VGA Single Lens Camera
The key factor that determines the price of a camera module is the imager diagonal; the relationship being almost a cubic power. This arises because the imager diagonal strongly influences the die size and hence the silicon cost per die, and also determines the diameter of the mating optics and hence their cost.

One way to decrease die size is to use smaller pixels. However image sensor manufacturers are already making die with the smallest possible pixels currently achievable. This is typically around 1.75 micrometers and most companies have road maps out to 0.9 micrometers.

As the die size is fixed for each generation of die, this means the diameter of the optics is also fixed. One of the few possibilities for decreasing the cost of cameras is to decrease the number of elements in the optical train. Typically a mega pixel camera will have up to four lenses, with as many as possible of these being made of glass to maximize the optical performance.

A VGA camera module may have three or two lenses, both of which are usually plastic. Condensing the optical train to a single plastic lens provides significant saving in the cost of the camera module but impacts the image quality.

Normally the result would be considered to be visually unacceptable. However for video streaming, or where the picture is viewed on a very low resolution screen, the difference cannot be discerned. This makes VGA single lens cameras ideal for handsets intended for secondary and tertiary markets.

Traditionally, camera modules are manufactured using chip-on-board assembly. In this approach the image sensor die is attached to a substrate and interconnected to it by wire bonds. An enclosure is then glued in place over the imager.

Meanwhile the lenses are made as discrete components and precisely aligned and positioned in a lens barrel. The imager is then powered up and the lens barrel is screwed in to the enclosure until a well focused image is obtained, then the barrel is locked in position.

Clearly, this is a slow and labor intensive process with plenty of opportunity for yield loss. The opportunity to use only a single lens opens the way to a radically different methodology to manufacture camera modules.