Apparatus and method for filling a ball grid array

• US 6,325,272 B1
• Filed: 10/09/1998
• Issued: 12/04/2001
• Est. Priority Date: 10/09/1998
• Status: Expired due to Fees

• Current Assignee: On Target Systems & Services Incorporated
• Original Assignee: Robotic Vision Systems, Inc. (Acuity Brands, Inc.)
• Inventors: May, John, Provencher, Timothy J.
• Primary Examiner(s): Elve, M. Alexandra
• Assistant Examiner(s): STONER, KILEY SHAWN
• Application Number:
  US09/169,851
• Time in Patent Office: 1,152 Days
• Field of Search: 228/41, 228/245, 228/180.22, 228/246, 228/6.1, 228/6.2, 228/33
• US Class Current: 228/41
• CPC Class Codes: B23K 3/0623 for shaped solder piece feeding, e.g. preforms, bumps, balls, pellets, droplets
• CPC Class Codes: H01L 21/4853 Connection or disconnection of other leads to or from a metallisation, e.g. pins, wires, bumps
• CPC Class Codes: H01L 2224/11003 for holding or transferring the bump preform
• CPC Class Codes: H01L 2224/11334 using preformed bumps
• CPC Class Codes: H01L 2924/01322 Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H05K 2201/0116 Porous, e.g. foam
• CPC Class Codes: H05K 2203/0113 Female die used for patterning or transferring, e.g. temporary substrate having recessed pattern
• CPC Class Codes: H05K 2203/0338 Transferring metal or conductive material other than a circuit pattern, e.g. bump, solder, printed component affixing a prefabricated conductor pattern H05K3/20
• CPC Class Codes: H05K 2203/041 Solder preforms in the shape of solder balls soldering leadless components having an array of bottom contacts H05K3/3436
• CPC Class Codes: H05K 2203/081 Blowing of gas, e.g. for cooling or for providing heat during solder reflowing
• CPC Class Codes: H05K 2203/082 Suction, e.g. for holding solder balls or components
• CPC Class Codes: H05K 3/3478 Applying solder preforms; Transferring prefabricated solder patterns

Abstract

An apparatus for placing solder balls in a pattern on a substrate, e.g., to form a ball grid array, the apparatus comprising a template having a first plane, a second plane, and a plurality of holes passing substantially orthogonally through the first and second planes parallel to an axis and corresponding in location to the pattern. Each of the holes is slightly larger than a solder ball diameter. The apparatus also including a porous base having first and second planes, wherein the first plane of the base contacts the second plane of the template. The base is permeable to a fluid in a first direction from the first plane of the template toward the second plane of the base. The apparatus further includes a fluid controller in fluid communication with the base for selectively causing the fluid to pass through the holes and through the base in the first direction to force the solder balls into the holes. The base optionally but preferably comprises a carbon material, such as a carbon graphite material, and the fluid preferably comprises air.

Claims

1. An apparatus for placing solder balls in a pattern on a substrate, each of the solder balls having a solder ball diameter, the apparatus comprising:

a template having a first plane, a second plane, and a plurality of holes passing substantially orthogonally through the first and second planes parallel to an axis and corresponding in location to the pattern, each of the holes being slightly larger than the solder ball diameter;

a porous base having first and second planes, the first plane of the base contacting the second plane of the template, the base being permeable to a fluid in a first direction from the first plane of the template toward the second plane of the base; and

a fluid controller in fluid communication with the base for selectively causing the fluid to pass through the holes and through the base in the first direction to force the solder balls into the holes,

wherein the base comprises a carbon material.

2. An apparatus as recited in claim 1, wherein the fluid comprises air.

3. An apparatus as recited in claim 1, wherein:

each of the holes includes a first section adjacent to the first plane of the template, the first section extending axially in the first direction from the first plane of the template a distance of at least about the solder ball diameter; and

each of the holes also includes a second section extending from the first section of that hole to the second plane of the template, the second section having an opening at the first section which is less than the solder ball diameter.

