TECHNET Archives

December 2004

TechNet@IPC.ORG

Options: Use Monospaced Font
Show Text Part by Default
Show All Mail Headers

Message: [<< First] [< Prev] [Next >] [Last >>]
Topic: [<< First] [< Prev] [Next >] [Last >>]
Author: [<< First] [< Prev] [Next >] [Last >>]

Print Reply
Subject:
From:
Kevin Jaworenko <[log in to unmask]>
Reply To:
TechNet E-Mail Forum <[log in to unmask]>, Kevin Jaworenko <[log in to unmask]>
Date:
Wed, 1 Dec 2004 10:31:53 -0600
Content-Type:
text/plain
Parts/Attachments:
text/plain (157 lines)
Add to that that the reflow profile was:

Max Temp reached: 214 degrees C.
Time above liquidous: 64 seconds
Soak time (145 - 183): 50 seconds.

-----Original Message-----
From: Kevin Jaworenko [mailto:[log in to unmask]]
Sent: December 1, 2004 10:29 AM
To: [log in to unmask]
Subject: Re: [TN] Help, Help, I have a QFN Package I don't know what to
do !


Thanks for the good questions back.

To answer the questions:

What is the lead finish of the QFN package? It is 85SN/15PB.

What is the component dimensions? They are 5.0mm by 5.0mm by 0.9mm

What paste am I using? We are using Kester easy profile 256.

How many layers in the PCB? This is a 4 layer PCB.

What is the PCB thickness? The PCB is 1.6mm thick.

Is this the only component that is not reflowing well? Yes



Thanks in advance.


-----Original Message-----
From: Morse, Carrie [mailto:[log in to unmask]]
Sent: December 1, 2004 9:32 AM
To: [log in to unmask]
Subject: Re: [TN] Help, Help, I have a QFN Package I don't know what to
do!


Good Questions.
Also...What type of solder paste are you using?
What does your recipe/profile look like?  Ramp, Soak, Reflow times and
temps?
What is the thermal mass of the board?  Ex: # Layers, Thickness, Type of
Layers?
Is this the only component that did not reflow well?

-Carrie


-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of David D. Hillman
Sent: Wednesday, December 01, 2004 10:06 AM
To: [log in to unmask]
Subject: Re: [TN] Help, Help, I have a QFN Package I don't know what to
do!

Hi Kevin! What is the lead finish of the QFN package? Having that
information will helpful to the TechNetee's in assisting you. Also, what
are the package dimensions?

Dave Hillman
Rockwell Collins
[log in to unmask]




G'day Everyone.

        Well as the subject states we are currently running a prototype
assembly with a new package style to me, a QFN (Quad Flat No-lead). I
had to look that one up myself.

        The problem is when we were trying to reflow the part, the
solder joint looks very poor, with little to no solder seen on the edge
of the component lead and the pad on the PCB, or a bubble of solder seen
on end of the component between the edge of the component lead and the
pad of the PCB.

        I'm currently setting up to X-ray the components to see if the
foot actually has a good solder joint underneath the component, where
the lead has been curled around the component, but has anyone else had
any dealings with this particular component type before and would be
willing to share?

        I looked up the component manufacture's website and they show
that this component has a required peak temperature of 235 (+5/-0)
degrees C.
That seems like a lot of heat for a non lead-free component.

        Feel free to email me offline if anyone likes.

Thanks in advance.

Kevin Jaworenko
Manufacturing Engineering Technologist
Vansco Electronics LP
(204) 453 - 3339 ext. 622
(204) 453 - 3663 FAX
[log in to unmask]

---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 or
(re-start) delivery of Technet send e-mail to [log in to unmask]: SET
Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the
posts: send e-mail to [log in to unmask]: SET Technet Digest Search the
archives of previous posts at: http://listserv.ipc.org/archives Please
visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for
additional information, or contact Keach Sasamori at [log in to unmask] or
847-615-7100 ext.2815
-----------------------------------------------------

---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 1.8e
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 or (re-start) delivery of Technet send e-mail to
[log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to
[log in to unmask]: SET Technet Digest
Search the archives of previous posts at: http://listserv.ipc.org/archives
Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16
for additional information, or contact Keach Sasamori at [log in to unmask] or
847-615-7100 ext.2815
-----------------------------------------------------

---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 1.8e
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 or (re-start) delivery of Technet send e-mail to
[log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to
[log in to unmask]: SET Technet Digest
Search the archives of previous posts at: http://listserv.ipc.org/archives
Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16
for additional information, or contact Keach Sasamori at [log in to unmask] or
847-615-7100 ext.2815
-----------------------------------------------------

---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 1.8e
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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest
Search the archives of previous posts at: http://listserv.ipc.org/archives
Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815
-----------------------------------------------------

ATOM RSS1 RSS2