Electronics Forum | Tue Sep 16 10:14:03 EDT 2003 | mantis
James, Could it be the convection in the reflow oven itself.Maybe somebody has increased the air flow or convection rate. I have seen an issue with an sot23 blowing off pad in a BTU paragon due to air flow in air curtains being too high. Hope this h
Electronics Forum | Tue Sep 16 10:25:34 EDT 2003 | James
We do have a convection oven and no one has messed with it. I am the only one who can change anything. I have it set at Medium right now on a conceptronics oven. Could this be too high? We have not had problems in the past with parts moving off o
Electronics Forum | Tue Sep 16 10:58:03 EDT 2003 | swagner
I am currently having a discussion with a pcb supplier about inadequate hasl thickness, we are measuring below 40 microinches of hasl when our spec calls for 100 microinches as the minimum. Our supplier came back with the statement the entire indust
Electronics Forum | Wed Sep 17 10:49:48 EDT 2003 | davef
We agree. Colin Lea showed that HASL less than 2 microns [80 uin] thick has limited shelf life and that shelf life gets worse as the HASL gets thinner. Unless you do not need shelf life, consider sticking with 100 to 500 uin. There is nothing wrong
Electronics Forum | Mon Sep 22 10:52:14 EDT 2003 | Carol
Is there a standard that tells you how many times you can replace a PBGA without reliability issues? I've read IPC-7095 (many times) and have not found a recommendation for this. We have Class 3 products.My thoughts are 2 times max. We place PBGAs
Electronics Forum | Thu Sep 25 10:27:45 EDT 2003 | davef
Datum: Many times the requirement for a heat sink is anticipated poorly by the designer. So, adding a clip becomes burdensome and too expensive for a respin. Other times, there is no off the shelf clip for the component, as you say. So, a well des
Electronics Forum | Thu Oct 09 13:27:47 EDT 2003 | MA/NY DDave
Hi Haverhill DavidF, SMTA, SMTnet, I should know this, since Dave does raise a good point that involves the Charge Coupled Model for how ESD creates an event. Be careful you don't blow those components as you seek to create higher and higher vacuum
Electronics Forum | Wed Oct 01 15:34:22 EDT 2003 | johnpatricelli
It won't help your operation of a pick and place machine, but if you are just beginning to train your Operators, an excellent beginners' reference for SMT parts and package recognition can be found at TopLine Dummy Components' website, http://www.top
Electronics Forum | Wed Oct 01 15:45:35 EDT 2003 | Jalinous Esfandayri
Hi Everyone: Does anyone know what the right silicone for bonding the pressure sensor bare die on PCB is? How do I prevent the fracture and keep good adhesive? Any help would greatly be appreciated. Regards, Jalinous Esfandyari Intelligent
Electronics Forum | Mon Oct 06 18:41:47 EDT 2003 | davef
In addition to our earlier comments, do not be misled into thinking that silicone materials, being rubbery, will transmit shock less. Nothing is farther from the truth. Many silicone rubbers are almost totally incompressible in the short time scale.