4. An apparatus as recited in claim 1, wherein:

the base is permeable to the fluid in a second direction opposite to the first direction; and

the fluid controller has a flow director which selectively causes the fluid to pass through the holes and through the base in the second direction to force the solder balls out of the holes at the first plane of the template.

5. An apparatus for placing solder balls in a pattern on a substrate, each of the solder balls having a solder ball diameter, the apparatus comprising:

a template having a first plane, a second plane, and a plurality of holes passing substantially orthogonally through the first and second planes parallel to an axis and corresponding in location to the pattern, each of the holes being slightly larger than the solder ball diameter;

a porous base having first and second planes, the first plane of the base contacting the second plane of the template, the base being permeable to a fluid in a first direction from the first plane of the template toward the second plane of the base;

a fluid controller in fluid communication with the base for selectively causing the fluid to pass through the holes and through the base in the first direction to force the solder balls into the holes; and

a backing surface contacting selected portions of the second plane of the base and defining a substantially sealed cavity between the second plane of the base and the backing surface, and wherein the fluid controller is operatively coupled to, and in fluid communication with, the cavity.

6. An apparatus for placing solder balls in a pattern on a substrate, each of the solder balls having a solder ball diameter, the apparatus comprising:

a template having a first plane, a second plane, and a plurality of holes passing substantially orthogonally through the first and second planes parallel to an axis and corresponding in location to the pattern, each of the holes being slightly larger than the solder ball diameter;

a porous base having first and second planes, the first plane of the base contacting the second plane of the template, the base being permeable to a fluid in a first direction from the first plane of the template toward the second plane of the base; and

a fluid controller in fluid communication with the base for selectively causing the fluid to pass through the holes and through the base in the first direction to force the solder balls into the holes,

wherein;

the template comprises a metallic material; and

the apparatus further includes a magnet disposed opposite the base with respect to the template for magnetically attracting the second plane of the template toward the first plane of the base.

7. An apparatus for placing solder balls in a pattern on a substrate, each of the solder balls having a solder ball diameter, the apparatus comprising:

a template having a first plane, a second plane, and a plurality of holes passing substantially orthogonally through the first and second planes parallel to an axis and corresponding in location to the pattern, each of the holes being slightly larger than the solder ball diameter;

a porous base having first and second planes, the first plane of the base contacting the second plane of the template, the base being permeable to a fluid in a second direction from the second plane of the base toward the first plane of the template; and

a fluid controller in fluid communication with the base for selectively causing the fluid to pass through the holes in the second direction to force the solder balls out of the holes,

wherein the base comprises a carbon material.

8. An apparatus as recited in claim 7, wherein the fluid comprises air.

9. An apparatus as recited in claim 7, wherein:

each of the holes includes a first section adjacent to the first plane of the template, the first section extending in the first direction from the first plane of the template toward the second plane of the template a distance of at least about the solder ball diameter, and

each of the holes also includes a second section extending from the first section of that hole to the second plane of the template, the second section having an opening at the first section which is less than the solder ball diameter.

10. An apparatus for placing solder balls in a pattern on a substrate, each of the solder balls having a solder ball diameter, the apparatus comprising:

a template having a first plane, a second plane, and a plurality of holes passing substantially orthogonally through the first and second planes parallel to an axis and corresponding in location to the pattern, each of the holes being slightly larger than the solder ball diameter;

a porous base having first and second planes, the first plane of the base contacting the second plane of the template, the base being permeable to a fluid in a second direction from the second plane of the base toward the first plane of the template;

a fluid controller in fluid communication with the base for selectively causing the fluid to pass through the holes in the second direction to force the solder balls out of the holes; and

a backing surface contacting selected portions of the second plane of the base and defining a substantially sealed cavity between the second plane of the base and the backing surface, and wherein the fluid controller is operatively coupled to, and in fluid communication with, the cavity.

11. An apparatus for placing solder balls in a pattern on a substrate, each of the solder balls having a solder ball diameter, the apparatus comprising:

a template having a first plane, a second plane, and a plurality of holes passing substantially orthogonally through the first and second planes parallel to an axis and corresponding in location to the pattern, each of the holes being slightly larger than the solder ball diameter;

a porous base having first and second planes, the first plane of the base contacting the second plane of the template, the base being permeable to a fluid in a second direction from the second plane of the base toward the first plane of the template; and

a fluid controller in fluid communication with the base for selectively causing the fluid to pass through the holes in the second direction to force the solder balls out of the holes,

wherein;

the template comprises a metallic material; and

the apparatus further includes a magnet positioned opposite the base from the template for magnetically attracting the second plane of the template toward the first plane of the base.

12. An apparatus for placing solder balls in a pattern on a substrate, each of the solder balls having a solder ball diameter, the apparatus comprising:

a template having a first plane, a second plane, and a plurality of holes passing substantially orthogonally through the first and second planes parallel to an axis and corresponding in location to the pattern, each of the holes being slightly larger than the solder ball diameter;

a porous base having first and second planes, the first plane of the base contacting the second plane of the template, the base being permeable to a fluid in a first direction from the first plane of the template toward the second plane of the base and the base being permeable to the fluid in a second direction from the second plane of the base toward the first plane of the template; and

a fluid controller in fluid communication with the base for selectively causing the fluid to pass through the holes and through the base in at least one of the first and second directions, the fluid controller when causing fluid to pass through the holes in the first direction thereby forcing the solder balls into the holes, and the fluid controller when causing the fluid to pass through the holes in the second direction thereby forcing the solder balls out of the holes,

wherein the base comprises a carbon material.

13. An apparatus for placing solder balls in a pattern on a substrate, each of the solder balls having a solder ball diameter, the apparatus comprising:

a template having a first plane, a second plane, and a plurality of holes passing substantially orthogonally through the first and second planes parallel to an axis and corresponding in location to the pattern, each of the holes being slightly larger than the solder ball diameter;

a porous base having first and second planes, the first plane of the base contacting the second plane of the template, the base being permeable to a fluid in a first direction from the first plane of the template toward the second plane of the base;

a fluid controller in fluid communication with the base for selectively causing the fluid to pass through the holes and through the base in the first direction to force the solder balls into the holes; and

a backing surface contacting selected portions of the second plane of the base and defining a substantially sealed cavity between the second plane of the base and the backing surface, and wherein the fluid controller is operatively coupled to, and in fluid communication with, the cavity,

wherein the cavity comprises a plurality of individual chambers, each of the chambers being associated with a region or other subset of the holes.

14. An apparatus as recited in claim 13, wherein the backing surface comprises a plurality of ribs defining the individual chambers.

15. An apparatus for placing solder balls in a pattern on a substrate, each of the solder balls having a solder ball diameter, the apparatus comprising:

a template having a first plane, a second plane, and a plurality of holes passing substantially orthogonally through the first and second planes parallel to an axis and corresponding in location to the pattern, each of the holes being slightly larger than the solder ball diameter;

a porous base having first and second planes, the first plane of the base contacting the second plane of the template, the base being permeable to a fluid in a second direction from the second plane of the base toward the first plane of the template;

a fluid controller in fluid communication with the base for selectively causing the fluid to pass through the holes in the second direction to force the solder balls out of the holes; and

a backing surface contacting selected portions of the second plane of the base and defining a substantially sealed cavity between the second plane of the base and the backing surface, and wherein the fluid controller is operatively coupled to, and in fluid communication with, the cavity,

wherein the cavity comprises a plurality of individual chambers, each of the chambers being associated with a region or other subset of the holes.

16. An apparatus as recited in claim 15, wherein the backing surface comprises a plurality of ribs defining the individual chambers.