Continuous mode solder jet apparatus and method

Abstract

A solder jet apparatus and method is disclosed. The solder jet apparatus is a continuous mode solder jet that includes a blanking system and raster scan system. The use of the raster scan and blanking systems allows for a continuous stream of solder to be placed anywhere on the surface in any desired X-Y plane. This allows for greater accuracy as well as greater product throughput. Additionally, with the raster scan system, repairs to existing soldered surfaces can be quickly and easily performed using a map of the defects for directing the solder to the defects.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation of application Ser. No. 10 / 616,184, filed Jul. 7, 2003, pending, which is a continuation of application Ser. No. 10 / 159,000, filed May 30, 2002, now U.S. Pat. No. 6,588,645, issued Jul. 8, 2003, which is a continuation of application Ser. No. 09 / 924,525, filed Aug. 8, 2001, now U.S. Pat. No. 6,443,350, issued Sep. 3, 2002, which is a continuation of application Ser. No. 09 / 569,215, filed May 11, 2000, now U.S. Pat. No. 6,325,271, issued Dec. 4, 2001, which is a continuation of application Ser. No. 09 / 388,032, filed Sep. 1, 1999, now U.S. Pat. No. 6,082,605, issued Jul. 4, 2000, which is a continuation of application Ser. No. 08 / 989,578, filed Dec. 12, 1997, now U.S. Pat. No. 5,988,480, issued Nov. 23, 1999.BACKGROUND OF THE INVENTION [0002] The present invention relates generally to applying solder to a substrate and, more particularly, to the selected placement of solder using a solder jet. [0003] Dep...

AI Technical Summary

Benefits of technology

The present invention is about a solder jet apparatus that can place solder anywhere on a surface in a continuous stream. It uses a raster scan system and blanking system, which allows for greater accuracy and product throughput. Additionally, it makes it easy to repair existing soldered surfaces by using a map of defects to direct the solder to the defects.

Problems solved by technology

Unfortunately, the stencils are expensive to design and produce and they wear out after repeated use.

When they wear out, solder seeps through the worn stencil areas across those areas where no solder is desired, causing shorts, or no solder is being placed where it is needed, causing a breach or open connection.

Additionally, stencils require periodic cleaning, which adds another processing step to clean the stencil as well as lessens the useful life of the stencil.

Solder balls, however, have quality control problems as their critical dimensions continue to decrease.

Further, working with solder balls is difficult because of their size and the methods needed to place them accurately.

When they fail to be placed accurately, or are missing entirely, problems occur in the resulting assembly of a semiconductor device attached to a substrate that must be corrected.

These problems include shorts or opens that must be fixed.

No easy solution yet exists for repairing missing or improperly sized solder balls after a semiconductor device has been mechanically attached in place on a substrate.

CVD does have limitations however.

These limitations include being unable to place the package directly on the surface of the printed circuit board (PCB) immediately after depositing the metal on the surface since a cooling step is typically needed.

Further, clean conditions are always necessary when using CVD, which requires expensive equipment and control.

Additionally, when clean conditions do not exist, shorts or opens in assemblies can occur that need to be repaired once they are discovered.

The ink jet technology is well established, but due to different problems associated with solder, ink jet technology is not directly applicable to solder jet technology.

Thus, applying ink jet solutions to solder jet problems is impractical.

This results in a highly inefficient system since the substrate must be stopped for each application of solder to a new location.

This also involves greater mechanical complexity since the table holding the substrate, or the solder jet apparatus itself, must be moved and aligned properly before solder can be deposited.

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