JP2001267347A - Method and apparatus for testing semiconductor bump electrode - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and an apparatus for testing a plurality of bump electrodes 14, for conducting a tension test of the plurality of the electrodes 14 on a semiconductor chip 13 in a short time. SOLUTION: A tensile strength of each bump electrode 14 is tested in the steps of heating the semiconductor chip 13 for mounting the bump electrodes 14 to a temperature for melting a metal of each electrode 14, then inserting each probe 7 into the molten metal of the electrode 14, cooling to solidify the metal of the electrode 14 together with the probe 7, sequentially pulling the solidified probes 7 in the electrodes 14, and detecting the tensile force each electrode 14, when it is pulled. Thus, all the electrodes 14 on the chip 13 can be set to a state in which the tension test can be conducted by one time heating and cooling irrespective of the number of the electrode 14. Thereafter, since only the tension tests can be sequentially continued, the more the number of the electrodes 14 are on the chip 13, the larger the effect of shortening the time is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and an apparatus for testing a semiconductor bump electrode, and more particularly to a method and an apparatus for testing the tensile strength of a semiconductor bump electrode.

[0002]

2. Description of the Related Art In order to reduce the cost of hybrid ICs for electronic devices such as computers and automobiles, high-density mounting is demanded. Among them, flip chip IC / CSP using semiconductor bump electrode (bump electrode)
(Chip Scale Package) ・ BGA
Flip-chip mounting methods such as (Ball Grid Array) have attracted attention as high-density mounting methods because the bonding area is smaller than other mounting methods and the bonding strength is higher.

[0003] In particular, in recent years, ICs have been highly integrated with high integration and multifunctional products, and therefore, the bump electrodes tend to be miniaturized.

The present applicant has filed an application for a test method and a test apparatus suitable for a tensile strength test of this type of bump electrode (Japanese Patent Application Laid-Open No. HEI 8-111417). This test method and test apparatus heats the probe inserted into the bump electrode to a temperature at which the metal of the bump electrode melts,
A probe heated to a temperature at which the metal of the bump electrode melts is inserted into the bump electrode to melt the metal of the bump electrode, and the molten metal of the bump electrode is cooled and solidified together with the probe. The probe solidified in the electrode is pulled in a direction perpendicular to the bump electrode until the bump electrode peels off.

[0005]

However, in the above method, each bump electrode is heated to a temperature at which the metal of the bump electrode melts, cooled until the metal of the molten bump electrode solidifies together with the probe, and then the test is performed. It takes time to complete one test,
Since an actual semiconductor chip has many bump electrodes, it takes a long time to test one semiconductor chip.

FIG. 2 is a graph showing the transition of the temperature of the bump electrode in the form of a graph. This takes about 120 seconds, which is the time required to connect the probe and the bump electrode before the test for each bump electrode.

Accordingly, the present invention has been made in view of the above-mentioned conventional problems, and a method and a test for testing a semiconductor bump electrode for performing a tensile strength test of a plurality of bump electrodes on a semiconductor chip in a short time. It is intended to provide a device.

[0008]

In order to achieve the above object, according to the first aspect of the present invention, each probe (7) inserted into each bump electrode (14) is placed directly above each bump electrode (14). The semiconductor chip (13) on which the bump electrodes (14) are mounted is heated to a temperature at which the metal of each bump electrode (14) melts, and each probe (7) is heated by the molten metal of each bump electrode (14). And the molten metal of each bump electrode (14) is cooled and solidified together with each probe (7), and the solidified probes (7) in each bump electrode (14) are sequentially pulled, The method is characterized in that the tensile strength of each bump electrode (14) is tested by detecting the tensile force at the time of pulling.

According to the second aspect of the present invention, after the semiconductor chip (13) on which the bump electrodes (14) are mounted is heated to a temperature at which the metal of each bump electrode (14) melts, each probe (7) is connected to each of the probes (7). The molten metal of each bump electrode (14) was inserted into the molten metal of the bump electrode (14), cooled and solidified together with each probe (7), and each of the solidified metal in each bump electrode (14) was cooled. The method is characterized in that the probe (7) is sequentially pulled, and the tensile strength of each bump electrode (14) is tested by detecting the tensile force when the probe (7) is pulled.

