KR20000007516A - Flip chip burn-in test substrate and burn-in testing method using thereof - Google Patents

Abstract

PURPOSE: A flip chip burn-in test substrate and burn-in testing method using thereof are enable to burn-in test the flip chip and a BGA(ball grid array) package by using single burn-in test socket. CONSTITUTION: The burn-in testing method comprises the steps of mounting a bonding pad(110) of a flip chip(100) to a substrate bonding pad(132) of a flip chip burn-in test substrate(130); connecting the flip chip burn-in test substrate(130) to a burn-in test socket(140); performing burn-in test by loading the burn-in test socket(140) to a burn-in region; identifying a fault of flip chip by unloading the flip chip; and removing the flip chip from the flip chip burn-in test substrate(130).

Description

Flip chip burn-in test board and burn-in test method using same

The present invention relates to a flip chip burn-in test substrate and a test method using the same, and more particularly, a flip chip burn-in test attached to a flip chip dedicated test substrate is a BGA or PGA type flip chip burn-in. One-in-one socket for flip chip and BGA package by mounting on flip-in test board and burn-in test by connecting flip chip burn-in test board to burn-in socket for BGA package or burn-in socket for PGA package The present invention relates to a flip chip burn-in test substrate and a burn-in test method using the same.

In general, a flip chip package includes a plurality of highly integrated semiconductor devices fabricated on a pure silicon wafer substrate, and then bumps are formed on bonding pads formed in each semiconductor device. It is manufactured through the process of aligning and connecting the flip chip to the bump formed on the printed circuit board in the state of forming the flip chip by sawing separately.

The flip chip package manufactured through such a procedure is subjected to burn-in test for early detection of a flip chip package which is likely to be defective due to poor physical and electrical stresses. Supplied to the consumer.

In the flip chip burn-in test method, a solder chip is bonded to a flip chip bonding pad in a state in which a non-surface conductive pattern and a terminal connected to the conductive pattern are formed on a flip chip test board, and a high melting point solder ball is attached to the conductive pattern. After mounting in a burn-in chamber, a burn-in test is performed by loading a test board for flip chip having a flip chip mounted therein.

Then, when the burn-in test is finished, the test board for flip chip is unloaded from the burn-in chamber, the good flip chip and the bad flip chip are tested again, the flip chip is removed from the flip chip test board, and then the bonding pad of the flip chip is Reflow the solder attached to it to form solder balls.

However, in the case of burn-in test of the conventional flip chip, the flip chip must be mounted on the flip chip dedicated burn-in test board to enable burn-in test, which is incompatible with other similar packages such as BGA package and PGA package. There is a problem.

In addition, when the flip chip is soldered to a dedicated burn-in test board and then tested and desoldering to separate the good and bad parts into separate chips, the solder balls are rippled again due to the shape of the solder balls. There is a problem in that the shape of the solder ball by the method such as low occurs.

Accordingly, the present invention takes account of such a conventional problem, and an object of the present invention is to burn-in a flip chip mounted on a BGA burn-in test socket for testing a BGA package or a PGA burn-in test socket for testing a PGA package. It's meant to be testable.

Still other objects of the present invention will become more apparent in the detailed description that follows.

1 is a rear view of a flip chip.

2 is a perspective view illustrating mounting a flip chip on a flip chip burn-in test substrate according to the present invention;

Figure 3a is a perspective view showing a flip chip mounted on a flip chip burn-in test substrate according to the present invention.

FIG. 3B is an enlarged cross-sectional view of the circle of FIG. 3A; FIG.

4 is a cross-sectional view taken along line II ′ of FIG. 5 showing an embodiment of a flip chip burn-in test substrate according to the present invention.

5 is a cross-sectional view taken along line II ′ of FIG. 5 showing another embodiment of a flip chip burn-in test substrate according to the present invention.

FIG. 6 is a partial perspective view showing that a BGA type test substrate having a flip chip mounted thereon is remounted in a burn-in socket; FIG.

7 is a flow chart illustrating a flip chip burn-in test method according to the present invention.

In order to achieve the object of the present invention, a flip chip burn-in test substrate has substrate bonding pads formed on one side of a substrate used for a printed circuit board, and electrically connected to the substrate bonding pads on the other side of the substrate. It is formed by forming a metal terminal having a high melting temperature.

The substrate bonding pads of the flip chip burn-in test substrate thus formed are mounted by solder balls formed on the bonding pads of the flip chip, wherein a solder compound lower than the melting temperature of the solder balls is formed on the upper surface of the substrate bonding pads, and the solder balls are separated from the substrate bonding pads. Minimize damage to the solder balls when soldering or desoldering.

The metal terminals of the substrate thus formed are burn-in tested after being connected to burn-in sockets for burn-in testing other types of BGA and PGA packages.

Hereinafter, a flip chip burn-in test substrate and a test method using the same will be described with reference to the accompanying drawings.

1 is a rear view of the flip chip.

