U.S. patent application number 09/956958 was filed with the patent office on 2002-01-31 for ic chip tester with heating element for preventing condensation.
This patent application is currently assigned to Advantest Corporation. Invention is credited to Kiyokawa, Toshiyuki, Kojima, Akio, Takahashi, Hiroyuki.
Application Number | 20020011863 09/956958 |
Document ID | / |
Family ID | 26487168 |
Filed Date | 2002-01-31 |
United States Patent
Application |
20020011863 |
Kind Code |
A1 |
Takahashi, Hiroyuki ; et
al. |
January 31, 2002 |
IC chip tester with heating element for preventing condensation
Abstract
An IC chip testing apparatus provided with an IC socket 206 to
which an IC chip is brought into electrical contact, a printed
circuit board 205 with one terminal which is electrically connected
to a terminal of a test head and with another terminal which is
electrically connected to a terminal of the IC socket 206, and a
heating element 208 provided at the printed circuit board 205. The
IC chip testing apparatus may be provided with a socket 320 to
which an IC chip to be tested is detachably mounted; a socket guide
382 holding the socket 320; a chamber 306 to the opening 392 of
which the socket guide 382 is attached so that an IC chip mounting
opening of the socket 320 faces inside the chamber and able to
maintain the inside at a predetermined state less than ordinary
temperature; a printed circuit board 400 which is electrically
connected to a terminal of the socket 320 and which is arranged at
the outside of the chamber opening 392 of the chamber 6; and a
heating board 406 which is provided around the chamber opening 392
of the chamber 306 and heats the printed circuit board 400 by heat
conduction. It is possible to prevent condensation of the printed
circuit board which tends to occur at the time of application of a
low temperature and radiation of heat from the IC socket which
tends to occur at the time of application of a high temperature or
low temperature.
Inventors: |
Takahashi, Hiroyuki; (Tokyo,
JP) ; Kojima, Akio; (Tokyo, JP) ; Kiyokawa,
Toshiyuki; (Tokyo, JP) |
Correspondence
Address: |
BIRCH STEWART KOLASCH & BIRCH
PO BOX 747
FALLS CHURCH
VA
22040-0747
US
|
Assignee: |
Advantest Corporation
|
Family ID: |
26487168 |
Appl. No.: |
09/956958 |
Filed: |
September 21, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09956958 |
Sep 21, 2001 |
|
|
|
09328499 |
Jun 9, 1999 |
|
|
|
6313653 |
|
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Current U.S.
Class: |
324/750.03 ;
324/756.02; 324/762.02 |
Current CPC
Class: |
G01R 31/2867 20130101;
G01R 31/2877 20130101; G01R 31/2865 20130101; G01R 1/0433 20130101;
G01R 31/2863 20130101; G01R 31/2806 20130101; G01R 31/01
20130101 |
Class at
Publication: |
324/760 |
International
Class: |
G01R 031/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 9, 1998 |
JP |
10-160772 |
Jul 17, 1998 |
JP |
10-203605 |
Claims
1. An electronic device testing apparatus comprising: a socket to
which an electronic device is brought into electrical contact, a
circuit board with one terminal which is electrically connected to
a terminal of a test head and with another terminal which is
electrically connected to a terminal of the socket, and a heating
element provided at the circuit board.
2. The electronic device testing apparatus as set forth in claim 1,
wherein the heating element is on the circuit board.
3. The electronic device testing apparatus as set forth in claim 1,
wherein the printed circuit board is provided in proximity to the
socket.
4. An electronic device testing apparatus comprising: a socket to
which an electronic device to be tested is detachably mounted; a
socket guide holding the socket; a chamber to the opening of which
said socket guide is attached so that an electronic device mounting
opening of the socket faces inside the chamber and able to maintain
the inside at a predetermined state less than ordinary temperature;
a circuit board which is electrically connected to a terminal of
the socket and which is arranged at the outside of the chamber
opening of the chamber; and a heating board which is provided
around the chamber opening of the chamber and heats the circuit
board by heat conduction.
5. The electronic device testing apparatus as set forth in claim 4,
wherein the heating board is attached around the chamber opening of
the chamber through a mounting base.
6. The electronic device testing apparatus as set forth in claim 5,
wherein the socket guide is detachably attached to the mounting
base.
7. The electronic device testing apparatus as set forth in claim 4,
wherein the circuit board contacts the heating board through a
circuit board holding ring so as to form a first air-tight space at
the circuit board side of the socket guide.
8. The electronic device testing apparatus as set forth in claim 7,
wherein a first seal member is interposed at the portion of contact
of the circuit board holding ring and the heating board.
9. The electronic device testing apparatus as set forth in claim 7,
wherein a second seal member is interposed at the portion of
contact of the circuit board and the circuit board holding
ring.
10. The electronic device testing apparatus as set forth in claim
4, wherein at the anti-chamber side of the circuit board is
attached a reinforcing plate so as to form a second air-tight space
with the circuit board and the reinforcing plate is provided with a
drying nozzle for feeding dry gas into the second air-tight
space.
11. The electronic device testing apparatus as set forth in claim
10, wherein the circuit board is electrically connected through a
plurality of movable pins on a movable pin holding ring projecting
out in a ring-shape from a test head sending test drive signals to
the electronic device mounted at the socket, the reinforcing plate
is provided at the inside of the movable pin holding ring, and the
second air-tight space formed between the circuit board and the
reinforcing plate is made air-tight by a seal ring provided at the
inside of the movable pin holding ring.
12. The electronic device testing apparatus as set forth in claim
4, wherein the circuit board is brought in contact with the heating
board through a seal member so as to form a first air-tight space
at the circuit board side of the socket guide.
13. The electronic device testing apparatus as set forth in claim
7, wherein the heating board is formed with a drying passage for
feeding dry gas into the first air-tight space.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an electronic device
testing apparatus for testing semiconductor integrated circuit
devices (hereinafter abbreviated as "ICs") and other electronic
devices, more particularly relates to an electronic device testing
apparatus able to prevent condensation on the printed circuit board
easily occurring during the application of a low temperature and
the radiation of heat from a socket easily occurring during the
application of a high temperature or low temperature.
