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Maxim >
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Lead-Free/RoHS Frequently Asked Questions (FAQ)
Lead-Free Questions
What is Maxim Integrated Products' definition of lead-free (Pb-free)?
Lead-free is defined as absence of a significant amount of lead (Chemical symbol Pb) in a package or part make-up. In an IC package, Pb is commonly found in the external lead finish or plating. In Chip Scale Packages (µCSP)/Wafer Level Packaging (WLP) and FlipChip, Pb may be found in the solder bumps.
What is Maxim Integrated Products lead-free material?
Lead-free (Pb-free) surface finishes on most leadframe based packages are commonly composed of 100% matte tin (followed by annealing for 1 hour at 150°C). The exception is a few leadframe based packages of other EU RoHS-compliant plating finishes such as nickel/palladium/gold. Ball Grid Array (BGA), µCSP/WLP/flip-chip packages usually contain balls or bumps of tin/silver/copper.
For all lead frame based packages except Power Cap family products with 100% matte tin plating, the plating thickness is 400 - 800 microinches (µ-inch), or 10 to 20 microns. Power Cap products include DS9034xxx series or PCT-1 or PCT+1, PCT-2 or PCT+2, PCT-3 or PCT+3 package codes.
If a package type is qualified as lead-free, does it mean that all products of that package type are shipped as lead-free?
No, it only means that we have the capability to make the parts as lead-free. The customer must make a request to the Maxim Integrated Products Business Units for approval.
What lead content products have you already transitioned to lead-free?
Most package types are already qualified as lead-free and others are in the qualification process. All Maxim Integrated Products part numbers can be identified as to their qualification status. If a package type is qualified as lead-free, then the Maxim Integrated Products Business Units will make the decision to manufacture and offer the product as lead-free per customer request. Please refer to the Lead-free Information page for packages qualified as lead-free.
Is it possible to get a lead-free part in a package type that is not qualified as lead-free?
If a customer requires that a package type not qualified as lead-free be manufactured and supplied, a request must be submitted to the Maxim Integrated Products Business Units.
Are there any package types that you will not make available as lead-free?
Due to technology limitations, some package types are not currently qualified as lead-free. These include certain Ball Grid Array and Flip Chip package formats.
Will there be any increase/decrease cost for lead-free products?
There will be no major changes in price for lead vs. lead-free packages.
How long does a lead-free package qualification take?
It takes at least 4 weeks to get qualification lots assembled and tested. An additional 10 weeks is required for QA Reliability tests.
Is there any change in die size or functionality used in lead-free products?
No. Revision to the die (product) were not necessary. Only packaging materials were changed as needed to comply with RoHS.
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Moisture Sensitivity Levels (MSL)
What is the Moisture Sensitivity Level (MSL) for surface mount devices in lead-free packages?
Please see the MSL section on the EMMI website.
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Lead-Free Package Markings
What is Maxim Integrated Products lead-free part numbering scheme?
Lead-free, RoHS-compliant part numbers have a (+) symbol suffix at the end of the full Maxim Integrated Products part number.
Example:
MAX1234EUI+
MAX4567CUT+T
MAX4556AESA+
How would lead-free parts be physically identified or marked?
All lead-free, RoHS-compliant products will have the (+) symbol marked on the top package in the area nearest Pin 1 lead, notch or dimple.
How would RoHS compliant parts with an exemption for lead be physically identified or marked?
Part numbers with a suffix containing the "pound" (#) symbol indicate a RoHS-compliant part which has an exemption for lead.
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Peak Reflow Temperatures and Profiles
What is Maxim Integrated Products Peak Reflow Temperature?
We meet JEDEC J-STD-020C for most package types as follows:
SnPb Eutectic Process—Package Peak Reflow Temperatures
| Package Thickness |
Volume mm³ < 350 |
Volume mm³ ≥ 350 |
| < 2.5mm |
240 +0/-5°C |
225 +0/-5°C |
| ≥ 2.5mm |
225 +0/-5°C |
225 +0/-5°C |
Pb-Free Process—Package Classification Reflow Temperatures
| Package Thickness |
Volume mm³
< 350 |
Volume mm³
350-2000 |
Volume mm³
< 2000 |
| < 1.6mm |
260 +0°C* |
260 +0°C* |
260 +0°C* |
| 1.6mm - 2.5mm |
260 +0°C* |
250 +0°C* |
245 +0°C* |
| ≥ 2.5mm |
250 +0°C* |
245 +0°C* |
245 +0°C* |
|
* Tolerance: The device manufacturer/supplier shall assure process compatibility up to and including the stated classification temperature (this means Peak reflow temperature +0°C. For example 260°C+0°C) at the rated MSL level.
