྷ 200°C ॡ ड़
300hޢĂᐁ̰ొனλ̂۞ڕېAg3Sn̬ܛ
ᛳ
Fig. 8 Platelike Ag3Sn formation for Sn-3.5Ag
solder joint in BGA packaging after aging at 200°C for 300 h ೩҃ᆧкĄဦ 11 ̝ଯྏរඕڍᙋ၁ΐ 0.5wt% ࿖ٺѩ Sn-58Bi ዤᐁ̚ĂᐁତᕇૻޘϤࣧА 9.1N ࢫҲҌ̂ࡗ 7.6NĂᐌ࿖ΐณ೩Ҍ 2.0wt%Ăᐁ ତᕇૻޘϺᚶᜈࢫҌ 7.3NĄ
3.7 ি౻ౄјؼّᖼຫ
ဦ 12(a) ࠎIn-49SnዤᐁॾੱЕၹ྅ਫ਼ዤޢ۞ ܛ ࠹ ᖐ Ă ᔵ д ᐁ ᄃ ዤ ါ ۞ ࠧ ࢬ ົ Ϡ ј AuIn2̬ܛᛳĂҭᐖၗଯྏរពϯᕝڻᐁ̰ ొĂᕝࢬӔனؼّᗼপᇈ[18] (ဦ 12(b))ĂϺӈ ࠧࢬ̝AuIn2̬ܛᛳ၆ѩၹ྅ຫ֭ᇆᜩĂ҃જ ၗᝈѡি౻ྏរݒពϯෘ৳ڻࠧࢬAuIn2̬ܛᛳؼ ҩ(ဦ 12(c))ĂᕝϺᖼೱࠎّপᇈ[19]Ą3.8 ᅙݓቯ໘ྋᕝ
В In-49Sn ЪܛႦᕇ่ 118°CĂࠎ˘ݭ۞Ҳ Ⴆᕇ࿖ዤᐁĂд̄ၹ྅ᄦ̚Ăྵޢ߱۞ਫ਼ዤ ޘυืҲٺ݈߱ĂѩγĂొ̶̮̄І၆ޘྵࠎୂ ຏĂֱଐڶӮᅮֹϡҲႦᕇዤᐁĄ (a) (b) (c) ဦ 9 (a) Sn-3.5Ag ᐁ ତ ᕇ གྷ 200°C ॡ ड़ ޢ Ă Ni3Sn4,ă(Au,Ni)Sn4 ᄃAg3Sn ˬ̬ܛᛳТ ॡϠјć(b) Sn-3.5Agᐁତᕇགྷ 200°C 1,000h ॡ ड़ ޢ BT ૄ ڕ ̈́ ዤ ါ ன ᚑ ࢦ ຫ ć (c) Sn-3.5Agᐁତᕇགྷ 200°Cॡड़ 1,000hޢ۞ଯ ᕝࢬĂӔனዤါࣤᗓன෪Fig. 9 (a) Ni3Sn4, (Au,Ni)Sn4 and Ag3Sn formation
for Sn-3.5Ag solder joint in BGA packaging after aging at 200°C; (b) Damage of the BT substrate and solder for Sn-3.5Ag solder joint of BGA package at 200°C for 1,000 h; (c) Spalling of the solder pad for Sn-3.5Ag solder joint of BGA package at 200°C for 1,000 h
дAl2O3ૄڕ˯፵ඕ 20µmݓ۞ᅙݓቯዤါ
(ဦ 13(a))Ă֭ങˢIn-49SnᐁĂͽᄦઇॾੱЕ ၹ྅ĄѩIn-49Sn/Agݓቯࠧࢬд 275°CซҖዤᐁͅᑕ 15minޢĂពϯᅙݓቯԣి໘ྋซˢዤᐁ̚Ă֭дࠧ
ࢬԛјෘ৳(ဦ 13(b))Ăጱዤᐁᄃૄڕ̶ᗓ [20]Ą
ဦ 10 Sn-58Bi ΐ̙Т Pb ӣณ̝ DSC ѡቢ Fig. 10 DSC analysis of Sn-58Bi solder with various
Pb contents 0.0 0.5 1.0 1.5 2.0 2.5 3.0 7.0 7.5 8.0 8.5 9.0 9.5 S h ear S tr ength (N ) Pb Content( wt.%) ဦ 11 Sn-58Bi ΐ̙Т Pb ӣณ̝ଯૻޘ Fig. 11 Ball shear strengths of Sn-58Bi solder with
various Pb contents AuIn2 (a) (b) AuIn2 (c)
ဦ 12 (a) In-49Sn ॾੱЕၹ྅ਫ਼ዤޢ̝ࠧࢬ̬ܛᛳݭၗć(b) In-49Sn ॾੱЕၹ྅ਫ਼ዤޢซҖᐖၗଯྏ រĂᕝࡍ࿅ᐁ̰ొ֭Ӕனؼّຫপᇈć(c) In-49Sn ॾੱЕၹ྅ਫ਼ዤޢซҖજၗᝈѡি౻ྏរĂ Ӕனڻ̬ܛᛳᕝপᇈ
