US 5,307,560 A · Automated test pin loading method

Abstract

There is disclosed a method, and apparatus useful in the method, for the automated loading of probes in a probe head intended for use in automated testing of printed circuit boards. The invention automatically places probes in a probe head at on-grid and at off-grid test points, with probes for the latter test points being vertically inclined from base ends which are on-grid to test ends which are off-grid, corresponding to the off-grid test points of the printed circuit board. In the method, the probes are stored in a dispensing unit which is fully populated with on grid probes at a uniform grid spacing. A mask is custom drilled for the circuit under test at on-grid locations and is used to permit transfer of selected probes from the dispensing unit to a probe cassette. The probe cassette is then transferred to a probe loading unit which is loaded with a stack of the probe plates intended for the probe head. The probe plates are independently raised and lowered following a procedure which transfers the probes from the probe cassette into the probe plates.

Claims15

Dependent claims

A method for preparation of a probe head useful in automated testing of printed circuit boards and comprising an assembly of probes received in aligned holes of a plurality of spaced apart probe head plates at selected test point positions therein, said method comprising:

a. storing a multitude of said probes in a probe storage unit at on-grid probe locations in a fully populated grid distribution of said probes at uniform and preselected probe-to-probe spacings;
b. preparing a selector mask with a plurality of through holes at preselected locations which coincide sufficiently with said on-grid probe locations in said probe storage unit to permit probes at said preselected locations to pass through said mask, and placing said selector mask in a dispensing station against said probe storage unit;
c. placing a probe cassette beside said mask at said dispensing station and transferring probes at said preselected locations from said dispensing station to said probe cassette;
and
d. transferring said probe cassette to an aligned position against a closely-spaced, stacked array of said probe head plates;
and
e. transferring said probes from said probe cassette to said stacked array of said plates.

4 more elements

A method for preparation of a probe head useful in automated testing of printed circuit boards and comprising an assembly of probes received in aligned holes of a plurality of at least three probe head plates which are supported in a spaced apart array with each of said holes being in a straight line alignment with respective holes in the adjacent head plates which comprises:

a. stacking closely together a plurality of at least three probe head plates into a stacked array, each of said plates being drilled with a respective field pattern of probe holes, with the field pattern of the holes in the lowermost plate of said stacked array being at positions selected to correspond to test point positions of a printed circuit board, including holes which are out of vertical alignment with respective holes in the uppermost plate, and the field patterns of the other plates of said stacked array including respective holes at locations intermediate their respective holes in said uppermost and lowermost plates such that upon movement of said plates from said stacked array to said spaced apart array, respective probes move into said straight-line alignment;
and
b. positioning test probes into holes in the uppermost plate of said closely stacked head plates with the lower ends of said probes also received in the holes of the next subjacent plate;
c. moving said uppermost plate and next subjacent plate into preselected and vertically spaced apart positions above the remainder of said plates, thereby tilting probes and causing the lower ends of said tilted probes to enter the holes of the next subjacent plate of said array of stacked plates.

1 more element

Dependencies are inferred from the claim text.

Automated test pin loading method

Life of this patent

Automated test pin loading method

Life of this patent

Abstract

Claims15