hello,
i think bake the boards at 140-150 c for 1-2 hours prior is enough. but before HAL it is better to bake the boards at 155 C for 2 hours.
======= 2001-10-03 您在来信中写道：=======
>I normally bake the bare boards for 1 hour at 100 � 5� C. This is sufficient to dry the boards prior to assembly. The only failures that I have encountered was with ridged-flex boards that were not pre-baked.
>
>
>
>On Wed, 03 October 2001, "Elensky, Richard" wrote:
>
>
>
>>
>
>> We "baked" boards at 55癈 for 12 hours (best we could do) (13" x 17" boards,
>
>> 4 layer, 12 per batch). The results were not good. Our survival rate was
>
>> about 80.
>
>>
>
>> Our PCB fab shop suggested 150癈 for 4 hours.
>
>>
>
>>
>
>> Richard Elensky
>
>> Sr. Manufacturing Engineer
>
>> [log in to unmask] <mailto:[log in to unmask]>
>
>>
>
>> Tel: 559-292-1111 x246
>
>> Fax: 559-292-9355
>
>>
>
>> Dantel
>
>> 2991 North Argyle Ave.
>
>> Fresno, CA, 93727
>
>> Visit our web site at:
>
>> http:// www.dantel.com <http://www.dantel.com>
>
>>
>
>>
>
>> ----------
>
>> From: Yu-Hung Shiau [SMTP:[log in to unmask]]
>
>> Sent: Wednesday, October 03, 2001 4:25 PM
>
>> To: [log in to unmask]
>
>> Subject: [TN] PCB baking conditions
>
>>
>
>> Hi,
>
>> * Is anybody sure about the temperatre and time for baking the bare
>
>> PCBs
>
>> that were humidified by condensed moisture to prevent SMT problems?
>
>> * Is 120F for 2 hrs appropriate?
>
>> Thank you for any input.
>
>> YH Shiau
>
>>
>
>>
>
>> ----------------------------------------------------------------------------
>
>> -----
>
>> Technet Mail List provided as a free service by IPC using LISTSERV
>
>> 1.8d
>
>> To unsubscribe, send a message to [log in to unmask] with following
>
>> text in
>
>> the BODY (NOT the subject field): SIGNOFF Technet
>
>> To temporarily halt delivery of Technet send the following message:
>
>> SET Technet NOMAIL
>
>> Search previous postings at: www.ipc.org > On-Line Resources &
>
>> Databases > E-mail Archives
>
>> Please visit IPC web site (http://www.ipc.org/html/forum.htm) for
>
>> additional
>
>> information, or contact Keach Sasamori at [log in to unmask] or
>
>> 847-509-9700 ext.5315
>
>>
>
>> ----------------------------------------------------------------------------
>
>> -----
>
>>
>
>> ---------------------------------------------------------------------------------
>
>> Technet Mail List provided as a free service by IPC using LISTSERV 1.8d
>
>> To unsubscribe, send a message to [log in to unmask] with following text in
>
>> the BODY (NOT the subject field): SIGNOFF Technet
>
>> To temporarily halt delivery of Technet send the following message: SET Technet NOMAIL
>
>> Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives
>
>> Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
>
>> information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
>
>> ---------------------------------------------------------------------------------
>
>
>------------------------------------------------
>"Get your free e-mail at http://www.myNRA.com"
>
>---------------------------------------------------------------------------------
>Technet Mail List provided as a free service by IPC using LISTSERV 1.8d
>To unsubscribe, send a message to [log in to unmask] with following text in
>the BODY (NOT the subject field): SIGNOFF Technet
>To temporarily halt delivery of Technet send the following message: SET Technet NOMAIL
>Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives
>Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
>information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
>---------------------------------------------------------------------------------
= = = = = = = = = = = = = = = = = = = =
致
礼！
jinrong
[log in to unmask]
2001-10-04
0� 0� 0� 0� 0� 0� 0� 0� 0� 0� 0� 0� 0� 0� 0� 0� 0� 0� 0� 0縈�!濎?1ē鷎Ⅷ漽诳�~窞' �喝蛉I4凟忰N款炈洷殊n 勘檩鎧�� 懑蛉I4凟徣<_蜠燄娰?~塭�鸮�舛嘭 驨[鸻圎.n7溍麾zX? 魣訁#艮r轓宽zjh鈼_醞\?u閎疥蟒埧M�!濎?遍蔺豝%枌"�?鎧�� 縃E縈�!濎?4