SE515028C2 - Improved soldering balls and the use of such - Google Patents

Improved soldering balls and the use of such

Info

Publication number
SE515028C2
SE515028C2 SE9901427A SE9901427A SE515028C2 SE 515028 C2 SE515028 C2 SE 515028C2 SE 9901427 A SE9901427 A SE 9901427A SE 9901427 A SE9901427 A SE 9901427A SE 515028 C2 SE515028 C2 SE 515028C2
Authority
SE
Sweden
Prior art keywords
solder
solder ball
ball
solder balls
protective layer
Prior art date
Application number
SE9901427A
Other languages
Swedish (sv)
Other versions
SE9901427L (en
SE9901427D0 (en
Inventor
Lars-Anders Olofsson
Original Assignee
Ericsson Telefon Ab L M
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Ericsson Telefon Ab L M filed Critical Ericsson Telefon Ab L M
Priority to SE9901427A priority Critical patent/SE515028C2/en
Publication of SE9901427D0 publication Critical patent/SE9901427D0/en
Priority to TW088108738A priority patent/TW410367B/en
Priority to PCT/SE2000/000671 priority patent/WO2000064625A1/en
Priority to AU46315/00A priority patent/AU4631500A/en
Publication of SE9901427L publication Critical patent/SE9901427L/en
Publication of SE515028C2 publication Critical patent/SE515028C2/en

Links

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
    • B23K35/02—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by mechanical features, e.g. shape
    • B23K35/0222—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by mechanical features, e.g. shape for use in soldering, brazing
    • B23K35/0244—Powders, particles or spheres; Preforms made therefrom
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L23/00—Details of semiconductor or other solid state devices
    • H01L23/48—Arrangements for conducting electric current to or from the solid state body in operation, e.g. leads, terminal arrangements ; Selection of materials therefor
    • H01L23/488—Arrangements for conducting electric current to or from the solid state body in operation, e.g. leads, terminal arrangements ; Selection of materials therefor consisting of soldered or bonded constructions
    • H01L23/498—Leads, i.e. metallisations or lead-frames on insulating substrates, e.g. chip carriers
    • H01L23/49811—Additional leads joined to the metallisation on the insulating substrate, e.g. pins, bumps, wires, flat leads
    • H01L23/49816—Spherical bumps on the substrate for external connection, e.g. ball grid arrays [BGA]
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00—Apparatus or processes for manufacturing printed circuits
    • H05K3/30—Assembling printed circuits with electric components, e.g. with resistor
    • H05K3/32—Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits
    • H05K3/34—Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits by soldering
    • H05K3/341—Surface mounted components
    • H05K3/3431—Leadless components
    • H05K3/3436—Leadless components having an array of bottom contacts, e.g. pad grid array or ball grid array components
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/0001—Technical content checked by a classifier
    • H01L2924/0002—Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
    • H05K2201/10—Details of components or other objects attached to or integrated in a printed circuit board
    • H05K2201/10613—Details of electrical connections of non-printed components, e.g. special leads
    • H05K2201/10954—Other details of electrical connections
    • H05K2201/10992—Using different connection materials, e.g. different solders, for the same connection
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K2203/00—Indexing scheme relating to apparatus or processes for manufacturing printed circuits covered by H05K3/00
    • H05K2203/04—Soldering or other types of metallurgic bonding
    • H05K2203/041—Solder preforms in the shape of solder balls
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K2203/00—Indexing scheme relating to apparatus or processes for manufacturing printed circuits covered by H05K3/00
    • H05K2203/04—Soldering or other types of metallurgic bonding
    • H05K2203/0435—Metal coated solder, e.g. for passivation of solder balls
    • 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
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Landscapes

  • Engineering & Computer Science (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • Power Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Electric Connection Of Electric Components To Printed Circuits (AREA)

Abstract

Solderability of a solder ball of solder having a high melting temperature to be used as an electrical and mechanical connection means in a ball grid array module, is improved by first removing native oxide from the solder ball (8), and, then, to prevent formation of new oxide on the solder ball, depositing a protective layer (9) of a metal enabling soldering of the solder ball by a conventional soldering paste.

