I don't think I could give you a step by step approach to Taguchi but I recommend it as an experimental method. We were waving 50,000 assemblies a week when the customer introduced a new design. There was an RF can surrounding the pcb which had to be 100% soldered to the edge of the pcb. Initial work showed that the board was too small for the can and we had 8 people per shift hand soldering the bits the wave missed. The can was manufactured using a progressive tool, megga money to change, the pcb was punch and crunch, expensive to change. Attempts to improve the wave process failed so we called in two wave consultants. One was kind enough to say it was impossible at the start of the day and didn't charge, the second spent a day, did charge and said it was impossible. So we did a Taguchi and our first attempt got us down to 1.5 reworkers per shift. Further honing of the Taguchi plus some other improvements got us to 0.5 reworkers per shift. In terms of understanding the wave process and being able to improve the process, Taguchi is fantastic. I recommend that you carefully tell your operators why you are doing the Taguchi and how it works. We had a later Taguchi sabotaged by a wave operator who didn't like running the machine on settings he knew would produce rubbish, he doesn't work here now! You have to gain the co-operation of your production department as to get points on your graphs you will have to build product that is 'bad'. You must carefully decide what your attributes are to be so opens, shorts and pull through might be your choice. On our first one we were only concerned with the % of the frame soldered to the board. The beauty of Taguchi is that if you change your mind about the importance of the attributes you can change the machine settings in line with a paper exercise on the Taguchi. Picking your independent variables for a wave is not easy and is best done in a brain storm once your team realise the definition of independent variable. I.e. preheater setting is not independent, topside pcb temp, is as conveyor speed would change topside temp for a given preheat setting. We have some software which helps with the arithmetic and array choice. I really do think Taguchi is a great tool. Rex Rex Waygood Technical Manager Hansatech EMS provides value manufacturing through engineering and quality Hansatech EMS Limited Benson Road Nuffield Industrial Estate Poole -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of John Queen Sent: 24 May 2009 13:55 To: [log in to unmask] Subject: [TN] Taguchi Guys have any of you used the Taguchi process for optimisation of Wave Solder Process. I am pretty interested in this, and can you direct me to examples of this process. --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 -----------------------------------------------------