I work for a company in Norway (in my spare time, LOL) who manufactures downhole electronics. It is a completely different world, building electronics that must survive, MUST survive, in the world's harshest environment, quickly going from typical 16-20 deg. C then to freezing while in arctic water in the north Atlantic, then quickly ramping up to as hot as 175 C during normal all-day drilling, sometimes hotter for a short-term controlled drill, then it is flooded with a mix of oil and mud and gravel and salt water, and the shock and vibration are beyond belief. You come away with a different perspective on high-rel electronics than you ever had before, believe me.



-----Original Message-----

From: TechNet [mailto:[log in to unmask]] On Behalf Of Bob Landman

Sent: Thursday, September 20, 2018 10:30 AM

To: [log in to unmask]

Subject: Re: [TN] High Temp SnPb solder



Interesting  discussion.  A friend's company designs/manufactures  electronics for oil well drill head instrumentation.  Temperatures reach 160C (they test to 175C).  They use Sn96 or SAC305 which works up to 220C.  There is another type of solder called HMP that is good to 300C as he recalls but everyone hates working with it.  Very hard to rework boards. 



I also asked re packaging, he remarked they are short of ok.  The plastic in commercial parts degrades over time, but the boards lifetime is probably less than the time for plastic to degrade.  



The environment is brutal.  Interesting fact: the instrumentation modulates the drill mud to send data back to the surface.  The baud rate is VERY slow ৘⻞ഀ਀ഀ਀䈀漀戀ഀ਀ഀ਀ⴀⴀⴀⴀⴀ伀爀椀最椀渀愀氀 䴀攀猀猀愀最攀ⴀⴀⴀⴀⴀഀ਀䘀爀漀洀㨀 吀攀挀栀一攀琀 㰀吀攀挀栀一攀琀䀀椀瀀挀⸀漀爀最㸀 伀渀 䈀攀栀愀氀昀 伀昀 䐀愀瘀椀搀 䠀椀氀氀洀愀渀ഀ਀匀攀渀琀㨀 吀栀甀爀猀搀愀礀Ⰰ 匀攀瀀琀攀洀戀攀爀 ㈀　Ⰰ ㈀　㄀㠀 ㄀　㨀㄀㜀 䄀䴀ഀ਀吀漀㨀 琀攀挀栀渀攀琀䀀椀瀀挀⸀漀爀最ഀ਀匀甀戀樀攀挀琀㨀 刀攀㨀 嬀吀一崀 䠀椀最栀 吀攀洀瀀 匀渀倀戀 猀漀氀搀攀爀ഀ਀ഀ਀䰀伀䰀 ⴀ 椀昀 眀攀 眀攀爀攀 昀漀氀氀漀眀椀渀最 琀栀攀 漀氀搀 爀甀氀攀猀 琀栀攀渀 琀栀攀爀攀 眀漀甀氀搀 渀漀琀 戀攀 愀 挀漀洀瀀漀渀攀渀琀 挀愀氀氀攀搀 愀 䈀䜀䄀⸀⸀⸀⸀⸀⸀⸀⸀⸀⸀⸀⸀⸀⸀ 㨀ⴀ⤀ഀ਀ഀ਀䐀愀瘀攀ഀ਀ഀ਀伀渀 吀栀甀Ⰰ 匀攀瀀 ㈀　Ⰰ ㈀　㄀㠀 愀琀 㤀㨀　㜀 䄀䴀Ⰰ 夀甀愀渀ⴀ挀栀椀愀 䨀漀礀挀攀 䬀漀漀 㰀樀欀漀漀䀀椀搀椀爀攀挀琀⸀挀漀洀㸀ഀ਀眀爀漀琀攀㨀ഀ਀ഀ਀㸀 愀挀挀漀爀搀椀渀最  琀漀 洀礀 戀漀漀欀 ⠀漀氀搀⤀Ⰰ 礀漀甀 猀栀漀甀氀搀 一伀吀 挀漀甀渀琀  漀渀 猀漀氀搀攀爀 愀猀 ഀ਀㸀 洀攀挀栀愀渀椀挀愀氀  猀甀瀀瀀漀爀琀 漀昀 䄀一夀 欀椀渀搀⸀  猀漀氀搀攀爀 椀猀 椀渀琀攀渀搀攀搀 琀漀  瀀爀漀瘀椀搀攀 ഀ਀㸀 攀氀攀挀琀爀椀挀愀氀 挀漀渀渀攀挀琀Ⰰ 甀猀攀 猀漀氀搀攀爀Ⰰ 攀猀瀀攀挀椀愀氀氀礀 栀椀最栀 琀攀洀瀀  猀漀氀搀攀爀 ⠀愀猀猀甀洀攀 ഀ਀㸀 礀漀甀 愀爀攀 最漀椀渀最 琀漀 甀猀攀 椀琀 愀琀 攀氀攀瘀愀琀攀搀 琀攀洀瀀 昀漀爀 猀攀爀瘀椀挀攀Ⰰ 漀爀 愀猀猀攀洀戀氀礀 ഀ਀㸀 猀攀焀甀攀渀挀攀 ⴀ 猀甀挀栀 愀猀 洀甀氀琀椀瀀氀攀 爀攀昀氀漀眀猀⸀⸀⸀ 椀琀 椀猀 搀椀昀昀椀挀甀氀琀 琀漀 挀漀甀渀琀  漀渀 ഀ਀㸀 洀椀挀爀漀猀琀爀甀挀琀甀爀攀 琀漀 戀攀 琀栀攀 猀愀洀攀 愀猀 礀漀甀 椀渀椀琀椀愀氀氀礀 瀀甀琀 搀漀眀渀⤀⸀ഀ਀㸀 愀猀 昀漀爀 䘀䔀䴀 瀀甀爀瀀漀猀攀Ⰰ 䤀 眀漀甀氀搀 甀猀攀 㔀　─ 戀漀漀欀  瘀愀氀甀攀 琀栀愀琀 琀攀氀氀 礀漀甀  ⴀ 椀昀 椀 ഀ਀㸀 眀攀爀攀 礀漀甀⸀⸀⸀ഀ਀㸀 洀礀 ㄀⸀㔀 挀攀渀琀猀⸀ഀ਀㸀 樀欀ഀ਀㸀 伀渀 匀攀瀀 ㈀　Ⰰ ㈀　㄀㠀Ⰰ 愀琀 㤀㨀㔀㐀 䄀䴀Ⰰ 匀琀愀搀攀洀Ⰰ 刀椀挀栀愀爀搀 䐀 眀爀漀琀攀㨀ഀ਀㸀ഀ਀㸀 䄀搀搀椀渀最 琀漀 眀栀愀琀 䐀愀瘀攀 猀愀椀搀㬀 礀漀甀 搀漀渀✀琀 最攀琀 猀漀洀攀琀栀椀渀最 昀漀爀 渀漀琀栀椀渀最℀ ഀ਀㸀 䐀椀昀昀攀爀攀渀琀ഀ਀㸀㸀 愀氀氀漀礀猀 栀愀瘀攀 搀椀昀昀攀爀攀渀琀 瀀栀礀猀椀挀愀氀 挀栀愀爀愀挀琀攀爀椀猀琀椀挀猀 愀渀搀 愀爀攀 甀猀攀搀 昀漀爀 ഀ਀㸀㸀 挀漀爀爀攀猀瀀漀渀搀椀渀最氀礀 搀椀昀昀攀爀攀渀琀 瀀甀爀瀀漀猀攀猀 愀渀搀 愀瀀瀀氀椀挀愀琀椀漀渀猀⸀ 䐀漀渀✀琀 愀琀琀攀洀瀀琀 琀漀 ഀ਀㸀㸀 甀猀攀 猀漀洀攀琀栀椀渀最 渀漀琀 䄀䄀䈀唀匀 愀渀搀 昀甀氀氀礀 搀漀挀甀洀攀渀琀攀搀 漀渀 琀栀攀 愀瀀瀀氀椀挀愀戀氀攀 䈀伀䴀⸀ഀ਀㸀㸀ഀ਀㸀㸀 ⴀⴀⴀⴀⴀ伀爀椀最椀渀愀氀 䴀攀猀猀愀最攀ⴀⴀⴀⴀⴀഀ਀㸀㸀 䘀爀漀洀㨀 吀攀挀栀一攀琀 嬀洀愀椀氀琀漀㨀吀攀挀栀一攀琀䀀椀瀀挀⸀漀爀最崀 伀渀 䈀攀栀愀氀昀 伀昀 䐀愀瘀椀搀 䠀椀氀氀洀愀渀ഀ਀㸀㸀 匀攀渀琀㨀 吀栀甀爀猀搀愀礀Ⰰ 匀攀瀀琀攀洀戀攀爀 ㈀　Ⰰ ㈀　㄀㠀 㘀㨀㔀㜀 䄀䴀ഀ਀㸀㸀 吀漀㨀 吀攀挀栀一攀琀䀀䤀倀䌀⸀伀刀䜀ഀ਀㸀㸀 匀甀戀樀攀挀琀㨀 刀攀㨀 嬀吀一崀 䠀椀最栀 吀攀洀瀀 匀渀倀戀 猀漀氀搀攀爀ഀ਀㸀㸀ഀ਀㸀㸀 䠀椀 䈀攀渀 ⴀ 礀攀猀Ⰰ 琀栀攀爀攀 愀爀攀 搀椀昀昀攀爀攀渀挀攀猀 椀渀 琀栀攀 洀攀挀栀愀渀椀挀愀氀 瀀爀漀瀀攀爀琀椀攀猀 愀渀搀 ഀ਀㸀㸀 琀栀攀 猀漀氀搀攀爀 樀漀椀渀琀 洀椀挀爀漀猀琀爀甀挀琀甀爀攀猀 昀漀爀 琀栀攀 ∀栀椀最栀 琀攀洀瀀∀ 愀氀氀漀礀猀⸀ 䴀漀猀琀 漀昀 ഀ਀㸀㸀 琀栀漀猀攀 愀氀氀漀礀猀 栀愀瘀攀 愀瀀瀀氀椀挀愀琀椀漀渀猀 椀渀 挀漀洀瀀漀渀攀渀琀 挀漀渀猀琀爀甀挀琀椀漀渀Ⰰ ഀ਀㸀㸀 猀瀀攀挀椀昀椀挀愀氀氀礀 椀渀 挀漀洀瀀漀渀攀渀琀 搀椀攀 愀琀琀愀挀栀洀攀渀琀⸀ 伀渀攀 瘀攀爀礀 挀漀洀洀漀渀 愀氀氀漀礀 甀猀攀搀 ഀ਀㸀㸀 昀爀攀焀甀攀渀琀氀礀 椀渀 愀 渀甀洀戀攀爀 漀昀 愀瀀瀀氀椀挀愀琀椀漀渀猀 椀猀 琀栀攀 ㄀　匀渀㠀㠀倀戀㈀䄀最 愀氀氀漀礀⸀ഀ਀㸀㸀ഀ਀㸀㸀 䐀愀瘀攀 䠀椀氀氀洀愀渀ഀ਀㸀㸀 刀漀挀欀眀攀氀氀 䌀漀氀氀椀渀猀ഀ਀㸀㸀 搀愀瘀椀搀⸀栀椀氀氀洀愀渀䀀爀漀挀欀眀攀氀氀挀漀氀氀椀渀猀⸀挀漀洀ഀ਀㸀㸀ഀ਀㸀㸀 伀渀 吀栀甀Ⰰ 匀攀瀀 ㈀　Ⰰ ㈀　㄀㠀 愀琀 㘀㨀㐀　 䄀䴀Ⰰ 䜀甀洀瀀攀爀琀Ⰰ 䈀攀渀 㰀戀攀渀⸀最甀洀瀀攀爀琀䀀氀洀挀漀⸀挀漀洀㸀ഀ਀㸀㸀 眀爀漀琀攀㨀ഀ਀㸀㸀ഀ਀㸀㸀 吀攀挀栀一攀琀琀攀爀猀Ⰰഀ਀㸀㸀㸀ഀ਀㸀㸀㸀 䨀ⴀ匀吀䐀ⴀ　　㘀 栀愀猀 愀 猀攀爀椀攀猀 漀昀 ✀栀椀最栀 琀攀洀瀀✀ 匀渀倀戀 愀氀氀漀礀猀 ⠀猀漀洀攀 眀椀琀栀 䄀最⤀ ഀ਀㸀㸀㸀 琀栀愀琀 愀爀攀 挀氀漀猀攀 椀渀 匀伀䰀⼀䰀䤀儀 琀攀洀瀀猀⸀ 䤀✀洀 昀愀洀椀氀椀愀爀 眀椀琀栀 匀渀㄀　倀戀㤀　 愀猀 愀 ഀ਀㸀㸀㸀 挀漀洀洀漀渀 栀椀最栀ⴀ琀攀洀瀀 戀愀氀氀 漀渀 挀攀爀愀洀椀挀 䈀䜀䄀猀Ⰰ 戀甀琀 䤀 栀愀瘀攀渀✀琀 猀攀攀渀 琀栀攀 漀琀栀攀爀猀 ഀ਀㸀㸀㸀 甀猀攀搀⸀ 䄀爀攀 琀栀攀爀攀 愀渀礀 搀椀昀昀攀爀攀渀挀攀猀 ⠀攀⸀最⸀ 洀攀挀栀愀渀椀挀愀氀 瀀爀漀瀀攀爀琀椀攀猀⤀ 愀洀漀渀最 ഀ਀㸀㸀㸀 琀栀攀猀攀 琀栀愀琀 眀漀甀氀搀 搀爀椀瘀攀 猀攀氀攀挀琀椀漀渀Ⰰ 漀琀栀攀爀 琀栀愀渀 琀栀攀 匀伀䰀⼀䰀䤀儀㼀ഀ਀㸀㸀㸀 䄀爀攀 猀漀洀攀 愀氀氀漀礀猀 洀漀爀攀 爀攀愀搀椀氀礀 愀瘀愀椀氀愀戀氀攀 琀栀愀渀 漀琀栀攀爀猀㼀ഀ਀㸀㸀㸀ഀ਀㸀㸀㸀 䈀攀渀ഀ਀㸀㸀㸀ഀ਀㸀㸀㸀ഀ਀