Solder deposit method on electronic packages for post-connection process

1 . A method for accurately depositing a volume of solder of a given melting point to a given height on a delineated area of given superficies on the face of an electronic component, said method comprising the steps of:

providing a slab of material having a bottom surface shaped and dimensioned for intimate contact with a zone of said face including said area, and a melting temperature substantially higher than said melting point;

drilling through said slab at least one bore substantially perpendicular to said bottom surface and having a lower opening in said bottom surface falling within said area when said bottom surface is in contact with said zone;

carving into said bottom surface and around said bottom opening, a cavity at least as deep as said height and shaped to be congruent with said delineated area;

intimately contacting said face with said slab's bottom surface;

inserting into said bore, a particle of said solder, said particle having a volume substantially equal to a product of said superficies times said height; and

exposing said component and slab to a temperature at least equal to said melting point; whereby said particle of solder melts, flows and deposits accurately over said delineated area.

2 . The method of claim 1 , wherein said delineated area is elongated about an axis;

said step of drilling comprises drilling a plurality of said bores leading to spaced-apart openings along a line parallel to said axis within said cavity; and

said step of inserting comprises inserting at least one of said particles in each of said bores, said particles having a cumulative volume equal to said product.

3 . The method of claim 1 , wherein said material comprises high density graphite.

4 . The method of claim 3 , wherein said solder comprise a gold alloy.

5 . The method of claim 4 , wherein said alloy is Au/Sn.

6 . The method of claim 2 , wherein said delineated area comprises an electronic package lead attachment area on a lead frame.

7 . The method of claim 2 , wherein said delineated area comprises a marginal, peripheral area on an electronic package lid.

8 . A device for accurately depositing a volume of solder to a given height on a limited area on the face of an electronic component which comprises:

a slab of material having a top surface, and a bottom surface shaped and dimensioned for conformingly resting upon a zone of said face including said area;

said slab having at least one bore having a upper opening in said top surface and a lower opening in said bottom surface, said lower opening being positioned above said area when said bottom surface rests upon said zone; and

said slab further having a cavity in said bottom surface and around said bottom opening, said cavity having a depth greater than said height, and being shaped to congruently fit over said limited area.

9 . The device of claim 8 , which comprises a plurality of said bores having lower openings positioned at regularly spaced-apart locations along a line.

10 . The device of claim 9 , wherein said limited area comprises at least one lead connection spot on an electronic package lead frame.

11 . The device of claim 9 , wherein said limited area comprises a marginal, peripheral area on an electronic package lid.

12 . The device of claim 9 , which further comprises a small volume of solder inserted in each of said bores.

13 . The device of claim 12 , wherein said volume is obtained by dividing the amount of solder to be deposited by the number of bores.

14 . The device of claim 13 , wherein each of said volume consists of a particle of solder.

15 . The device of claim 14 , wherein said particle of solder has a shape selected from the group consisting of a sphere, a cylinder, and a quadranglarly sided shape.