Prototype and small batch assembly

Outsourcing vs. doing it yourself

Sending boards to China can be all right if you have the quantities for it, but for small batches the low cost per board is offset by high setup fees, and your lead times are stretched not just by the trip across the ocean but also by the fact that your job will be queued behind much larger jobs, some of which can take days to complete.

You can get short runs done in the US, but again you might find your small job stuck behind larger jobs, and the larger US contract assemblers are often not interested in small jobs at all.

Wherever you outsource to, your project is completely out of your hands until it’s shipped back to you. There’s no building a board and double checking it before you go on to do the full run.

Doing your prototyping and small batch assembly yourself cuts the lead times down to nothing, gives you complete control over the quality of your end product (including the ability to find and fix boner errors on your part before the whole batch is run), and saves you money in the long run. Equipment is an investment that you can utilize long after your current job is complete. Outsourced assembly is an expense you incur every time you have a job to send out.

(Equipment can even become an extra income source if you utilize its downtime by taking in small assembly jobs from others.)

What you’ll need to do it yourself

For an in-house prototyping and/or short-run assembly line, at the minimum you’ll need is a stencil printer, a component placer, and a reflow soldering oven. You’ll probably want a way to inspect the quality of your finished assembly. Rework and repair tools wouldn’t go amiss either. If you’re not using no-clean solder paste (and in many cases even if you are), you’ll want a way to clean your assemblies as well.

Since this is pickandplace.com, we’ll only focus on selecting the best component placer for your needs here. This machine will be the biggest expense in your new assembly line.

There are three types of pick and place machines you’ll probably consider: manual, automated benchtop and the lower end automated batch machines.

Manual (and semi-automatic) pick and place machines

Typical manual pick and place machine

These are the least expensive models, typically selling between $1,000 and $12,000. They range from something as simple as a board holder, hand rest, bins for your components and a vacuum pick-up pipette to sophisticated vision systems, pick & place head guiding systems, controlled component lowering, motorized parts carousels, tape and strip feeder capability and more.

All of the manual and semi-automatic placers have one thing in common: you will be involved with placing every single component on every single board. Unlike with automatic machines, you can’t just load a board and let it go.

Who are these machines suited for?

You probably in the market for a manual or semi-automatic system if:

• You don’t expect to be assembling a lot of boards
• You’re building too many boards for hand assembly to be feasible
• High precision (repeatability) and accuracy aren’t critical to your products
• You require more accuracy than you can get with hand assembly
• The income from the products you’ll be making won’t be high enough to justify an automated machine

Automated benchtop machine

Adafruit Industries’ Limor Fried with their benchtop automatic pick and place machine. (Image source: Forbes)

These offer many of the features of full-sized machines at less cost ($20k to $35k, generally, not including feeders). You’ll be able to get flying and bottom vision alignment, teach-in programming, more feeder capacity, greater accuracy and repeatability, and of course faster placement rates than you could get with the manual and semi-automatic placers.

One thing to note, however, is that while benchtop machines can save you money compared to a full-sized machine, they may not save you much floor space. They will require a sturdy table, and the length and width dimensions of the machine itself can be as large as some of the lower-end full-sized machines.

A significant advantage of automated machines over the manual/semi-automatics is that you don’t have to sit there making every placement yourself.

Who are automated benchtop pick and placers suited for?

• You require higher precision (repeatability) and accuracy than hand assembly or manual/semi-automatic machines can offer
• You have a lot of components on your board
• You don’t want to have to place all the components yourself, one at a time
• You need to build boards faster than you could with a manual or semi-automatic system
• The income from the products you’ll be making (and/or your ability to take in contract jobs on top of your own products) justifies an investment in a benchtop machine.

Automated low-volume batch machine

Sparkfun’s pick and place machine

These are everything automated benchtop machines have to offer, plus increased stability due to their being built on a sturdy base. You’ll also be able to get a larger feeder capacity, larger placement area, faster placement rates, and greater accuracy and repeatability than you could with a benchtop.

With a full-sized machine, you can also get an in/out shuttle, which means that you don’t have to reach into the machine to load and unload the board.

Who are full-sized pick and place machines suited for?

• You need to handle larger boards or panels
• You need even higher precision (repeatability) and accuracy than a benchtop offers
• You need to build boards even faster than you could with an automated benchtop placer
• You need to place a component range that benchtop machines can’t handle
• The income from the products you’ll be making (and/or your ability to take in contract jobs on top of your own products) justifies an investment in a full-sized pick and place machine.