[0003] 2. Description of the Related Art
[0004] A handler of an IC chip testing apparatus or other
electronic device testing apparatus conveys a large number of IC
chips held on a tray into it, brings them into electrical contact
with a test head in a state with a high temperature or low
temperature thermal stress applied, and has them tested at the IC
testing apparatus. When the tests are completed, the IC chips are
conveyed out from the test head and reloaded on trays in accordance
with the results of the test so as to sort them into categories
such as good chips and defective chips.
[0005] The handlers of the related art may be roughly classified by
type of application of temperature into chamber type handlers which
reload IC chips to be tested on a special tray called a "test
tray", convey it into a temperature application chamber to bring
the IC chips to a predetermined temperature, then push the IC chips
against the test head in the state loaded on the test tray and heat
plate type handlers which load IC chips on a heat plate (also
called a "hot plate") to apply a high temperature thermal stress to
them, then pick up a several number of the IC chips at a time by
suction heads and convey them to the test head against which they
are then pushed.
[0006] In both types of handlers, the test head against which an IC
chip is pushed is provided with an IC socket having contact pins
and one or more printed circuit boards (mother board, daughter
boards, sub-boards, etc.) electrically connected to the IC socket.
The printed circuit boards are connected to input-output terminals
of the test head. The IC chip is tested by the testing apparatus
through the test head.
[0007] When applying a high temperature or low temperature thermal
stress in a chamber type handler, however, while the IC chip is
given a high temperature or low temperature in the chamber, when
the IC chip is brought into contact with the IC socket, the heat is
dissipated from there and therefore the problem arises of a
fluctuation in the applied temperature during the tests. In
particular, in a test head of a type directly connected to the IC
socket and mother board and other printed circuit boards, the heat
conducted to the IC socket is easily radiated to the printed
circuit boards. When applying a low temperature thermal stress,
further, condensation occurs at the printed circuit boards and
therefore there was a danger of a detrimental effect on the signal
characteristics.
[0008] Also in a heat plate type handler, while the IC chip is
given a high temperature, when the IC chip is brought into contact
with the IC socket, the heat is dissipated from there and therefore
the problem arises of a fluctuation in the applied temperature
during the tests in the same way.
[0009] Also in a test head of a type where a spacing frame is
arranged between the IC socket and thee print circuit board, when
the IC chip is given an extremely low temperature stress of about
-50.degree. C., the low temperature conducts through the coaxial
cable and the daughter board connecting the IC socket and the print
circuit board and therefore there is a danger that condensation
occurs at the printed circuit boards.
[0010] Further, in a testing apparatus testing an IC chip inside a
chamber in this way, since the chip mounting opening of the socket
in which the IC chip is mounted faces inside the chamber and the
terminals of the socket are connected to the test head through a
printed circuit board outside the chamber (performance board), the
structure is one susceptible to entry of outside air behind the
socket. Therefore, there is the problem of a susceptibility to
condensation at the printed circuit board behind the socket or the
test head. If condensed moisture flows to electrical contact
portions, there is the danger of causing short-circuits at the
electrical wiring. Therefore, condensation must be prevented at all
costs.
[0011] Accordingly, in the testing apparatuss of the related art, a
large distance was set between the socket and the printed circuit
boards and a spacing frame or other heat insulating structure was
arranged between them to prevent condensation at the printed
circuit boards behind the socket and the test head.
[0012] If a large distance is set between the socket and the
printed circuit boards in this way, however, the electrical path
from the socket to the printed circuit boards (electrical cables
etc.) becomes longer and noise more easily occurs, so the
reliability of the tests is liable to drop. Further, it is not
possible to use general purpose printed circuit board holding rings
and other parts and it is necessary to prepare special spacing
frames and other heat insulating structures, so the manufacturing
costs rise.
SUMMARY OF THE INVENTION
[0013] A first object of the present invention is to provide an
electronic device testing apparatus which can prevent the
condensation at the printed circuit boards which easily occurs at
the time of application of a low temperature and the radiation of
heat from the socket which easily occurs at the time of application
of a high temperature or low temperature.
[0014] A second object of the present invention is to provide an
electronic device testing apparatus which can, by a relatively
inexpensive structure, effectively prevent the occurrence of
condensation behind a socket where an electronic device is mounted
for testing.
[0015] To achieve the first object of the present invention,
according to a first aspect of the present invention, there is
provided an electronic device testing apparatus comprising a socket
to which an electronic device is brought into electrical contact, a
circuit board with one terminal which is electrically connected to
a terminal of a test head and with another terminal which is
electrically connected to a terminal of the socket, and a heating
element provided at the circuit board.
[0016] The heating element is preferably printed on the circuit
board.
[0017] The printed circuit board is preferably provided in
proximity to the socket.
[0018] In the electronic device testing apparatus of the first
aspect of the present invention, since the printed circuit board is
provided with a heating element, it is possible to heat the printed
circuit board in accordance with the temperature to be applied so
as to reduce the temperature gradient between the electronic device
and the printed circuit board and therefore suppress radiation of
heat from the socket to the printed circuit board. Further, since
the heating element also serves as an auxiliary means for
application of a high temperature, it is possible to shorten the
time for raising the temperature and possible to expect an
improvement in the throughput of the electronic device testing
apparatus. On the other hand, by heating the printed circuit board
at the time of application of a low temperature, it is possible to
prevent condensation from occurring at the printed circuit
board.
[0019] In the present invention, the heating element is not
particularly limited in where it is provided, but should at least
be provided around the socket when applying a high temperature.
This is since it is sufficient to keep heat from being conducted to
the printed circuit board through the socket. As opposed to this,
when applying a low temperature, it is desirable to provide the
heating element substantially across the entire area of the printed
circuit board. This is because condensation occurs when the ambient
temperature drops and such condensation must be prevented across
the entire area of the printed circuit board.
[0020] In the electronic device testing apparatus of the first
aspect of the present invention, the method of provision of the
heating element is not particularly limited. A heating unit may be
mounted on the printed circuit board or the heating element may be
printed on the printed circuit board. As the method of printing the
heating element on the printed circuit board, the method of forming
a pattern by etching, the method of printing planar nichrome
wiring, etc. may be mentioned. By printing the heating element on
the printed circuit board, interference etc. with other components
connected on the printed circuit board is eliminated and the
printed circuit board can be placed even in narrow spaces.