A plurality of flip chip bonding pads 110 are formed on the back surface of the flip chip 100, and the high melting point solder balls 120 are melted at a relatively high temperature, for example, 315 ° C. in the flip chip bonding pad 110. It is statbed.

The flip chip 100 thus formed is electrically coupled to a BGA burn-in test socket, a PGA burn-in test socket, to be described later, and then flip chip burn-in for burn-in testing in a burn-in chamber (not shown). Is temporarily attached to the test substrate.

As shown in FIG. 2, the flip chip burn-in test substrate 130 according to the present invention includes a substrate body 131, a substrate bonding pad 132, and a burn-in socket connection terminal 133.

In detail, the substrate body 131 is formed of an organic material, and a substrate bonding pad region 132a is formed on an upper surface of the substrate body 131 formed in a flat rectangular shape that is somewhat larger than the flip chip 100, and the substrate body 131. A burn-in socket connection terminal region (not shown) is formed at a lower portion of the substrate to be electrically connected to the substrate bonding pad 132 by wiring.

As described above, a conductive substrate bonding pad 132 is formed in the substrate bonding pad region 132a, and solder (Pb / Sn), tin (Sn), gold (Au), and the like are formed on an upper surface of the substrate bonding pad 132. By the combination of the low melting point solder compound 132b having a property of melting at about 183 ℃ is applied.

Of course, the position of the substrate bonding pad 132 corresponds to the position of the bonding pad 110 of the flip chip 100 mentioned above, and the size of the substrate bonding pad 132 is the bonding pad 110 of the flip chip 100. It is formed to be somewhat larger than), the number of bonding pads 110 and the number of substrate bonding pads 132 of the flip chip 100 is configured to be the same.

The reason why the solder compound 132b formed on the upper surface of the substrate bonding pad 132 configured as described above is mixed with solder, tin, and gold is used to form the substrate bonding pad 132 when the substrate bonding pad 132 is recycled. This is to facilitate.

FIG. 3A is a perspective view illustrating a state in which a substrate bonding pad and a bonding pad of a flip chip are connected, and FIG. 3B is an enlarged sectional view of the circle of FIG. 3A.

As shown in FIG. 3A, the substrate bonding pads 132 and the flip chip 100 are attached to each other. At this time, the upper surface of the substrate bonding pads 132 has a solder ball formed on the flip chip 100 with a melting temperature. It is preferable that a solder compound 132b composed of solder, tin, and gold lower than the melting temperature of 120 is formed.

Since the melting temperature of the solder compound 132b is lower than the melting temperature of the solder ball 120 attached to the bonding pad 110 of the flip chip 100, the attach temperature of the solder ball 120-solder compound 132b is increased. When set higher than the melting temperature of the solder compound 132b and lower than the melting temperature of the solder ball 120 attached to the bonding pad 110 of the flip chip 100, the solder ball 120 does not melt and the solder compound 132b. The solder ball 120 is mounted on the solder compound 132b of the substrate bonding pad 132 in a molten state.

Meanwhile, the burn-in socket connection terminal is installed in the burn-in socket connection terminal region 134a formed under the substrate body 131.

The burn-in socket connection terminal is formed of a metal ball or a metal pin having a very high melting point in the same size shape as the solder ball 120.

At this time, when the burn-in socket connection terminal according to the present invention is electrically coupled with the BGA burn-in test socket, the burn-in socket connection terminal 133 becomes a metal ball as shown in FIG. When the in socket connection terminal is electrically coupled with the PGA burn-in test socket, the burn-in socket connection terminal 135 is preferably a metal pin as shown in FIG. 5.

In addition, the burn-in socket connection terminals 133 and 135 are formed of metal balls and metal pins that are much higher than the solder ball 120 melting temperature of the flip chip 100, so that the burn-in socket connection terminals during the burn-in test performed in a high temperature environment. The 133 and 135 are not lost, and the flip chip burn-in test substrate according to the present invention can be recycled again and again.

The flip chip burn-in test board 130 formed as described above has only a partial BGA burn-in test socket 140 as shown in FIG. 6 when the burn-in socket connection terminal 133 mentioned above is a metal ball. Into the burn-in chamber (not shown) is mounted on the burn-in test is performed.

Meanwhile, when the burn-in socket connecting terminal 135 is a metal pin, the burn-in socket connection terminal 135 is inserted into a burn-in chamber (not shown) while being mounted in a PGA burn-in test socket (not shown) to perform a burn-in test.

When the burn-in test is finished, other tests are performed, and then the solder compound 132b of the substrate bonding pad 132 is lower than the melting temperature of the solder ball 120 attached to the bonding pad 110 of the flip chip 100. A temperature higher than the temperature is applied to the solder balls 120 and the substrate bonding pads 132 attached to the bonding pads 110 of the flip chip 100 so that the solder balls 120 of the flip chips 100 are not melted, but only the substrate. The solder compound 132b formed on the bonding pad 132 is melted so that the solder ball 120 of the flip chip 100 may be desoldered in its original shape.

