You've received several good technical replies; I share one more from the view of applying (or not applying) the standard. It is probably not a good idea to use an assembly acceptance document to judge whether the design was good--it's too late. In your specific case, the designer has already made a decision, deliberate or otherwise, not to consider "design for manufacturability."
IPC-A-610 Revision B page v of the Foreward, Acceptance criteria and the Use of this Manual states that in the event of conflict, the following order of precedence shall apply:
1. Procurement as agreeed between customer and vendor.
2. Master drawing or master assembly drawing reflecting the customers detailed requirements.
3. When involed by the customer or per contractual agreement . . . IPC-A-610 can be adopted or used.
4. Other documents to extent specified by the customer.
You'll undoubtedly receive additional opinions on whether the solder connection is good enough, but without a whole lot more data (end use environment in particular) most people will be hard pressed to provide a defensable answer to your question whether 30% hole fill is acceptable for your design.
==========================================
APEX - the industry's premier trade show in Electronics
Manufacturing, January 16-18, 2001, San Diego, California.
More information on website www.apex2001.org
--------
Jack Crawford, IPC Director of Assembly Standards and Technology
2215 Sanders Road, Northbrook IL 60062-6135
[log in to unmask]
847-790-5393
fax 847-509-9798
>>> [log in to unmask] 11/30/00 12:08PM >>>
To all TechNet members,
I am requesting assistance with the intent interpretation of the barrel vertical fill requirement with ground plane exception in section 4.1 of the IPC-A-610 revision B.
History:
I have a board design with two 1.0 oz ground planes at layers 4 and 8 in a 12 layer board. The engineer designed an ineffective thermal relief pad to connect a leaded component's ground through-hole to the ground plane. Also the component involved can not be wave solder due to thermal restrictions of it's design. To make the situation worse, the component's ground lead, which causing all the problems, is connected directly to the steal shielding measuring 2x2x1. Our contract manufacture is not able to solder past the first ground plane which leaves a 30% vertical fill. Our requirement is Class 2, 75% vertical fill except when there is a thermal plane. We are in the process of redoing the design but I need assistance with defending the supplier.
Question:
Figure 4-2 shows the vertical fill stopping at the Metal Core/Thermal/Heatsink plane half way through the board. The paragraph following states that the vertical fill has to be 50% when there is a thermal heat sink plane. Our design uses the ground plains as thermal/heatsinks. Is the intent of the picture and the text to state that it is allowable for the solder not to pass the thermal plane. With my design, would it be acceptable to have a vertical fill of 30%.
Please reply with your opinions to my question,
Thank You,
Doug Smith
Supplier Quality Engineer.
[log in to unmask]
---------------------------------------------------------------------------------
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
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
---------------------------------------------------------------------------------
|
