JP2007073762A - Method of releasing in burn-in test and alignment device for use in burn-in test - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reliably prevent generation of a drag dent in the surface of a bump electrode caused by the material of a wiring board in a releasing step in a burn-in test. <P>SOLUTION: A method of releasing in a burn-in test includes a series of steps of: bringing inspecting electrodes of a plurality of semiconductor integrated circuit elements formed on a semiconductor wafer 1, located on the upper surface of a wafer tray 30 into contact with probe electrodes provided on a wiring substrate 13 of an inspection board 5 supported by a reception base 23; collectively inspecting electrical characteristics of the plurality of semiconductor integrated circuit elements; sucking a stage 29 on the lower surface of the wafer tray 30; and releasing the probe electrodes from the inspecting electrodes. The releasing method comprises a step (a) of releasing fixing of a position of the inspecting board 5 in a horizontal direction immediately before the stage 29 is sucked on the lower surface of the wafer tray 30, and a step (b) of releasing the probe electrodes from the inspecting electrodes with the fixing of the position of the inspecting board 5 being released and with the stage 29 being sucked on the lower surface of the wafer tray 30. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to burn-in inspection, and more particularly to a separation method in burn-in inspection and an alignment apparatus used for burn-in inspection.

  2. Description of the Related Art Conventionally, a semiconductor device in which a plurality of semiconductor integrated circuit elements (hereinafter referred to as “semiconductor chips”) are formed on a semiconductor wafer has electrically connected the semiconductor chip and the lead frame with bonding wires and sealed with resin or ceramics. It has been mounted on a circuit board in a stopped state.

  However, in recent years, the progress of miniaturization and price reduction of electronic devices in which semiconductor devices are mounted has been remarkable, and the demand for miniaturization and price reduction of semiconductor devices has been increasing. The method of mounting on a circuit board while being cut out from a semiconductor wafer is becoming mainstream, and such a semiconductor chip is provided at a low price and the quality of such a semiconductor chip (bare chip) is guaranteed. Is strongly desired.

  Here, in order to guarantee the quality of the semiconductor chip, the semiconductor chip having a latent defect is removed in advance by performing an inspection such as burn-in in a state where a plurality of semiconductor chips are formed on the semiconductor wafer. It is necessary. At this time, it is not realistic in terms of time and cost to perform burn-in inspection for each of the plurality of semiconductor chips or to perform burn-in inspection for each of the plurality of semiconductor chips. Therefore, a method for performing a burn-in inspection on all semiconductor chips formed on a semiconductor wafer is being developed.

  In order to perform a burn-in inspection on a plurality of semiconductor chips formed on a semiconductor wafer, it is necessary to simultaneously apply a voltage to each pad electrode in the semiconductor chip to operate each semiconductor chip. is there. Therefore, for example, a probe card in which probe needles made of a conductive material are arranged needs to be prepared in accordance with the arrangement of the pad electrodes in the semiconductor chip. However, very many (usually tens of thousands or more) probe needles must be arranged on the probe card in accordance with the arrangement of the pad electrodes, and this can be realized in terms of quantity and price. Have difficulty.

  Therefore, in recent years, as a probe electrode, a bump electrode that is a protruding connection electrode is used instead of a probe needle, and by arranging the bump electrode on the probe card according to the arrangement of the pad electrode in the semiconductor chip, Since each of the pad electrodes and each of the bump electrodes can be brought into contact with each other, a voltage can be simultaneously applied to each of the pad electrodes. As described above, by using the bump electrode as the probe electrode, it is possible to perform a burn-in inspection on a plurality of semiconductor chips formed on the semiconductor wafer in a lump (see, for example, Patent Document 1).

  Here, in order to reliably contact each of the plurality of pad electrodes in the semiconductor chip and each of the plurality of bump electrodes arranged on the probe card, the arrangement position of the pad electrodes and the arrangement position of the bump electrodes are determined. While observing, both must be aligned with high precision.

  In general, in the alignment apparatus, each of the bump electrodes and the pad electrodes in the plurality of semiconductor chips formed on the semiconductor wafer are referenced with respect to the positions of the plurality of bump electrodes arranged on the probe card. This is done by relatively moving the semiconductor wafers so that they are in contact with each other. Further, for example, an alignment mark such as an opening is formed on the probe card, and the position of the alignment mark subjected to the image processing is recognized using an image recognition device, and each of the bump electrode and each of the pad electrodes is recognized. There has also been proposed a method of relatively moving the semiconductor wafer so as to come into contact with each other (see, for example, Patent Document 2).

  As described above, in order to perform a burn-in inspection on a plurality of semiconductor chips formed on a semiconductor wafer, the bump electrodes on the probe card and the pad electrodes on the semiconductor wafer are accurately aligned. In addition, it is also important to uniformly bond each bump electrode on the probe card (: first substrate) and each pad electrode on the semiconductor wafer (: second substrate).

