ASSOCIATION CONNECTING ELECTRONICS …

1 IPC-HDBK-005 guide to SolderPaste AssessmentDeveloped by the solder Paste Task Group (5-24b) of the Assemblyand Joining Processes Committee (5-20) of IPCU sers of this publication are encouraged to participate in thedevelopment of future :IPC3000 Lakeside Drive, Suite 309 SBannockburn, Illinois60015-1219 Tel 847 847 CONNECTINGELECTRONICS INDUSTRIES Table of .. and Definitions .. solder Paste .. 12 APPLICABLE .. Industry Standards .. Electrotechnical CommissionDocuments .. of Wetting .. of Wetting .. Measurement .. Affecting Solderability DuringReflow Soldering Process.

2 Surface Finish .. Air solder Leveling (HASL) .. Coating .. Solderability Preservatives (OSP).. Lead Composition/Finish .. Metal .. Composition .. Coated Leads .. Coated Leads .. or Pt Plated Leads .. Coating Processes .. Paste .. Alloy .. Particle Size .. Testing .. Paste Wetting Tests .. Test Documents .. Solderability Test Methods .. Test Method Selection .. 64 PRINTING solder Needs .. Variables .. Control Variables .. Paste Print Quality Control Variables .. Variables .. Paste Variables .. Variables .. Printer Variables .. and Operator Variables.

3 95 ABILITY OF solder PASTE TO RETAINCOMPONENTS (TACK).. Test Shortcomings .. Life .. Tack Strategies .. Tack Life Strategies .. Variables .. Testing .. Testing .. Test Guidelines .. Testing Apparatus .. Procedure .. Slump .. Slump .. Performance .. Inspection .. Control Variables .. 137 solder PASTE FUME COLLECTION .. Vapor Collection .. Toxicity .. System Maintenance .. 14 January 2006 IPC-HDBK-005v8 solder Ball Tests .. of solder Balling .. Beads .. Paste Segregation .. of Coalescence .. Strategies .. Strategies .. Testing .. Causes.

4 Defects .. 1710 CLEANABILITY OF solder PASTES Methods and Materials .. 1711 COMPATIBILITY OF solder PASTE FLUXRESIDUES (PROBE TESTABILITY).. Plan Overview .. for Improved ATE-Compatibility .. Characteristics .. Control Variables .. Open Time .. Conditions .. Points .. Probe Design and ATE Equipment .. Build-up .. Dryness .. 2012 SHELF Procedures .. Variables .. 21 APPENDIX AMass Reflow Assembly of 02\ 22 APPENDIX BQualification of solder Beadingand Tombstoning in PassiveDevices using 29 APPENDIX CA Materials Based Solution forthe Elimination of 38 FiguresFigure 3-1 Surface Tension and Contact Angle ofMolten solder .

5 3 Figure 3-2 Effect of Alloy Composition on Areaof Spread .. 6 Figure 5-1 The Extensional Nature of Tack .. 10 Figure 5-2 The Interaction of Various FactorsAffecting solder Paste Working Life .. 10 Figure 8-1 solder Beading .. 15 Figure 8-2 solder Spatter .. 15 Figure 9-1 Tombstoned Component .. 16 Figure 9-2 Floating Tombstone or DrawBridging Defect .. 17 Figure 11-1 Overview for ATE Testing Plan .. 19 TablesTable 3-1 Factors of Wetting and Their Effects .. 4 Table 3-2 Common Solderability Test Methods .. 6 Table 5-1 Main Control Variables Affecting SolderPaste Working Life .. 10 Table 11-1 Questions for Probe Testing FlowChart/ guide .

6 19 Table 12-1 Test Recommendations for Shelf LifeDetermination .. 21 IPC-HDBK-005 January 2006viGuide to solder Paste Assessment1 SCOPEThis handbook is a companion to the solder paste standardJ-STD-005 and should be considered to be a guide to helpassess the applicability of a solder paste for its use in sur-face mount technology (SMT) processes. This documentalso suggests some test methods that can help with design-ing and testing solder pastes. It is intended for use by bothvendors and users of solder PurposeSolder pastes are unique materials, whoseperformance in a surface mount process depends on a vari-ety of variables, many of them interacting.

7 J-STD-005 pro-vides test methods for classification of solder paste basedon the use of a variety of testing techniques. However,these solder paste classifications do not have a direct cor-relation to identify the type and characteristics of a specificsolder paste that is needed in any given SMT document has been written as a guide to assess theapplicability of a solder paste for a specific process, giventhe tremendous number of permutations of different mate-rials, atmospheres and process variables currently appropriate, references are given to papers anddocuments with further information.

8 Due to the sheer num-ber of possible interacting factors, specific solder pasteselection criteria cannot be given. The solder paste selectedand the assembly process used will need to form solderconnections that meet the requirements of industry stan-dards such as J-STD-001 and/or ChecklistSolder paste vendors often provide practi-cal information about their products. When this informa-tion is available much time and money can be saved inqualifying the product s capabilities. The following listingsare examples of information that is usually of value to pro-cess engineers and designers.

9 Items marked with an aster-isk (*) are usually of greatest value.*Is the paste recommended for use in clean or no-cleanprocesses and is there a recommended cleaning process?*What is the ideal or recommended reflow profile?*What is the flux classification per J-STD-004 or equiva-lent flux standard? *What are the results of copper mirror testing? *What is the halides content? *What percentage of Flux Solids (Non-Volatile Content)? *Corrosion *Surface Insulation Resistance (SIR)*What is the characterization of solder paste per J-STD-005? *Powder Size *Powder Shape *Metal Percent *Viscosity *Slump * solder Ball *Tack *Wetting*What is the solder powder alloy designation per J-STD-006?

10 Acid Value Flux Specific Gravity Paste Flux Viscosity Visual Flux Spread Wetting Balance FungusDoes it meet Telcordia (formerly Bellcore) GR-78-CORE requirements? Copper Mirror Halides by Silver Chromate SIR - Terms and DefinitionsThis handbook uses termsand definitions common to the ELECTRONICS manufacturingindustry and defined inIPC-T-50 Terms and Definitions forInterconnecting and Packaging Electronic Using solder PasteSolder paste is the material thatprovides a wetted solder connection between solderablesurfaces. To accomplish that end, it consists of: A flux vehicle to break down surface oxides on the sur-faces to be wetted, and solder alloy in the form of very small solder balls thatwill coalesce into a solder connection when be usable, the solder paste must: Have reasonable working life under ambient temperatureand humidity conditions.