【正文】 picture of the ponent being placed, this picture is pared to the ponent description in the machine program ? Step 7 ? The puter checks for bent leads and correct placement on the PCB ? Step 8 ? Component is placed on the PCB ? Step 9 ? Above steps repeated for all ponents ? Step 10 ? Board exits from the machine Vision System 22 Pick and Place Process Steps ? There are 2 categories of Pick and Place Machine: ? Fully Automatic ? Semi Automatic ? The Pick and Place process setup has 8 steps that need to be followed: ? Step 1 Adjusting conveyor rails ? Step 2 Installation of board supports (as required) ? Step 3 Component Set up ? Step 4 Nozzle Set Up ? Step 5 Load Machine Program ? Step 6 Component Replacement ? Step 7 Inspection ? Step 8 Machine tear down Semi Automatic Fully Automatic 23 Proper Adjustment Sensor Step 1 – Adjusting Conveyor Rails 1. Pasted boards ** from the Screen Printer go into the Pick and Place using conveyor rails 2. Rails are also used to transport PCBs out of the Pick and Place after ponents are placed 3. Rails need to be adjusted for the proper width and thickness of the PCB 4. Some systems do this automatically, others require a manual adjustment 5. Sensors allow the PCB to stop in the correct position in the Pick and Place machine automatically ** It is important to handle PCBs by the edges only to avoid smearing the solder paste Tips Transport System 24 Step 2 – Installing Board Supports 1. Based on PCB size, thickness and ponent placement locations, board supports or fixtures may need to be added 2. Board supports prevent the PCB from sagging during ponent placement 3. Work Instructions will provide this information 25 Step 3 – Component Setup 2 3 1 4 ** Sections to be customized by local sites based on areas of operator responsibilities and type of Pick and Place ? Tape and Reel: 1. Tape and Reel ponents are loaded first 2. Machine Program and Feeder Set Up instructions will list all ponents required and correct feeder locations 3. Dedicated feeder locations may be used for mon chip resistors and capacitors ? Engineering sets up dedicated feeders for frequently used ponents, regardless of product being run, to minimize set up time 4. Other feeder locations may need to be set up for each product 26 Step 3 – Component Setup (cont.) ** Sections to be customized by local sites based on areas of operator responsibilities and type of Pick and Place ? Tubes / Sticks 1. Tubes of ponents are loaded after tape and reel ? Stacked on top of feeders ? Emptied directly into feeders 2. Components in tubes must be checked for polarity and part number before loading ? Check polarity markings against process documentation 3. Tubes loaded with incorrect polarity and part numbers, will create a large quantity of rework very quickly ? PCBs may be damaged or scraped during the rework process 2 3 1 27 Step 3 – Component Setup (cont.) ** Sections to be customized by local sites based on areas of operator responsibilities and type of Pick and Place ? Matrix Trays/Waffle Packs: 1. Matrix Trays are loaded using 2 methods: ? Stacked so empty trays index down and are replaced by full trays ? One at a time 2. To prevent rework, ponents in trays must be checked for polarity and part number before loading ? Check polarity markings against process documentation 3. Trays should be handled carefully to avoid damaging or bending ponent leads Stacking System Check Polarity Proper Handling 28 Step 4 – Nozzle Setup ** Sections to be customized by local sites based on areas of operator responsibilities and type of Pick and Place 1. Nozzles e in various sizes and are used to “pick” and “place” ponents 2. The proper nozzle size must be installed for accurate placement of ponents 3. Nozzle size will be specified on process documentation 4. Some machines have nozzle “holders” where different nozzle sizes are kept ? During placement, a pick up head will automatically select the correct sized nozzle ? These machines place larger sized ponents 5. Incorrect selection of nozzles may cause ponent scrap or machine down time Nozzles Process Documentation Nozzle Holders 29 Step 5 – Load Machine Program ? All Pick and Place machines have a machine program which contains the board “description”: 1. Circuit board type and size 2. Catalog of quantity and descriptions of ponents required 3. Feeder location 4. Component locations and orientation 5. Sequence in which ponents will be placed ? These programs are developed by Engineering with all of this information provided ? Operators should never adjust these parameter settings. Changing of these parameters could create quality and safety concerns**! ** If there is a problem, notify the correct personnel