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To what reflow process temperatures are the lead-free packages qualified?
For most SMD (Surface Mount Devices), our standard qualification is at 260°C peak reflow temperature with 3 reflows. See exceptions below.
What is Maxim Integrated Products standard qualification lead-free Peak Reflow Temperature?
260 (+5/-0) degrees Celsius.
| Profile |
Pb-Free Profile
(JEDEC-020D)* |
| Average ramp-up rate (Ts max to T peak) |
3°C/seconds max. |
Preheat:
- Temperature Min (Ts min)
- Temperature Max (Ts max)
- Time (Ts min to Ts max) |
150°C
200°C
60-120 seconds |
Time maintained above:
- Temperature (TL)
- Time (tL) |
217°C
60-150 seconds |
| Peak temperature |
255-260°C |
| Time within 5°C of the peak temp (260°C) |
30 seconds |
| Average ramp-down rate (T peak to Ts max) |
6°C/seconds max. |
| Time 25°C to peak temperature |
8 minutes max. |
NOTE: The reflow profile in the above table is only for qualification and is not meant to specify board assembly profiles. Actual board assembly profiles must be based on the customer's specific board design, solder paste and process, and should not exceed the parameters in the table.
What is Maxim Integrated Products standard qualification Tin/Lead (Eutectic) Peak Reflow Temperature?
240 (+5/-0) degrees Celsius.
See exceptions below.
| Profile |
Sn-Pb Profile
(JEDEC-020D) |
| Average ramp-up rate (Ts max to T peak) |
3°C/seconds max. |
Preheat:
- Temperature Min (Ts min)
- Temperature Max (Ts max)
- Time (Ts min to Ts max)
|
100°C
150 °C
60-120 seconds
|
Time maintained above:
- Temperature (TL)
- Time (tL)
|
183°C
60-150 seconds
|
| Peak temperature |
235-240°C |
| Time within 5°C of the peak temp (240°C) |
20 seconds |
| Average ramp-down rate (T peak to Ts max) |
6°C/seconds max. |
| Time 25°C to peak temperature |
6 minutes max. |
NOTE: The reflow profile in the above Table is only for qualification and is not meant to specify board assembly profiles. Actual board assembly profiles must be based on the customer's specific board design, solder paste and process, and should not exceed the parameters in the table.
Are there product or package exceptions where the standard Pb-Free or Eutectic qualification reflow profiles? How do you determine which products these are and what is the different profile to use for each?
Yes there are exceptions due to the materials used in certain package types. These products have special suffixes added to the normal product part number as listed below with their profiles.
Product Part Numbers with G36 suffixes have a peak temperature of 225 (+5/-0) degrees Celsius.
| Profile |
Sn-Pb Profile
(JEDEC-020D) |
| Average ramp-up rate (Ts max to T peak) |
3°C/seconds max. |
Preheat:
- Temperature Min (Ts min)
- Temperature Max (Ts max)
- Time (Ts min to Ts max)
|
100°C
150°C
60-120 seconds
|
Time maintained above:
- Temperature (TL)
- Time (tL)
|
183°C
60-150 seconds
|
| Peak temperature |
220-225°C |
| Time within 5°C of the peak temp (225°C) |
20 seconds |
| Average ramp-down rate (T peak to Ts max) |
6°C/seconds max. |
| Time 25°C to peak temperature |
6 minutes max. |
Product Part Numbers with G42 suffixes and Power Cap family products have a peak temperature of 240 (+5/-0) degrees Celsius.
| Profile |
Sn-Pb Profile
(JEDEC-020D) |
| Average ramp-up rate (Ts max to T peak) |
3°C/seconds max. |
Preheat:
- Temperature Min (Ts min)
- Temperature Max (Ts max)
- Time (Ts min to Ts max)
|
100°C
150°C
60-120 seconds
|
Time maintained above:
- Temperature (TL)
- Time (tL)
|
183°C
60-150 seconds
|
| Peak temperature |
235-240°C |
| Time within 5°C of the peak temp (240°C) |
20 seconds |
| Average ramp-down rate (T peak to Ts max) |
6°C/seconds max. |
| Time 25°C to peak temperature |
6 minutes max. |
Product Part Numbers with G13, G14, G15, G16, G27, G28, GC6 suffixes have a peak temperature of 250 (+5/-0) degrees Celsius.
