JP3515904B2 - Semiconductor wafer temperature test equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screening test apparatus for finding latent defects by energizing an integrated circuit formed on a semiconductor wafer at high temperature in the wafer state.

[0002]

2. Description of the Related Art A screening test apparatus generally called a burn-in apparatus packages IC chips obtained by dividing a semiconductor wafer, and then conducts a current test in a hot atmosphere of a predetermined temperature to detect potential defects. Screening is performed by making it actual.

Since such a conventional apparatus requires a large constant temperature apparatus and generates a large amount of heat, it is necessary to separate the apparatus from other manufacturing lines and to perform it in a separate room. It is desirable to perform a burn-in test at the stage of the wafer before being made into chips, because it is wasteful because defective products are found after packaging because it requires time and effort. .

In the burn-in system for meeting such a demand, it is necessary to maintain the wafer at a uniform temperature when applying a heat load to the semiconductor wafer. For example, when maintaining the wafer at an arbitrary temperature selected from the range of 120 to 150 ° C., it is required to maintain a temperature difference of ± 1 ° C. or less with respect to the target temperature. As a temperature control plate for a wafer used for this purpose, a series of refrigerant flow paths and heaters are built in a plate-like body made of a material having good heat conductivity such as copper, aluminum, or alloys thereof, A coolant for cooling the wafer to a temperature lower than the target temperature is supplied to the semiconductor wafer, and the heater is heated to adjust the temperature of the plate-shaped body to bring the semiconductor wafer brought into contact with the plate-shaped body to a predetermined target temperature. A temperature controlled plate adapted to be maintained is disclosed. (See Japanese Patent Laid-Open No. 8-340030).

Most of the heat generated by energizing the semiconductor wafer is removed by the contact with the temperature control plate, but a part of the heat is emitted as radiant heat or the surrounding atmosphere or electrical contacts. It is released through. Therefore, the amount of heat radiated between the peripheral portion of the wafer having a low ambient temperature and the central portion of the wafer surrounded by the heat generating portion is different. For example, when the calorific value of the entire disk-shaped wafer having a diameter of about 20 cm is 1.2 kw, a temperature difference of about 10 ° C. occurs between the central portion and the peripheral portion, so that the accuracy of the burn-in test is not improved. There is a risk that it will drop significantly.

As a means for eliminating such non-uniformity of the temperature distribution of the wafer, a temperature distribution symmetrical to the temperature distribution of the wafer such that the temperature of the central portion of the temperature control plate is low and the temperature of the peripheral portion is high. There is a method of adjusting the temperature of the wafer by appearing, but a method of forming a cooling medium flow path in the temperature control plate and flowing a cooling liquid through it is an option.
If the cooling fluid leaks from the temperature control plate or the piping to the peripheral equipment, it may cause serious damage. Furthermore, in order to increase the test efficiency, it is necessary to operate many temperature control plates at the same time, but these many temperature control plates satisfy various conditions such as specific heat, viscosity, boiling point, electrical insulation, and corrosiveness. In order to supply the expensive cooling liquid at a predetermined temperature, there are disadvantages that the equipment becomes complicated and the size becomes large, and the position of the temperature control plate is restricted by the piping. Furthermore, including the center of the temperature control plate,
The method in which the temperature control plate is cooled to a certain temperature level or lower and the temperature difference is generated by the electric heater has a drawback that the loss is large in terms of heat balance.

Further, in the burn-in test apparatus, it is required that a test current be surely flowed to a large number of IC circuits formed on a wafer which is kept at a predetermined test temperature. As the energizing means, probe means capable of reliably contacting and energizing thousands to tens of thousands of energizing contacts on the wafer surface, and an energizing substrate holding the probe means are required. The current-carrying substrate having these probe means naturally undergoes thermal expansion under the influence of heat generation of the wafer. Therefore, even if the coefficient of thermal expansion of the wafer and the coefficient of thermal expansion of the probe means are made to coincide with each other, the yield of ICs formed on the wafer is different for each wafer, and therefore the calorific value is naturally different and the wafer is also different. Similarly, the current-carrying board that holds the probe means also deforms under the influence of heat from the surrounding environment.
Unless the temperature of the current-carrying board is kept uniform in the specified temperature range,
It is unavoidable that the probe means and the energizing contact on the wafer surface are misaligned and the connection between them is cut off.

A large precision positioning device is required to accurately position the current-carrying substrate holding the probe means on the wafer. Since it is not possible to attach these devices to the individual wafer burn-in devices in terms of cost, first, the one in which the energized substrate and the wafer are positioned is mounted on the temperature control plate described above, and then the energized substrate is mounted. It has been proposed to perform a wafer burn-in test by connecting the power-on test control device and the power-on test control device. In that case, the close contact between the wafer positioned on the probe means and the temperature control plate side is also essential to uniformly maintain the heat transfer between the temperature control plate and the wafer.

When the wafer is placed on the temperature control plate, it may be directly placed on the temperature control plate and brought into contact therewith, or the wafer and the probe means may be accurately positioned and connected to each other to transfer heat. It is considered that the plate is placed on the temperature control plate via the plate. In any case, the adhesion between the temperature control plate and the wafer is controlled by the vacuum pressure supplied between them. When using the heat transfer plate, it is necessary to provide a connection port between the vacuum pressure supply path and the vacuum source on the side of the heat transfer plate. However, such a configuration in which the vacuum pressure supply port is provided on the side surface of the temperature control plate causes the temperature of the temperature control plate to be non-uniform during the transfer of heat to and from the surrounding atmosphere surrounding the temperature control plate, and the wafer temperature is disturbed. Is the cause.

[0010]

A first object of the present invention is to disclose a wafer burn-in apparatus capable of performing a highly accurate screening test by uniformly maintaining a semiconductor wafer and a means for energizing the wafer at a target temperature. Especially. A second object of the present invention is to disclose an apparatus capable of performing a highly accurate wafer burn-in test efficiently at low cost. A third object of the present invention is to disclose a wafer burn-in apparatus capable of supplying a test current by reliably contacting a large number of circuit elements formed on a wafer with probe means. A fourth object of the present invention is to
It is an object of the present invention to disclose a wafer burn-in device which does not cause contact failure between a wafer current-carrying portion and probe means due to thermal expansion by maintaining the probe means and the current carrying substrate holding the probe means at a uniform temperature.

[0011]

A first gist of the present invention is to provide a plate having a good thermal conductivity with a smooth surface on the surface thereof, and a radiating fin projectingly provided on the back surface of the plate. A temperature adjusting plate of a semiconductor wafer provided with a heater on the back surface or inside of the strip, a temperature adjusting plate at the time of a burn-in test of the semiconductor wafer, a semiconductor wafer to be tested, and a means for energizing the wafer, In a test chamber formed so as to include a test apparatus including, a blower path that includes an air heater and a blower and passes through the heat radiation fins is formed in the test chamber, and a means for energizing the wafer is provided. Is composed of a first conductive substrate having a probe means on one surface for contacting the individual integrated circuits formed on the semiconductor wafer and a second conductive substrate for supplying current to the first conductive substrate, First communication Other side of the substrate, sometimes the heating body is provided in the burn-in test apparatus for a semiconductor wafer, comprising.

In the above description, aluminum, copper, alloys thereof, graphite and the like are typical examples of the heat-conductive plate-like body which constitutes the temperature control plate. It is desirable that the heat radiation fins be integrally extended from a plate-shaped body made of these materials. The heat radiation fins may be evenly provided in a certain area including the center of the plate-shaped body, but the shape of the heat radiation fins varies depending on the air blowing direction, but for example, if the air blowing direction is substantially parallel to the temperature control plate plane. if you did this,
The center of the heat dissipation fin group projects most from the back surface of the plate,
The degree of protrusion (separation distance) from the back surface of the plate-shaped body becomes smaller from the center toward the periphery of the heat dissipation fin group,
If the shape of the heat radiation fins is determined, the cooling efficiency is highest near the center of the temperature control plate, and can be gradually reduced toward the periphery. Alternatively, even if the radiation fins are formed so that the radiation fins are installed densely in the central portion of the back surface of the plate-like body and sparsely in the peripheral portion,
The heat dissipation fins can provide a temperature difference between the center of the temperature control plate and the central region surrounding it.

Since a test chamber is required for each wafer to be tested, it is desirable that the test chamber be as flat and small in volume as possible in order to downsize the entire apparatus. The test chamber needs to be opened and closed when the energizing means to the wafer and the wafer positioned and fixed to the energizing means are closely attached to and detached from the temperature control plate, so that the operation does not hinder the operation. You need to have a structure. For example, a wafer and a current-carrying substrate equipped with probe means for positioning and holding the wafer are moved from the side directly above the smooth surface of the temperature-control plate, and then the temperature-control plate and the wafer are brought into close contact with each other and the current-carrying is performed from above. Assuming that the energizing connector descends to the board to perform the attaching / detaching operation, the test chamber includes a lower half forming member that surrounds the probe below the temperature control plate and an upper half forming member that moves up and down together with the connector. When the connector is electrically connected to the conductive substrate, the upper half forming member and the lower half forming member may contact each other to form a test chamber. When a wafer or the like is mounted from above the temperature control plate, a test chamber that moves in the left-right direction and opens and closes may be configured.

In such a test chamber, at least a temperature control plate, a wafer, a probe means for contacting an energizing probe as an energizing means to the wafer, an energizing substrate to the probe means, etc. are included, and a blower is provided. An air heater is provided. Therefore, the blower may be in any position as long as the air blown out from the blower is provided at a position where a circulating blower path that always passes through the heat radiation fins can be formed. In the air heater, an electric heater such as a sheathed heater with fins facilitates accurate temperature control.

On the other hand, the heater (plate heater) provided in the heat-conductive plate-shaped body may be attached to the back surface of the peripheral portion of the plate-shaped body so as to be able to exchange heat, or it may be integrally formed in the plate-shaped body. It may be buried. Also in this plate heater, in accordance with the temperature distribution of the wafer, an electric heater is used to form the density of the heating wires so that the heating wires are sparsely distributed toward the center and denser toward the periphery. It is preferable that the temperature distribution is symmetrical to the temperature distribution of 1. Thereby, the temperature control plate and the semiconductor wafer are
By transferring heat, the temperature distribution of the wafer can be made uniform. The heater is a heat conductive plate embedded in the heat conductive plate, or a plate or sheet heater formed by embedding the heat wire in a metal plate or a heat resistant sheet. The one closely contacted with the shape is used.

The first energizing substrate is provided with a probe means (for example, a probe card) for energizing an integrated circuit formed on a semiconductor wafer which is a device under test, on one surface thereof. In order to secure the contact with the DUT for energization, it is necessary to avoid deformation such as warpage due to the non-uniform temperature distribution of the energized substrate as much as possible. When the semiconductor wafer is energized, the semiconductor wafer generates heat due to the circuit resistance and its temperature rises, but the influence naturally extends to the first energized substrate. As a result, the first conductive substrate has a higher temperature in the central portion than in the peripheral portion in accordance with the temperature distribution of the semiconductor wafer, and further, the heat radiation of the first conductive substrate itself in the peripheral portion is higher than that in the central portion. Since it is easier, the first current-carrying substrate also has a non-uniform temperature distribution in which the central portion facing the central portion of the semiconductor wafer has a high temperature and the peripheral portion has a reduced temperature.

This non-uniform temperature distribution inevitably causes deformation even in the first current-carrying substrate mainly made of a material having a small coefficient of thermal expansion such as a glass plate or a ceramic plate, and deformation such as warpage occurs. The heating element is for heating the first current-carrying substrate in close contact with the first current-carrying substrate from the surface opposite to the surface on which the probe means is provided, and for eliminating the uneven temperature distribution, It is a heating element that operates so as to produce a temperature distribution opposite to that of the first energizing board (a peripheral portion is high and a central portion is low or there is no heat generation).