[0021] In the electronic device testing apparatus of the first
aspect of the present invention, the relative arrangement of the
socket and the printed circuit board is not particularly limited.
The invention may be applied to not only a test head of the type
where the socket is substantially directly connected to the printed
circuit board, but also a test head of the type where the socket is
connected to the printed circuit board through a socket board,
spacing frame, etc. In particular, as explained above, the effect
of prevention of radiation of heat and prevention of condensation
becomes greater when the printed circuit board is provided in
proximity to the socket.
[0022] To achieve the second object of the present invention,
according to a second aspect of the present invention, there is
provided an electronic device testing apparatus comprising a socket
to which an electronic device to be tested is detachably mounted; a
socket guide holding the socket; a chamber to the opening of which
said socket guide is attached so that an electronic device mounting
opening of the socket faces inside the chamber and able to maintain
the inside at a predetermined state less than ordinary temperature;
a circuit board which is electrically connected to a terminal of
the socket and which is arranged at the outside of the chamber
opening of the chamber; and a heating board which is provided
around the chamber opening of the chamber and heats the printed
circuit board by heat conduction.
[0023] In the present invention, the heating board is not
particularly limited, but preferably is a board containing a rubber
heater or other planar heating element. Further, the electronic
device tested by the testing apparatus of the present invention is
not particularly limited, but an IC chip is shown as a preferable
example.
[0024] The heating board is preferably provided around the chamber
opening of the chamber through a mounting base.
[0025] The socket guide is preferably detachably mounted to the
mounting base.
[0026] The circuit board preferably contacts the heating board
through a circuit board holding ring so as to form a first
air-tight space at the circuit board side of the socket guide. Note
that in the present invention, the "air-tight space" is not
necessarily a completely air-tight space and may also communicate
with the outside through some space. An air-tightness of an extent
enabling a dry gas to be sealed in the space is sufficient.
[0027] A first seal member is preferably interposed at the portion
of contact of the circuit board holding ring and the heating
board.
[0028] A second seal member is preferably interposed at the portion
of contact of the circuit board and the circuit board holding
ring.
[0029] At the anti-chamber side of the circuit board is preferably
attached a reinforcing plate so as to form a second air-tight space
with the circuit board and the reinforcing plate is preferably
provided with a drying nozzle for feeding dry gas into the second
air-tight space. Note that as the dry gas, dry air is
preferable.
[0030] Preferably, the circuit board is electrically connected
through a plurality of movable pins on a movable pin holding ring
projecting out in a ring-shape from a test head sending test drive
signals to the electronic device mounted at the socket, the
reinforcing plate is provided at the inside of the movable pin
holding ring, and the second air-tight space formed between the
circuit board and the reinforcing plate is made air-tight by a seal
ring provided at the inside of the movable pin holding ring.
[0031] The circuit board may be brought in contact with the heating
board through a seal member so as to form a first air-tight space
at the circuit board side of the socket guide.
[0032] The heating board is preferably formed with a drying passage
for feeding dry gas into the first air-tight space.
[0033] In the electronic device testing apparatus according to the
second aspect of the present invention, since a heating board is
provided around the chamber opening of the chamber with an inside
cooled to a temperature less than ordinary temperature and the
printed circuit board is heated by heat conduction, the printed
circuit board positioned behind the socket is heated to a
temperature above the dew point of the ambient gas. Therefore, it
is possible to effectively prevent the occurrence of condensation
at the printed circuit board behind the socket and the test
head.
[0034] Further, in the electronic device testing apparatus
according to the second aspect of the present invention, since no
special spacing frame or other heat insulating structure is
employed, it is possible to use general purpose printed circuit
board holding rings and other parts and the manufacturing costs
become lower. Further, since it is no longer necessary to separate
the printed circuit board and the socket by more than the necessary
amount of distance, the electrical path from the socket to the
printed circuit board (electrical cables etc.) can be shortened,
greater resistance to noise can be obtained, and the reliability of
the tests can be improved.
[0035] Further, in the present invention, by bringing the printed
circuit board into contact with the heating board through a printed
circuit board holding ring so as to form a first air-tight space at
the printed circuit board side of the socket guide and forming in
the heating board a drying passage for feeding dry gas in the first
air-tight space, the first air-tight space can be filled with a dry
gas. This enables condensation behind the socket guide to be
further effectively prevented.
[0036] Further, in the present invention, by attaching a
reinforcing plate at the anti-chamber side of the printed circuit
board so as to form a second air-tight space with the printed
circuit board and attaching to the reinforcing plate a drying
nozzle for feeding dry gas into the second air-tight space, the
second air-tight space can also be filled with a dry gas. This
enables condensation behind the printed circuit board as well to be
further effectively prevented.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] These and other objects and features of the present
invention will become more apparent from the following description
of the preferred embodiments given with reference to the attached
drawings, in which:
[0038] FIG. 1 is a plan view of an IC chip testing apparatus
according to a first embodiment of the present invention;
[0039] FIG. 2 is a sectional view along the line II-II of FIG.
1;
[0040] FIG. 3 is a sectional view showing details of a contact
section of a test head of FIG. 2;
[0041] FIG. 4 is a plan view of a socket guide of FIG. 3;
[0042] FIG. 5 is plan view of a performance board of FIG. 3;
[0043] FIG. 6 is a sectional view along the line VI-VI of FIG.
5;
[0044] FIG. 7 is a plan view of a performance board of an IC chip
testing apparatus according to another embodiment of the present
invention;
[0045] FIG. 8 is a sectional view of a test head of an IC chip
testing apparatus according to another embodiment of the present
invention;
[0046] FIG. 9 is a sectional view of a test head of an IC chip
testing apparatus according to still another embodiment of the
present invention;
[0047] FIG. 10 is a schematic overall view of an IC chip testing
apparatus according to a first embodiment of the present
invention;
[0048] FIG. 11 is a sectional view of key parts of the IC chip
testing apparatus;
[0049] FIG. 12 is a sectional view of key parts showing the state
before attachment of the socket guide shown in FIG. 11 to the
chamber side; and
[0050] FIG. 13 is a sectional view of key parts of the IC chip
testing apparatus according to another embodiment of the present
invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0051] Preferred embodiments of the present invention will be
discussed in detail below:
[0052] First Embodiment
[0053] As shown in FIG. 1, the IC chip tester apparatus 1
corresponding to the electronic device tester apparatus of the
present embodiment is comprised of a handler 10, test head 20, and
tester 30. The test head 20 and the tester 30 are connected via a
cable 40. The pre-test IC chips carried on a feed tray 102 of the
handler 10 are pushed against the contact sections of the test head
20 by X-Y conveyors 104, 105, the IC chips are tested through the
test head 20 and the cable 40, and then the IC chips finished being
tested are placed onto sorting trays 103 in accordance with the
results of the tests.