Description

515 028 2 i att lodkulomas toppar som vetter bort från anslutningspaddarna kommer att befinna sig på olika höjder. Detta illustreras schematiskt till vänster i Pig. 1 på bifogade ritning där en lodkula l visas ”flytande” ocentrerad på lod 2 på ett substrat 3 i en BGA-modul (icke visad), medan en lodkula 4 visas vilande ocentrerad på substratet 3 eller i själva verket på en anslutningspadd (icke visad) på substratet 3. 515 028 2 in that the peaks of the solder balls facing away from the connecting pads will be at different heights. This is schematically illustrated on the left in Pig. 1 in the accompanying drawing where a solder ball 1 is shown "floating" uncentrated on solder 2 on a substrate 3 in a BGA module (not shown), while a solder ball 4 is shown resting unconcentrated on the substrate 3 or in fact on a connection pad (not shown) ) on the substrate 3.

Såsom framgår av Fig. 1 befinner sig lodkulornas 1 och 4 toppar på olika höjd.As can be seen from Fig. 1, the peaks of the solder balls 1 and 4 are at different heights.

Dålig lödbarhet hos lodkulorna kan även resultera i ett alltför kort isolatíonsavstånd mellan lodkulorna på modulen och i värsta fall kortslutning av intill varandra liggande lodkulor. Detta illustreras schematiskt till höger i Pig. 1 där intill varandra liggande lodkulor 5 och 6 vilar ocentrerade på substratet 3 på sådant sätt att dei själva verket berör varandra vilket resulterar i kortslutning.Poor solderability of the solder balls can also result in too short an insulating distance between the solder balls on the module and in the worst case short circuit of adjacent solder balls. This is schematically illustrated to the right in Pig. 1 where adjacent solder balls 5 and 6 rest uncentrated on the substrate 3 in such a way that they actually touch each other which results in a short circuit.

REDoGöRELsE FÖR UPPFINNINGEN Ändamålet med uppfinningen består i att eliminera ovannämnda nackdelar hos kända lodkulor.SUMMARY OF THE INVENTION The object of the invention is to eliminate the above-mentioned disadvantages of known solder balls.

Detta ernås enligt uppfinningen genom förbättring av lödbarheten hos lodkulor av lod med hög smälttemperatur genom att först avlägsna naturlig oxid från lodkulorna och därefter innan ny oxid bildats påföra ett skyddande metallskikt på lodkulorna som möjliggör lödning av lodkulorna på anslutningspaddar.This is achieved according to the invention by improving the solderability of solder balls of high melting solder by first removing natural oxide from the solder balls and then before forming a new oxide applying a protective metal layer to the solder balls which enables soldering of the solder balls on connection pads.

Genom den förbättrade lödbarheten hos lodkulorna enligt uppfinningen uppträder inga problem med centreringen av lodkuloma på anslutningspaddarna. Lödfogarna som sådana kommer således att förbättras.Due to the improved solderability of the solder balls according to the invention, no problems arise with the centering of the solder balls on the connection pads. The solder joints as such will thus be improved.

FIGURBESKRIVNING Uppfinningen kommer att beskrivas närmare nedan under hänvisning till bifogade ritning, på vilken ovan beskriven Pig. 1 visar en utföringsfonn av på ett substrat % 515 028 3 lödda, kända lodkulor, Pig. 2 visar en lodkula enligt uppfinningen och Pig. 3 visar på ett substrat lödda lodkulor enligt uppfinningen.DESCRIPTION OF THE DRAWINGS The invention will be described in more detail below with reference to the accompanying drawing, in which Pig. 1 shows an embodiment of soldered, known solder balls, soldered on a substrate%, Pig. 2 shows a solder ball according to the invention and Pig. 3 shows soldered solder balls according to the invention on a substrate.

BESKRIVNING AV UPPFINNINGEN Pig. 2 visar en lodkula 7 enligt uppfinningen.DESCRIPTION OF THE INVENTION Figs. 2 shows a solder ball 7 according to the invention.

Lodkulan 7 består av en kärna 8 av lod med hög smälttemperatur, företrädesvis Pb9OSn1 0 eller Pb88Sn1OAg2.The solder ball 7 consists of a core 8 of solder with a high melting temperature, preferably Pb9OSn10 or Pb88Sn1OAg2.

Såsom angivits ovan i samband med beskrivningen av Pig. 1 kommer lödbarheten att bli dålig till följd av den naturliga oxiden på lodkulorna om dylika lodkulor löds på anslutningspaddar (icke visade) medelst vanlig lödpasta, vilket resulterar i att lodkulorna inte centreras på anslutningspaddarna eller flyter på lodet på anslutningspaddarna såsom visas i Pig. l.As stated above in connection with the description of Pig. 1, the solderability will be poor due to the natural oxide on the solder balls if such solder balls are soldered to connection pads (not shown) by means of ordinary solder paste, resulting in the solder balls not being centered on the connection pads or floating on the solder on the connection pads as shown in Fig. l.