As such a heating element, a plate made of a material having good thermal conductivity, or a thin plate made of a heat-resistant material (silicon rubber, mica, polyimide resin, etc.) having a thickness that does not significantly impede heat conduction. Or a film, etc., in which the electric heating wire or the planar heating zone is buried so that the peripheral part has a high wiring density and the central part is sparse or nonexistent, the thin plate or film or the heat conductive plate, For example, a conductive circuit paint is directly printed on the surface of the first energizing substrate or the like (via an insulating coating if necessary), and a heating circuit pattern in which the amount of generated heat is unevenly distributed in the peripheral portion is printed. For example, a film shape in which metal foil such as copper or aluminum formed in a spiral shape or a meandering shape is sandwiched between heat-resistant plastic films, the inside or surface of a heat conductive plate such as aluminum, copper, or brass. The plate-shaped ones that retain the electric heating line and the electric tropical zone can be mentioned. This heating element eliminates the temperature difference between the peripheral portion and the central portion of the first current-carrying substrate, thereby preventing contact failure of the probe means.

A second aspect of the present invention is that the heat-conductive plate-like body has a smooth surface on the surface thereof, and a radiation fin is provided on the back surface of the plate-like body so as to project from the plate-like body. A test including a temperature adjusting plate of a semiconductor wafer provided with a heater on the back surface or inside, a temperature adjusting plate at the time of burn-in test of the semiconductor wafer, a semiconductor wafer as an object to be tested, and an energizing means to the wafer. In a test chamber formed to include the device, a blower passage that includes an air heater and a blower and passes through the heat radiation fins is formed in the test chamber, and a means for energizing the wafer is provided. It is composed of a first conductive substrate having a probe means for contacting each integrated circuit formed on a semiconductor wafer on one surface and a second conductive substrate for supplying current to the first conductive substrate,
A heating element is provided on the other surface of the first conductive substrate, and the heating element and the second conductive substrate are adjacent to each other via a heat insulating means. It is in the burn-in test equipment.

As mentioned above, the probe means may be, for example:
The thin plate-shaped flat surface is provided with a large number (for example, thousands) of current-carrying protrusions corresponding to the current-carrying contacts on the wafer (for example, a probe card). The first current-carrying substrate plays a role of supplying a test current to each of the current-carrying protrusions.
Therefore, the first current-carrying substrate is formed of a flat plate (for example, a glass plate or a ceramic plate) having a small thermal expansion coefficient and having a wiring pattern connected to the current-carrying protrusion, and the wiring pattern is converged. And a plurality of first electrical connection portions (first connectors) that are coupled together. An energizing circuit that is coupled to the plurality of first connectors through a conducting means to collectively organize a large number of conducting paths and a second energizing circuit for connecting the energizing circuit to an energization test control device through a cable. A similar rigid substrate with a connector is the second conducting substrate.

In particular, it is desirable that the first conductive substrate is made of a material having the same coefficient of thermal expansion as that of the frame member forming the skeleton of the probe means in order to hold the probe means. It is desirable to be composed of a material with a low rate. If the frame member constituting the skeleton of the probe means is deformed by thermal expansion due to nonuniform temperature, contact failure will be immediately caused. The temperature of the central part of the first conductive substrate increases due to the heat generated during the conductive test of the wafer, and the temperature difference between the central part and the peripheral part where heat is easily dissipated to the surrounding environment becomes large. Deformation occurs where the central part bulges (warps). The first means for preventing this deformation is the heating element described above.

In addition to such a heating element, an effective means for making the temperature distribution of the first conducting substrate more uniform and more precise is provided between the first conducting substrate and the second conducting substrate. It is a heat insulating means. Examples of the heat insulating means include a heat insulating space at equal intervals and a heat insulating material made of a material that can withstand a test temperature. It is desirable that the widths of the equally spaced heat insulating spaces be at least 2 mm or more in consideration of air permeability. As a heat insulating material, like a plate made of foamed silicone rubber, it does not deteriorate even when exposed to a high temperature of 100 to 150 ° C., and countless fine bubbles are evenly distributed to have a high heat insulating effect. Although a heat insulating material such as a foamed silicon rubber plate having a thickness of about 2 to 5 mm is inferior in heat insulating performance to the heat insulating space, it facilitates the assembly and configuration of the device in this portion.

Due to the presence of the heat insulating means, the heat conduction from the first conducting substrate to the second conducting substrate is cut off, and the thermal influence exerted on the other side is greatly reduced between the two.
As a result, it is ensured that the air flow in the test chamber flows along the first conducting board, and the temperature deviation between the peripheral portion and the central portion of the first conducting board is eliminated. On the other hand, even on the side of the second conductive substrate, the thermal effect of the first conductive substrate is prevented from affecting the side of the second conductive substrate. Therefore, in a high temperature (for example, 100 ° C. or higher) environment, thermal expansion causes the test to end. There is an effect that it is possible to avoid the problem that it is difficult to smoothly attach and detach the connector on the side of the energization test control device and the second connector on the side of the second energization board.

A third gist of the present invention is that the heat-conductive plate-like body has a smooth surface on its front surface, and a radiating fin is provided on the back surface of the plate-like body so as to project therefrom. A test including a temperature adjusting plate of a semiconductor wafer provided with a heater on the back surface or inside, a temperature adjusting plate at the time of burn-in test of the semiconductor wafer, a semiconductor wafer as an object to be tested, and an energizing means to the wafer. In a test chamber formed so as to include the device, an air passage including an air heater and a blower and passing through the heat radiation fins is formed in the test chamber, and the temperature in the test chamber is the temperature. A heat insulating wall that laterally surrounds the adjusting plate, the wafer, and the energizing means to the wafer is formed, and the energizing means to the wafer is contacted to each integrated circuit formed on the semiconductor wafer. And a second conductive substrate that supplies current to the first conductive substrate, and a heating element is provided on the other surface of the first conductive substrate. Is provided in a burn-in test apparatus for semiconductor wafers.

