SMT Quick-Tips 3: Selecting a Pick and Place Machine
From: Author:Mark Hardy Publish time:2021-08-31 15:05 Clicks:0
Ease of Use
Because small to mid-volume assembly operations must switch projects often, ease of setup and use is a much more important factor than it is for large volume operation where a single setup may handle a run of hundreds of thousands of components. The job-shop assembler must be agile enough to switch among a wide range of board sizes and component selections quickly to meet a variety of production demands. The machine must also be able to handle a broad range of component sizes, from very small to very large, without a strain on setup and testing.
In contrast, large production machines are often made up of several modules of pick and place systems, positioned in-line where they’re needed most for fine pitch parts, chip shooters, or optional tasks. This allows the high volume producer to customize a line to optimize production speed, efficiency and quality. In these environments, a longer setup can be tolerated, because it will be made up in production efficiency.
First, some basic questions:
- Does the model you’re looking at come with a computer, or just the software? This is neither good nor bad, since some users prefer to install the software on their own PCs; however, a fully integrated system assures there will be no software compatibility issues, and this can streamline the installation and setup.
- Does the machine run on a familiar graphical user interface (GUI) such as Windows™ or a proprietary system? Most every operator will be immediately familiar with the intuitive interface of Windows conventions, a key factor in accelerating usability, particularly for a new machine. A proprietary GUI may require a longer learning curve.
Skill sets of the operator should be augmented by the machine provider with:
- Good documentation
- Hands-on training or videos
- A utility to teach the machine common components and repetitive routines
For machines handling over 8,000 CPH, expect a higher learning curve because complexity increases significantly.
Flexibility
An important utility to look for that gives the custom assembler great flexibility is a Universal CAD Translator function (UCT). The UCT allows users to import the pick-and-place data to the machine’s database to help create the program and scale it. When a project is begun, the user selects the program to run from an archived set of files. This permits quick change over from one board to another since all the programming is memorized.
Another feature to look for is a master feeder and component database. Once the operator stores component data, it’s there forever and can be accessed and imported into any new board configuration setup. This database grows as you add components, so over time, you’ll spend less time programming and more time producing. Often, the database will remember inventory, so as you use components, the remaining stock will always be available to check. This is a great feature for scheduling and inventory planning.
Be sure to see if the system you’re considering only stores data for particular boards rather than an entire component database. If so, it will only remember specific board component data, and it won’t show all available inventory.
Optimization
Certain utilities are often provided with a well-designed machine to aid in setting up and programming the system. One of the most important utilities affecting optimized performance is offline software.
Offline software allows the user to simulate the pick and place machine’s routine in a remote environment for programming. It can be installed on any computer and looks just like the machine’s GUI. It allows the user to manipulate the program to sort functions and modify program lines for most efficient use and speed, for instance, by aggregating like-type components in the same sequence, minimizing tool changes and the time it takes to perform those functions. It can also create board references for multi-boards prior to running on the machine.
To speed job change-over, software interface should include sub-routines for common operations such as setting up matrix trays, identifying strip feeders, and teaching for vision centering. Expanding on the last point, image interpretation should be clear and straightforward; if it isn’t – and the machine has a hard time recognizing a component – the result could be a misplaced component, resulting in a lot of unnecessary rework. A well designed software interface will capture a range of image qualities for each component type that are all representative of an acceptable part, and store it as an approved file. This improves speed, repeatability and efficiency, and final board quality.
Other considerations
Just as important as the physical features of a quality pick and place machine are the “soft” features. Make sure to check on:
- Availability of on-site or factory training?
- Remote diagnostics – can your vendor provide this via online support?
- Critical software updates – Do they come free or with a cost?
- Is the software interface available for pre-sale review?
VENDOR SUPPORT
When evaluating any type of SMT machine, consider factory support as one of the most important assets of your purchase. The best way to learn how a company treats its customers is by word of mouth. Talk to several customers to find out how happy they are with the machine, the seller, and the support they provide. Where is the manufacturing plant? Can they help troubleshoot alignment issues over the phone? Do they offer field service? Do they have spare parts in stock for immediate shipment? While there isn’t much of a used market for manual, machine-assisted or enhanced manual pick and place machines, it’s still a good idea to ask your supplier about their older machines in the field, and if down the road, spare parts are available, and about their capability to customize a spare part if the machine becomes obsolescent. Ask what the expected life-cycle of the product is. The industry standard is seven years. Remember, there is a difference between a true manufacturer and an equipment supplier or distributor.
