JPH0121620B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for testing flip-chip integrated circuits. A flip chip integrated circuit is a type of integrated circuit in which a large number of bumps serving as electrode portions are formed on one side of a chip. This flip-chip integrated circuit is normally used by being integrally bonded with solder to the surface of a ceramic substrate having input/output terminals to ensure conductivity. However, because burn-in of flip-chip integrated circuits is extremely difficult, defective flip-chip integrated circuits are often fixed onto ceramic substrates, and defective flip-chip integrated circuits are discovered after the semiconductor device is completed. This is often the case. In such a case, it is very complicated to replace the defective flip-chip integrated circuit, and this is a factor that hinders productivity improvement. Also, sometimes problems arise in which the entire semiconductor device, including the normal flip-chip integrated circuit, has to be abandoned.

An object of the present invention is to perform burn-in of a flip-chip integrated circuit and eliminate defective flip-chip integrated circuits before incorporating the flip-chip integrated circuit into a semiconductor device.

The flip-chip integrated circuit testing method of the present invention includes a plurality of electrode portions for connecting to a plurality of bumps that require energization of one flip-chip integrated circuit, and a plurality of terminals for connection to a power source. , the plurality of electrode portions of a test board having at least one set of test circuits comprising the electrode portion and a plurality of conductive portions connecting the terminals and the plurality of bumps of the flip-chip integrated circuit are connected to each other using a conductive organic material. a step of electrically connecting the plurality of terminals of the test board with a power source and conducting a burn-in test by energizing the flip-chip integrated circuit; and heating or contacting the flip-chip integrated circuit with a solvent. The present invention is characterized in that the steps of removing the conductive organic binder and separating the flip-chip integrated circuit from the test substrate are sequentially performed.

In the test method of the present invention, a burn-in test substrate is used in place of the ceramic substrate of the semiconductor device. Then, a flip-chip integrated circuit to be tested is wired onto this test board, and after burn-in, the flip-chip integrated circuit is separated from the test board and a burn-in test is performed.

This test board includes a plurality of electrode sections for connecting to a plurality of bumps that require energization during burn-in of one flip-chip integrated circuit, a plurality of terminals for connecting to an external power supply, and the electrode section and It has at least one set of test circuits comprising a plurality of conductive parts connecting the terminals.

The first step of the present invention is to bond, with a conductive organic binder, bumps that require energization of at least one flip-chip integrated circuit to the electrode portions constituting a set of test circuits on the test board.
When having multiple sets of test circuits, burn-in of multiple flip-chip integrated circuits can be performed at one time.

The second step is a step of connecting the plurality of terminals of the test board to an external power source and applying power to the flip-chip integrated circuit to perform burn-in. In addition to energizing a flip-chip integrated circuit, the flip-chip integrated circuit can also be energized under environmental conditions similar to the environment in which the flip-chip integrated circuit is used.

The third step is, after burn-in, heating or contacting the conductive organic binder with a solvent to melt or dissolve the conductive organic binder and take out the burned-in flip-chip integrated circuit from the test substrate.

To explain this method in detail, for example, the test board 1 shown in FIGS. 1 and 2 can be used as the test board. This test board 1 is made of transparent ceramics such as sapphire or quartz, and three sets of test circuits 2 are formed on the board 1. Each circuit 2 includes five electrode portions 31 for connection to bumps of a flip-chip integrated circuit;
32, 33, 34, 35 and five terminals 41, 4
2, 43, 44, 45 and five electrode parts 31~
35 and terminals 41 to 45, respectively. Incidentally, on the upper surfaces of the conductive parts 51 to 55, an insulating film 6 of a glass layer is formed by, for example, film thickness printing.
Using this test board 1, as shown in the cross section of FIG.
Apply. Before the conductive rubber 7 is cured, the solder bumps 81 of the flip-chip integrated circuit 8 are pressed onto the uncured conductive rubber 7. A cross section in this state is shown in FIG. In this state, the conductive rubber 7 is cured, and the electrode parts 31 to 35 of the test board 1 and the solder bumps 81 of the flip-chip integrated circuit 8 are bonded. Next, the connector 9 is fitted onto the terminals 41 to 45 of the test board 1 as shown in the cross section in FIG. 5, and the terminals 41 to 45 are connected to an external power source (not shown). Next, necessary current and signals are passed through the connector to burn-in each flip-chip integrated circuit 8 on the test board 1. After burn-in, the test board 1 is separated from the connector 9, and the conductive rubber 7 is immersed in or sprinkled with a suitable solvent that dissolves or swells the bonding force and weakens the bonding force. The flip chip integrated circuit 8 is separated from 35. Burn-in of the flip-chip integrated circuit 8 is thereby achieved.