In the test apparatus according to the third aspect, the heat insulating wall surrounding the wafer, the means for energizing the wafer and the side of the temperature control plate in a circulating state is in contact with the side surfaces of these members or a part of the members. It may be provided so as to form a closed space in a state of being fixed to the above, or may be provided at a slight interval. In addition to the heat insulation of the material, the heat insulation wall encloses the above-mentioned members where the uneven temperature distribution directly affects the test accuracy, and minimizes the effects of flowing airflow and radiative cooling. Prevents partial uneven temperature. The heat-insulating wall reduces the thermal influence of the air flow and the ambient temperature in the test chamber on the current-carrying means, the temperature-controlling plate, the wafer, etc. The temperature difference between the ambient temperature and the peripheral temperature is largely eliminated, and precise test temperature control of the wafer is realized, and contact failure between the current-carrying contact of the wafer and the probe means due to thermal deformation of the probe means and the current-carrying substrate (energization error). ) Can be prevented in advance.

A fourth gist of the present invention is that the heat-conductive plate-like body has a smooth surface on the front surface thereof, and a radiation fin is projectingly provided on the back surface of the plate-like body and A test apparatus including a temperature adjusting plate of a semiconductor wafer having a heater provided on the back surface or inside, a temperature adjusting plate at the time of burn-in test of the semiconductor wafer, a semiconductor wafer as an object to be tested, and an energizing means to the wafer. In a test chamber formed so as to enclose, an air heater and a blower are provided, and a blower passage that passes through the heat radiation fins is formed in the test chamber, and the temperature in the test chamber is the temperature. A heat insulating wall surrounding the adjustment plate, the wafer, and the energizing means to the wafer from the side is formed, and the energizing means to the wafer is connected to each integrated circuit formed on the semiconductor wafer. And a second energizing substrate that energizes the first energizing substrate, and a heating element is formed on the other surface of the first energizing substrate. Is provided, and the heating element is adjacent to the second current-carrying substrate via a heat insulating means in the burn-in test apparatus for a semiconductor wafer.

The test apparatus according to the fourth aspect of the invention is characterized by the interaction of the heating element described in the first aspect, the heat insulating means described in the second aspect, and the heat insulation wall described in the third aspect by the combined structure. When comparing the effects of the devices described in the above-mentioned first summary to third summary, the uniformity of the temperature distribution of the energized substrate, the probe means, the wafer, etc. is significantly improved, and it is possible to perform an extremely accurate wafer burn-in test. it can.

According to a fifth aspect of the present invention, in the burn-in test apparatus defined by any one of the first to fourth aspects, the heating element is capable of transferring heat to and from the first current-carrying substrate on one side. The burn-in test apparatus for a semiconductor wafer is characterized in that the burn-in test apparatus for semiconductor wafer is provided on the first current-carrying substrate via a heat equalizing plate composed of closely-contacting heat conductive plates.

As described above, the first conducting substrate holding the probe means is affected by the heat generation of the wafer during the burn-in test, and is influenced by the flow of air in the test chamber and is adjacent to the first conducting substrate. As a result, the temperature of the peripheral portion where heat is easily dissipated tends to be significantly lower than the temperature of the central portion because of the influence of the second conductive substrate, which causes the contact failure of the probe means. The heat equalizing plate quickly guides the heat, which tends to stay in the central portion of the first energizing board, to the peripheral portion. The soaking plate needs to be a material having excellent thermal conductivity as compared with the material of the first current-carrying substrate. For example, an aluminum plate or a copper plate having a thickness of 1 to 2 mm or more is used.

In order to provide the heat equalizing plate on the first current-carrying substrate, a method of bringing the heat-uniforming plate into close contact with a heat-conducting grease or the like, though depending on the property of the current-carrying substrate, is sufficiently effective. The heat of the central portion of the current-carrying substrate quickly moves to the peripheral portion through the heat equalizing plate, so that the temperature difference between the peripheral portion and the central portion of the current-carrying substrate is eliminated. As the heat transfer grease, for example, one obtained by kneading a heat conductive metal oxide powder in silicon oil can be mentioned. In particular, a graphite sheet or the like having a directivity with respect to heat conduction (in other words, the heat conductivity in the plane direction is remarkably superior) may be used as a material for rapidly moving the heat in the central portion to the peripheral portion.

When the effect of the heat equalizing plate is viewed from the side of the heat generating element, the heat generating element provided on one surface of the heat equalizing plate so as to be able to exchange heat is a heat generating element regardless of the wiring pattern. The temperature is different between the place where the heating wire is provided and the place where the heating wire is not provided, and the temperature unevenness cannot be avoided depending on the place. The heat equalizing plate has an effect of largely eliminating, mitigating, and averaging such heat unevenness in the process in which the heat passes through the heat equalizing plate and reaches the first current-carrying substrate. The presence of the soaking plate has the effect of reducing the temperature difference appearing on the first current-carrying substrate, thus reducing the heat load on the heating element and facilitating temperature adjustment.

The test apparatus defined in the first to fifth aspects has a configuration in which the heating element, the heat insulating wall, the heat insulating means, and the heat equalizing plate are appropriately combined and applied. Since the individual effects of each do not have a factor that hinders the other action effects, the action effect of one of these configurations alone exerts a load (barrier height) that the other configuration overcomes. These interactions, by virtue of these interactions, contribute more to the test accuracy than their mere sum, rather than the specifications in which each of them is independently adopted, and therefore a device with all these components is most effective. Excellent test accuracy.

In the wafer burn-in test, a large temperature difference occurs between the central portion and the peripheral portion of the wafer because the heat generated by the electric resistance of the individual integrated circuits on the wafer is different from the heat generated in the periphery of the wafer. It is easy to dissipate the heat, and conversely, the heat gets more concentrated toward the center, which is a major cause. This situation is the same also in the case of the first energizing board. Therefore, the lower the ambient temperature surrounding the peripheral portion of the wafer, the larger the temperature difference between the wafer central portion and the peripheral portion, and the larger the temperature difference required for the temperature control plate.