[0054] The handler 10 is provided with a board 109. On the board
109 are provided conveyors 104, 105 for the IC chips to be tested,
explained later. The board 109 further is formed with an opening
110. As shown in FIG. 2, IC chips are pushed against contact
sections 201 of the test head 20 arranged behind the handler 10
through this opening 110.
[0055] The board 109 of the handler 10 is provided with two X-Y
conveyors 104, 105. Among these, the X-Y conveyor 104 is configured
to be able to move a movable head 104c from a region of the sorting
trays 103 to feed trays 102, empty trays 101, the heat plate 106,
and two buffer sections 108, 108 by rails 104a, 104b provided along
its X-direction and Y-direction. Further, the movable head 104c is
designed to be able to be moved in the Z-direction (that is, the
vertical direction) by a not shown Z-axial actuator. Two IC chips
to be tested can be picked up, conveyed, and released at one time
by two suction heads 104d provided at the movable head 104c.
[0056] As opposed to this, the X-Y conveyor 105 is configured to be
able to move a movable head 105c between the two buffer sections
108, 108 and the test head 20 by rails 105a, 105b provided along
its X-direction and Y-direction. Further, the movable head 105c is
designed to be able to be moved in the Z-direction (that is, the
vertical direction) by a not shown Z-axial actuator. Two IC chips
can be picked up, conveyed, and released at one time by two suction
heads 105d provided at the movable head 105c.
[0057] The two buffer sections 108, 108 move back and forth between
the operating regions of the two X-Y conveyors 104, 105 by the
rails 108a and not shown actuators. The buffer section 108 at the
top in the figure works to convey IC chips conveyed from the heat
plate 106 to the test head 20, while the buffer section 108 at the
bottom works to eject the IC chips finished being tested at the
test head 20. The provision of these two buffer sections 108, 108
enables the two X-Y conveyors 104, 105 to operate simultaneously
without interfering with each other.
[0058] In the operating region of the X-Y conveyor 104 are provided
a feed tray 102 on which IC chips to be tested are loaded, four
sorting trays 103 on which tested ICs are stored sorted into
categories according to the test results, and an empty tray 101.
Further, a heat plate 106 is provided at a position in proximity to
the buffer section 108.
[0059] The heat plate 106 is for example a metal plate and is
formed with a plurality of indentations into which IC chips are
dropped. Pre-test IC chips from the feed tray 102 are transferred
to the indentations 106a by the X-Y conveyor 104. The heat plate
106 is a heat source for applying a predetermined thermal stress to
the IC chips. The IC chips are heated to a predetermined
temperature by the heat plate 106, then pushed against the contact
sections of the test head 20 through one of the buffer sections
108.
[0060] The top (contact sections 201) of the test head 20 according
to the present embodiment, as shown in FIG. 3, is provided with
frog rings 202 electrically connected to the test head 20 through
cables 203. Each of the frog rings 202 has a plurality of pogo pins
204 (contact pins having movable pins supported to be able to
advance and retract in the axial direction by springs and biased in
a direction where the movable pins project out by the springs)
provided facing upward in a ring. A performance board 205 is
provided with terminals contacting the pogo pins 204. Further, two
IC sockets 206, 206 are mounted to the top of the performance board
205 (corresponding to the printed circuit board according to the
present invention) in an electrically connected state. Due to this,
the contact pins (not shown) of the IC sockets 206 are electrically
connected to the test head 20 body through the performance board
205, pogo pins 204, frog rings 202, and cables 203.
[0061] Note that each of the two IC sockets 206 has fitted into it
a socket guide 207 having an opening 207a and guide pins 207b as
shown in FIG. 4 and that an IC chip held by a suction head 105d is
pushed against an IC socket 206 through the opening of the socket
guide 207. At this time, the guide pins 207b provided at the socket
guide 207 are inserted into the guide holes 105d1 formed in the
suction head 105d, whereby the IC chip and IC socket 206 are
positioned with respect to each other.
[0062] In particular, the performance board 205 according to the
present embodiment, as shown in FIG. 5 and FIG. 6, is provided with
a heating element 208 in the area around where an IC socket 206 or
socket guide 207 is attached. The heating element 208, as shown in
FIG. 6, may be formed as any layer in the multiple layer structure
of the printed circuit board comprising the performance board 205.
In the figure, a heating element layer 208 is formed at the top
surface of the performance board 205 and ground layers 208a, 208a
are formed above and below it. By providing the ground layers 208a,
it is possible to suppress noise from occurring from the heating
element layer 208. The ground layers 208a, however, are not
essential to the present invention.
[0063] The heating element layer 208 may be provided at the
performance board 205 comprised of a printed circuit board by
forming a pattern of the heating element by etching and also by
forming nichrome wiring planarly or other methods of mounting
heating elements. Whatever the case, wiring for carrying a current
becomes necessary, so in the example shown in FIG. 5, a power
supply wiring 208b is formed to the edge of the performance board
205 and a connector 208c is formed there. The specific technique is
not limited in any way. Other means may also be employed.
[0064] Further, in the present embodiment, a temperature sensor 209
is provided at any location in the area where the heating element
208 is provided so as to manage the temperature of the heating
element 208. By incorporating the temperature information from the
temperature sensor 209, problems such as overheating or
underheating are prevented. The control of the temperature of the
heating element 208, however, does not have to be precise. Rough
control to the extent of controlling the supply of the power to the
heating element 208 is sufficient. At this time, the power may be
supplied by the inverter method so as to prevent noise from the
heating element 208.
[0065] Next, the operation will be explained.
