Browse Prior Art Database

STUCK NOZZLE DETECTION SYSTEM

IP.com Disclosure Number: IPCOM000009845D
Original Publication Date: 2000-May-01
Included in the Prior Art Database: 2002-Sep-23
Document File: 2 page(s) / 81K

Publishing Venue

Motorola

Related People

Steve Pisto: AUTHOR

Abstract

Stuck nozzles will continue to cause defects until they are manually unstuck and properly reseated. This can be many hours and defects later. Lines are shut down as maintenance crews spend valuable production time checking the 120 nozzles used by the CP6s. The object of this publication is to outline a system that detects stuck nozzles and automatically stops the machine before defects occur.

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MOTOROLA

Technical Developments

STUCK NOZZLE DETECTION SYSTEM

by Steve Pisto

INTRODUCTION

Fuji CP6s are high-speed chip place machines used to populate soldered circuit boards. These machines use various sized nozzles to pick and place components. Nozzle assemblies commonly referred to as pinwheels hold nozzles. Nozzles use spring preload pressure to ensure that they are seated downwards against their stops. If a nozzle is not seated properly against its stop, machine defects occur. Nozzles get stuck often for various reasons and cannot overcome their spring pressure. These "stuck" nozzles cause mispicks and other defects such as skewed and missing parts.

PROBLEMS TO BE SOLVED

Stuck nozzles are common to Fuji CP6s for many reasons. Contamination in the fonn of oxidation, dirt or component fragments is the most oommoll cause. When too much contamination builds up on the nozzle shaft, it becomes stuck in its holder.

While contamination is the greatest cause for stuck nozzles, it can be caused by other factors.

When CP6 nozzles are pushed too far into their holder, their alignment pins can get hung up on the holder assembly passages and cause them to become unseated or stuck. Nozzles can be pushed up too far for many reasons. If calibration of ZO is incorrect or if the tooling plate area is not properly leveled, it

Motorola. Inc. 2000

can cause nozzles to push up and jam. If a part description is written incorrectly as having a wrong part height, nozzle jamming will occur. Parts being accidentally placed on a misplaced part can stick a nozzle. A nozzle erroneously installed without a spring will also cause a nozzle to run unseated.

SOLUTION TO THE PROBLEM

Stuck nozzles will continue to cause defects unt...