Text item: I would also be interested to know what height delta between solder mask and SMT pad will start to affect the volume of paste deposited. An important part of surface mount assembly process control is making sure the proper amount of solder paste is deposited on the pads. The amount deposited varies due to many factors. A few of these issues are: The PCB, the printing parameters, and the paste characteristics. Also, the amount of paste required to make a solder joint which meets ANSI/J-STD-001 varies from pad to pad because of many other issues like: lead coplanarity, amount of solder on the pad from HASL, placement accuracy, reflow conditions,........... I am interested in whether there is an industry standard or how others have calculated the minimum and maximum volumes of paste required. I would appreciate any comments on this subject. Bill Barthel Electronic Assembly Corporation [log in to unmask] (414) 751-3651 Text item: External Message Header The following mail header is for administrative use and may be ignored unless there are problems. ***IF THERE ARE PROBLEMS SAVE THESE HEADERS***. Resent-Sender: [log in to unmask] Precedence: list X-Loop: [log in to unmask] X-Mailing-List: <[log in to unmask]> archive/latest/2176 Resent-From: [log in to unmask] Resent-Message-Id: <"GDyu_1.0.m89.yzKym"@ipc> X-Mailer: Microsoft Mail V3.0 Encoding: 18 TEXT Message-Id: <[log in to unmask]> Date: Mon, 08 Jan 96 10:18:00 CST Subject: Solder Paste Deposit Spec. To: "'TechNet'" <[log in to unmask]> From: "Barthel, Bill" <[log in to unmask]> Old-Return-Path: <miso!bldg5.plexus.plexus.com!BBarthel> Received: by ipc.org (Smail3.1.28.1 #2) id m0tZL3S-0000PzC; Mon, 8 Jan 96 11:08 CST Resent-Date: Mon, 8 Jan 1996 09:42:23 -0800 Received: from ipc.org by simon.ipc.org via SMTP (940816.SGI.8.6.9/940406.SGI) id JAA01043; Mon, 8 Jan 1996 09:42:23 -0800 Received: from simon.ipc.org ([168.113.24.64]) by SSD.intel.com (4.1/SMI-4.1) id AA24593; Mon, 8 Jan 96 09:58:55 PST Received: from SSD.intel.com by relay.hf.intel.com with smtp (Smail3.1.28.1 #2) id m0tZLqW-000qEAC; Mon, 8 Jan 96 09:59 PST