[0066] A pre-test IC chip carried on the feed tray 102 of the
handler 10 is picked up and held by the X-Y conveyor 104 and
transferred to an indentation 106a of the heat plate 106. By
leaving it there for exactly a predetermined time, the IC chip
rises to a predetermined temperature. Therefore, the X-Y conveyor
104 transferring the not yet heated IC chip from the feed tray 102
to the heat plate 106 releases the IC, then picks up and holds an
IC chip which had been left at the heat plate 106 and had been
raised to the predetermined temperature and transfers it to a
buffer section 108.
[0067] The buffer section 108 to which the IC chip has been
transferred moves to the right end of the rail 108a, is picked up
and held by the X-Y conveyor 105, and, as shown in FIG. 3, is
pushed against an IC socket 206 of the test head 20 through the
opening 110 of the board 109.
[0068] At this time, the heat of the now high temperature IC chip
is conducted to the ordinary temperature IC socket 206 and starts
to be radiated to the performance board 205 as well, but since the
performance board 205 of the present embodiment is provided with
the heating element 208 and the area around the IC socket is heated
to a suitable temperature, the temperature gradient between the IC
chip and the performance board 205 becomes smaller and the amount
of heat radiated to the IC socket 205 is suppressed. Therefore, it
is possible to test the IC chip at the initially desired
temperature and improve the reliability of the test results.
[0069] Further, since a drop in the temperature of the IC chip is
suppressed by the heating element 208 provided at the performance
board 205, it is possible to set the heating temperature at the
heat plate 106 low and it is thereby possible to expect a
shortening of the time for raising the temperature, that is,
improve the throughput of the IC chip testing apparatus 1.
[0070] Second Embodiment
[0071] In the above embodiment, the explanation was given using as
an example an IC chip testing apparatus 1 applying a high
temperature thermal stress to the IC chip, but the electronic
device testing apparatus of the present invention may also be
applied to one applying a low temperature thermal stress. FIG. 7 is
a plan view (plan view corresponding to FIG. 5) of a performance
board according to another embodiment of the IC chip testing
apparatus of the present invention.
[0072] In this embodiment, the IC chip testing apparatus is one
which applies a low temperature thermal stress to the IC chip, then
pushes it against an IC socket of the test head and executes the
tests. Liquid nitrogen or another low temperature gas is supplied
to a region normally near the contact section 201 of the test head
20. In particular, as shown in FIG. 7, the performance board 205 of
this embodiment is provided with a heating element 208 over
substantially its entire area. The invention is not limited to
this, but the heating element 208 of the present embodiment is
designed to prevent condensation on the performance board 205, so
it is preferable to provide the heating element 208 in the region
where the electronic device is provided and not only the area
around the IC socket 206.
[0073] The structure of the contact section 201 of the test head 20
of the present embodiment is basically the same as that of the
embodiment shown in FIG. 3, so will be explained with reference to
that figure, but since the IC chip is allowed to stand in this low
temperature atmosphere so that the IC chip will fall to the
predetermined temperature, this is pushed against an IC socket 206
of the test head 20 for the test.
[0074] At this time, the heat of the now low temperature IC chip is
conducted to the performance board 205 through the IC socket 206,
whereby the air near the surface of the performance board 205 is
cooled and condensation starts, but since the performance board 205
of the present embodiment is provided with the heating element 208
and substantially the entire performance board 205 is heated to a
suitable temperature, it is possible to prevent the occurrence of
condensation.
[0075] Further, the IC chip testing apparatus of the present
invention is particularly effective for a test head 20 provided
with the IC sockets 206 and performance board 205 in close
proximity as in the embodiment shown in FIG. 3, but does not
exclude a test head 20 of a type such as shown for example in FIG.
8 or FIG. 9.
[0076] In the test head 20 shown in FIG. 8, the performance board
205 (corresponding to printed circuit board of the present
invention) is mounted above the test head body 20a. A spacing frame
211 is provided above the performance board 205 via spacer columns
210 able to move vertically somewhat in the Z-direction.
[0077] A socket board 213 is provided above the spacing frame 211
through socket board spacers 212. IC sockets 214 are provided on
this socket board 213. The performance board 205 and the socket
board 213 are connected by a plurality of coaxial cables 215.
[0078] As opposed to this, in the test head 20 shown in FIG. 9, a
performance board 205 is attached above the test head body 20a. A
device specific adapter (DSA) performance board 216 (corresponding
to the printed circuit board of the present invention) is provided
above the performance board 205 through spacer columns 210 able to
move vertically somewhat in the Z-direction. A spacing frame 211 is
provided further above this, while a socket board 213 is provided
through socket board spacers 212. Further, the DSA performance
board 216 and socket board 213 are connected by connector boards
217, while the DSA performance board 216 and base board 209 are
connected by a connector 218 and coaxial cables 215.
[0079] Even in IC chip testing apparatuss provided with such test
heads 20, by provision of the heating elements 208 shown in FIG. 5
to FIG. 7 at the performance board 205 shown in FIG. 8 and the DSA
performance board 216 shown in FIG. 9 (even plus the performance
board 205), a similar action and effect as in the above embodiment
can be exhibited.
[0080] Third Embodiment
[0081] As shown in FIG. 10, the IC chip testing apparatus 302
according to this embodiment is one which tests, as devices to be
tested, IC chips in the state of ordinary temperature, low
temperature, or high temperature and is provided with a handler 304
and a not shown test use main unit. The handler 304 successively
conveys IC chips to be tested to IC sockets provided on the test
head and stores the IC chips finished being tested on predetermined
trays sorted in accordance with the test results.
[0082] In this embodiment, the handler 304 is provided with a
chamber 306. The top of the test head 310 is exposed at a test
stage 308 in the chamber 306. The top of the test head 310 is shown
in FIG. 11. Sockets 320 are mounted at the top of the test head
310. The chip mounting openings of the sockets 320 face the inside
of the chamber 306 so that IC chips 322 conveyed by the suction
heads 324 can be successively detachably mounted.
[0083] The IC sockets 320 provided at the test head 310 are
connected to the test use main unit (not shown) through cables. The
IC chips 322 detachably mounted at the IC sockets 320 are connected
to the test use main unit through cables and the IC chips 322 are
tested by test signals from the test main unit. The relation among
the IC sockets 320 and chamber 306 and the test head 310 will be
explained later in detail.
