摘要:
Desired control of the thickness and composition of a solder coat on the J-leads of an integrated circuit Quad package is obtained by orienting the packages while being solder coated in a "leads-up" orientation as a series of strips mounting the packages are passed through a solder wave of a wave soldering apparatus on a pallet. The Quad or other shaped integrated circuit or other electronic packages which have leads extending exteriorly thereof, thus have the critical lead crest portions coated with substantially the same solder layer thickness and composition. This permits reliable electrical connections between the crest portions of the leads and printed circuit board metal traces (metallization), particularly in surface mounting of the package to a printed circuit board. An additional feature of the invention is a pallet for holding a series of package-holding elongate frames which pallet is used for conveying the packages through the wave soldering apparatus.
摘要:
A connector (10) having two rows of opposed terminals (11, 12) joined by a pair of solder bars (13, 14) is mounted on a printed circuit board (16) with the terminals overlaying circuit board edge contact pads (15, 19) on opposite sides of the board. The assembled connector and circuit board is placed in a fixture whereafter pairs of comb devices are manipulated to position the comb tines between adjoining pairs of terminals. The fixture is conveyed at a fast rate in a first direction past a pair of heaters (34, 35) for preheating the two rows of terminals, the solder bars, and the circuit board pads. Next, the fixture is returned in a second opposite direction at a slow rate past the heaters to melt and thereby solder bond the comb held terminals to their corresponding board pads.
摘要:
A method for soldering the underside of a substrate between leads. A paste of solder emulsified in a flux material is printed onto a carrier and film. The paste is adhered to the film by drying or reflowing before being placed onto the substrate between the projecting leads. The substrate and film are then heated. The molten solder having an affinity for plated surface areas of the substrate and no affinity for the polyimide film transfers and self-aligns to the plated surfaces of the substrate. The method allows selective soldering of the underside surface of a substrate having leads without soldering these leads, or selective soldering of some plated areas of a substrate while leaving other plated areas free of solder.
摘要:
A leadless integrated circuit chip carrier apparatus and method of assembly to a printed circuit board. A plurality of castellations are provided in the perimeter walls of the carrier member and solder preforms are deformably fitted in the castellations for reflow vapor phase soldering to the printed circuit board. A spacer member is disposed between the carrier member and the printed circuit board and has a thermal coefficient of expansion matched to that of the solder. The spacer includes a high thermal conductivity planar metal portion sandwiched between an adhesive epoxy layer which facilitates assembly of the carrier to the circuit board.
摘要:
A progressively-increasing clamping force lead (10) includes a resilient contact finger (22) having an outer arcuate loop portion (26) and a locking tab (34) having a camming surface (70) projecting at an angle from an outer end of the arcuate loop portion toward a planar surface (56) of a clamping finger (20). In the assembling of the lead (10) to the substrate circuit device (16), as the locking tab (34) engages and rides up an adjacent edge (64) of the substrate circuit device, the locking tab causes progresive flexing of an inner connecting portion (36) of the contact finger (22) and progressive coiling of the arcuate loop portion (26) of the contact finger to cause the arcuate loop portion to engage a contact pad (14) with a progressively-increasing force. Subsequently, the arcuate loop portion (26) and the locking tab (34) seat firmly on the contact pad (14) to retain the lead (10) securely on the substrate circuit device (16). The lead (10) then may be soldered to the contact pad (14).
摘要:
A method and apparatus for loading solder preforms on to the pins of a multiple pin connector. A positioning plate has open sockets in the pattern of the pins of the connector to be loaded, the sockets being sized to receive a single solder preform in each one. A slidable retainer fits into a channel below the positioning plate to partially close the sockets and retain preforms therein. Loose preforms are contained in a dam attached to the top of the positioning plate and are shaken into the sockets on a vibrator table. The dam and excess preforms are removed and the positioning plate is covered by a cover plate to hold the preforms in place. The connector pins are then inserted through slots in the retainer, through the preforms and through holes in the cover plate. The retainer is removed, allowing the preforms to drop on the pins and the loaded connector is removed from the apparatus.
摘要:
An electrical terminal includes a mounting portion for insertion in a hole in a circuit board, a rectangular seating portion joining the mounting portion including a pair of shoulders for engaging a surface of a circuit board when the mounting portion is inserted in a hole in a circuit board. The seating portion includes a hole transverse to the mounting portion, and a cold-formed solder element extending through the hole. Each end of the solder element is cold formed to provide a mass of solder on each surface of the seating portion.
摘要:
Solder is applied to a series of individual pins or the pins installed in a connector block by filling the peripheral depressions of a gear-like wheel with a solder paste and rolling the gear across successive pins. As each pin extends into and contacts the solder paste, the pin or solder or both are heated to flow the solder.
摘要:
An electrical terminal structure is disclosed which is provided with a flow deposited quantity or band of solder adhered to a selected portion of the terminal and limited from spreading over the surface of the terminal by the presence of a soldernonwettable material adjacent to but not necessarily touching the terminal. A method of mounting the banded electrical terminals in plated apertures provided in a substrate is also disclosed, wherein the solder bands are applied to the terminals according to the above mentioned application technique. A technique of flattening the solder bands, and the resulting terminal structures having flattened solder bands adhered thereto are also disclosed. Flattening of the solder bands facilitates insertion of the banded terminals into the plated apertures by changing the shape of the solder bands and by reducing their structural integrity though the creation of numerous hairline fractures.