The temperature adjusting plate of the apparatus of the present invention sets the temperature of the air heater so that the temperature in the test chamber formed during the test is lower than the wafer test temperature by several degrees to several tens of degrees. By performing the test in this state, the wafer is heated to generate a temperature difference from the central portion to the peripheral portion, but the central portion of the temperature control plate is kept at a lower temperature than the peripheral portion by the air blow and the heat radiation fins. Since the peripheral part is heated by the plate heater and kept at a higher temperature than the central part, the difference in the temperature distribution of the wafer during the test can be adjusted within ± 1 ° C as a whole. it can.

The present wafer burn-in test apparatus also includes
During the burn-in test, most of the members that directly and indirectly contact the wafer and influence the wafer temperature can be enclosed in advance in a small-volume test chamber. The temperature difference can be kept small, the load on the temperature control plate is small, and the temperature can be controlled more accurately. Also, the equipment is compact and consumes less energy.

[0036]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a bottom view of the essential parts of an embodiment of a temperature control plate in the test apparatus of the present invention. The temperature control plate 1 is a plate having good heat conductivity,
It has an aluminum disc 2, and the peripheral edge of the disc 2 is
A rising wall 2c is formed by rising a certain width upward from the peripheral portion toward the center. The rising wall 2c
The disk surface 2a surrounded by is a mirror-like smooth surface. Concentric ring-shaped vacuum suction grooves 3a to 3d are formed at equal intervals around the center of the disk. Has been done.
3f is a vacuum supply groove that connects these vacuum suction grooves 3a to 3d to each other, and one end of a vacuum supply path 3 that penetrates the disc 2 in the axial direction is opened in the full 3f. Vacuum supply path 3
The other end of is connected to the vacuum supply tube 3g.

In the vicinity of the center of the disk 2 and the vicinity thereof,
Similarly to the vacuum supply path 3, the back surface 2 of the disk 2 is parallel to the axial direction.
b through the surface 2a, the temperature sensor storage hole 4a,
4b is drilled. A central temperature sensor 5a and a peripheral temperature sensor 5b are housed therein so as to be vertically movable. These temperature sensors 5a and 5b are
In b, the coil springs 5s and 5s are lightly urged downward, and the temperature measuring unit 5h provided at the lower end thereof is
5h projects downward from the surface 2a. 8 and 8 are
O-rings attached to the lower end openings of the storage holes 4a and 4b prevent vacuum leakage. As shown in FIGS. 2 and 3, on the back surface 2b of the disk 2, a large number of heat radiation fins 6, 6, ...
Are hung vertically in parallel with each other.

Further, in the disc 2, a plate heater 7 formed of an electrically insulated electric heating wire heater is embedded in a circular shape with its wiring density dense in the peripheral portion and sparse in the central portion. In the plate heater, instead of the heating wire embedding method, a plate-shaped heater having an electric heating wire such as an electrically insulated nichrome wire built in a ring-shaped flat plate made of a metal having good thermal conductivity is provided on the back surface 2b. It may be attached in a state of being in close contact. Of course, the wiring density of the plate-shaped heater is also arranged so that the peripheral portion of the disk 2 is dense and becomes sparse as it approaches the central portion. Further, a sheet-like heat generating element which generates heat on the entire surface may be integrally attached to the peripheral portion of the back surface of the disc by adhesion or the like.

In the test apparatus of the present application, when the wafer is placed in a thermal relationship with the temperature control plate 1, the wafer is placed directly on the surface 2a of the temperature control plate and brought into contact with the temperature control plate 1, and the vacuum pressure supplied between the two. Although it is possible to bring the wafers 50 into close contact with each other, as shown in FIG. 2, the heat transfer plate 60 made of a heat conductive smooth plate such as an aluminum plate for the wafer 50 accurately positioned and connected to the probe means.
It can also be installed on the surface of the temperature control plate via. In the latter case, although illustration is omitted, in order to secure the adhesion between the wafer 50 and the lower surface 61 of the heat transfer plate 60, as shown in FIG.
A vacuum supply path similar to that shown in FIG. 2 is formed on the surface and inside of the heat transfer plate 60.

In FIG. 3, reference numeral 62 denotes a connecting portion having a check valve mechanism protruding from the protrusion provided on the side surface of the heat transfer plate 60, which can be connected to the vacuum source side, and the vacuum supply indicated by the broken line 63. It communicates with the road, and is provided so as to project to the outside of the rising wall from a notch 2d provided in a part of the rising wall 2c of the disc 2. In the burn-in test, the wafer 50 positioned by the probe means is set on the lower surface of the heat transfer plate 60, and when the wafer 50 is brought into close contact with the heat transfer plate 60 by the vacuum pressure, the coupling member on the vacuum source side is attached. Remove from the connection portion 62. The check pressure is held between the wafer and the heat transfer plate by the check valve, and the wafer and the heat transfer plate are kept fixed.

Except for the lower surface of the temperature control plate 1 as described above, a flat box-shaped upper half 10a of the test chamber having an open lower surface is provided so as to surround the side surface and the upper surface.
A fan 9a as a blower and an air heater 9 composed of a sheathed heater with fins are provided on the inner surface of the side wall of the upper half of the test chamber. The sheath heater 9 inputs the detection signal of the central temperature sensor 5a to the temperature controller C1,
The control signal adjusts the power supplied to the heater 9 to control the blowing temperature. Similarly, the operation of the plate heater 7 is controlled by the ambient temperature sensor 5b and the temperature controller C2, and the temperature of the temperature adjusting plate is adjusted to a predetermined temperature.

