Bed Of Nails Tester Concept

Central camming mechanism pull plates inward.

Bed of nails tester concept. Click to view more boxprober 6 sided bed of nails tester test 6 sides ergonomically designed 6 sided bed of nails circuit board test fixture. The first step in bed of nails testing is to design and build a test fixture for your specific pcb design. Pressure pressure p is defined as the force per unit area mathematically calculated by the equation. Side access electrically probes outside panel connectors.

Central camming mechanism pull plates inward. Probes top bottom and all 4 sides. Designed primarily for testing products in plastics. Although the concept of the in circuit test fixture or bed of nails is broadly the same whatever manufacturer is used there are a number of variations on the basic theme.

It will have a main connector that interfaces to the tester and wires that are taken from the connector to individual pins probes or nails that make contact with the required. A bed of nails tester is a traditional electronic test fixture which has numerous pins inserted into holes in an epoxy phenolic glass cloth laminated sheet g 10 which are aligned using tooling pins to make contact with test points on a printed circuit board and are also connected to a measuring unit by wires. The bed of nails test method gets its name from these protruding pins. Mechanically or electrically actuated options.

In circuit test fixture basics. In this way. Some functionality of digital circuits can also be measured although their complexity usually makes a full check uneconomic. The fixture contains a multitude of small spring loaded test pins that protrude from a wide base that can secure the pcb.

Using a bed of nails in circuit test equipment it is possible gain access to the circuit nodes on a board and measure the performance of the components regardless of the other components connected to them. 1 where f is the force applied and a is the area. A bed of nails is an oblong piece of wood the size of a bed with nails pointing upwards out of it. This sort of solution would require you to route test signals to a central location instead of being able to place them anywhere on the board but would eliminate the difficulty hassle associated with the physical construction of a traditional bed of nails test rig.

Assuming the nails are numerous enough the weight is distributed among them so that the pressure exerted by each nail is not enough to puncture the person s skin. The in circuit test fixture is required to interface the main tester with the particular board under test. Paul hewitt demos pressure by having his assistant lie on a bed of nails and paul hits a block of stone on assistant s chest with a sledge hammer. Parameters such as resistance capacitance and so forth are all measured along with the operation of analogue components such as operational amplifiers.

It appears to the spectator that anyone lying on this bed would be injured by the nails but this is not so. The unit will also optically read leds and key segments off lcd displays. 6 sided bed of nails circuit board test fixture. Bed of nails a piece of wood with nails driven through it such that the sharp end of the nail protrudes upwards.

For boards with a relatively small number of test points i ve found this to be worth the trade off. Probes top bottom and all 4 sides.