Technische Information / Application …

1 1 / 15 Technische Information / Application Recommendation solder Paste Series F 640 V_10_05 1. Specification of Heraeus solder paste series F 640 Alloy: Composition (%): (1) (2) (3) SnAg4 Other SAC on request Melting Point ( C) (1) 217 C (2) 217 C (3) 221 C Shape: Spherical Particle size ( m): 25-45 20-38 Type 3 Type 4 (on request) Density (g/cc): 7,4 Oxidation level (ppm): < 150 solder paste: Metal content (%): 88 1 By weight Viscosity (Pas): 130 40 Physica CSS 10 s-1 Copper plate corrosion: Pass J-STD-004 Silver Chromate Test: Pass J-STD-004 Copper Mirror Test: Pass J-STD-004 Shelf life (per month): Cartridges Minimum of 3 Jars Minimum of 6 2-10 C 2 / 15 2.

2 solder paste properties Item Typical Property Test Method Alloy (Standard:) SnAg4Cu0,5 --- Flux Content (Standard) : 11% Weight percent Powder size (Standard): Type 3 --- Shape: Sphere --- Solidus-Liquidus: 217 C --- Chlorine Content: < 20 ppm IPC-TM-650 Bromide Content: < 20 ppm IPC-TM-650 Copper Plate Corrosion Test: Pass J-STD-004 Silver Chromate Test: Pass J-STD-004 / Bellcore 2E+10 Ohm Copper Mirror Test: Pass J-STD-004 / Bellcore 2E+10 Ohm Electric Insulation Resistence Test (SIR) 40C/93%/168H: 1,5E+09 ohm 2E+10ohm Siemens SN 59650 Bellcore Voltage applied Moisture Resistance, SIR (Bias DC50V): 85C/85%/500H: 6,5E+09 ohm Acc. DIN IEC 61189 See Diagramm solder ball Test (air): Good Heraeus Benchmarker 2 Tackiness Time of keeping 100g minimum: 24 hours JIS_Z-3284 Hot Slump: Benchmarker 2 Viscosity : See specifications Physica CSS D= 10 s-1 Test results: Copper Plate Corrosion Test Silver Chromate Test Copper Mirror Test 3 / 15 3.

3 Viscosity curve Test method: CSS 0 Pa to 2000 Pa within 2 min Equipment: Physica MCR 300 Plate/Plate r=50 mm Test result: Temperature ( C) Yieldpoint (Pa) Viscosity@ 10s-1 (Pas) Viscosity@ 2000 Pa (Pas) 15 653 200 201 20 523 153 108 25 452 125 62 30 402 104 43 35 362 89 25 4. Slump Observe the minimum spacing across which the paste has not merged after reflowing the substrate with the temperature condition of 5 min 150 C. Yieldpoint vs Temperature01002003004005006007001520253 035T [ C]Viscosity [Pa]Viscosity@2000Pa vs Temperature0501001502002501520253035T [ C]Viscosity [Pas] 4 / 15 5.

4 solder balling Test method: Prepare two test pieces by printing the paste on each alumina plate (50 x 50 x ) with a thick stencil provided with three diameter apertures with a distance between centers of 15mm. Reflow one if them in 1 hour after printing and the other after storing it at 25 2 C 60 20%RH for 24 hours. Inspect the degree of reflowing referring to solder balling evaluation standard using the x 10 magnifying glass. Category: Status of coalescence of solder : Illustration: 1 The molten solder from paste has melted into one solder ball. 2 The molten solder from the paste has melted into one large solder ball with no more than three isolated small solder balls with diameter less than 75 m.

5 3 The molten solder from the paste has melted into on large solder ball surrounded by more than three solder balls with diameters less than 75 m which do not form a semi-continuous halo. 4 The molten solder from paste has melted into one ball accompanied by a large number of smaller solder balls which may form a semi-continuous halo, or has melted to form a number of similarly sized balls. Test results: Test substrate before reflow 5 / 15 6. solder wettability Test method: Test result: Use as test plate a copper plate, in size polished by #1500 abrasive paper an washed by alcohol.

6 Print the solder paste with a thick stencil provided with three diameter apertures and reflow one if them in 1 hour after printing (storing it at 25 2 C 60 20%RH ). Test substrate before reflow 7. Voltage applied sir Test method: Print the solder past to each comb type electrode JIS type-II (stencil thickness: ) Put the test piece in a climate chamber under the conditions of 85 2 C and 85 2% RH (DC50 V) Measure the insulation resistance at every hour, DC50V for the measurement. Substrate before test Example for a soldered Example for migration Substrate Test result: F640 SIR 85 C / 85% / 50 V 1,00E+071,00E+081,00E+091,00E+101,00E+11 1,00E+121,00E+13025507510012515017520022 5250275300325350375400425450475500 HoursOhm 6 / 15 8.

7 Printability Print parameters: Stencil: Benchmarker II150 m Printer: EKRA X5 Squeegee: 200mm / steel 60 Print speed: 50 mm/s Stencil separation speed: 10mm/s Atmosphere: 25 C 1 C Test patterns: Aperture Test 10 groups of fine pitch apertures with same width ranging from 120 m to 300 m in 20 m steps, vertical, horizontal and 45 angle. 300 m 280 m 260 m 240 m 120 m 140 m 160 m 180 m 200 m 220 m 7 / 15 a) Print - Result of 15 prints b) Print - Result of 15 prints after storage 7d@30 C c) Print-Result 5th print Vertical 200 m Horizontal 200 m 45 200 m 8 / 15 Spread Test 5 rows of 25*50 mil pads with different gap between the pad in each row, ranging from 4mils to 12mils (100 m to 300 m).

8 Result: Initial 5 min. 150 C Hot Slump Test Inspect 5th board spread and aperture, place board in a box oven at 150 C and 180 C for 5min within 10min of printing and re-inspect spread and aperture. Result: Pitch 0,4mm Initial 5 C Pitch 0,4mm Initial 5 C 9 / 15 Print After Wait The test determines the time which can elapse between two prints without having to clean the stencil. Print 5 boards; clean the stencil; print 6th board = initial; wait eg.

9 30/45/60 minutes ; print 7th board = PAW; inspect the narrow pad (horizontal and vertical) of a 25mil 100P BQFP. Generally a 15% or more reduction is considered a failure. Re-start the test with shorter time Note: For specific customer applications any other aperture may be used (eg. BGA, CSP, BGA) horizontal vertical Results: 10 / 15 9. Wetting Print at least 2 boards each combination (board surface, atmosphere, profile); reflow & inspect wetting area* A , B , C and D area A : area B : area C : area D : *the pictures show printed paste Wetting results: 11 / 15 Screen Life Test: Stencil: Benchmarker II150 m for SLT Printer: EKRA X5 Squeegee: 200mm / steel 60 Print speed: 50 mm/s Stencil separation speed: 10mm/s Test method: Print (knead) solder paste on the sealed-up stencil continuously up to 8 hours to observe viscosity variation.

10 Atmosphere: 25 C 1 C Result of 8 hours: Yield Point03006009001200012345678 Time / hTau 0 [Pa] 12 / 15 10. Use of Heraeus solder Paste In order to make the paste use of HERAEUS solder PASTE, please refer to the following guideline carefully before use. 1. Preparation for printing Temperature After taking the solder paste out of the fridge, in which the temperature is controlled to be below 10 C, wait ca. 2 hours that the paste temperature comes back to room temperature. Caution: Do not open the jar while it is cold, or it causes condensation of moisture on the paste, and could be a case of poor performance, such as increase of viscosity, solder balling and etc.