Do not reply to me please reply to Nguyes Quoc Khanh
Sorry,
That I totally miss understood Nguyes Quoc Khanh I'll re -post his first questions again with my reply below I'll stay out of it as not to confuse any one. Again I'm sorry I guess the big red Monday Monster got my head and just would not let go.
I only have one think on my mind and it's bass time. I'm heading to the lake on Thursday. To get my fishing pole and t. box ready. Every one have a great holiday and be careful.
Oh there 's that monster and please help Mr. Khank.
Thanks every one your great. I can't be right all the time.
Nancy T.
****************************************************************************
***********************
> NGUYEN QUOC KHANH <[log in to unmask]>
> FUJITSU COMPUTER PRODUCTS OF VIETNAM, INC.
> PCBA MANUFACTURING DEPARTMENT-PCBA ENGINEERING SECTION
>
>>> Nguyen Quoc Khanh <[log in to unmask]> 05/21/01 12:21PM >>>
Dear Technetters,
Could any body help me with explaining the acceptable (Class 1) and process indicator (Class 2,3) level of solder ball in IPC-A-610C, section 6.5.3.1 or 12.4.10?
* "Entrapped or encapsulated solder balls that are within 0.13mm [0.00512in] of lands or conductors" => We do not need to control the minimum electrical clearance, don't we?
* "Entrapped or encapsulated solder balls that are exceed 0.13mm [0.00512in] in diameter." => It is acceptable if the diameter is over 0.13mm.
* "More than five solder balls/splashes (0.13mm [0.00512in] or less) per 600mm2 [0.93in2]." => How about the upper limit of solder ball quantity?
About the defective level (Class 1,2,3), my understanding based on the explanation in the book is that if our solder ball does not violate minimum electrical clearance and is entrapped or encapsulated or attached to a metal surface, it is acceptable reagardless of diameter, the location and the quantity of the ball. Is it correct?
Every information is highly appreciated.
Thanks.
***************************************************************************************************
NGUYEN QUOC KHANH <[log in to unmask]>
FUJITSU COMPUTER PRODUCTS OF VIETNAM, INC.
PCBA MANUFACTURING DEPARTMENT-PCBA ENGINEERING SECTION
---- Original Message -----
From: "Nancy Trumbull" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Tuesday, May 22, 2001 4:18 AM
Subject: Re: [TN] (TN) IPC-A-610C/Solder ball
Good Morning Q.
Question 1. Acceptable Class 1 and process indicator for Class 2, 3
Answer : I think the best way to explain is to tell you what both are. So if you would get your book and go to page 1.4.1 for class 1. By reading the term you will see that class one is more or less just items like toys , some computer, Just something that you hope will work and understand if it doesn't.
Now a process indicator is section 1.4.3.4 page 1-3. This is something that will not affect form, fit or function of a product and please remember ALL THREE OF THESE ARE IMPORTANCE. IF ANY THREE OF THESE FAIL THAN IT IS A BAD PART AND NO LONGER IS A PROCESS INDICATOR.
Question 2 Do we need to control electrical clearance.
Answer: First you need to understand want electrical clearance is , so go to page 1-3 section 1.4.5. By reading this you will understand that you need to control the minimum distance between any conductive material. As; a component lead and land / pattern on the board. Remember you can create an ark of electrical energy. This would be the same as a solder bridge or conductive connection. YES YOU ALWAYS NEED TO BE CONCERNED ABOUT YOUR ELECTRICAL CLEARANCE.
Reason: If a solder ball gets between to conductive materials and is closer than your electrical clearance you will have a circuit.
Question 3 It is acceptable if the diameter is over 0.13
Answer: Statement is " that are within " So NO the solder ball needs to be < = to 0.13mm
Question 4 How about the upper limit.
Answer: Your upper limit is " more than five solder balls" So they are more concerned about the size. But remember you need to meet your indicators, for form, fit and function. To many may cause problems / rattles in your part, So you always need to remember does points when you make your decision.
Question 5 entrapped or encapsulated or attached to a metal surface is ok. Regardless of size
Answer: My understanding has always been size is not a factor. The importance factor here is WILL THE SOLDER BALL / SPLASH BECOME DISLODGED DURING NORMAL SERVICE ENVIRONMENT. This mean you will need to test your condition under your customer specification to ensure that your entrapment / encapsulation will hold during usage. So be careful sometimes it does not take a lot of heat , cold , damp weather or shaking to dislodge a ball.
Hope this helps
Nancy T.
>>> "Nguyen Quoc Khanh" <[log in to unmask]> 05/22/01 10:44AM >>>
Good morning,
Thanks for your reply. It's me again.
Could you help me to explain the matter mentioned in my last e mail?
Q. KHANH
----- Original Message -----
From: "Nancy Trumbull" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Monday, May 21, 2001 4:23 AM
Subject: Re: [TN] (TN) IPC-A-610C/Solder ball
> Good Morning,
>
> Give me a call or e-mail me off line and I'll try to help you out.
> You really sound as if you need a one on one conversation.
> You can also contact IPC directly. They are our experts when it comes to
understanding the books.
> Nancy T.
>
> 616-9660800 Ext: 1242
> e-mail [log in to unmask]
>
>
>
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