[0084] As shown in FIG. 10, the handler 304 has an IC magazine 330
for storing IC chips to be tested and storing tested IC chips
sorted into classes. The IC magazine 330 holds loader use trays
332A on which IC chips to be tested are carried, sorting trays 332B
to 332E on which tested IC chips are carried sorted into classes,
empty trays 332F, and option trays 332G. These trays 332A to 332G
are arranged at predetermined intervals along the X-direction and
are stacked in the Z-direction (height direction).
[0085] IC chips carried on a loader tray 332A are conveyed to a
soak stage 336 inside the chamber 306 using the first XY-conveyor
334 attached to the handler 304. Further, IC chips finished being
tested at the test head 310 are finally loaded and sorted on the
sorting trays 332B to 332E of the IC magazine 330 using the second
XY-conveyor 335. Among the sorting trays 332B to 332E, for example,
the tray 332C is the tray for good devices, while the other trays
are the trays for the defective devices or devices for
retesting.
[0086] The empty trays 332F are conveyed to and stacked over the
sorting trays 332B to 332E which have become filled with the tested
IC chips and are used as sorting trays. The option trays 332G are
used for other applications.
[0087] The inside of the chamber 306 is of an air-tight structure
except for the portion for the transfer of IC chips which is
designed to be able to open and close by a shutter etc. For
example, it can maintain a high temperature state of room
temperature to about 160.degree. C. or a low temperature state of
room temperature to about -60.degree. C. The inside of the chamber
306 is divided into a soak stage 336, a test stage 308, and an exit
stage 340.
[0088] The soak stage 336 has a turntable 338 arranged in it. The
surface of the turntable 338 has indentations 342 for temporarily
holding IC chips arranged at a predetermined pitch along the
circumferential direction. In the present embodiment, there are two
indentations 343 formed in the radial direction of the turntable
338. The two indentations 342 are arranged at a predetermined pitch
in the radial direction. The turntable 338 turns clockwise. The IC
chips dropped into the indentations 342 of the turntable 338 at the
loading position 344 by the first XY-conveyor 334 are given a
thermal stress until the temperature conditions to be tested are
reached while the turntable 338 is being indexed in the direction
of rotation.
[0089] At a takeout position 346 about 240 degrees in the direction
of rotation from the loading position 344 based on the center of
rotation of the turntable 338, the suction heads attached to one of
the three contact arms 348 are positioned above the turntable 338.
At that position, IC chips can be taken out from the indentations
342 by the suction heads. The three contact arms 348 are attached
at angles of substantially equal amount in the circumferential
direction with respect to the shaft 350 and can be indexed 120
degrees at a time in the clockwise direction of rotation about the
shaft 350. Note that this "index" means to repeatedly turn by a
predetermined angle, then stop, then again turn by a predetermined
angle. At the time of this indexing of a contact arm 348, the time
when the arm 348 is stopped corresponds to the time during which IC
chips are mounted in sockets of the test head 310 and tested plus
the time for attachment or detachment of the IC chips to or from
the sockets. The stopping time of this indexing is the same as the
stopping time of the indexing at the turntable 338. The turntable
338 and the contact arms 348 are indexed synchronously.
[0090] In the embodiment, the suction heads of one of the three
contact arms 348 are positioned above the takeout position 346 of
the soak stage 336, the suction heads of another of the contact
arms 348 are positioned above the contact heads 310 of the test
stage 308, and the suction heads of the other of the contact arms
348 are positioned above the inlet 352 of the exit stage 340.
[0091] The IC chips loaded in the indentations 342 of the turntable
338 at the loading position 344 of the turntable 338 are given a
predetermined thermal stress while being indexed from the loading
position 344 to the takeout position 346 and are picked up by the
suction heads of a contact arm 348 at the takeout position 346. The
IC chips picked up by the suction heads are positioned above the
test head 310 by the indexing of the contact arm 348 in the
clockwise direction. At that position, as shown in FIG. 11, the IC
chips 322 picked up and held by the suction heads 324 are attached
to the sockets 320 and tested.
[0092] The IC chips 322 attached to the sockets 320 above the test
head 310 and finished being tested are picked up again by the
suction heads 324 and positioned above the inlet 352 of the exit
stage 340 by the indexing of the contact arm 348 shown in FIG. 10
in the clockwise direction. At this position, the tested IC chips
are slid to the exit position 354 by an exit shifter in the
direction of the arrow A. At the exit position of the exit stage
340, the IC chips arranged above the exit shifter are returned from
the temperature of the test, that is, the low temperature or the
high temperature, to ordinary temperature. In the case of a low
temperature test, the IC chips are returned to ordinary temperature
at the exit stage 340 so it is possible to effectively prevent
condensation from occurring on the IC chips directly after being
taken out from the chamber 306.
[0093] The IC chips arranged above the exit shifter at the exit
position 354 of the exit stage 340 are returned to ordinary
temperature, then shifted in the direction of the arrow B by a not
shown exit arm and moved to an exit turn arranged at the receiving
position 356. The exit turn is designed to be able to move back and
forth between the receiving position 356 and the eject position 358
by turning in the direction of the arrow C. The suction heads of
the second XY-conveyor 335 are designed to be able to move to the
eject position 358 of the exit turn. The tested IC chips arranged
at the eject position by the exit turn are conveyed by the conveyor
335 to one of the sorting trays 332B to 332E based on the test
results.
[0094] In the device testing apparatus 302 according to the present
embodiment, a soak stage heat exchanger 360 is arranged at the
ceiling of the soak stage 336 inside the chamber 306 of the handler
304 and a test stage heat exchanger 362 is arranged at the side
wall of the test stage 308. These heat exchangers 360 and 362 are
provided with cooling units using liquid nitrogen etc. as a coolant
and blowers for circulating the cold air inside the chamber when
the testing apparatus 302 is able to perform low temperature tests.
When the testing apparatus 302 is able to perform high temperature
tests, the heat exchangers 360 and 362 are provided with heating
units and blowers. When the testing apparatus is able to perform
low temperature tests and high temperature tests, the heat
exchangers 360 and 362 are provided with cooling units, heating
units, and blowers and are used switching between the cooling units
and heating units. These heat exchangers 360 and 362 are controlled
by a temperature controller 370. The temperature controller 370
receives as input output signals from a temperature sensor 372
arranged at the test stage 308, temperature sensor 374 arranged at
the soak stage 336, and other sensors and can control the amount of
heat exchange (output) of the heat exchangers 360 and 362 in
accordance with the output signals from these sensors.
