Introduction to pick and place equipment selection
For most purposes, selecting pick and place machine can be broken down into three simple steps:
- Understanding how equipment is specified by manufacturers.
- Calculating your product requirements:
- Speed/capacity
- Maximum and minimum component sizes
- Precision and accuracy
- Board or panel size
- Number and types of component feeders
- Benchmarking machines from various manufacturers against your requirements.
There are special considerations that differ based on the type of manufacturing you'll be doing. Are you an original equipment manufacturer (OEM)—in other words, are you manufacturing your own product?—or are you a contract or custom manufacturer, where you either manufacture someone's else's products or you custom manufacture your line of products based on your customer's needs. Perhaps you do a mix of both.
Contract assemblers and custom manufacturers need more flexibility in their placement capabilities and faster, easier job changeovers while OEMs doing some or all of their production in-house are looking for accuracy, speed and ease of use.
If this is your first pick and place machine, the availability of onsite installation, training and support from experienced, factory-trained technicians may be a big factor in determining which machine you purchase. Having someone help ensure you get your production off on the right foot can make all the difference for a young or growing company.
You may also have specific production needs—perhaps you're doing prototyping, or LED components are part of your assembly mix.
SMT/circuit board assembly production process basics
You may have been assembling your boards by hand up to this point, and you're looking to be able to produce more boards faster. Or you may have been outsourcing the assembly to a contract electronics assembly house. Either way, it's helpful to know some basics about SMT production before you make any costly investments in equipment.
The basic equipment for PCB production are the screen or stencil printer, the pick and place machine and the reflow oven.
- The screen printer applies solder paste to the PCB on the pad locations.
- The pick and place machine picks up, inspects and places SMT components on programmed locations.
- The reflow oven brings the PCB assembly up to a temperature high enough to liquefy the solder paste (this is called "liquidus").
When the PCB assembly cools, it is finished and ready to go.
For mixed-technology assemblies (containing both surface mount and through-hole components), a wave solder machine may also be required to solder the through-hole leads.
You may also need board defluxing, stencil cleaning, and automated optical inspection equipment.
The following presentation provides more information about the circuit board assembly process:
