초록 ▼

Clear thermoplastic is vacuum molded to produce rectangular, frustro-pyramidal shaped cavities in a horizontal matrix for holding rectangular solder preforms. No-clean flux liquid is dispensed onto a preform placed in each cavity, then another holder is placed upside-down on the first holder, the ho

Clear thermoplastic is vacuum molded to produce rectangular, frustro-pyramidal shaped cavities in a horizontal matrix for holding rectangular solder preforms. No-clean flux liquid is dispensed onto a preform placed in each cavity, then another holder is placed upside-down on the first holder, the holders are flipped and then no-clean flux liquid is dispensed on the dry side of the preform. Holes in the cavity bottoms drain and circulate drying air to the preform bottoms. A hole in one corner and a different width slot in an opposite corner of each holder, allow multiple holders to be stacked on a bottom frame with different sized threaded posts. An empty holder and then a dust cover are stacked on the posts to hold and protect the preforms. A top frame is stacked on the posts and nuts are screwed onto the posts to form a carrier. The cavities are sized relative to the preforms to hold the preforms in position during carrier transport. The holders are unstacked and each positioned at a station with different sized posts on a rotating table of a pick-and-place machine. A robot arm with rubber tipped vacuum probe picks up the preforms and places them on a circuit board. Grippers on the arm are used to move a heated component on top of the preform for reflow soldering. The circuit board can be used without cleaning with solvents or CFC\s.

대표청구항 ▼

A solder-preform holder comprising: means for supporting multiple planar solder-preforms by their edges in horizontal position with no other surfaces in close proximity to major surfaces of the preform to prevent trapping liquid on the top or bottom surfaces of the preform and to allow air to circul

A solder-preform holder comprising: means for supporting multiple planar solder-preforms by their edges in horizontal position with no other surfaces in close proximity to major surfaces of the preform to prevent trapping liquid on the top or bottom surfaces of the preform and to allow air to circulate to both major sides of the preform and to prevent damage or contamination to a delicate layer of no-clean flux on the major surfaces of the preform; means for horizontally positioning said support means for holding the multiple solder-preforms in a two-dimensional array within a horizontal plane; means for positioning multiple preform holders in a vertical stack for maintaining sufficient horizontal spacing between the major surfaces of the preform and other surfaces to prevent trapping of liquid and allow circulation of drying air on the top and bottom surfaces of the preform and for maintaining the preforms in approximately horizontal position in relation to the plane of the preform array regardless of tilting or horizontal acceleration during transport; means for circulating air from outside the holder across the bottom of the preforms in the preform holders. A solder-preform carrier comprising: means for supporting multiple planar solder-preforms by their edges in horizontal position with no other surfaces in close proximity to the major surfaces of the preforms to prevent trapping liquid on the top or bottom surfaces of the preforms and to allow air to circulate to both major sides of the preforms and to prevent damage or contamination to a delicate layer of no-clean flux on the major surfaces of the preforms; means for horizontally positioning said supporting means for holding the multiple solder-preforms in a two-dimensional array within a horizontal plane; means for vertically positioning multiple preform holders in an accurately spaced vertical stack for maintaining sufficient horizontal spacing between the major surfaces of the preform and other surfaces to prevent trapping liquid and provide circulation of air on the top and bottom surfaces of the preforms and for maintaining the preforms in approximately horizontal position in relation to the plane of the preform array regardless of tilting or horizontal acceleration during transport; means for circulating air from outside the bottoms of the cavities across the bottom of the preforms in the preform holders; means for horizontally positioning the holders in the vertical stack in relation to each other; means for clamping the holders in the vertical stack rigidly together in compression; and handle means for manually lifting the vertical stack.