members as the support members move up and down and conform to the underside topography of the substrate the apparatus is especially suited for underside support of printed circuit boards during assembly processes for printing pick and place operations and automated inspection for surface mount style substrates application_number US 201213444726 A description the present technology may include a non locking substrate support system in the substrate support system the upwardly biasing element for the support pins may include either a spring foam compressed air or the like for springs and foam they may follow the generalized formula of hooke 39 s law where the force to compress the biasing element is proportional to the amount of displacement other embodiments of the present technology may not follow hooke 39 s law for example while compression springs follow hooke 39 s law which is linear conical springs also known as tapered springs can be used in lieu of compression springs as an upwardly biasing element the stress at a given load or deflection rate for a tapered spring becomes non linear once the larger diameter adjacent coils come in contact with one another during compression this loss of active coils will cause the tapered spring to become stiffer.