As shown in FIG. 2, the wafer 50 is mounted on the temperature control plate by mounting the wafer 50, which is the subject,
The first conducting board 70 holding the probe means on the upper surface and the second conducting board 80 for supplying a test current to the first conducting board 70 are accurately positioned and fixed, and then the transfer board is made of an aluminum plate. It is fixed on the lower surface of the heat plate 60 and fixed by vacuum pressure as described above. The probe means is a probe card (not shown) in which a large number of current-carrying protrusions corresponding to the current-carrying contacts on the wafer are formed on a thin plate-like plane, and is formed by a ring-shaped frame 71 made of a material having a small coefficient of thermal expansion such as ceramics. , Is fixed and held on the upper surface of the first current-carrying substrate 70 made of an insulating substrate (for example, a glass plate) having a small thermal expansion coefficient. On the upper surface of the first current-carrying substrate, a wiring pattern for connecting to the current-carrying protrusion of the probe means is formed, and the wiring pattern is the first connector 7
2, 72, ..., The second connector 8 provided on the lower surface of the second current-carrying substrate 80 via the strip-shaped cable 75.
2, 82, ...

The second conducting board 80 is provided with third connectors 81, 81 on its lower surface for organizing the conducting network to the probe means and connecting it to the conducting test control board 90. The energization test control board 90 is the lower half 10b of the test chamber.
Is fixed to the upper surface of. The lower half portion 10b rises toward the upper half portion 10a of the test chamber and abuts the lower edge thereof to close the test chamber space 10. At that time, when the third connector 81 and the connection terminal provided on the energization test control board 90 side are connected and the lower half portion 10b is lowered to open the test chamber, the third connector 81 causes the control board 90 The connection terminal comes off. Of course, the main body of the energization control board 90 does not necessarily have to be provided in the test chamber, and its connection terminal is
It should be provided. The wafer 50, the probe means, the first conductive board 70, and the second conductive board 80 are held by a dedicated positioning device while maintaining a predetermined relational position via a fixed frame member (cassette forming member) (not shown). As a result, as a transferable test member, the temperature control plate 1 is set as described above.

A heat insulating wall 30 is provided so as to surround the side surfaces of these test members and the side surfaces of the temperature control plate 1 when the test members are set on the temperature control plate 1. An upper edge of the heat insulating wall is in contact with a peripheral edge of an upper surface of the temperature control plate, and a lower edge of the heat insulating wall is formed of a plastic body extending near a side surface of the second current-carrying board. However, the material of the body may be metal. Further, a film-shaped heating element 25 is adhered to the lower surface 73 of the first conductive board 70 to cover the lower surface 73, and between the heating element and the upper surface 83 of the second conductive board 80, As the heat insulating means, the heat insulating space 20 composed of equally spaced voids is interposed and fixed.

As shown in FIG. 4, the heat generating element 25 is hermetically sealed in such a manner that a copper foil forming a substantially ring-shaped heat generating circuit 25a is sandwiched between circular heat resistant resin films 26 (for example, polyimide resin sheets). The heating circuit consists of
The peripheral part is arranged most densely, and from the peripheral part to the central part,
The arrangement density is slightly sparse, and the central portion 26a is arranged without any elements. A circular aluminum thin plate (for example, having a thickness of 2 to 3) is used instead of the heat-resistant resin film heating element.
A heating circuit made of a nichrome wire may be embedded and buried in the thin plate in an insulating state within about 3 mm. The aluminum thin plate may be a ring-shaped plate having a void in the center. 25a is an electrical connection terminal.

During the energization test, the temperature control plate,
The peripheral portions of the wafer, the first conductive substrate and the second conductive substrate have a lower temperature than the central portion due to the influence of the ambient atmosphere, which causes the test accuracy to deteriorate.
The temperature difference between the central portion and the peripheral portion of the first current-carrying substrate causes the warp due to the thermal expansion of the first current-carrying substrate, which causes the contact failure between the probe means and the wafer. By enclosing the sides of these members, the effect of the circulating air flow by the fan 9a is blocked, so that a heat retaining effect is exerted, and the temperature drop in the peripheral portion is significantly mitigated. It is most effective to provide the heat insulating wall so as to close the side surface of the member to be tested or the temperature control plate, but even if there is a gap between the heat insulating wall and the side surface to allow airflow in and out, a certain degree of effect is recognized.

In order to exert the constant heat insulating effect and the cooling effect of the air flow by the heat insulating space 20, it is preferable that the heat insulating space is a space having an equal interval, so that the air flow can easily enter and leave the heat insulating space. In order to do so, it is desirable that the distance between the heating element 25 and the second current-carrying substrate is 2 mm or more. Insulation space is the best in heat insulation,
By the fixed frame member, positioning both current-carrying boards,
When forming the space, the structure of the fixed frame member is complicated. In the case of interposing a heat insulating material such as a heat insulating plate instead of the heat insulating space, the positioning structure for the both conducting boards is simplified. The heat insulating space blocks the heat conduction between the first conducting board side and the second conducting board side, and the influence of the cooling effect of the air flow is
Depending on the configuration of the heating element, the direction of reducing the temperature difference between the central portion and the peripheral portion of the first conducting board by directly or indirectly through the heating element to reach the central portion of the first conducting board. Act on.

The heating element 25 is provided in order to surely eliminate the temperature deviation of the first conducting board 70 which cannot be eliminated even by such heat insulating means,
By applying a predetermined amount of heat to the peripheral portion, which has a lower temperature than the central portion, according to the temperature deviation, the temperature distribution of the first conducting substrate is made uniform. In the first conductive substrate, the central portion or the peripheral portion indicates a position corresponding to the central portion or the peripheral portion of the semiconductor wafer held and fixed by the first conductive substrate, and the first conductive substrate is the semiconductor wafer. It does not mean that it has a disk shape similar to. In this way, the heating element 25 and the heat insulating space 20 prevent the central portion of the substrate from bulging and deforming due to the thermal influence of the semiconductor wafer. As a result, the probe means held on the first conducting board is
Prevents poor contact with the energized contacts of the wafer during the burn-in test. The heat insulating wall 30 and the heat insulating space 20 (or the heat insulating material) combined with the heating element are effective even if they are used alone in combination with the heating element 25. The effects of each work synergistically, and show remarkable effects.

