Solder / SMD Inspection Camera

For some time I wanted an camera to inspect solder joints / SMD parts.

What I wanted it to have was:

  • +-30x zoom.
  • Automatic focus with an option to manual focus.
  • Ability to make pictures.
  • Polarised filter.
  • Camera on an arm so it can be pulled over the PCB and pushed back when not in use.
  • Not one of those cheap cameras with build on much too small screen.
  • Connection to the PC, preferred display on the PC screen.

I found a few options, but they ware either too expensive, or the quality too low. Some time went by and then I came across a camera module at a HAM flea market. This one was not too expensive, but was only a camera module that was open on all sides. Therefore the first job was to design an enclosure. I was inspired by a professional version:

The enclosure I 3D printed in PLA. For the rails I used some old printer guide rails with slide bearings on them.

The left picture is when the camera is not in use. It is pushed completely to the back and the slides are locked in place with a magnet. The other 2 pictures are when it is slide out and in use.

Inside the enclosure it looks like this:

It contains a PCB that receives bus signals, drives the LED ring and forwards messages that are meant for the camera.  For the connection of the camera to the PC, it contains a 4ch composite to USB converter (I had this one and did not want to order an extra 1ch version).

The cable that exits the camera enclosure connects to a controller.

With this controller box I can set the zoom level, focus level, intensity of the LEDs and the iris.

In the back panel is a USB plug, this one is connected to the composite to USB converter in the camera. The other input is a 12V power adapter and a programming plug for if I need to make a firmware update.
For the cable between this camera enclosure and the controller used a USB3 cable with the ends cut off. This way I have the 4 usb2 wires and an extra 4 wires for signals and power.

Underneath the camera I made a LED rind to illuminate the area.  Under that I made a polarising filter.

With this filter I can change the polarisation angle of the LED ring with respect to the angle of the filter on the camera lens by rotating the polarisation ring. This makes it possible to make text on IC’s visible that would normally be hard to see. For example, below is one picture with the filter at a random angle and then rotated to a good visibility:

More details on the PCB’s:

The LED ring / camera controller board:

Controller Board / 28pin PIC breakout board:

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