Thus, even if there are a plurality of bump electrodes on the semiconductor chip, the plurality of bump electrodes are heated by a heating jig to a temperature at which the bump electrodes are melted together with the semiconductor chip on which the bump electrodes are mounted. Can also be melted together.

Further, since there is no heater for heating the probe below the load cell unlike the conventional apparatus, there is no need to dispose a thermal insulator under the load cell to prevent heat transfer.

Also, if a plurality of bump electrodes are provided, the probe support jig is provided at a corresponding position corresponding to the number of bump electrodes, so that a plurality of probes can be collectively inserted into a plurality of bump electrodes. Can be.

Further, the plurality of bump electrodes and the plurality of probes combined together on the semiconductor chip in this manner can be cooled together with the semiconductor chip by the cooling jig. By these means, all the bump electrodes on the semiconductor chip can be put into a state where a tensile test can be performed by one heating and cooling regardless of the number of the bump electrodes, and thereafter only the tensile test is sequentially and sequentially performed. From what you can do,
The greater the number of bump electrodes on the semiconductor chip, the greater the effect of time reduction.

According to the third aspect of the present invention, each probe (7) inserted into each bump electrode (14) and a probe support for positioning and supporting each probe (7) with respect to each bump electrode (14). A jig (6), a heating jig (8) for heating the semiconductor chip (13) on which the bump electrodes (14) are mounted to a temperature at which the metal of each bump electrode (14) melts, 14) a cooling jig (9) for cooling and solidifying the metal together with each probe (7), a load cell (11) for converting a force or a weight into an electric signal proportional to the cooling jig (9), and the load cell (1).
A movable part (10) for holding and raising and lowering 1) and a jig (12) for sequentially connecting each probe (7) below the load cell (11) are provided.

This is a configuration necessary for the test apparatus to perform the test method described above. However, since there is no heater for heating the probe below the load cell as in the conventional apparatus, there is no need to arrange a thermal insulator under the load cell to prevent heat transfer.

In the invention according to claim 4, the heating jig (8)
Is characterized in that the metal of each bump electrode (14) on the semiconductor chip (13) is heated and melted almost simultaneously.

Thus, even if there are a plurality of bump electrodes on the semiconductor chip, the plurality of bump electrodes are collectively heated by heating the semiconductor chip on which the bump electrodes are mounted to a temperature at which the bump electrodes melt. Can be melted.

According to the fifth aspect of the present invention, the probe support jig (6) is arranged such that the probe (7) is directly above each bump electrode (14) with respect to each bump electrode (14) on the semiconductor chip (13). ) Is positioned and supported.

With this arrangement, if there are a plurality of bump electrodes, the probe support jig is also provided at a corresponding position corresponding to the number of bump electrodes, so that the plurality of probes can be positioned and supported immediately above the plurality of bump electrodes. And can be inserted all at once.

In the conventional apparatus, at the time of a test, an operator had to precisely position the probe at the center of each bump electrode using an optical microscope or the like. The alignment accuracy is determined by the device side, and during the test, the hook on the probe and the tip of the tension jig under the load cell can be hooked in sequence, which simplifies the positioning work for each bump electrode by the operator, which makes it easier. Be able to work.

In the invention according to claim 6, the cooling jig (9)
Is characterized in that the metal of each bump electrode (14) melted on the semiconductor chip (13) is cooled and solidified almost simultaneously with each probe (7) inserted into each bump electrode (14).

Thus, the plurality of bump electrodes and the plurality of probes combined on the semiconductor chip can be collectively cooled together with the semiconductor chip by the cooling jig.

[0023]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing an overall configuration of a semiconductor bump electrode test apparatus according to an embodiment of the present invention.