[0095] In the following explanation, the explanation will be given
of the case where the testing apparatus 302 is one able to perform
both high temperature tests and low temperature tests and the
testing apparatus is used mostly for performing low temperature
tests. As shown in FIG. 11 and FIG. 12, at the test stage 308, the
bottom of the chamber 306 comprised of a heat insulating material
etc. and the main base 380 holding the chamber 306 are partially
cut away and sockets 320 held on the test head 310 fit there.
[0096] The sockets 320 are held by socket guides 382. Each of the
socket guides 382, as shown in FIG. 12, has a plurality of guide
holes 384. The guide holes 384 are designed to have inserted into
them guide rods 386 affixed to the chamber 306 side for positioning
with the chamber 306.
[0097] The guide rods 386 are attached to a base ring 388. The base
ring 388 is affixed to a mounting base 390 and constitutes the
chamber opening 392. The mounting base 390 has a heat insulating
property similar to that of the chamber 306 and is affixed
detachably to the bottom opening of the chamber 306 and the main
base 380.
[0098] As shown in FIG. 11, the socket guide 382 has a plurality of
guide pins 394 attached to it projecting out toward the inside of
the chamber 306. The guide pins 394 are inserted into the guide
holes 396 of the guide plate 395 attached to a suction head 324 for
positioning of the IC chip 322 picked up and held by a suction head
324 and the socket 320.
[0099] Behind the socket 320 (outside of chamber) is connected a
low temperature use socket adapter 398 which is electrically
connected to the terminals of the socket 320. The adapter 398 is
affixed to the surface of the substantial center of the printed
circuit board 400 and facilitates the electrical connection of the
terminals of the socket 320 and the printed circuit board 400. At
the bottom surface of the printed circuit board 400 are
electrically connected a plurality of movable pins 404 on a movable
pin holding ring 402 projecting out in a ring shape from the test
head 310. The movable pins 404 are attached to the movable pin
holding ring 402 facing upward and are also called pogo pins
(contact pins having movable pins supported to be able to advance
and retract in the axial direction by springs and biased in a
direction where the movable pins project out by the springs). They
are pushed against the bottom terminals of the printed circuit
board 400 for electrical connection with the printed circuit board
400. Note that the printed circuit board 400 is also called a
performance board.
[0100] The test head 310 receives drive signals from the test use
main unit, not shown, and sends test drive signals to the IC chip
322 attached to the socket 320 through the movable pin holding ring
402, movable pins 404, printed circuit board 400, and adapter
398.
[0101] In the present embodiment, as shown in FIG. 11 and FIG. 12,
a heating board 406 having an opening at its center is bolted etc.
to the bottom surface of the mounting base 390. The heating board
406 is also called an HIFIX heater and comprised of a rubber heater
or other planar heating element 408 sandwiched between aluminum
sheets etc. At the bottom surface of the heating board 406 is
affixed in advance a first seal member 412. The first seal member
412 is configured for example as a silicone sponge rubber sheet or
other sheet having elasticity. The top surface of the printed
circuit board holding ring 414 detachably contacts the bottom
surface of the inner circumference side of the heating board 406
through the first seal member 412 which seals the space between
them. Further, the second seal member 416 is attached between the
printed circuit board holding ring 414 and the printed circuit
board 400 and seals the space between them. The second seal member
416 is comprised of a synthetic resin sheet the same as or
different from that of the first seal member 412.
[0102] As a result of the sealing by the first seal member 412 and
the second seal member 416, a first air-tight space 418 is formed
at the printed circuit board side of the socket guide 382. This
first air-tight space 418 has communicated with it a radial drying
passage 410 formed in the heating board 406. Dry gas can be filled
into the first air-tight space 418 from there. As the dry gas for
being filled inside the first air-tight space 418, for example dry
air having a condensation temperature lower than the temperature
inside the chamber 306 may be used. For example, when the inside of
the chamber 306 is about -55.degree. C., the condensation
temperature of the dry air sealed inside the first air-tight space
418 through the drying passage 410 is preferably about -60.degree.
C. The temperature of the dry air is for example about room
temperature.
[0103] As shown in FIG. 11 and FIG. 12, the printed circuit board
holding ring 414 is arranged at a position corresponding to the
position of the movable pins 404 contacting the bottom terminals of
the printed circuit board 400. The top surface of the holding ring
414 contacts the bottom surface of the heating board 406 to push
the printed circuit board 400 downward and secure the electrical
contact with the movable pins 404 and printed circuit board
400.
[0104] A reinforcing plate 420 is attached to the bottom surface of
the center portion of the printed circuit board 400 (anti-chamber
side) through a plurality of spacers 422. The reinforcing plate 420
is for preventing the printed circuit board 400 from bending and is
positioned inside of the movable pin holding ring 402. A second
air-tight space 424 is formed between the reinforcing plate 420 and
the printed circuit board 400 by attaching a ring-shaped third seal
member 426 between the outer circumference of the reinforcing plate
420 and the inner circumference of the movable pin holding ring
402. This third seal member 426 is comprised of a ring of a
synthetic resin the same as or different from the first seal member
and seals the space between the reinforcing plate 420 and the
printed circuit board 400.
[0105] The reinforcing plate 420 has a drying nozzle 460 attached
to it for feeding dry gas into the second air-tight space 424. As
the dry gas to be introduced inside the second air-tight space 424,
use may be made of dry air with a condensation temperature somewhat
higher than the dry air introduced inside the first air-tight space
418, for example, about -40.degree. C. The temperature of the dry
air is about the room temperature. The condensation temperature of
the dry air introduced inside the second air-tight space 424 may
somewhat higher than the condensation temperature of the dry air
introduced inside the first air-tight space 418 because the second
air-tight space 424 is further away from the inside of the chamber
306 than the first air-tight space 418 and has a lower possibility
of condensation.
[0106] Note that a space 430 is also formed between the seal ring
428 attached to the outer circumference of the socket adaptor 398
and the printed circuit board 400, but since the dry air inside the
second air-tight space 424 is introduced into this space 430
through through holes formed in the printed circuit board 400, it
is also possible to effectively prevent condensation at that
portion.
