| Lead-Free Questions |
| 1. |
Q. |
What is your definition of lead-free? |
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A. |
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 (UCSP and FlipChip), Pb is found in the Solder Bumps.
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| 2. |
Q. |
What is Maxim Integrated Products lead-free material? |
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A. |
Lead-free (Pb-free) surface finishes are most commonly composed of 100% matte tin, with the exception of a few package types that consist of other RoHS-compliant plating finishes such as nickel palladium. All UCSP and flip-chip packages contain lead. However, the lead contained in these packages is currently RoHS compliant. Studies to find a Pb-free solution for UCSP and flip-chip packages are ongoing. |
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| 3. |
Q. |
What is Maxim Integrated Products lead-free Peak Reflow Temperature? |
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A. |
We meet JEDEC J-STD-020C 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* |
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* 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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| 4. |
Q. |
Will Maxim Integrated Products continue to provide both lead-free and lead contain versions of the products?
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A. |
Yes, some customers don't want lead-free, therefore Maxim Integrated Products will continue to build leaded and non-leaded versions of the parts.
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| 5. |
Q. |
If a part is qualified as lead-free, does it mean that we are getting it as lead-free?
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A. |
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.
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| 6. |
Q. |
Are there any products that you will not make available as lead-free?
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A. |
Due to technology limitations, some package types are not currently qualified as lead-free. Examples: Ball Grid Array (BGAs) and Flip Chips. Maxim Integrated Products BGAs are eutectic and the majority of Maxim Integrated Products BGA packages are 63%Sn / 37%Pb. However, we do have some volume of 10mm Chip Scale Ball Grid Array (CSBGA) packages which are Sn/Ag/Cu and contain no lead.
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| 7. |
Q. |
Will there be any increase / decrease cost for lead-free products?
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A. |
There will be no major changes in price for lead vs. lead-free packages.
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| 8. |
Q. |
Is it possible to get a lead-free part that is not qualified as lead-free?
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A. |
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.
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| 9. |
Q. |
How long does a lead-free package qualification take?
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A. |
It takes at least 4 weeks to get qual lots assembled and tested. An additional 10 weeks is required for QA Reliability tests.
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| 10. |
Q. |
What reflow process temperatures are lead-free packages qualified?
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A. |
For all SMD (Surface Mount Devices), qualification is at 260°C peak reflow temperature.
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| 11. |
Q. |
Where can I find the Maxim Integrated Products reflow profile?
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A. |
The profiles are available here:
Peak Solder Reflow Profile for Packages Containing Lead (PDF, 6K).
Peak Solder Reflow Profile for Lead-free Packages (PDF, 8K).
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| 12. |
Q. |
What lead-free reflow profile is recommended for PC board reflow?
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A. |
Reflow should follow Pb Free profile in IPC/JEDEC J-STD-020 spec.
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| 13. |
Q. |
What is the Moisture Sensitivity Level (MSL) for lead-free packages?
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A. |
Please see the Lead-free Information page on the EMMI website.
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| 14. |
Q. |
For lead-free products, what types of solder pastes are available and would work in board reflow at 260°C maximum temperature?
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A. |
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.
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| 15. |
Q. |
What lead content products have you already transitioned to lead-free?
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A. |
Many 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 part is qualified as lead-free, then the Maxim Integrated Products Business Units will make the decision to manufacture and offer the package as lead-free per customer request. Please refer to the Lead-free Information page for packages qualified as lead-free.
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| 16. |
Q. |
Is there any change in die size used in lead-free products?
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A. |
No. Revision to the die (product) were not necessary. Only packaging materials were changed as needed to comply with RoHS.
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Packages Qualified as Lead-Free
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Lead-Free Peak Reflow Graph (PDF, 7K)
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Lead frames for all parts have a plating thickness of 400 - 800 microinches (µ-inch), or 10 to 20 microns.
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Lead-free packages have a surface finish that is comprised of 100% matte tin.
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| Lead-Free Markings |
| 1. |
Q. |
What is Maxim Integrated Products lead-free part numbering scheme?
