I may be speaking from ignorance here - someone will correct me if I
am.
In line with Bills' comment below, doesn't IPC-4101 cover the
electrical voltage breakdown 'through' the board material - and is
specified on the slash sheets in the Dielectric Breakdown category? (Or
perhaps it is the Electrical Strength?)
For example, for Slash sheet #26, the Dielectric Breakdown is specified
as 40kV for material that is >0.50mm (0.0197-in).
If it is the Electrical Strength, then the number for this material is
30kV/mm for material that is < 0.50mm.
Just my .02 worth.
Regards,
James Jackson
Oztronics
On 2014-03-10 15:58, Brooks, William wrote:
> Okay... I'm sorry but this isn't very funny...
> This forum uses ascii text messages only... whatever text editor you
> are using is not using plain text.
> Please reconfigure your mail editor to use plain text for this forum.
> Thank you kindly... :)
>
> To comment on the topic...
>
> The interpretations I have seen here of the spec assume a lot...
> This voltage requirement came from the military PCB material specs...
> MIL-P-13949 if I remember correctly. Also The old "0.0002 in./volt"
> (0.00508 mm/volt) reference in there originally came from MIL-I-46058.
>
> The issue with voltage spacings being different across the surface of
> a board rather than thru it can be explained simply.
> The surfaces of the layers are exposed to chemical processing 'dirt'
> or other contaminants... the inner core materials are basically cross
> sectionally homogenous and are less likely to have imperfections or
> ionic paths... or other ways for arcing to occur thru the material...
> It's much more likely that a voltage will 'leak' or find a lower
> resistance path across the surface of the pcb material than it will
> thru it.
>
> The number I recall is 700VDC per mil thru the material max. (that
> means zero margin or tolerance).
> The IPC chart was for spacing across the surface outside and inside
> the board for multilayer boards...
> Is that how you see it?
>
>
> William Brooks, CID+
> Senior MTS (Contract)
> 2747 Loker Ave West
> Carlsbad, CA 92010-6603
> 760-930-7212
> Fax: 760.918.8332
> Mobile: 760.216.0170
> E-mail: [log in to unmask]
>
>
>
>
> -----Original Message-----
> From: DesignerCouncil [mailto:[log in to unmask]] On Behalf Of
> Jack Olson
> Sent: Monday, March 10, 2014 1:37 PM
> To: [log in to unmask]
> Subject: Re: [DC] FW: [DC] IPC-2221B Electrical Spacing
>
>
> ��z{S���}�ĝ��xjǺ�*'���O*^��m��Z�w!j��D��!�ɔ�́ݡ�Ё�Ёͅ����$����ѕ��������QH�ѡ�́����((����()%A
> ��ɕ�ѽȁ���Q���������QɅ�͙�Ȱ�5�Ɍ�
> ��ѕȰ�ݕ���́�����)MՉ�����I�m
> t�%A
> ����������ɥ����M������()e�̰�ѡ��Ʌ܁��ѕɥ��������ə��а�չ�����ɉ�����ɥ�ѥ����хє������)����Ʌѽ�䰁��́��ѡ��ɕѥ������մ��ͽ��ѥ�����������ȁ�����9�)�ɥ�������9����ɕ�ձ�ȃ�qѽ�ѣ�t����ѡ����������ѡ�������ȸ�9��������ѥ��)������̰������������������ͥ���������ѡ����ѡ�Ёݽձ�������Ɉ��ӊé��ə��а)ѡ��ɕѥ������մ�((���
> ���̀́�́�ɕ����ѕ�����UI9Q��х�����䁅��������ѕɴ�ɕ���������)�́ѡ��������́�Ս���Ёݥ������YId����͕�مѥٔ�)=���A=MM% 1���ѕɹ�ѥٔ�ݽձ�����Ѽ��ե���Ѽ�
>
���̀́ݥѠ�ѡ���ፕ�ѥ�����)ѡ���ͽ��ѥ��������ѕ�Ё�Ёչ��ȁمɥ��́��٥ɽ����х����ɕ�ͽ�́���)ݡ�ѕٕȁѡ�����ѽ��ȁ����ѡ�́�ե���ȁ��ɕ����́�ՙ������Ёѥ���Ѽ���ٕ���)��䁱�ѕ�Ё������̸()��ѡ�ȁA=MM% 1���ѕɹ�ѥٔ��́ѡ�Ё�ӊé���ͥ����ѡ�Ѐ�����ͽ��ѥ�����)��Ёɕ�եɕ�����ݕ���YId����ȁ���ѡ�����ɐ��M嵵���䁥́�ɕ�а���Ё��)�ԁ!Y�Ѽ��ե���������嵕�ɥ���х������������ԁ���������ݥѠ�ѡ�)���Ʌ��ѥ������݅��������ݥ�Ёѡ�Ё��䁉ɥ����ѡ���ѡ�ӊé����ٕ�Ք��'�eٔ)������и
