IT3/IT5
Connector System
T
IPS FOR
SMT
A
SSEMBLY
Document Number:
ETAD-F0458
Revision 3.10
Page
58
of
73
Voids:
Are small pockets of gas
tha t get trapped in solder joints. There are many di fferent
types of voids and possible causes , but the onl y type tha t can be addressed through reflow
profiling a re produced by solder pas te and referred to as
process voids.
E
xc
e
ss
iv
e
V
o
id
in
g
Possible Cause
Suggested Action
Process voids, volatiles in solder
pas te did not ha ve enough
time/temp to outgas
Increase soak time or tempera ture; consul t
solder pas te manufa cturer’s guidelines
Voids in center of ea ch ball
Verify tha t the lighter a reas in the centers a re
pins and adjus t the inspection routine (see
section on false calls)
Mi crovoids , a t the PWB interfa ce
Conta ct PWB supplier
Solder in Vias:
If
solder
is detected
in a via
, i t has likel y been ta ken from a neighboring joint,
lea ving that
joint with insufficient solder
.
S
o
ld
e
r
in
V
ia
Possible Cause
Suggested Action
Poor solder paste pri nt
Check pas te print quali ty
Da maged solder mask dam
Inspect mask between pads and vias for
fla king or other signs of poor adhesion
11.4 X-Ray Inspection
False Calls: Automated X-ray Inspection (AXI)
is an effective way to screen for defects, but
depending on the specific equipment of programs, can sometimes return false failures.
A
X
I
Fa
ls
e
C
a
lls
Failure Mode
Suggested Action
Voids in center of every
ball
At certain x-ra y settings, the pins can appea r as
lightened a reas in the center of each ball (see
exa mple below). Modi fy inspection routine.
Shorts detected when
they do not exis t
Check for Head-In-Pillow defect mode (see example
below)
Nov.1.2022 Copyright 2022 HIROSE ELECTRIC CO., LTD. All Rights Reserved.