In FIG. 1, reference numeral 2 denotes a main body of the test apparatus, and a base 3 is provided at a lower portion. The base 3 is extended long to the left side, and from the left side, a setting step A and a heating step B
A cooling step C and a test step D;

Reference numeral 4 denotes a movable pallet for positioning and fixing a semiconductor chip (or semiconductor wafer) 13 to be tested on the upper surface. The transfer pallet 4 is transported from the process A to the process D by the pallet transport device 3a provided on the upper surface of the base 3 with the semiconductor chip 13 placed thereon.

In addition, on the base 3 side, a heating jig 8 such as a hot plate is provided in the heating step B, and heating is controlled by the main body 2. In the cooling step C, a cooling jig 9 using water, air, nitrogen gas, or the like is provided, and cooling is controlled by the main body 2.

Reference numeral 6 denotes a probe support jig, which is positioned and gripped by a probe support jig transport device 5 provided on an upright wall from the base 3 and synchronized with the transfer pallet 4 transported by the pallet transport device 3a. It is transported from A to step D.

The probe support jig 6 has a probe support hole 6a at a position corresponding to the position of each bump electrode 14 on the semiconductor chip 13, and supports the probe 7 so that it can drop freely in the direction of gravity. I have.

The probe 7 is a thin metal rod having good heat conduction and good wettability with the solder of the bump electrode 14, and the tip end contacting the bump electrode 14 is formed in a needle shape, and It is formed in a hook shape so as to be connected to the tension jig 12 during the test. The hook portion has a shape for preventing the probe 7 from falling off after the probe 7 is set in the probe support hole 6a.

In the test process D, a movable part, which is movable in the vertical and horizontal directions and the front and rear directions with respect to the main body 2, is provided above the main body 2 of the test apparatus by a movable mechanism (not shown) provided in the main body 2. 10 are provided. A load cell 11 is attached directly below the distal end of the movable unit 10, and a tension jig 12 for hooking on a hook of the probe 7 and pulling up is attached directly below the load cell 11.

The load cell 11 is a converter that converts a force (load) or weight into an electric signal proportional to the force (load) or weight, and converts the force (load) or weight into an electric signal proportional to the force (load) or weight. The electric signal is converted into a signal, and the electric signal is transmitted to a detection unit (not shown) arranged in the main body 2.

Next, the operation of the semiconductor bump electrode testing apparatus of the present embodiment will be described.

First, in the setting step A, the transfer pallet 4 corresponding to the semiconductor chip 13 of the device under test is positioned and set on the pallet transport device 3a, and the semiconductor chip 13 of the device under test is positioned and set on the transfer pallet 4. I do.

Next, the probe supporting jig 6 corresponding to the semiconductor chip 13 of the device under test is similarly positioned and gripped by the probe supporting jig transporting device 5, and the probe supporting jig 6 is inserted into the probe supporting hole 6a. The probe 7 is inserted and the probe 7 is placed on the bump electrode 14 of the semiconductor chip 13.
Is in a riding state.

Next, the respective transfer devices of the transfer pallet 4 and the probe support jig 6 are moved in synchronization with each other, and are moved to the heating step B while the probe 7 is on the bump electrode 14.

In the heating step B, the transfer pallet 4 and the semiconductor chip 13 are heated by the heating jig 8 and the temperature at which the solder of the bump electrodes 14 on the semiconductor chip 13 melts (for example, eutectic solder is used as the solder). About 250
(° C). The probe 7 placed on the bump electrode 14 at the same time when the solder of the bump electrode 14 is melted.
Is inserted into the solder of the bump electrode 14 melted by its own weight.

Next, the respective transfer devices of the transfer pallet 4 and the probe support jig 6 are moved synchronously as before, and are moved to the cooling step C with the probe 7 inserted in the bump electrode 14.

In the cooling step C, the transfer pallet 4 and the semiconductor chip 13 are cooled by the cooling jig 9 to solidify the molten solder of the bump electrodes 14 on the semiconductor chip 13. When the molten solder solidifies, the probe 7 inside is firmly fixed to the bump electrode 14.

