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Sender: "piclist-bounces@mit.edu" Date: Thu, 24 Sep 2020 14:49:39 -0700 Subject: Re: [EE] Hand soldering fine pitch packages Thread-Topic: [EE] Hand soldering fine pitch packages Thread-Index: AdaSvku4Fi7UtvPuT32S6u4vQa4BNg== Message-ID: References: List-Help: List-Subscribe: , List-Unsubscribe: , In-Reply-To: Reply-To: Microcontroller discussion list - Public. Accept-Language: en-US X-MS-Exchange-Organization-AuthAs: Anonymous X-MS-Exchange-Organization-AuthSource: TS500.efplus4.local X-MS-Has-Attach: X-Auto-Response-Suppress: All X-MS-Exchange-Organization-SenderIdResult: Pass X-MS-Exchange-Organization-PRD: mit.edu X-MS-TNEF-Correlator: received-spf: Pass (protection.outlook.com: domain of gmail.com designates 209.85.217.54 as permitted sender) receiver=protection.outlook.com; client-ip=209.85.217.54; helo=mail-vs1-f54.google.com; dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to; bh=zZLOcuo0VvLnHR9YGDPdRvjjR7zsfClGbfyrtquhZ8k=; b=O2Qg+wkVnsj5gR5EdWWAa9UgqVclVRh5Qy5vQMpfIYdQUlKlxXb50D7qxmfgi7uNED jkVAZMsJbgmg5dptQm4cNur1T0l9fyuNkdPbTL2ywQ92LL4VP4/PL5w1O1Ly1WnyP22J YaY/H+6zT49DGYF9PGuLYHj1bkCx+ooWYUZ9un7kHR4gvQeYg9ohkjRJA5xlxx+9xYhV icUf8LjnmyPtxfC6hFnDc8G/e2xpm2UMht0+8MkiTAfIxbq4mIxkya6iZt1GBfgGDNa9 FF1VJWP3S9X03nBq/ZP5K/v09CVzZ2nIKOYD4CS/99fZIlWzfTQIlyXI0tu0RVy9bdtv nl6w== authentication-results: spf=pass (sender IP is 209.85.217.54) smtp.mailfrom=gmail.com; mit.edu; dkim=pass (signature was verified) header.d=gmail.com; mit.edu; dmarc=pass action=none header.from=gmail.com; errors-to: piclist-bounces@mit.edu list-id: "Microcontroller discussion list - Public." list-post: x-beenthere: piclist@mit.edu x-mailman-version: 2.1.6 x-received: by 2002:a67:e2c3:: with SMTP id i3mr1116371vsm.13.1600984192111; Thu, 24 Sep 2020 14:49:52 -0700 (PDT) x-topics: [EE] x-content-filtered-by: Mailman/MimeDel 2.1.6 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 I flood (like really flood) the entire row with solder, let it set, then place the PCB on its edge so the row is now vertical and slowly remelt the solder from top to bottom. The surface tension collects the excess on the way down and usually, for a 0.4mm pitch, only the last 2 or 3 pins require a touch-up with wick. For all four rows of a 120 pin QFP this usually takes a lot less time than the aligning part. Extra flux not usually required. Make sure you don't drop the molten blob of solder at the end on other parts of the board. --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .