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Solder Paste for Thermal Cycling application (-40 to 150 Degree Celcius)

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#79372

Solder Paste for Thermal Cycling application (-40 to 150 Degree Celcius) | 23 November, 2017

Hi to all experts, Can anyone advice us what solder alloy to use for thermal cycling products. We are facing a lot of issues using normal solder paste SAC305. After thermal cycling the solder is cracking. Any suggestion is welcome. Thanks in advance.

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#79440

Solder Paste for Thermal Cycling application (-40 to 150 Degree Celcius) | 7 December, 2017

Help me understand your issue better ... Are you looking to:

* Improve your products that are used for thermal cycling testing of products of other companies?

* Change your production materials so that you pass thermal cycling testing of your product?

For some background on thermal cycling testing of LF solder connections, look here:

LEAD-FREE SOLDERS (SAC305 AND SN3.5AG) FOR HIGH TEMPERATURE APPLICATIONS [https://drum.lib.umd.edu/bitstream/handle/1903/11272/George_umd_0117N_11847.pdf?sequence=1&isAllowed=y] George_umd_0117N_11847.pdf (13.65Mb) No. of downloads: 2810

Date 2010 Author George, Elviz Advisor Pecht, Michael G Metadata Show full item record Eutectic tin lead was the most widely used solder interconnect in the electronics industry before the adoption of lead-free legislation. But eutectic tin lead solder has a low melting point (183oC) and was not suited for some high temperature applications, such as oil and gas exploration, automotive, and defense. Hence, for these applications, the electronics industry had to rely on specialized solders. In this study, ball grid arrays (BGAs), quad flat packages (QFPs), and surface mount resistors assembled with SAC305 and Sn3.5Ag solder pastes were subjected to thermal cycling from -40oC to 185oC. Commercially available electroless nickel immersion gold (ENIG) board finish was compared to proprietary Sn-based board finish designed for high temperatures. The data analysis showed that the type of solder paste and board finish used did not have an impact on the reliability of BGAs. The failure site was on the package side of the solder joint. The morphology of intermetallic compounds (IMCs) formed after thermal cycling was analyzed.

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#79443

Solder Paste for Thermal Cycling application (-40 to 150 Degree Celcius) | 10 December, 2017

Hi Dave, thanks for the response.

* Improve your products that are used for thermal cycling testing of products of other companies? Yes we want to improve our products to pass thermal cycling and prolong the lifespan of the baord. * Change your production materials so that you pass thermal cycling testing of your product? We are looking for a solder paste to improve the thermal cycling capability of our product. We are using SAC305 but then after a few thermal cycling application or -40 to 150 Deg C, after 1 to 2 year the solder degrades/cracks. Hopefully can help to suggest any solder we can use to prolong the lifespan of our board.

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#82827

Solder Paste for Thermal Cycling application (-40 to 150 Degree Celcius) | 18 June, 2019

Hi!

You can choose low-temperature solder paste. The low-temperature solder paste is tin and antimony with a melting point of 138 °C. When the components of the patch cannot withstand the temperature of 200 ° C and above and the patch reflow process is required, the solder paste process is performed using a low temperature solder paste. Protected from high temperature reflow soldering originals and PCBs, it is very popular in the LED industry. Its alloy composition is tin-bismuth alloy. The reflow soldering temperature of the low temperature solder paste is 170-200 °C.

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#82854

Solder Paste for Thermal Cycling application (-40 to 150 Degree Celcius) | 21 June, 2019

The only problem with non silver tin bismuth is its very prone to shock damage and components fall off,literally. Would only recommend it with Silver additions and around 1%.

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#82855

Solder Paste for Thermal Cycling application (-40 to 150 Degree Celcius) | 21 June, 2019

REL alloys from Aim solders maybe worth looking into for this application. May I ask what your profile on reflow is like please, especially peak

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#82875

Solder Paste for Thermal Cycling application (-40 to 150 Degree Celcius) | 24 June, 2019

Can you please tell us which components cracked? Component type, size, pitch, pin Qty, etc. The solder cracked in thermal cycling is very complicated and difficult to solve.

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#83076

Solder Paste for Thermal Cycling application (-40 to 150 Degree Celcius) | 25 July, 2019

Hi I have solved the issue. The component cracking are the big 1210, 0603 and 0402 capacitors. After studying and testing in many type of solder. The best to use is SnPb and the components are the key - there are component which will tend to expand or shrink during thermal cycling process. We replaced using the manufacturer recommendation and its quite expensive and very long waiting time.

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#83163

Solder Paste for Thermal Cycling application (-40 to 150 Degree Celcius) | 3 August, 2019

We use SNPb for such applications (PCBA for aircraft). We tried SAC305 but recieve no good quality, so now only SNPb. If you will find good solution - please write. Because now we have some problems with BGA - no SNPb balls. And need to reball (addition heating is NG) such BGAs.

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#83377

Solder Paste for Thermal Cycling application (-40 to 150 Degree Celcius) | 3 September, 2019

Is there any other competitor to REL solder paste?

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SMTA-Richard

#83391

Solder Paste for Thermal Cycling application (-40 to 150 Degree Celcius) | 5 September, 2019

There are multiple solder alloy options and we have tested many of them in a consortium project. There also are very specific challenges associated with testing using the -40/150 C profile. This is way too complicated to discuss in a chat room.

Send me an email: richard.coyle@nokia-bell-labs.com

This message was posted via the Electronics Forum @ SMTASMTA

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SMTA-Tony

#83392

Solder Paste for Thermal Cycling application (-40 to 150 Degree Celcius) | 5 September, 2019

There are competitors to REL solder alloys from AIM. Tin-Copper-Nickel-Bismuth alloys (Nihon Superior) are an alternative option which do very well in thermal cycle testing. The reflow profiles required are similar to SAC305 profiles. You may also want to check into SBX and REL alloys from Alpha. There may be others on the market as well.

This message was posted via the Electronics Forum @ SMTASMTA

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