Jumper wire

A substrate 10 of HgCdTe is provided with an upper surface region 11 formed by an annealing procedure, or as an epitaxial layer or evaporated film. A layer of insulating material 12 is formed in which windows are provided. The windows are partially filled with a thin layer of metal 13 which is deposited therein to form a metal-semiconductor diode with the upper surface region. The metal layer is deposited to a thickness on the order of 10-50 nm thick and is sufficiently thin to be semi-transparent to infrared radiation. A thick layer of metal 14 is deposited to form an expanded contact and an anti-reflection coating 15 is provided. External conductors in the form of jumper wires 16 are ball bonded to the contact 14. 

Jumper wire kit Low current red LED Mini-Lamp, 25 ma (tungsten)... 

A jumper wire of the right length can be taken from a kit of different sizes, or it can be made by cutting a piece of thin solid 22-gauge copper wire. Leadwires on resistors are bent to a U-shape, so each end can be poked into the breadboard holes. Thus the input wire and the 2.2K are connected together via a vertical row of holes. The other end of that 2.2K, and the lOK, and a wire going to pin 3 are all connected together via another row of holes. Input and output wires can be attached to clip leads. 

All modifications to PCBAs should be defined and detailed in approved engineering and/or methods documents. Jumper wires are considered components and are defined by engineering documentation for routing, termination, staking, and wire type. 

Lifted pins should be cut short enough to prevent the possibility of being shorted to the pad from which they were lifted should they be pushed back down. If the component hole from which the pad was lifted does not contain a jumper wire, it should be filled with solder. 

Jumper wires may be used on all classes of equipment electronic assemblies and in thick-film hybrid technology. The wire may be terminated in PTHs, on terminal standoffs, on circuit lands, or on component leads. It should be noted for Class 3 equipment that a wire cannot be placed into the same PTH with a component lead. 

Recommended jumper wire is solid, insulated, plated copper wire. It should be the smallest wire diameter that can reliably carry the required current, and the insulation should be capable of withstanding soldering temperatures. 

Jumper wires should be routed in the shortest x-y route possible (see Rg. 52.39). Wire routing must be documented for each part number. Assemblies having the same part number must be routed in the same pattern. 

When jumper wires are used on the primary side (component side) of the PCBA, no wire is to pass over or under any components for Class 2 or 3. The wire may pass over lands, provided the wire can be moved away from the land for component replacement. To prevent damage to the wire from excessive heat, care must be taken to avoid running wires near heatsinks or components that generate high temperatures. 

When jumper wires are used on the secondary side of the PCBA, the jumper wire should not pass through component footprints unless the layout of the assembly proliibits routing in other areas. If this condition occurs, it should be considered a process indicator. There is an exception to this is rule for edge connectors on the PCBA. Jumper wires should not pass over test points or vias used as a test point. 

Jumper wires should be staked to the base material with an approved adhesive or tape dots or strips intended for this purpose. If adhesives are used, they must be fully cured as part of... 

When a jumper wire is attached to leads on the secondary side of the PCBA or to axial components on the primary side of the PCBA, it must form a full 180 to 360° loop around the component lead. When a jumper wire is soldered to other component package styles, the wire should be lap-soldered to the component lead. 

Jumper wires may be installed into a PTH with another component lead for Class 1 and 2 equipment however, this is unacceptable for Class 3 equipment. Jumper wires may also be installed into via holes (see Fig. 52.40). 

FIGURE 52,40a Example of jumper wire connected to plated through-holes (IPC). 

Incorrect heater or jumper wires used or heaters omitted... 

Before the Second World War, the standard insulation for wire used in telecommunications in the UK was waxed acetylated cotton, the conductor being tinned copper wire, while for tropical use the conductors were oleo-resinous enamelled copper wire. Jumper wire had braided wool insulation. 

Over the next two decades extruded PVC with a lacquered, lapped rayon secondary coating for protection against soldering temperatures and for identification was the standard wire insulation. The jumper wire over this period was PVC-coated tinned copper wire with a cellulose lacquered rayon braid secondary coating containing a nonflammability additive. 

Later in the 1970s nylon-coated PVC jumper wire was used in the UK, the nylon coating giving toughness and cut-through resistance, but at the same time introducing a flammability problem. This was rapidly overcome, however, by the introduction of a single shot extrusion of PVC crosslinked by irradiation. 

Have checks been completed for jumper wires and locked shutoffs ... 

Despite the improvements in conveyor safety, guards and other safeguards are sometimes removed, thus disabling these safety devices. In one case, a maintenance worker bypassed a safety limit switch by using a jumper wire to disengage the switch. A serious injury occurred because the maintenance worker failed to remove the temporary wire. 

Part type Chip R/C QFP Mini Tr SSOP/TSOP Connector DIP Jumper wire... 

Wave soldering alloy Melting point (°C) QFP pull strength (kgO Jumper wire pull strength (kgf) Elongation (%)... 

FIG. 38 Thermal cycle tests for a single-sided jumper wire using several lead-free and eutectic Sn-Pb wave solder alloys. Thermal cycling conditions were -40°C to 85 C for 30-min dwell times. Wire plating tested were a) Sn-Pb, b) Sn-Bi, and c) Sn. With jumper wires, the Sn-Ag-Bi wave solder outperforms the remaining materials over a wide range of finishes. (Courtesy of Panasonic.)... 

FIG. 40 Comparison of jumper wire wettability for various lead-free alloys and eutectic Sn-Pb as the benchmark. Eutectic Sn-Pb wet 100% of the land (terminal pad) while all the lead-free alloys exhibited a reduced level of coverage. (From Ref. 25.)... 

Wave FR-4 Thermal fatigue test (-40 to 125°C, 30-min dwell time) Creep test, FUlet lifting (JR-01 board) DIPIC Jumper wire... 

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