För att enligt uppfinningen förbättra lödbarheten hos dylika lodkulor avlägsnas först naturlig oxid från kärnan 8, exempelvis medelst en syra, t. ex. HCl, eller ett reducerande medel.In order to improve the solderability of such solder balls according to the invention, natural oxide is first removed from the core 8, for example by means of an acid, e.g. HCl, or a reducing agent.

Därefter påförs ett skyddande metallskikt 9 på den från naturlig oxid befriade kärnan 8 innan ny oxid bildats på kärnan 8 samt för att skydda kärnan 8 mot syre.Thereafter, a protective metal layer 9 is applied to the core 8 freed from natural oxide before new oxide is formed on the core 8 and to protect the core 8 from oxygen.

Enligt uppfinningen väljs för skiktet 9 en metall som möjliggör lödning av lodkulorna 7 på ett substrat medelst en vanlig lödpasta.According to the invention, a metal is selected for the layer 9 which enables soldering of the solder balls 7 on a substrate by means of an ordinary solder paste.

Metallen för skyddsskiktet 9 väljs ur en grupp bestående av Ag, Au, ln, Pd, Pt och Sn.The metal for the protective layer 9 is selected from a group consisting of Ag, Au, ln, Pd, Pt and Sn.

När under hänvisning till Pig. 3, i Pig. 2 visade lodkulor 7 enligt uppfinningen löds på anslutningspaddar (icke visade) på ett substrat 10 i en BGA-modul medelst 028 flr :31 vanlig lödpasta kommer de till följd av den förbättrade lödbarheten att centreras på lödpastan på i Fig. 3 visat sätt. Vid lödning av lodkulorna 7 enligt uppfinningen kommer skyddsskiktet 9, om det består av Sn eller In, att smälta av hettan från lödpastan som kommer att löda mot kärnans 8 oxidfria yta. Om skyddsskiktet 9 består av Au eller Ag kommer detsamma att lösas i lödpastan. Om skyddsskiktet 9 består av Pt eller Pd kommer detsamma att ligga kvar på lodkulornas 7 yta och lödpastan kommer att löda mot skyddsskiktet 9.When referring to Pig. 3, and Pig. 2 solder balls 7 according to the invention were soldered on connection pads (not shown) on a substrate 10 in a BGA module by means of ordinary solder paste, they will, due to the improved solderability, be centered on the solder paste in the manner shown in Fig. 3. When soldering the solder balls 7 according to the invention, the protective layer 9, if it consists of Sn or In, will melt off the heat from the solder paste which will solder against the oxide-free surface of the core 8. If the protective layer 9 consists of Au or Ag, the same will be dissolved in the solder paste. If the protective layer 9 consists of Pt or Pd, the same will remain on the surface of the solder balls 7 and the solder paste will solder against the protective layer 9.

När en BGA-modul med lodkulor 7 enligt uppfinningen löds mot en annan elektronisk anordning, exemplevis ett kretskort (icke visat), kommer lodkulomas 7 lödbarhet mot anslutningspaddar på kretskortet ävenledes att förbättras tack vare att det skyddande metallskiktet 9 ligger kvar på den yta av lodkulorna 7 som vetter bort från BGA-modulen.When a BGA module with solder balls 7 according to the invention is soldered to another electronic device, for example a circuit board (not shown), the solderability of the solder balls 7 to connection pads on the circuit board will also be improved due to the protective metal layer 9 remaining on the surface of the solder balls 7 facing away from the BGA module.

Av det ovanstående torde det vara uppenbart att problemen med de kända lodkuloma elimineras genom förbättringen av lodkulornas lödbarhet enligt uppfinningen.From the above it should be obvious that the problems with the known solder balls are eliminated by the improvement of the solderability of the solder balls according to the invention.