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A. |
Lead-free, RoHS-compliant part numbers have a (+) symbol at the end of the full Maxim Integrated Products part number.
Example:
MAX1234EUI+
MAX4567CUT+T
MAX4556AESA+
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| 2. |
Q. |
How would lead-free parts be physically identified or marked?
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A. |
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
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| 3. |
Q. |
How would RoHS compliant parts with an exemption for lead be physically identified or marked?
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A. |
Part numbers with the "pound" (#) symbol indicate an RoHS-compliant part which has an exemption for lead.
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| Peak Reflow Temperatures and Profiles |
| 1. |
Q. |
What is Maxim Integrated Products lead-free Peak Reflow Temperature? |
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A. |
255 (+5/-0) degrees Celsius.
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| 2. |
Q. |
What is Maxim Integrated Products Lead Peak Reflow Temperature?
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A. |
We meet JEDEC J-STD-020C 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* |
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* 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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| 3. |
Q. |
Where can I find the Maxim Integrated Products reflow profile?
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A. |
The profiles are available here:
Peak Solder Reflow Profile for Packages Containing Lead (PDF, 6K).
Peak Solder Reflow Profile for Lead-free Packages (PDF, 8K).
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| 4. |
Q. |
What lead-free reflow profile is recommended for PC board reflow?
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A. |
Reflow should follow Pb Free profile in IPC/JEDEC J-STD-020 spec.
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| Lead Questions |
| 1. |
Q. |
Will Maxim Integrated Products continue to provide both lead-free and lead contain versions of the products?
|
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A. |
Yes, some customers don't want lead-free, therefore Maxim Integrated Products will continue to build leaded and non-leaded versions of the parts.
|
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| 2. |
Q. |
Are there any products that you will not make available as lead-free?
|
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A. |
Due to technology limitations, some package types are not currently qualified as lead-free. Examples: Ball Grid Array (BGAs) and Flip Chips. Maxim Integrated Products BGAs are eutectic and the majority of Maxim Integrated Products BGA packages are 63%Sn / 37%Pb. However, we do have some volume of 10mm Chip Scale Ball Grid Array (CSBGA) packages which are Sn/Ag/Cu and contain no lead.
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| 3. |
Q. |
What is Maxim Integrated Products Lead Peak Reflow Temperature?
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A. |
We meet JEDEC J-STD-020C 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* |
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* 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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| 4. |
Q. |
What is Maxim Integrated Products lead material?
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A. |
Material is 85%Sn (tin) /15%Pb (lead) plating on external leads.
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| 5. |
Q. |
Where can I find the Maxim Integrated Products reflow profile?
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A. |
The profiles are available here:
Peak Solder Reflow Profile for Packages Containing Lead (PDF, 6K).
Peak Solder Reflow Profile for Lead-free Packages (PDF, 8K).
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| 6. |
Q. |
What is the Moisture Sensitivity Level for packages containing lead?
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A. |
Please refer to the Moisture Sensitivity Level page on the EMMI website.
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| RoHS |
| 1. |
Q. |
Do Maxim Integrated Products qualified lead-free products meet Restriction on Hazardous Substance (RoHS) and European Economic Community (EEC) guidelines?
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A. |
Yes.
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| RoHS Substances: |
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Substances regulated by RoHS: Lead, cadmium, hexavalent chromium, mercury, PBBs, and PBDEs
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Possible RoHS substances in end products: Lead
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Possible RoHS substances in packing materials: Cadmium
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Components and Substances Contained in Plastic Packages
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Components in plastic packages: Leadframes, die attach, bond wire, molding, surface finish, silicon chip.
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Substances in plastic packages: Copper, iron, zinc, phosphorus, nickel, magnesium, gold, silver, antimony trioxide, bromine, tin, lead, silicon.
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Components and Substances Contained in UCSP packages
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Components in plastic packages: Silicon chips, die coats, UBM's (under bump metals) and solder balls.