Transfer pallet 4 and probe support jig 6 again
Are moved in synchronization with each other, and the inspection process D is performed in a state where the probe 7 has been inserted into the bump electrode 14 and solidified.
Move to

In the inspection step D, the movable portion 10 is moved by a movable mechanism (not shown) arranged in the main body 2 and the plurality of bump electrodes 14 are inspected one by one in order. Specifically, the tension jig 12 under the load cell 11 is hooked on the hook of the probe 7, and the probe 14 firmly fixed in the bump electrode 14 is pulled in a direction perpendicular to the bump electrode 14, and The tensile strength at the time when the sample broke was measured.

In the above-described embodiment, even if there are a plurality of bump electrodes 14 on the semiconductor chip 13, the heating jig 8 is brought to a temperature at which the bump electrodes 14 are melted together with the semiconductor chip 13 on which the bump electrodes 14 are mounted. , The plurality of bump electrodes 14 can be melted at one time.

Further, since there is no heater for heating the probe below the load cell as in the conventional apparatus, there is no need to arrange a thermal insulator under the load cell to prevent heat transfer.

The probe 7 to be inserted is also the bump electrode 1
If there are a plurality of 4, a plurality of probes 7 can be collectively inserted into a plurality of bump electrodes 14 by holding the probe supporting jig 6 at a corresponding position by the corresponding number.

Further, the plurality of bump electrodes 14 and the plurality of probes 7 combined together on the semiconductor chip 13 can be cooled together with the cooling jig 9 together with the semiconductor chip 13. As a result, all the bump electrodes 14 on the semiconductor chip 13 can be put into a state where a tensile test can be performed by one heating and cooling operation regardless of the number of the bump electrodes 14, and thereafter only the tensile test is sequentially performed. Since the process can be performed continuously, the effect of shortening the time is increased by the number of bump electrodes 14 on the semiconductor chip 13.

In the conventional apparatus, the operator had to accurately position the probe at the center of each bump electrode at the time of testing.
The positioning accuracy of the probe 7 with respect to the probe 7 is determined by the apparatus side.
What is necessary is just to hook the tip of the lower one of the tension jigs 12, and the positioning work for each bump electrode 14 by the operator becomes easy.

When all the tests are completed, the probe support jig 6 is removed together with the probe, and the solder attached to the tip of the probe is dropped and reused in another step. The transfer pallet 4 is also removed and the semiconductor chip 13 is replaced and used for the next test.

This means that even if the type of the semiconductor chip (or semiconductor wafer) 13 as the device under test changes, the transfer pallet 4 for positioning and fixing and the probe support jig 6 corresponding to the arrangement of the bump electrodes 14 are changed. By doing
The test equipment can be used for general purposes.

(Other Embodiments) In the above-described embodiment, the probe support jig 6 and the probe 7 are set in the setting step A, and a state in which the probe 7 rides on the bump electrode 14 is formed. The probe support jig 6 in which the probe has been set in advance is lowered from the heating step B in a position where the bump electrode 14 has been melted in the heating step B. You may make a state that contains.

Although the setting step A, the heating step B, the cooling step C, and the test step D are arranged in a straight line, the transfer part of the transfer pallet 4 and the probe supporting jig 6 is used as a rotary table, and the desorption step and the heating step are performed. You may comprise so that a process, a cooling process, and a test process may be circulated. Further, the composition of the steps may be divided as described above, or conversely, the steps may be integrated and set, heated, cooled, tested, and removed at one place, for example.

Probe support hole 6a of probe support jig 6
Are the bump electrodes 14 which have clamped the probe 7 and melted.
When the probe 7 is solidified together with the solder, the clamp may be released and the probe 7 may be freely pulled out and supported.

The heating jig 8 may directly heat the upper surface of the semiconductor chip 13 instead of from below the transfer pallet 4, for example, when infrared rays are used.
Similarly, the upper surface of the semiconductor chip 13 may be directly cooled by cooling air or the like.

