Pick-And-Place Buyers Guide:How equipment manufacturers
specify their equipment:
By knowing how equipment manufacturers specify their equipment and identifying those particular items in your product(s) will enable you to select the right equipment for you production need.
Speed or CPH:
The machines are referenced for speed using “CPH” value. CPH or components per hour also known as “tact time”, is the rate at which the components are picked up, inspected, and placed onto a PCB. Most P&P machines have a rating reference known as IPC 9850 which signifies the rated CPH of a specific part mix and placement array standardized PCB. This speed value is more accurate than tact time and can be used to reference one machine against another. Tact time is simply a “best case” speed rating quoted by the machine manufacturer. This value is less accurate than the IPC 9850 rating, many manufacturers will design a PCB and use more accessible pickup locations so the machine will seem faster than typical production scenarios.
When referencing manufacturer speed ratings de-rate (or lessen) their stated speed by at least 20% to allow for the more stringent IPC 9850 rating. If tact time is the yardstick, deduct 30% from CPH as this will provide closer to “real world” production speeds.
Pick and place equipment is also specified for feeder slots to show the maximum number of different parts available for setup at one time. The feeder slots referenced are 8mm feeder slots. A machine user must understand that not all of their parts will come in 8mm tape and identify how big the parts are and what feeder sizes they require. Most tape feeders if other than 8mm will take up the space of two or more feeder slots, check with the equipment manufacturer to understand how many slots are occupied by 12mm, 16mm. 24mm, and larger format tape feeders.
Matrix trays and tube (or stick) feeders must be researched also to ensure how many, if any, 8mm feeder slots are occupied. Some machines have tray holders that hold one or multiple JEDEC trays and they may or may not take up considerable feeder slots locations depending upon the machine type and manufacturer.
Tube (stick) feeders are also devices that may take up feeder slots. Verify with the machine manufacturer how many feeder slots are occupied with a tube feeder. Depending upon the type of tube feeder, even if the program only has one part delivered in a tube, ten or more feeder slots may be used for the tube feeder base.
Maximum part size is a fairly simple specification, reference the maximum part size needed to be processed and the maximum part size that can be picked up, inspected, and placed by the assembler. One point to look out for is to ensure that the large part can be inspected; some manufacturers have the ability to handle the part but do not have the ability to inspect it. When referencing part size, also reference the maximum part height to ensure there will be no problems or interference on the assembler.
Minimum part size is a major factor when selecting pick and place equipment. Reference the smallest part that can be successfully picked, inspected, and placed by the machine. Research with the equipment supplier if a special nozzle and/or feeder is required to process parts of a certain size. (0201 chip handling is considered today’s norm for smaller components.)
Fine Pitch Capability:
Reference the pitch inspection capabilities of the equipment; do not be fooled by manufacturers referencing motor specification or motor accuracy. There is more to fine pitch placement than motor accuracy. It does not matter how accurate a motor is if the machine (system) cannot pick up, inspect, and place fine pitch leaded and ball grid components. (0.012” fine pitch is basically a standard with the equipment today)STEP 2: Identify Your Product Specifications