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Substances in plastic packages: Silicon chips, resin, aluminum, nickel (V), copper, tin and lead.
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| ISO 14001 |
| 1. |
Q. |
Is Maxim Integrated Products ISO 14001 Certified?
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A. |
Each Maxim manufacturing, assembly and test facility is ISO 14001 registered, with the exception of the Maxim wafer fab located in San Antonio, Texas. The San Antonio registration date has been extended until production ramp-up is reached. The registration date has not been re-scheduled at this time.
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| General Information |
| 1. |
Q. |
For lead-free products, what types of solder pastes are available and would work in board reflow at 260°C maximum temperature?
|
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A. |
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.
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| 2. |
Q. |
Can lead-free and leaded parts be mixed during board reflow? What reflow temperature would be used in this scenario?
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A. |
Maxim Integrated Products lead-free parts can be mixed with leaded parts and reflowed at a lower temperature (240°C) with proper reflow conditions and compatible solder paste. However, reliability of leaded Maxim Integrated Products parts 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.
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| 3. |
Q. |
What is the solder paste currently used by most SMT (Surface Mount Technology) Manufacturers for PC board reflow?
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A. |
Current PC board reflow uses eutectic solder Sn63/Pb37. This solder is also compatible with Matte Tin plated leads.
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| 4. |
Q. |
What are the melting points of solder alloy and its pure components?
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A. |
| Element/Alloy |
Melting point (liquidus) |
| Pure Lead |
328°C (620°F) |
| Pure Tin |
232°C (450°F) |
| 85Sn/15Pb |
200°C (392°F) |
| 70Sn/30Pb |
193°C (380°F) |
| 63Sn/37Pb |
183°C (361°F) |
| 60Sn/40Pb |
190°C (375°F) |
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| 5. |
Q. |
What type of plating chemistries are available for 100% matte tin?
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A. |
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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! |
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| 6. |
Q. |
Is there a plan to remove Halogens from mold compounds for Maxim Integrated Products products?
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A. |
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 |
| 1. |
Q. |
How do you calculate chemical level parts per million?
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A. |
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 / .1473 x 1,000,000 = 2546 ppm.
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| 2. |
Q. |
How do you calculate chemical level % of the constituent by weight?
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A. |
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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| Moisture Sensitivity Levels MSL |
| 1. |
Q. |
What is the Moisture Sensitivity Level (MSL) for lead-free packages?
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A. |
Please see the Lead-free Information page on the EMMI website.
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| 2. |
Q. |
What is the Moisture Sensitivity Level for packages containing lead?
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A. |
Please refer to the Moisture Sensitivity Level page on the EMMI website.
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| Tin Whiskers |
| 1. |
Q. |
Have you tested for Tin Whiskers? Describe qualification tests performed.
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A. |
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.
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| 2. |
Q. |
What is the acceptance criteria for Tin Whiskers? What is the method of identifying tin whiskers?
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A. |
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.
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| 3. |
Q. |
What regular monitor and assembly process controls are in place for Tin Whiskers?
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A. |
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 Lookup |
| Package and constituent information is available for specific part numbers. To view this information, enter the desired part number in the field below and click Search.
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| Qualifications and Testing |
| 1. |
Q. |
Why is there a need to qualify Maxim Integrated Products packages and assembly process technologies for 100% Matte Tin Plate?
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A. |
All package body sizes, assembly materials (mold compound and die attach epoxy), assembly processes (downbond 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.
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| 2. |
Q. |
What type of Reliability tests are important and recommended to assess packaging and plating reliability for 100% matte tin?
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A. |
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.
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| 3. |
Q. |
Is there a standard assembly solderability test for 100% matte tin? What is the steam aging condition prior to solderability testing?
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A. |
Existing Solderability Standard:
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For the Western markets, most people are doing the MIL-STD-883 solderability test at 260°C with steam aging.
For the European markets, most people are doing the IEC solderability test at 240°C with steam aging.
Steam aging times vary from 4-24 hours with most doing 8 hours. |
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