  For example, in recent years, as a first method for uniformly bonding a first substrate and a second substrate, the first substrate is lowered and placed below the first substrate on the stage. When the first substrate is bonded to the supported second substrate, the first substrate is lowered while the second substrate is floating from the stage, and the first substrate (the bonding side) ) Has been proposed (see Patent Document 3, for example). Further, as a second method, when the first substrate is lowered and bonded to the second substrate disposed below the first substrate, the first substrate is attached to the upper surface of the first substrate. A method has been proposed in which the first substrate is lowered in a state where the elastic member is provided, and the first substrate (bonding side) is aligned with the second substrate (bonding side) (for example, Patent Document 4 or Patent Document 5).

  Hereinafter, an apparatus used for burn-in inspection will be described with reference to FIG. FIG. 13 is a diagram showing an apparatus used for burn-in inspection. In general, the burn-in inspection requires a long time (on average, about 3 hours) while the burn-in inspection requires a short time (on average, about 5 minutes). Each of the steps is performed in a separate apparatus, and is often divided into an alignment apparatus 36 and a burn-in inspection apparatus 37 as shown in FIG. Furthermore, since there is a large difference between the burn-in inspection time (on average, about 3 hours) and the alignment operation time (on average, about 5 minutes), the alignment device 36 has a bonding function and a separation function. Often used as both.

  In the above case, the semiconductor wafer is transferred between the alignment device 36 and the burn-in inspection device 37 while being mounted on the inspection board 5. Specifically, as shown in FIG. 13, the inspection board 5 includes a probe card 6 as a main component, and is arranged on the probe card 6 on the probe card 6 constituting the inspection board 5. The semiconductor wafer is mounted in a state where each of the plurality of bump electrodes is bonded to each of the pad electrodes in the plurality of semiconductor chips formed on the semiconductor wafer. As shown in FIG. 13, the inspection board 5 on which the semiconductor wafer is mounted is transported between an alignment device 36 and a burn-in inspection device 37, and in the alignment device 36, a bonding process / separation process is performed. In the burn-in inspection apparatus 37, a burn-in inspection process is performed.

The burn-in inspection will be briefly described below with reference to FIGS. 14 (a) and 14 (b) and FIGS. 15 (a) and 15 (b). 14 (a) and 14 (b) are principal part process sectional views showing the bonding method in the burn-in inspection, and FIGS. 15 (a) and 15 (b) are principal part processes showing the separating method in the burn-in inspection. It is sectional drawing. Here, since the burn-in inspection will be described later in detail (see [Best Mode for Carrying Out the Invention]), it will be briefly described in the following description.
<Bonding process by alignment device>
First, as shown in FIG. 14A, each of a plurality of bump electrodes (not shown) arranged on the contact probe 15 in the probe card 6 constituting the inspection board 5 and the wafer tray 30 in the alignment apparatus. Alignment of the semiconductor wafer 1 with respect to the inspection board 5 so that each of the pad electrodes (not shown) in the plurality of semiconductor chips (not shown) formed on the semiconductor wafer 1 placed on the inspection board 5 corresponds to each other. Do step.

  Next, as shown in FIG. 14 (b), the stage 29 is raised, and each of the pad electrodes in the plurality of semiconductor chips formed on the semiconductor wafer 1 installed in the wafer tray 30 is replaced with the inspection board 5. Each of the bump electrodes arranged on the contact probe 15 in the probe card 6 to be configured is brought into contact with each other. Next, as shown in FIG. 14B, the seal ring 31 provided on the upper surface of the wafer tray 30 is contact probe by using a vacuuming nozzle (not shown) connected to the high vacuum coupler 32. The atmosphere in the space formed by being in close contact with the vacuum is evacuated.

In this way, by adjusting the atmosphere in the space from the atmospheric state to the vacuum state, using the atmospheric pressure outside the space, between each bump electrode and each pad electrode, each bump electrode and each pad electrode Can be applied instantaneously and uniformly in a direction perpendicular to the surface where each bump electrode and each pad electrode are in contact with each other, so that each bump electrode and each pad electrode are parallel to each other. And it can stick together uniformly.
<Inspection process with burn-in inspection equipment>
After the bonding process of each bump electrode and each pad electrode, the inspection board 5 on which the semiconductor wafer 1 is mounted is taken out from the alignment apparatus and transferred into the burn-in inspection apparatus. In the burn-in inspection apparatus, a voltage is simultaneously applied to each semiconductor chip using each bump electrode bonded to each pad electrode at a high temperature (for example, a temperature of 125 ° C.), and each semiconductor chip is simultaneously applied. Operate and test for electrical characteristics in each of the semiconductor chips.
<Drawing process by alignment device>
After the semiconductor chip inspection process by burn-in, the inspection board 5 on which the semiconductor wafer 1 is mounted is taken out from the burn-in inspection apparatus and transferred into the alignment apparatus. In the alignment apparatus, as shown in FIG. 15A, the stage 29 is aligned with the wafer tray 30 so that the wafer tray 30 and the stage 29 correspond to each other.