FIG. 3 is an enlarged view of a tip portion of a semiconductor bump electrode testing apparatus according to another embodiment of the present invention. The pulling jig 12 may be formed as a claw such as a tweezer, and the upper end of the probe 7 in the form of a rod may be clamped and pulled. Reference numeral 7a denotes an embossed portion for preventing falling off.

[Brief description of the drawings]

FIG. 1 is a diagram showing an overall configuration of a semiconductor bump electrode test apparatus according to an embodiment of the present invention.

FIG. 2 is a graph showing transition of the temperature of a bump electrode.

FIG. 3 is an enlarged view of a tip portion of a semiconductor bump electrode testing apparatus according to another embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 6 probe supporting jig 7 probe 8 heating jig 9 cooling jig 10 movable part 11 load cell 12 tension jig 13 semiconductor chip (or semiconductor wafer) 14 semiconductor bump electrode

Claims (6)

[Claims] 1. A test method for sequentially testing the tensile strength of a plurality of semiconductor bump electrodes (14) formed on a semiconductor chip (13), wherein each probe (7) is inserted into each of the bump electrodes (14). ) Is placed directly above each of the bump electrodes (14), and the semiconductor chip (13) on which the bump electrodes (14) are mounted is heated to a temperature at which the metal of each of the bump electrodes (14) melts. Each of the probes (7) is inserted into the molten metal of each of the bump electrodes (14), and the molten metal of each of the bump electrodes (14) is cooled and solidified together with each of the probes (7). Each of the probes (7) solidified in the bump electrode (14) is sequentially pulled, and the tensile strength of each of the bump electrodes (14) is tested by detecting a pulling force at the time of pulling. The method of testing the conductor bump electrode. 2. A test method for sequentially testing the tensile strength of a plurality of semiconductor bump electrodes (14) formed on a semiconductor chip (13), wherein the semiconductor chip (1) on which the bump electrodes (14) are mounted is mounted.
3) is heated to a temperature at which the metal of each of the bump electrodes (14) melts, and then each probe (7) is inserted into the molten metal of each of the bump electrodes (14), and each of the molten bump electrodes (14) is melted. The metal of (14) is cooled and solidified together with the respective probes (7), and the respective probes (7) solidified in the respective bump electrodes (14) are sequentially pulled, and the tensile force at the time of pulling is detected. Testing the tensile strength of each of the bump electrodes (14). 3. A test apparatus for fixing a probe (7) to each semiconductor bump electrode (14) to be tested and testing the tensile strength of each bump electrode (14) by pulling the probe (7). The probes (7) inserted into the bump electrodes (14), respectively; and a probe support jig (6) for positioning and supporting the probes (7) with respect to the bump electrodes (14). And a semiconductor chip (13) on which the bump electrodes (14) are mounted is connected to each of the bump electrodes (14).
A heating jig (8) for heating the metal to a temperature at which the metal melts;
A cooling jig (9) for cooling and solidifying the molten metal of each bump electrode (14) together with each probe (7).
A load cell (11) for converting a force or a weight into an electric signal proportional thereto, a movable part (10) for holding and moving the load cell (11) up and down, and the probes under the load cell (11). And a jig (12) for connection with the semiconductor bump electrode (7). 4. The semiconductor according to claim 3, wherein the heating jig heats and melts the metal of each of the bump electrodes on the semiconductor chip substantially simultaneously. Testing equipment for bump electrodes. 5. The probe support jig (6) is arranged such that the probe (7) is located directly above each bump electrode (14) with respect to each bump electrode (14) on the semiconductor chip (13). 4. The apparatus for testing a semiconductor bump electrode according to claim 3, wherein the semiconductor bump electrode is positioned and supported. 6. The probe (7) that inserts the metal of each of the bump electrodes (14) melted on the semiconductor chip (13) into each of the bump electrodes (14). 4. The apparatus for testing a semiconductor bump electrode according to claim 3, wherein said semiconductor bump electrode is cooled and solidified almost simultaneously.