The ceramic ring-shaped frame 71 provided upwardly around the first energization board 70 has a heat conductive seal made of a heat conductive rubber sheet on the lower surface of the rising wall 2c provided at the peripheral edge of the disk 2. It is in contact through the material 15. Therefore, the heat of the temperature control plate is transferred to the ring-shaped frame 71 through the sealing material 15, so that the wafer 50
The heat release from the sides of the is significantly reduced. Further, since the heat from the rising wall 2c and the heat conductive sealing material 15 reaches the first conducting board 70, it also contributes to the temperature rise of the peripheral portion of the first conducting board and the heat distribution of the first conducting board 70. It is expected that the effect of preventing the displacement of the energizing contact due to the deviation of the above will be expected. The heat transfer rubber sheet is made of, for example, a thin sheet-like material in which a powder of metal oxide having excellent thermal conductivity such as titania or boron oxide is dispersed in silicon rubber. Examples include Shin-Etsu Chemical Co., Ltd. heat dissipation rubber sheet, TC-20BG, and thickness of 0.2 mm.

FIG. 5 shows another embodiment of the present invention. The difference from the embodiment shown in FIGS. 1 to 4 is that aluminum is provided between the first energizing substrate 70 and the heating element 25. And a space provided between the heating element and the second current-carrying board as a heat insulating means, with a structure in which a soaking plate 28 made of a highly heat-conductive thin plate made of copper, an alloy thereof, or the like is interposed so as to be able to exchange heat. Instead of the above, a heat insulating material 22 having a plate shape or a sheet shape and capable of withstanding a temperature of at least 100 ° C. or higher is provided. The heating element 25 is the same as that described above. For example, when the material is an aluminum plate, the soaking plate 28 is a thin plate having a thickness of 1 to 2 mm and sufficiently exhibits its effect, and is made of glass or ceramic which is a material having a small thermal conductivity. The heat of the central portion of the one conducting board 70 is quickly moved to the peripheral portion to equalize the heat distribution, and the heat generated from the heating element 25 is dispersed and smoothed to be transmitted to the first conducting board. The soaking plate 75 is
In addition to the metal plate, a graphite thin plate having a property that heat specifically moves in the plane direction may be used. The heat-transferable close contact between the heat equalizing plate and the first current-carrying substrate may be abutted, for example, via heat transfer grease or the like. The heating element may be adhered to a soaking plate or may be a heating circuit pattern directly printed through an insulating film.

The heat insulating material can be achieved by using a heat-resistant foamed rubber sheet (for example, a foamed silicone rubber sheet having a thickness of 3 mm) or the like, although it depends on the heat insulation performance. The presence of the heat insulating means (20, 22) exerts not only the effect of improving the temperature distribution of the first energization board but also the effect of suppressing the temperature rise of the second energization board. The effect of preventing the accident that the attachment / detachment of the third connectors 81, 81, ... Having a multi-pin structure that interrupts the connection is blocked by thermal expansion. Also, as shown in FIG.
If the notch 2d (see FIG. 1) has to be provided on the rising wall 2c of the disk 2 by providing the connection part 62 to the vacuum source side on the side surface of 0, the part near the notch 2d Although the temperature of the heat transfer plate 60 is disturbed and inevitably affects the temperature of the wafer, such a defect is avoided by providing the heat insulating wall 30.

Next, the operation of the present apparatus will be described. The test member in which the first and second current-carrying substrates, semiconductor wafers, etc. are positioned and fixed to form a cassette is mounted on the heat transfer plate 60 of the temperature control plate 1, and the wafer and the heat transfer plate 60 are separated by vacuum pressure. At the same time, the temperature measuring portions 5h of the temperature sensors 5a and 5b are lightly pressed to the wafer near the lower surface of the heat transfer plate or directly to the wafer to measure the temperature. On the other hand, below the first energizing board 70 and the second energizing board 80, the lower half of the test chamber 10b capable of forming the test chamber 10 by contacting the upper edge of the upper half 10a of the test chamber is provided with the energization test control. It is provided so as to move up and down together with the substrate 90. Therefore, when the energization connection portion of the energization test control board 90 is connected to the third connector 81, the test chamber is simultaneously sealed and the fan 9a starts rotating. Reference numerals 11a and 11b are guide members for the test chamber. As a result, the air blown from the blower fan 9a passes through the air heater 9 and passes through the radiating fin groups 6, ..., And then circulates along the peripheral wall of the test chamber 10 and returns to the blower fan again. Are formed.

When the wafer 50 generates heat by energizing the wafer 50, the temperature control plate 1, the fan 9a, the air heater 9, and the plate heater 7, the temperature sensors 5a and 5b near the surface of the heat transfer plate 60 detect the detected temperature. The controller C1, C
Send to 2. The air heater 9 has a burn-in test temperature of 2
The temperature controller C1 is set so as to maintain the test chamber space at an appropriate predetermined temperature which is lower by 0 to 30 ° C. If the temperature near the central portion of the wafer starts to rise above the set value according to the temperature detected by the central temperature sensor 5a, the air heater 9
The current to F is limited or the supply of current is stopped. Along with that, the temperature of air blown to the radiating fins decreases,
The central portion of the temperature control plate is cooled, so that the temperature of the central portion of the wafer is lowered. On the other hand, when the temperature near the center of the wafer is lower than the set value, a larger current corresponding to the temperature difference is supplied to the air heater 7, and the air temperature in the test chamber rises, which passes through the fins 6. Supplied to a temperature control plate to raise the wafer temperature.

Similarly, the operation of the plate heater 7 is controlled by the temperature controller C2 according to the temperature detected by the ambient temperature sensor 5b. Then, in accordance with the wiring density installed according to the temperature distribution of the wafer, even in the peripheral portion, the heat generation amount is small near the center of the disc 2 and slightly higher near the peripheral edge. To be done. The test chamber may be a closed space, or may be configured such that a damper capable of appropriately introducing outside air is provided on the wall surface by an opening / closing opening. Thus, the temperature control plate 1 creates a symmetrical temperature distribution on the surface of the temperature control plate, which is opposite to that of the semiconductor wafer. The semiconductor wafer is brought into contact with this temperature control plate via the heat transfer plate 60 to transfer heat, thereby eliminating the non-uniformity of the temperature distribution, and for a predetermined target temperature, the entire surface of the wafer is covered. With the accuracy within ± 1 ° C, it is possible to carry out the energization test while maintaining a uniform temperature.

