Abstract: The terminals of a device under test are temporarily electrically connected to corresponding contact pads on a load board by a series of electrically conductive pin pairs. The pin pairs are held in place by an interposer membrane that includes a top contact plate facing the device under test, a bottom contact plate facing the load board, and a vertically resilient, non-conductive member between the top and bottom contact plates. Each pin pair includes a top and bottom pin, which extend beyond the top and bottom contact plates, respectively, toward the device under test and the load board, respectively. The top and bottom pins contact each other at an interface that is inclined with respect to the membrane surface normal. When compressed longitudinally, the pins translate toward each other by sliding along the interface. The sliding is largely longitudinal, with a small and desirable lateral component determined by the inclination of the interface.

Abstract: Seed sensors that surround the conventional mounting location on existing seed tubes. The seed sensors sense seeds using electromagnetic fields, including RF and microwave fields. In one embodiment, a first seed sensor has a coaxial Fabry-Perot resonant cavity which is formed between two coaxial portions of a conduit that surround the seed tube. Another seed sensor uses a capacitive design. In one embodiment, the driving signals are applied 180 degrees out of phase. The detected phase shift between the reference and reflected signals provides reliable seed counting. Electronics extract the signal from the sensing field.

Abstract: The terminals of a device under test are temporarily electrically connected to corresponding contact pads on a load board by a series of electrically conductive pin pairs. The pin pairs are held in place by an interposer membrane that includes a top contact plate facing the device under test, a bottom contact plate facing the load board, and a vertically resilient, non-conductive member between the top and bottom contact plates. Each pin pair includes a top and bottom pin, which extend beyond the top and bottom contact plates, respectively, toward the device under test and the load board, respectively. The top and bottom pins contact each other at an interface that is inclined with respect to the membrane surface normal. When compressed longitudinally, the pins translate toward each other by sliding along the interface. The sliding is largely longitudinal, with a small and desirable lateral component determined by the inclination of the interface.

Abstract: Seed sensors that surround the conventional mounting location on existing seed tubes. The seed sensors sense seeds using electromagnetic fields, including RF and microwave fields. In one embodiment, a first seed sensor has a coaxial Fabry-Perot resonant cavity which is formed between two coaxial portions of a conduit that surround the seed tube. Another seed sensor uses a capacitive design. In one embodiment, the driving signals are applied 180 degrees out of phase. The detected phase shift between the reference and reflected signals provides reliable seed counting. Electronics extract the signal from the sensing field.

Abstract: The terminals of a device under test are temporarily electrically connected to corresponding contact pads on a load board by a series of electrically conductive pin pairs. The pin pairs are held in place by an interposer membrane that includes a top contact plate facing the device under test, a bottom contact plate facing the load board, and a vertically resilient, non-conductive member between the top and bottom contact plates. Each pin pair includes a top and bottom pin, which extend beyond the top and bottom contact plates, respectively, toward the device under test and the load board, respectively. The top and bottom pins contact each other at an interface that is inclined with respect to the membrane surface normal. When compressed longitudinally, the pins translate toward each other by sliding along the interface.

Abstract: The terminals of a device under test are temporarily electrically connected to corresponding contact pads on a load board by a series of electrically conductive pin pairs. The pin pairs are held in place by an interposer membrane that includes a top contact plate facing the device under test, a bottom contact plate facing the load board including a rocker base protrusion, and a vertically resilient, non-conductive member between the top and bottom contact plates. Each pin pair includes a top and bottom pin, which extend beyond the top and bottom contact plates, respectively, toward the device under test and the load board, respectively. The top and bottom pins contact each other at an interface that is inclined with respect to the membrane surface normal. When compressed longitudinally, the pins translate toward each other by sliding along the interface. The sliding is largely longitudinal, with a small and desirable lateral component determined by the inclination of the interface.

Abstract: The terminals of a device under test are temporarily electrically connected to corresponding contact pads on a load board by a series of electrically conductive pin pairs. The pin pairs are held in place by an interposer membrane that includes a top contact plate facing the device under test, a bottom contact plate facing the load board, and a vertically resilient, non-conductive member between the top and bottom contact plates. Each pin pair includes a top and bottom pin, which extend beyond the top and bottom contact plates, respectively, toward the device under test and the load board, respectively. The top and bottom pins contact each other at an interface that is inclined with respect to the membrane surface normal. When compressed longitudinally, the pins translate toward each other by sliding along the interface. The sliding is largely longitudinal, with a small and desirable lateral component determined by the inclination of the interface.

Abstract: A test fixture (120) is disclosed for electrically testing a device under test (130) by forming a plurality of temporary mechanical and electrical connections between terminals (131) on the device under test (130) and contact pads (161) on the load board (160). The test fixture (120) has a replaceable membrane (150) that includes vias (151), with each via (151) being associated with a terminal (131) on the device under test (130) and a contact pad (161) on the load board (160). In some cases, each via (151) has an electrically conducting wall for conducting current between the terminal (131) and the contact pad (161). In some cases, each via (151) includes a spring (152) that provides a mechanical resisting force to the terminal (131) when the device under test (130) is engaged with the test fixture (120).