| Profile |
Sn-Pb Profile
(JEDEC-020D) |
| Average ramp-up rate (Ts max to T peak) |
3°C/seconds max. |
Preheat:
- Temperature Min (Ts min)
- Temperature Max (Ts max)
- Time (Ts min to Ts max)
|
150°C
200°C
60-120 seconds
|
Time maintained above:
- Temperature (TL)
- Time (tL)
|
217°C
60-150 seconds
|
| Peak temperature |
245-250°C |
| Time within 5°C of the peak temp (250°C) |
30 seconds |
| Average ramp-down rate (T peak to Ts max) |
6°C/seconds max. |
| Time 25°C to peak temperature |
8 minutes max. |
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Lead Containing Product Questions
Will Maxim Integrated Products continue to provide lead containing versions of it's products?
Yes, some customers don't want lead-free, therefore Maxim Integrated Products will continue to build leaded and non-leaded versions of the parts.
What is Maxim Integrated Products lead containing material?
For most lead frame based packages, the material is 85% Sn (tin)/15% Pb (lead) plating on external leads. For BGA and µCSP/WLP packages, the solder balls or bumps contain Tin/Lead combinations. For some specialty packages, certain components within the package contain exemptions for lead (example: Resistor).
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EU RoHS
Do Maxim Integrated Products qualified as lead-free products meet Restriction on Hazardous Substance (RoHS) and European Economic Community (EEC) guidelines per Directive 2002/95/EC?
Yes.
RoHS Substances:
Substances regulated by EU RoHS:
Lead, cadmium, hexavalent chromium, mercury, PBBs, and PBDEs
Possible RoHS substances in end products: Lead
Possible RoHS substances in packing materials: Cadmium
Components and Substances Contained in most leadframe based Plastic Packages:
Components: Leadframes, die attach, bond wire, molding compound, surface finish (plating), silicon chip.
Substances: Copper, iron, zinc, phosphorus, nickel, magnesium, gold, silver, tin, resin, lead (non Pb-free product), silicon and antimony trioxide and bromine (Sb2O3 and Br may be used as flame retardants in some molding compounds).
Components and Substances Contained in most µCSP/WLP packages:
Components: Silicon chips, die coats, UBMs (under bump metals) and solder bumps.
Substances: Silicon chips, resin, aluminum, nickel (V), copper, titanium, nickel, vanadium, tin, silver and lead (Pb is in non Pb-free products).
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ISO 14001
Is Maxim Integrated Products ISO 14001 Certified?
Each Maxim manufacturing, assembly and test facility is ISO 14001 registered. To obtain copies of these documents see this link.
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General Information
For lead-free products, what types of solder pastes are available and would work in board reflow at 260°C maximum temperature?
At 260°C and below, the predominant lead-free solder pastes are:
Sn/Ag4.0/Cu.5 217°C (240-255°C)
Sn/Ag2.5/Cu.8/Sb.5 216°C (225-240°C)
Sn/Ag3.5 221°C (245-255°C)
Sn/Cu.75 227°C (250-260°C)
Sn/Bi3.0/Ag3.0 213°C (225-244°C)
NOTE: This list is a summary of solder paste types commonly used in the industry. Maxim Integrated Products doesn't recommend any usage of these pastes nor guarantees any benefits by using them.
Can Maxim Integrated Products' standard reflow temperature range lead-free and leaded parts be mixed during board reflow? What reflow temperature would be used in this scenario?
Maxim Integrated Products lead-free termination parts can be mixed with leaded termination parts and reflowed at a lower temperature (240°C) with proper reflow conditions and compatible solder paste. However, the reliability of Maxim Integrated Products parts with leaded terminations are not guaranteed at higher reflow temperature (above 240°C). Some reference sources show data that define a reduction in solder joint reliability by as much as 33% less than Eutectic solder joints when lead and lead-free metallurgies are mixed.
What are the melting ranges of solder alloys and their pure components?
