Browse Prior Art Database

Heat storage connector lead for non-contact test of solder joint

IP.com Disclosure Number: IPCOM000014794D
Original Publication Date: 2000-May-01
Included in the Prior Art Database: 2003-Jun-20
Document File: 4 page(s) / 47K

Publishing Venue

IBM

Abstract

1. Point of invention Disclosed is a new shape of connector lead. Non-contact test of solder joint is enabled with this connector lead. 2. Background It is difficult to test solder joint of surface mount type connector with grid array leads. Connector housing hides solder joint that makes visual inspection inappropriate for the solder joint (Fig-1). Open-short test by directly probing the connector lead achieves to detect the solder open failure electrically. However, tester probe may damage connector lead during the test (Fig-2).

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Heat storage connector lead for non-contact test of solder joint

1. Point of invention

 Disclosed is a new shape of connector lead.
Non-contact test of solder joint is enabled with
this connector lead.

2. Background

 It is difficult to test solder joint of surface
mount type connector with grid array leads.
Connector housing hides solder joint that makes
visual inspection inappropriate for the solder
joint (Fig-1). Open-short test by directly
probing the connector lead achieves to detect
the solder open failure electrically. However,
tester probe may damage connector lead during
the test (Fig-2).

 X-ray fluoroscope is helpful in finding solder
short between adjacent leads without physically
contacting connector leads, but not capable of
finding solder open.

Proposed connector lead shape enables damage
free and non-contact testing capable of finding
open joint.

3. Principle of invention

 As shown in Fig-3, connector consists of lead
with heat storage and housing. Connector lead
and printed circuit board copper pattern form a
thermally conductive path via good solder joint.
Heat which is given to connector lead propagates
from connector lead to copper pattern on the
printed circuit (Fig-4).

 On the other hand, heat to connector lead with
poor solder joint does not propagate to copper
pattern efficiently due to lack of thermal
conductive path (Fig-5). As a result, difference
in temperature of connector lead is observed
between good and poor solder joint after heating
connector. Non-contact test of...