Laser beam system for micro via formation

Details Laser beam system for micro via formation Laser beam system for micro via formation

2001-03-07

2002-11-19

Heinrich, Samuel M. (Department: 1725)

Electric heating

Metal heating

By arc

Reexamination Certificate

active

06483074

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates to a via formation system and more particularly to a laser system used for forming a micro via.
2. Related Art
FIGS. 1-5
illustrate a related art method of forming a microvia over a plated through hole (PTH) of a substrate. In particular,
FIG. 1
illustrates a cross sectional view of a related art substrate
12
, having a PTH
10
formed therein. The PTH
10
includes an opening
14
and a capture pad
16
formed using conventional techniques. As illustrated in
FIG. 2
, a dielectric material
18
is deposited within the opening
14
of the PTH
10
, filling the opening
14
of the PTH
10
, and coating a lower surface
20
of the substrate
12
. A plated stud
22
is attached to a capture pad
24
of the PTH
10
, as shown in FIG.
3
.
FIG. 4
illustrates an additional step after related art
FIG. 3
wherein a dielectric material
18
B is added to a top surface
26
of the substrate
12
. A cavity
16
is formed in the dielectric material
18
B by chemical etching, drilling or other mechanical method. The plated stud
22
is required to protect the dielectric material
18
B from being removed by the chemical etching or drilling processes used during formation of the cavity
16
.
FIG. 5
illustrates related art
FIG. 4
after an object
28
, such as a microvia, is attached to the plated stud
22
.
SUMMARY OF THE INVENTION
A first general aspect of the present invention provides a laser beam system comprising:
a laser system providing a bimodal focused beam, and wherein an energy density at a centroid of the beam is at least 10 percent less than the average energy density of the beam.
A second general aspect of this invention provides an apparatus comprising:
a laser source producing a laser beam; and
a beam shaping lens for forming the laser beam into a bimodal focused beam wherein an area of reduced energy density at a centroid of the bimodal focused beam is at least 10% less than an average energy density of the bimodal focused beam.
A third general aspect of this invention provides a method comprising:
applying a focused laser beam onto a circuit board wherein the focused laser beam removes a dielectric above a surface of a capture pad of a Plated Through Hole (PTH) while maintaining the dielectric within the PTH to a substantially flush level with the surface of the capture pad.


REFERENCES:
patent: 4128752 (1978-12-01), Gravel
patent: 5055653 (1991-10-01), Funami et al.
patent: 5539175 (1996-07-01), Smith et al.
patent: 5657138 (1997-08-01), Lewis et al.
patent: 5776220 (1998-07-01), Allaire et al.
patent: 5826772 (1998-10-01), Ariglio et al.
patent: 6040552 (2000-03-01), Jain et al.
patent: 62104692 (1987-05-01), None
patent: 3052790 (1991-03-01), None
patent: 10034365 (1998-02-01), None

Affiliated with

Also associated with

Rating

Laser beam system for micro via formation does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Laser beam system for micro via formation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Laser beam system for micro via formation will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2943075