��
�eЁ��ɔ�Ѽ����Ёͽ��ѥ��̰�儁���ф�((��%���ԁ݅�Ё�ЁѼ����Ёѡ���������ѥ��́���
> ���̰̀�ѡ����ԁ��������ٔ)Ѽ��ե����ЁѼ�
> ���̀̀��ɽ�Սѥ�������݅���̰�������ɕ̰���������䰁�ь��)��������(()=��5����5�Ȁ�������Ё�Ѐ���āA4��1���� ɽ����ɽ��������ͥ��̹�����ɽє�((������5�ɥ��(�(��Q��Ё�����Ё�����ѡɽ՝���́ѕ�и(�(�� ��Ёɕ��ɑ̰(�(��1����(�(����=�����5�Ȁ���а��Ѐ����ذ�����5�ɥ��5ձ٥������(�����5�ɥ�5ձ٥����%A
> �=I���ɽє�(���(���(������
> ���O
> �
> �
> ��
> �
> �
> (����
>
>
> <Snipped>
>
> _____________________________________________________________________________
> Scanned by IBM Email Security Management Services powered by
> MessageLabs. For more information please visit http://www.ers.ibm.com
>
> This email is intended only for the use of the party to which it is
> addressed and may contain information that is privileged,
> confidential, or protected by law. If you are not the intended
> recipient you are hereby notified that any dissemination, copying or
> distribution of the email or its contents is strictly prohibited. If
> you have received this message in error, please notify us immediately,
> by replying to the message and deleting it from your computer.
>
> WARNING: Internet communications are not assured to be secure or
> clear of inaccuracies as information could be intercepted, corrupted,
> lost, destroyed, arrive late or incomplete, or contain viruses.
> Therefore, we do not accept responsibility for any errors or omissions
> that are present in this email, or any attachment, that have arisen as
> a result of e-mail transmission.
> _____________________________________________________________________________
>
> ______________________________________________________________________
> This email has been scanned by the Symantec Email Security.cloud
> service.
> For more information please contact helpdesk at x2960 or
> [log in to unmask]
> ______________________________________________________________________
>
>
> ---------------------------------------------------------------------------------
> DesignerCouncil Mail List provided as a free service by IPC using
> LISTSERV 16.0.
> To unsubscribe, send a message to [log in to unmask] with following text
> in
> the BODY (NOT the subject field): SIGNOFF DesignerCouncil.
> To temporarily stop/(restart) delivery of DesignerCouncil send: SET
> DesignerCouncil NOMAIL/(MAIL)
> For additional information, or contact Keach Sasamori at
> [log in to unmask] or 847-615-7100 ext.2815
> ---------------------------------------------------------------------------------
______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please contact helpdesk at x2960 or [log in to unmask]
______________________________________________________________________
---------------------------------------------------------------------------------
DesignerCouncil Mail List provided as a free service by IPC using LISTSERV 16.0.
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF DesignerCouncil.
To temporarily stop/(restart) delivery of DesignerCouncil send: SET DesignerCouncil NOMAIL/(MAIL)
For additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815
---------------------------------------------------------------------------------
|