Element/Alloy Melting point (liquidus):
Pure Lead 327.5°C (621.5°F)
Pure Tin 232°C (450°F)
85Sn/15Pb 183-205°C (361-401°F)
70Sn/30Pb 183-193°C (361-379°F)
63Sn/37Pb 183-193°C (361-379°F)
60Sn/40Pb 183-190°C (361-374°F)
What type of plating chemistries are available for 100% matte tin?
For high speed auto plating lines, MSA based electrolytes are most common. Numerous vendors such as Fidelity, Englehardt, LeaRonal, Isihara, Schlotter and other proprietary and home brews are readily available. For manual/rack/barrel plating lines, sulfuric acid based electrolytes are most common. Even more sources are readily available from numerous vendors such as above and lots of non-proprietary home brew chemistries. These are very inexpensive!
Is there a plan to remove Halogens from mold compounds for Maxim Integrated Products products?
Our "green molding compounds" are the only molding compounds that don't have bromine. Aside from the green molding compounds, all of our other molding compounds contain bromine and antimony. The bromine contained in our "non-green molding compounds" is "elemental bromine" and is used as a flame retardant. Elemental bromine does not meet the definition of a PBB (polybrominated biphenyl) or PBDE (polybrominated diphenyl ether).
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Calculations
How do you calculate chemical level parts per million?
Take the weight of the constituent (i.e., lead) and divide by the unit weight. Multiply the outcome by 1,000,000. For example: the weight of lead in the part is 0.000375 grams and the unit weight is 0.1473 grams, therefore ppm = 0.000375 / 0.1473 x 1,000,000 = 2546 ppm.
How do you calculate chemical level % of the constituent by weight?
Take the weight of the constituent (i.e., lead) and divide by the unit weight. For example: the weight of lead in the part is 0.000375 grams and the unit weight is 0.1473 grams, therefore % = 0.000375 / 0.1473 = 0.002546 x 100 = 0.2546%.
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Tin Whiskers
Have you tested for Tin Whiskers? Describe qualification tests performed.
Tin whiskers are tested during package qualification at assembly site.
Tests performed are:
Prolonged storage at 85°C/85% RH for 500 hours and 1000 hours.
Storage under 50-55°C for 1, 3, 6 and 12 month interval.
What is the acceptance criteria for Tin Whiskers? What is the method of identifying tin whiskers?
Less than 50 microns in any dimension of whiskers is considered acceptable. Visual inspection is performed under 30X magnification. There is currently no JEDEC/IPC standard for tin whisker testing, inspection and acceptance criteria.
What regular monitor and assembly process controls are in place for Tin Whiskers?
Tin Whiskers are controlled and monitored in assembly by:
Visual inspection at 30X magnification. Frequency of 6X/shift, Sample size = 125 parts.
Plating bath analysis once a day for Tin, acids and bath organic content.
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Product Content Information
Package and constituent information is available for specific part numbers. To view this information, enter the desired part number and click Search:
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Qualifications and Testing
Why is there a need to qualify Maxim Integrated Products packages and assembly process technologies for 100% Matte Tin Plate?
All package body sizes, assembly materials (mold compound and die attach epoxy), assembly processes (down bond and die coat) and fab processes behave differently in a higher reflow environment (above 240°C). Sufficient reliability data is required from all of these packages and process/fab technologies to assure that product will survive and special packaging requirements are determined to eliminate potential field failures.
Note that package and process qualifications can be extended to other packages and process technologies by similarity.
What type of Reliability tests are important and recommended to assess packaging and plating reliability for 100% matte tin?
Recommended Reliability Tests are:
IR or Convection reflow at 260°C peak temperature with preconditioning.
85/85, HAST, Pressure Pot (Autoclave), High Temperature Storage, DHTL.
Temperature cycling with IR or convection reflow as precondition.
Solderability testing with and without aging.
Note that package preconditioning would depend on the Moisture Level rating of the package and materials used in lead-free assembly.
Is there a standard typical solderability test for 100% matte tin? What is the steam aging condition prior to solderability testing?
Existing Solderability Standard:
For the Western markets, most companies are using the MIL-STD-883 solderability test at 260°C with steam aging. For the European markets, most companies are using the IEC solderability test at 240°C with steam aging. Steam aging times vary from 4-24 hours with most companies doing 8 hours.
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