Faulty flip-chip integrated circuits are removed by burn-in, and only flip-chip integrated circuits that pass the test are used as flip-chip integrated circuits for the next semiconductor device. Although the explanation has been made using a transparent substrate as the test substrate, if this transparent substrate is used, for example, the conductive portions 31 on the test substrate 1 can be viewed from the back side of the substrate with a television camera or the like having pattern recognition ability. .about.35 and the bumps 8 of the flip-chip integrated circuit 8, and there is an advantage that the bumps of the flip-chip integrated circuit can be automatically fixed to the electrode portions.

If this television camera is not used, the test board does not need to be transparent. Also, although only three test circuits are shown on the test board for the sake of simplicity, normally several to several hundred test circuits are assembled, and a large number of flip-chip integrated circuits are burn-in at one time. . Furthermore, the terminals formed on the board can also be provided all around the test board.

As a conductive organic binder, conductive rubber seems to be the best. Because this conductive rubber is flexible, even if distortions such as thermal expansion coefficients occur between the test board and the flip-chip integrated circuit during burn-in, the conductive rubber absorbs the distortion and improves the flip-chip integrated circuit. It has the advantage of not causing abnormal distortion to the circuit. More preferably, a thermoplastic soft resin-like conductive polymer is used.
In this case, the hardening and softening of the binder heats the test substrate above its softening point. Alternatively, by cooling the flip-chip integrated circuit to below its softening point, it becomes possible to fix the flip-chip integrated circuit to the test board and separate it. In this case, the softening temperature needs to be higher than the test temperature during burn-in.

The flip-chip integrated circuit can be separated from the test substrate by dissolving or swelling the conductive organic binder with a suitable solvent or the like in conjunction with heating to lose its adhesive strength.

The test board can be used repeatedly. In this case, in the case of a thermoplastic conductive organic binder, repeated use may be possible.
However, when a thermosetting conductive organic binder is used, it is necessary to apply an uncured conductive organic binder to the conductive portion every burn-in. In special cases, a conductive organic binder may be applied to the tips of the bumps of the flip-chip integrated circuit, and the flip-chip integrated circuit with the bumps coated with the binder may be pressed and bonded to a test substrate.

The above-described method for testing flip-chip integrated circuits of the present invention focuses on the fact that the conductive organic binder can easily eliminate its action as a binder by heat or a solvent, and uses the method of testing the flip-chip integrated circuit between the solder bumps of the flip-chip integrated circuit and the electrode portion of the test substrate. A removable bond was achieved, thereby making burn-in possible. By the test method of the present invention,
Since it is possible to check individual flip-chip integrated circuits by burn-in, only defect-free flip-chip integrated circuits can be supplied as components of semiconductor devices. For this,
This eliminates waste such as repair work due to defects in the flip-chip integrated circuit after assembly of the semiconductor device and disposal of the semiconductor device.

[Brief explanation of drawings]

FIG. 1 is a plan view of a test board explained as a specific example of the test method of the present invention, and FIG. 2 is an A of FIG.
3 is a partial sectional view illustrating the first step of the test method of the present invention, FIG. 4 is a partial sectional view of a flip-chip integrated circuit fixed to a test board, and FIG. FIG. 3 is a partial cross-sectional view of the test board assembled to the connector. 1...Test board, 2...Test circuit, 31-35
... Electrode part, 41-45... Terminal, 51-55... Conductive part, 6... Insulating film, 7... Conductive rubber, 8... Flip chip integrated circuit, 81... Solder bump, 9... Connector.

Claims (1)

[Claims] 1. A plurality of electrode sections for connecting to a plurality of bumps that require energization of one flip chip integrated circuit, a plurality of terminals for connection to a power source, and the electrode section. and a plurality of conductive parts connecting the terminals, the plurality of electrode parts of the test board having at least one set of test circuits and the plurality of bumps of the flip-chip integrated circuit are electrically connected using a conductive organic binder. a step of connecting the plurality of terminals of the test board to a power source and conducting a burn-in test by energizing the flip-chip integrated circuit; heating the flip-chip integrated circuit or contacting it with a solvent to 1. A method for testing a flip-chip integrated circuit, comprising sequentially performing the steps of removing the organic binder and separating the flip-chip integrated circuit from the test substrate. 2. The test method according to claim 1, wherein the conductive organic binder is a thermoplastic conductive rubber.