In-49Sn solder joint of the BGA package after ball shear tests; (c) IN-49Sn solder joint in BGA packaging showing brittle fracture after bending fatigue tests
(a)
(b)
ဦ 13 (a) Al2O3ૄڕܑࢬ፵ඕᅙݓቯዤါ̝ၟ
ࢬܛ࠹ć(b) ᅙݓቯᄃIn-49Snዤᐁд 275°Cͅ
ᑕ 15 ̶ᛗޢĂࠧࢬனෘᓀ
Fig. 13 (a) Cross-sectional image of Ag thick layer on Al2O3 substrate; (b) Cracks formation
for Ag thick layer with I-49Sn solder reaction at 275°C for 15 minutes
3.9 ژۏౄјዤᐁ̙ማᒅ
Sn-4Ag-0.5Cu ዤᐁॾੱЕၹ྅ਫ਼ዤޢពϯ։ р ۞ ତ Ъ ّ Ă ͷ ᄃ ዤ ါ ม ѣ ໂ ָ ۞ ማ ᒅ ّ ( ဦ 14(a))Ă҃ѩ Sn-Ag-Cu ዤᐁј̶۞Ӏયᗟϫ݈̪ ӧᕘ̄ၹ྅ຽࠧ [21]Ă˵јࠎ࿖ዤᐁᑕϡ۞˘ ࣎ᅪᘣĂࠎ˞ࡎѩӀᅪᘣĂώࡁտϺဘྏ൴ण ј۞ Sn-Ag-Cu ࿖ዤᐁĂSn-4Ag-5Cu ࠎ̝̚ ˘Ą ᔵDSC̶ژពϯѩSn-4Ag-5CuາዤᐁЪܛϺ ࠎВј̶ĂͷႦᕇᄃSn-4Ag-0.5Cuዤᐁତܕ (ဦ 15(a) ဦ 15(b))Ăѩγ፟ୠૻޘՀᅈٺSn-4Ag- 0.5CuЪܛĂ҃ѩ˘CuӣณSn-4Ag-5CuЪܛዤ ါ۞ማᒅّໂमĂܛ࠹̶ژ൴ன̰ొԛјధк̂ ېCu6Sn5̬ܛᛳ (ဦ 14(b))Ăֱ̂Cu6Sn5̬ܛᛳጱ ᐁᄃዤါڱማᒅ [16]Ą (a) Sn-4Ag-0.5Cu Ag3Sn Cu6Sn5 (b) Sn-4Ag-5Cu ဦ 14 ј Sn-Ag-Cu ዤᐁਫ਼ዤޢܛ࠹ᖐ Fig. 14 Morphology of two solder joints of the BGApackage after reflow
195 200 205 210 215 220 -0.4 -0.3 -0.2 -0.1 0.0 0.1 He at Flow (w /g) Temperature (o C) (a) Sn-4Ag-0.5Cu 195 200 205 210 215 220 225 230 235 -0.4 -0.3 -0.2 -0.1 0.0 0.1 H eat Flow (w/ g ) Temperature (o C) (b) Sn-4Ag-5Cu ဦ 15 ј Sn-Ag-Cu ዤᐁ̝ DSC ѡቢ Fig. 15 DSC analysis of two Sn-Ag-Cu solders
[9] B. Trumble,“Get the Lead Out,” IEEE Spectrum, May 1998, pp. 55−60.
4. ඕ! ኢ
[10] P. Zarrow, “Lead-Free: Don’t Fight a Fact, Deal with it,” Circuit Assembly, August 1999, pp. 18−20. ࿖ᐁЪܛଂᘲॡֹϡҌ̫Ăૄٺனˠ۞ᒖ ܲຍᙊ҂ณĂฟ൴࿖ዤᐁͽפ็࿖ᐁЪܛߏ ̄யຽ۞ЇચĂᔵώ͛Еᓝధк࿖ዤᐁॾ ੱЕၹ྅ᄦࡁտٙ൴னຫયᗟĂҭߏགྷϤຫ፟ ந۞ᒢྋĂዋ༊Ᏼፄ࿖ዤᐁј̶ᄃᄦણᇴĂ̄ ၹ྅ქҒயݡ۞ॡ̪ߏ͟ΞޞĄ
[11] A. Grusd, “Connecting to Lead-Free Solders,” Circuit Assembly, August 1999, pp. 32−38.