Abstract: The terminals of a device under test are temporarily electrically connected to corresponding contact pads on a load board by a series of electrically conductive pin pairs. The pin pairs are held in place by an interposer membrane that includes a top contact plate facing the device under test, a bottom contact plate facing the load board, and a vertically resilient, non-conductive member between the top and bottom contact plates. Each pin pair includes a top and bottom pin, which extend beyond the top and bottom contact plates, respectively, toward the device under test and the load board, respectively. The top and bottom pins contact each other at an interface that is inclined with respect to the membrane surface normal. When compressed longitudinally, the pins translate toward each other by sliding along the interface. The sliding is largely longitudinal, with a small and desirable lateral component determined by the inclination of the interface.

Abstract: The terminals of a device under test are temporarily electrically connected to corresponding contact pads on a load board by a series of electrically conductive pin pairs. The pin pairs are held in place by an interposer membrane that includes a top contact plate facing the device under test, a bottom contact plate facing the load board, and a vertically resilient, non-conductive member between the top and bottom contact plates. Each pin pair includes a top and bottom pin, which extend beyond the top and bottom contact plates, respectively, toward the device under test and the load board, respectively. The top and bottom pins contact each other at an interface that is inclined with respect to the membrane surface normal. When compressed longitudinally, the pins translate toward each other by sliding along the interface. The sliding is largely longitudinal, with a small and desirable lateral component determined by the inclination of the interface.

Abstract: The terminals of a device under test are temporarily electrically connected to corresponding contact pads on a load board by a series of electrically conductive pin pairs. The pin pairs are held in place by an interposer membrane that includes a top contact plate facing the device under test, a bottom contact plate facing the load board including a rocker base protrusion, and a vertically resilient, non-conductive member between the top and bottom contact plates. Each pin pair includes a top and bottom pin, which extend beyond the top and bottom contact plates, respectively, toward the device under test and the load board, respectively. The top and bottom pins contact each other at an interface that is inclined with respect to the membrane surface normal. When compressed longitudinally, the pins translate toward each other by sliding along the interface. The sliding is largely longitudinal, with a small and desirable lateral component determined by the inclination of the interface.

Abstract: A test fixture (120) is disclosed for electrically testing a device under test (130) by forming a plurality of temporary mechanical and electrical connections between terminals (131) on the device under test (130) and contact pads (161) on the load board (160). The test fixture (120) has a replaceable membrane (150) that includes vias (151), with each via (151) being associated with a terminal (131) on the device under test (130) and a contact pad (161) on the load board (160). In some cases, each via (151) has an electrically conducting wall for conducting current between the terminal (131) and the contact pad (161). In some cases, each via (151) includes a spring (152) that provides a mechanical resisting force to the terminal (131) when the device under test (130) is engaged with the test fixture (120).

Abstract: The terminals of a device under test are temporarily electrically connected to corresponding contact pads on a load board by a series of electrically conductive pin pairs. The pin pairs are held in place by an interposer membrane that includes a top contact plate facing the device under test, a bottom contact plate facing the load board, and a vertically resilient, non-conductive member between the top and bottom contact plates. Each pin pair includes a top and bottom pin, which extend beyond the top and bottom contact plates, respectively, toward the device under test and the load board, respectively. The top and bottom pins contact each other at an interface that is inclined with respect to the membrane surface normal. When compressed longitudinally, the pins translate toward each other by sliding along the interface.

Abstract: A test fixture (120) is disclosed for electrically testing a device under test (130) by forming a plurality of temporary mechanical and electrical connections between terminals (131) on the device under test (130) and contact pads (161) on the load board (160). The test fixture (120) has a replaceable membrane (150) that includes vias (151), with each via (151) being associated with a terminal (131) on the device under test (130) and a contact pad (161) on the load board (160). In some cases, each via (151) has an electrically conducting wall for conducting current between the terminal (131) and the contact pad (161). In some cases, each via (151) includes a spring (152) that provides a mechanical resisting force to the terminal (131) when the device under test (130) is engaged with the test fixture (120).

Abstract: The terminals of a device under test are temporarily electrically connected to corresponding contact pads on a load board by a series of electrically conductive pin pairs. The pin pairs are held in place by an interposer membrane that includes a top contact plate facing the device under test, a bottom contact plate facing the load board, and a vertically resilient, non-conductive member between the top and bottom contact plates. Each pin pair includes a top and bottom pin, which extend beyond the top and bottom contact plates, respectively, toward the device under test and the load board, respectively. The top and bottom pins contact each other at an interface that is inclined with respect to the membrane surface normal. When compressed longitudinally, the pins translate toward each other by sliding along the interface. The sliding is largely longitudinal, with a small and desirable lateral component determined by the inclination of the interface.

Abstract: A test fixture (120) is disclosed for electrically testing a device under test (130) by forming a plurality of temporary mechanical and electrical connections between terminals (131) on the device under test (130) and contact pads (161) on the load board (160). The test fixture (120) has a replaceable membrane (150) that includes vias (151), with each via (151) being associated with a terminal (131) on the device under test (130) and a contact pad (161) on the load board (160). In some cases, each via (151) has an electrically conducting wall for conducting current between the terminal (131) and the contact pad (161). In some cases, each via (151) includes a spring (152) that provides a mechanical resisting force to the terminal (131) when the device under test (130) is engaged with the test fixture (120). In some cases, the spring (201) is housed within a pair of nested, open-ended tubes (202, 203) that can slide longitudinally with respect to each other.