[Brief description of drawings]

FIG. 1 is an explanatory view of an embodiment of a temperature adjusting plate portion of a burn-in test apparatus according to the present invention, as seen from a plane direction.

FIG. 2 is an explanatory diagram showing a wafer burn-in test apparatus in a use state as viewed from a cross-sectional direction AA of FIG.

FIG. 3 is an explanatory diagram showing a main part of a shape as seen from the direction of the BB cross section of FIG. 2;

4 is an explanatory diagram showing an example of a heating circuit pattern of the heating element of FIG.

FIG. 5 is an explanatory diagram showing a main part of another embodiment of the present invention.

[Explanation of symbols]

1 Temperature control plate 2 discs 2c Standing wall 2d notch 3 Vacuum supply path 3a-d Vacuum suction groove 4a, b Temperature sensor storage hole 5a, b Temperature sensor 5h temperature measuring section 6 radiating fins 7 plate heater 8 O-ring 9 Air heater 10 test room 10a upper half of test room 15 Heat transfer rubber sheet 20 insulation space 22 Thermal insulation 25 heating element 28 Soaking plate 30 insulation wall 50 semiconductor wafers 60 heat transfer plate 63 Vacuum supply path 70 First conductive board 71 ring frame 72 First connector 80 Second conductive board 81 Third Connector 82 Second connector 90 Electricity test control board

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-8-340030 (JP, A) JP-A-8-29080 (JP, A) Jitsuko Sho 58-3125 (JP, Y2) (58) Field (Int.Cl. ⁷ , DB name) H01L 21/66 G01R 31/26

Claims (5)

(57) [Claims] 1. A heat-conductive plate-like body having a smooth surface, a heat radiation fin projecting from the back surface of the plate-like body, and a heater on the back surface or inside the plate-like body. Is provided so as to include a temperature adjusting plate of a semiconductor wafer, a temperature adjusting plate at the time of burn-in test of the semiconductor wafer, a semiconductor wafer which is an object to be tested, and a test device including energizing means to the wafer. In the test chamber, an air heater and an air blower are provided in the test chamber to pass through the radiating fins, and the means for energizing the wafer is an individual means formed on a semiconductor wafer. Of the first energizing substrate and a second energizing substrate for energizing the first energizing substrate, the surface of the other side of the first energizing substrate. Has a heating element Burn-in test apparatus of a semiconductor wafer, characterized in that it is provided. 2. A heat-conductive plate-like body having a smooth surface on the front surface thereof, a radiating fin protruding from the back surface of the plate-like body, and a heater provided on the back surface or inside the plate-like body. Formed so as to include a temperature adjusting plate of a semiconductor wafer provided with a semiconductor wafer, a temperature adjusting plate at the time of burn-in test of the semiconductor wafer, a semiconductor wafer which is an object to be tested, and a means for energizing the wafer. In the test chamber, a blower path including an air heater and a blower and passing through the heat radiation fins is formed in the test chamber, and the energizing means to the wafer is an individual semiconductor wafer formed on the semiconductor wafer. Of the first energizing substrate and a second energizing substrate for energizing the first energizing substrate, the surface of the other side of the first energizing substrate. Has a heating element Provided, the said second conducting substrate and the heat generating member, a burn-in test apparatus for a semiconductor wafer, characterized in that adjacent through a heat insulating means. 3. A heat-conductive plate-shaped body having a smooth surface, a heat radiation fin protruding from the back surface of the plate-shaped body, and a heater on the back surface or inside the plate-shaped body. Is provided so as to include a temperature adjusting plate of a semiconductor wafer, a temperature adjusting plate at the time of burn-in test of the semiconductor wafer, a semiconductor wafer which is an object to be tested, and a test device including energizing means to the wafer. In the test chamber, which is provided with an air heater and a blower, the air passage that passes through the radiation fins is formed in the test chamber,
Inside the test chamber, there is formed a heat insulating wall that laterally surrounds the temperature control plate, the wafer, and an energization unit for the wafer, and the energization unit for the wafer is formed on a semiconductor wafer. Of the first energizing substrate and a second energizing substrate for energizing the first energizing substrate, the surface of the other side of the first energizing substrate. The semiconductor wafer burn-in test apparatus is characterized in that a heating element is provided in the. 4. A heat-conductive plate-shaped body having a smooth surface, a heat radiation fin protruding from the back surface of the plate-shaped body, and a heater on the back surface or inside the plate-shaped body. Is provided so as to include a temperature adjusting plate of a semiconductor wafer, a temperature adjusting plate at the time of burn-in test of the semiconductor wafer, a semiconductor wafer which is an object to be tested, and a test device including energizing means to the wafer. In a test chamber that includes an air heater and a blower, a blower path that passes through the heat radiation fins is formed in the test chamber, and in the test chamber, the temperature control plate and the wafer, and A heat-insulating wall that encloses the energizing means to the wafer from the side is formed, and the energizing means to the wafer is
It comprises a first conductive substrate having on one surface a probe means for contacting each integrated circuit formed on a semiconductor wafer, and a second conductive substrate for supplying current to the first conductive substrate. A heating element is provided on the other surface of the one conducting substrate, and the heating element is adjacent to the second conducting substrate via a heat insulating means, and the burn-in of the semiconductor wafer is performed. Test equipment. 5. A heating element is provided on the first conducting board via a soaking plate made of a heat-conducting plate which is in close contact with the first conducting board so as to exchange heat with one surface. , Claim 1
5. The burn-in test apparatus for semiconductor wafers according to any one of 4 to 4.