[12] ఄڌ႔ăͳކ౼ĂĶॾੱЕၹ྅ϡ̈ዤᐁ ۞ᄦౄ͞ڱ̈́྅ཉķ, ̚රЩ઼൴ځӀ८ ࣞĂ̳Ә̚ (९ཱི 91109034)Ă2003Ą
ણ҂͛ᚥ
[13] M. J. Chiang, S. Y. Chang and T. H. Chuag, “Reflow and Burn-in of an Sn-20In-0.8Cu BGA Package with Au/Ni/Cu Pad,” Journal of Electronic Materials, 2003 in press.
[1] J. H. Lau (Editor), Ball Grid Array Technology, McGraw-Hill, Inc., New York, 1995.
[2] S. C. Bolton, A. J. Mawer and E. Mammo, “Influence of Plastic Ball Grid Array Design/Material upon Solder Joint Reliability,” The International Journal of Microcircuits and Electronic Packaging, Vol. 18, No. 2, 1995, pp. 109−121. [14] ͳชୂĂĶSn0.9Cu ॾੱЕၹ྅ࠧࢬͅᑕࡁտķ, ઼ϲέ៉̂ጯՄफ़ࡊጯᄃ̍ጯࡁտٙჇ̀ኢ ͛Ă2002 ѐĄ [15] ӓपᄫĂĶSn20In2.8Ag ॾੱЕၹ྅ࠧࢬͅᑕ ࡁտķ, ઼ϲέ៉̂ጯՄफ़ࡊጯᄃ̍ጯࡁտٙ Ⴧ̀ኢ͛Ă2002 ѐĄ
[3] Y. W. Chan, T. H. Ju, S. A. Herob, Y. C. Lee, J. S. Wu and M. J. Lii, “Reliability Modeling for Ball Grid Array Assembly with a Large Number of Warpage Affected Solder Joints,” ASME Advances in Electronic Packaging, Vol. 19, 1997, pp. 1507−1514. [16] ዑځ྿ĂĶSn-Ag-Cu ዤᐁॾੱЕၹ྅ࠧࢬͅᑕ ࡁտķ, ઼ϲέ៉̂ጯՄफ़ࡊጯᄃ̍ጯࡁտٙ ౾̀ኢ͛Ă2003 ѐĄ [17] ҴߌࣖĂĶSn37PbăSn36Pb2Agăᄃ Sn3.5Ag ዤ ᐁॾੱЕၹ྅ࠧࢬͅᑕࡁտķ, ઼ϲέ៉̂ጯ Մफ़ࡊጯᄃ̍ጯࡁտٙ౾̀ኢ͛Ă2002 ѐĄ [4] Q. Yu, T. Kashiwamura, M. Shiratori and K. Satoh,
“Reliability and Structure Optimization of BGA Packages,” ASME Advances in Electronic Package, Vol. 19, 1997, pp. 1761−1767.
[18] T. H. Chuang, S. Y. Chang, L. C. Tsao, W. P. Weng and H. M. Wu, “Intermetallic Compounds Formed during the Reflow of In-49Sn Solder Ball-Grid Array Packages,” Journal of Electronic Materials, Vol. 32, No. 3, 2003, pp. 195−200.
[5] O. Yu and M. Shiratori, “Thermal Fatigue Reliability Assessment for Solder Joints of BGA Assembly,” Advances in Electronic Packaging, Vol. 26, No. 1, 1999, pp. 239−246.
[6] O. Yu and M. Shiratori, “Effects of BGA Solder Geometry on Fatigue Life and Reliability Assessment,” ܑࢬ၁྅ጯົᄫ, Vol. 1, No. 4, 日 文, 1998, pp. 278−283.
[19] ͳކ౼ĂĶSn-58BiăSn-51In ᄃ Sn-37Pb ॾੱ Еၹ྅۞જၗি౻ࡁտ̈́Ξያޘ̶ژķ, ઼ϲέ ៉̂ጯՄफ़ࡊጯᄃ̍ጯࡁտٙ౾̀ኢ͛Ă2003 ѐĄ
[7] R. Rorgren, P. E. Tegehall and P. Carlsson, “Reliability of BGA Packages in an Automotive
Environment,” Journal of Surface Mount
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[20] เ˷ްĂĶ̄ၹ྅ In49Sn ࿖ዤᐁᄃᅙݓቯ̈́ ᅙૄڕ̝ࠧࢬͅᑕࡁտķ, ઼ϲέ៉̂ጯՄफ़ࡊ ጯᄃ̍ጯࡁտٙჇ̀ኢ͛Ă2000 ѐĄ
[8] M. Avery, L. Gopalakrishnan and R. Srivastava, “Interconnect Reliability of Micro BGA and Chip Scale Packages,” Journal of Surface Mount Technology, July 1999, pp. 6−14.
[21] M. Abtew and G. Selvaduray, “Lead-free Solder in
Microelectronics,” Materials Science and