Claims (6)

10 15 20 51% G28 PATENTKRAV10 15 20 51% G28 PATENT REQUIREMENTS 1. Förfarande för att förbättra lödbarheten hos en lodkula av lod med hög smälttemperatur, kännetecknat av att naturlig oxid avlägsnas från lodkulan och att ett skyddsskikt (9) av en metall som möjliggör lödning av lodkulan medelst en konventionell lödpasta påförs för förhindrande av att ny oxid bildas på lodkulan.Method for improving the solderability of a solder of solder with a high melting temperature, characterized in that natural oxide is removed from the solder and that a protective layer (9) of a metal which enables soldering of the solder by means of a conventional solder paste is applied to prevent new oxide formed on the solder ball. 2. Förfarandet enligt kravet 1, kännetecknat av att naturlig oxid avlägsnas medelst en syra eller ett reducerande medel.The process according to claim 1, characterized in that natural oxide is removed by means of an acid or a reducing agent. 3. Förfarandet enligt kravet 1, kännetecknat av att den påförda metallen väljs ur en grupp bestående av Ag, Au, In, Pd, Pt och Sn.The method according to claim 1, characterized in that the applied metal is selected from a group consisting of Ag, Au, In, Pd, Pt and Sn. 4. Lodkula av lod med hög smälttemperatur, kännetecknad av att den är befriad från naturlig oxid och försedd med ett skyddsskikt (9) av en metall som möjliggör lödning av lodkulan medelst en vanlig lödpasta.Solder ball of solder with a high melting temperature, characterized in that it is free of natural oxide and provided with a protective layer (9) of a metal which enables soldering of the solder ball by means of an ordinary solder paste. 5. Lodkulan enligt kravet 4, kännetecknad av att skyddsskiktet (9) består av Ag, Au, ln, Pd, Pt eller Sn.The solder ball according to claim 4, characterized in that the protective layer (9) consists of Ag, Au, ln, Pd, Pt or Sn. 6. Användning av en lodkula (7) med en kärna (8) av lod med hög smälttemperatur som är befriad från naturlig oxid och försedd med ett skyddsskikt (9) av en metall som möjliggör lödning av lodkulan (7) medelst en vanlig lödpasta som ett elektriskt och mekaniskt förbindelseorgan i en ball-grid-array-modul.Use of a solder ball (7) with a core (8) of high melting solder which is free of natural oxide and provided with a protective layer (9) of a metal which enables soldering of the solder ball (7) by means of an ordinary solder paste which an electrical and mechanical connector in a ball-grid array module.
SE9901427A 1999-04-21 1999-04-21 Improved soldering balls and the use of such SE515028C2 (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
SE9901427A SE515028C2 (en) 1999-04-21 1999-04-21 Improved soldering balls and the use of such
TW088108738A TW410367B (en) 1999-04-21 1999-05-27 Improved solder balls and use thereof
PCT/SE2000/000671 WO2000064625A1 (en) 1999-04-21 2000-04-07 Improved solder balls and use thereof
AU46315/00A AU4631500A (en) 1999-04-21 2000-04-07 Improved solder balls and use thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
SE9901427A SE515028C2 (en) 1999-04-21 1999-04-21 Improved soldering balls and the use of such

Publications (3)

Publication Number Publication Date
SE9901427D0 SE9901427D0 (en) 1999-04-21
SE9901427L SE9901427L (en) 2000-10-22
SE515028C2 true SE515028C2 (en) 2001-05-28

Family

ID=20415300

Family Applications (1)

Application Number Title Priority Date Filing Date
SE9901427A SE515028C2 (en) 1999-04-21 1999-04-21 Improved soldering balls and the use of such

Country Status (4)

Country Link
AU (1) AU4631500A (en)
SE (1) SE515028C2 (en)
TW (1) TW410367B (en)
WO (1) WO2000064625A1 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20180045051A (en) * 2014-11-05 2018-05-03 센주긴조쿠고교 가부시키가이샤 Solder material, solder paste, foam solder, solder joint, and method for controlling solder material

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5340411A (en) * 1993-10-12 1994-08-23 Hughes Aircraft Company Surface treatment method for fatigue-resistant solder
EP0747954A3 (en) * 1995-06-07 1997-05-07 Ibm Reflowed solder ball with low melting point metal cap
WO1997001866A1 (en) * 1995-06-29 1997-01-16 Minnesota Mining And Manufacturing Company Ball grid array package utilizing solder coated spheres
US5899737A (en) * 1996-09-20 1999-05-04 Lsi Logic Corporation Fluxless solder ball attachment process

Also Published As

Publication number Publication date
TW410367B (en) 2000-11-01
WO2000064625A1 (en) 2000-11-02
SE9901427L (en) 2000-10-22
AU4631500A (en) 2000-11-10
SE9901427D0 (en) 1999-04-21

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