[0107] In the electronic device testing apparatus 302 of the
present embodiment, a heating board 406 is attached around the
chamber opening 392 of the chamber 306 with an inside cooled to a
temperature below ordinary temperature and the printed circuit
board 400 is heated by heat conduction through the printed circuit
board holding ring 414. Therefore, it is possible to effectively
prevent condensation from occurring at the printed circuit board
400 behind the socket and the test head 310.
[0108] Further, in the IC chip testing apparatus 302 according to
the present embodiment, since a special spacing frame or other heat
insulating structure is not employed, it is possible to use general
purpose printed circuit board holding rings 414 and other parts and
the manufacturing costs become lower. Further, since it is no
longer necessary to separate the printed circuit board 400 and the
socket 320 by more than the necessary amount of distance, the
electrical path from the sockets 320 to the printed circuit board
400 (electrical cables etc.) can be shortened, greater resistance
to noise can be obtained, and the reliability of the tests can be
improved.
[0109] Further, in the IC chip testing apparatus 302 according to
this embodiment, by bringing the printed circuit board 400 into
contact with the heating board 406 through a printed circuit board
holding ring 414 so as to form a first air-tight space 418 at the
printed circuit board side of the socket guide 382 and forming in
the heating board 406 a drying passage 410 for feeding dry gas in
the first air-tight space 418, the first air-tight space 418 can be
filled with a dry gas. This enables condensation behind the socket
guide 382 to be further effectively prevented.
[0110] Further, in the IC chip testing apparatus 302 of the present
embodiment, by attaching a reinforcing plate 420 at the
anti-chamber side of the printed circuit board 400 so as to form a
second air-tight space 424 with the printed circuit board 400 and
attaching to the reinforcing plate 420 a drying nozzle 460 for
feeding dry gas into the second air-tight space 424, the second
air-tight space 424 can also be filled with a dry gas. This enables
condensation behind the printed circuit board 400 as well to be
further effectively prevented.
[0111] Fourth Embodiment
[0112] As shown in FIG. 13, the test stage 308a of the testing
apparatus according to this embodiment is configured so that the
printed circuit board 400a constituting the test board is directly
heated by the heating board 406. Below, only the points of
difference from the testing apparatus according to the first
embodiment will be explained. The explanation of common portions
will be partially omitted.
[0113] The center of the mounting base 390a affixed to the bottom
opening of the chamber 306 has attached to it a base ring 388a and
forms the chamber opening 392a. A socket guide 382a is bolted etc.
to the base ring 388a so that the socket 320 is positioned at the
center of the chamber opening 392a.
[0114] Behind the mounting base 390a (outside of chamber) is bolted
etc. a heating board 406 having an opening at its center through a
mounting plate 450 serving also as a heating insulating member and
a sealing member. The heating board 406 is also called an HIFIX
heater and is comprised of a rubber heater or other planar heating
element 408 sandwiched between aluminum sheets. The bottom surface
of the heating board 406 has a first seal member 412 attached to it
in advance. The first seal member 412 is comprised for example of a
silicone sponge rubber sheet or other sheet having elasticity.
[0115] In the present embodiment, when connecting and affixing to
the socket 320 the socket adapter 398a attached to the substantial
center of the printed circuit board 400a serving as the test board,
the surface of the outer circumference of the printed circuit board
400a comes into direct contact with the bottom of the heating board
406 through the first seal member 412 and the printed circuit board
400a is directly heated by the heating board 406.
[0116] The heating board 406 is formed with a radial drying passage
410. Dry gas can be filled into the first air-tight space 418a
formed between the socket guide 382a and the printed circuit board
400a. As the dry gas for being filled inside the first air-tight
space 418a, for example dry air having a condensation temperature
lower than the temperature inside the chamber 306 may be used. For
example, when the inside of the chamber 306 is about -55.degree.
C., the condensation temperature of the dry air sealed inside the
first air-tight space 418a through the drying passage 410 is
preferably about -60.degree. C. The temperature of the dry air is
for example about room temperature.
[0117] In the electronic device testing apparatus according to this
embodiment, a heating board 406 is attached around the chamber
opening 392a of the chamber 306 with an inside cooled to a
temperature below ordinary temperature and the printed circuit
board 400a is heated directly by heat conduction. Therefore, the
printed circuit board 400a positioned behind the socket 320 is
heated to a temperature above the dew point of the ambient gas.
Therefore, it is possible to effectively prevent condensation from
occurring at the printed circuit board 400a behind the socket.
[0118] Further, in the IC chip testing apparatus according to the
present embodiment, since a special spacing frame or other heat
insulating structure is not employed, the manufacturing costs
become lower. Further, since the distance between the printed
circuit board 400a and the sockets 320 becomes remarkably short,
the electrical path from the sockets 320 to the printed circuit
board 400a (electrical cables etc.) can be shortened, greater
resistance to noise can be obtained, and the reliability of the
tests can be improved.
[0119] Further, in the IC chip testing apparatus according to this
embodiment, by bringing the printed circuit board 400a into contact
with the heating board 406 so as to form a first air-tight space
418a at the printed circuit board side of the socket guide 382 and
forming in the heating board 406 a drying passage 410 for feeding
dry gas in the first air-tight space 418a, the first air-tight
space 418a can be filled with a dry gas. This enables condensation
behind the socket guide 382 to be further effectively
prevented.
[0120] Other Embodiments
[0121] Note that the present invention is not limited to the above
embodiments and can be changed in various ways within the scope of
the invention.
[0122] For example, in the third and fourth embodiments, the
explanation was mainly given of the case of conducting low
temperature tests inside the chamber 306 shown in FIG. 10, but the
present invention can also be applied even when conducting ordinary
temperature tests inside the chamber 6. Further, the testing
apparatus 2 shown in FIG. 10 is of a type enabling both ordinary
temperature tests and high temperature tests as well in the chamber
6, but the testing apparatus according to the present invention can
also be applied to a testing apparatus conducting only low
temperature tests or a testing apparatus conducting only ordinary
temperature tests. Further, in the testing apparatus according to
the present invention, the method of handling the IC chips in the
handler 4 is not limited to the illustrated embodiments.
* * * * *