The burn-in test method of the flip chip using the flip chip burn-in test substrate of the present invention configured as described above will be described with reference to the flowchart of FIG. 7.

First, the flip chip 100 fabricated on a pure silicon wafer by a semiconductor manufacturing process is sawed into individual chips, and then, a pre-preparation step for burn-in test is applied to the bonding pad 110 of the flip chip 100. After attaching the melting point solder ball 120, the solder ball 120 of the flip chip 100 is aligned with the solder compound 132b of the substrate bonding pad 132 of the flip chip burn-in test substrate 130, and then reflowed. It mounts on the upper surface of the molten solder compound 132b by the method (step 10).

At this time, the burn-in socket connection terminals 133 and 135 formed on the flip chip burn-in test substrate 132 are preferably metal balls or metal pins. In the present invention, metal balls are used as a preferred embodiment.

At this time, the mounting temperature at which the solder ball 120 of the flip chip 100 is mounted on the substrate bonding pad 132 is lower than the melting temperature of the solder ball 120 of the flip chip 100, and the solder formed on the substrate bonding pad 132 is formed. It is set higher than the melting temperature of compound (132b).

When the flip chip 100 is mounted on the substrate bonding pad 132, the metal ball type burn-in socket connection terminal 133 of the flip chip burn-in test substrate is placed at the designated position of the BGA burn-in test socket 140. (Step 20).

Subsequently, the BGA burn-in test socket 140 to which the flip chip burn-in test substrate 130 is connected is loaded into a burn-in chamber (not shown) (step 30) and the burn-in test is performed. 40).

Subsequently, when the burn-in test is finished, the BGA burn-in test socket 140 is unloaded from the burn-in chamber (step 50), and a good quality inspection is in progress so that the flip chip is classified as good or bad ( Step 60), the flip chips 100 attached to the flip chip burn-in test substrate 130 after sorting are separated from the flip chip burn-in test substrate 130 (step 70).

At this time, the temperature at which the solder ball 120 of the flip chip 100 is desoldering from the solder compound 132b of the substrate bonding pad 132 is lower than the melting temperature of the solder ball 120 of the flip chip 100. , Higher than the melting temperature of the solder compound 132b.

Thereafter, the solder ball 120 of the flip chip 100 desoldered from the solder compound 132b is processed by a reflow method (step 80), and then a subsequent process is performed.

As described in detail above, the flip chip burn-in test is performed by remounting the flip chip to the BGA burn-in test socket or the PGA burn-in test socket while the flip chip is mounted on the BGA type flip chip burn-in test board. This allows the burn-in test of flip chip and BGA packages, flip chip and PGA packages with a single burn-in test socket.

Claims (10)

Mounting the bonding pads of the flip chip to the substrate bonding pads of the flip chip burn-in test substrate; Connecting the flip chip burn-in test substrate to a burn-in test socket; Loading the burn-in test socket into a burn-in area to perform a burn-in test; Unloading the flip chip after the burn-in test is completed to check for a flip chip failure; Removing the flip chip from the flip chip burn-in test substrate. The method of claim 1, wherein the mounting of the bonding pad of the flip chip to the substrate bonding pad comprises mounting a solder ball having a predetermined melting temperature on the flip chip bonding pad, and then not melting the solder ball. Burn-in test method using a flip chip burn-in test substrate, characterized in that by melting only to attach the flip chip bonding pad and the substrate bonding pad. 2. The burn-in test method according to claim 1, wherein the solder balls formed on the flip chip removed from the flip chip burn-in test substrate are heated and processed once again. A substrate body; A substrate bonding pad formed in the substrate body opposite to the bonding pad of the flip chip and mounted on the bonding pad; And a burn-in socket connecting terminal protruding from the substrate body so as to be connected to the burn-in socket and formed at a position other than where the substrate bonding pad is formed. 5. The flip chip burn-in test according to claim 4, wherein solder balls having a predetermined melting temperature are formed on the bonding pads of the flip chip, and the substrate bonding pads are formed with a solder compound lower than the melting temperature of the solder balls. Board. 6. The flip chip burn-in test substrate according to claim 5, wherein the solder compound is configured such that solder, tin and gold have a predetermined composition ratio. 6. The flip chip burn-in test substrate according to claim 5, wherein the burn-in test connection terminal is a metal ball having a higher melting temperature than the solder ball. 8. The flip chip burn-in test substrate according to claim 7, wherein the burn-in socket is a burn-in test socket for a ball grid array connected to the metal ball. 6. The flip chip burn-in test substrate according to claim 5, wherein the burn-in test connection terminal is a metal pin having a higher melting temperature than the solder ball. 10. The flip chip burn-in test substrate according to claim 9, wherein the burn-in socket is a burn-in test socket for a pin grid array (PGA) connected to the metal pin.