  Next, after the stage 29 is raised and the upper surface of the stage 29 is attracted to the lower surface of the wafer tray 30, the seal ring 31 is formed in close contact with the contact probe 15 as shown in FIG. While releasing the atmosphere in the space from the vacuum state to the atmospheric state, the stage 29 is lowered to separate the pad electrode and the bump electrode, thereby separating the inspection board 5 and the semiconductor wafer 1 from each other. .

  As described above, the burn-in inspection is completed.

As described above, the burn-in inspection is roughly classified into the bonding process / burn-in inspection process / separation process. Specifically, after the bonding process between each bump electrode and each pad electrode by the alignment apparatus, the burn-in inspection apparatus uses the burn-in inspection. A semiconductor chip inspection step is performed, and subsequently, a step of separating each bump electrode and each pad electrode by the alignment apparatus is performed.
Japanese Patent Laid-Open No. 7-231019 Japanese Patent Laid-Open No. 11-154694 Japanese Patent Laid-Open No. 08-304835 JP 11-326857 A JP 2001-189553 A

  However, the separation method in the burn-in inspection has the following problems.

  In the separation method according to the conventional example in the burn-in inspection, as shown in FIG. 15 (a), during the alignment step of the stage 29 with respect to the wafer tray 30, the pressing force by the horizontal cylinder 21 and the vertical cylinder 22 is used. Since the inspection board 5 on which the semiconductor wafer 1 is mounted is regulated, internal stress is generated in the wiring board 13 in the probe card 6 constituting the inspection board 5. Further, when the pad electrode and the bump electrode are separated, the upper surface of the stage 29 is attracted to the lower surface of the wafer tray 30, thereby generating further internal stress on the wiring substrate 13.

  In the separation method according to the conventional example in the burn-in inspection, the upper surface of the stage 29 is attracted to the lower surface of the wafer tray 30, and the seal ring 31 is in close contact with the contact probe 15 as shown in FIG. While releasing the atmosphere in the space from the vacuum state to the atmospheric state, the stage 29 is lowered to perform a step of separating each pad electrode from each bump electrode.

  As described above, in a state where the internal stress is generated in the wiring board 13, there is a possibility that the wiring board 13 may be bent or distorted due to the internal stress when the atmosphere in the space is released from the vacuum state to the atmospheric state. In addition, when exposed to the atmosphere as described above, each pad electrode and each bump electrode are in contact with each other so as to separate each pad electrode and each bump electrode between each pad electrode and each bump electrode. Since force cannot be applied in a direction perpendicular to the surface, it is difficult to uniformly separate each pad electrode and each bump electrode, and further, the wiring board 13 is bent or distorted. In this case, it is more difficult to uniformly separate each pad electrode and each bump electrode, so that a difference occurs in timing for separating each pad electrode and each bump electrode.

  For this reason, the surface which each pad electrode and each bump electrode contact with each other by the internal stress which generate | occur | produces in the wiring board 13 between each pad electrode and each bump electrode which remain in the bonded state in the step of separating Since a force acts in a horizontal direction, there is a problem that a drag impression mark is generated by the bump electrode on the surface of the pad electrode.

  Here, as a method for uniformly bonding the first substrate and the second substrate, as described above, the second substrate (side to be bonded) is copied to the first substrate (side to be bonded). A method (for example, refer to Patent Document 3 described above) or a method for aligning the first substrate (the side to be bonded) to the second substrate (the side to be bonded) (for example, refer to Patent Documents 4 and 5 described above). When the bonding is performed between each pad electrode on the semiconductor wafer (first substrate: bonding side) and each bump electrode on the probe card (second substrate: bonding side), In order to paste each pad electrode and each bump electrode so that the probe card is copied or along the semiconductor wafer to the probe card, when bonding each pad electrode and each bump electrode, Since misalignment between the pad electrode and the bump electrode is generated on the surface of the pad electrode, indentation marks dragging by the bump electrodes there is a problem that occurs. Further, even when the pad electrodes and the bump electrodes are separated from each other, a positional shift occurs between the pad electrodes and the bump electrodes as in the case of bonding. It is expected that a dragging impression will be generated.

  Thus, in the burn-in inspection, in the bonding process, it is necessary not only to bond each pad electrode and each bump electrode uniformly but also to bond them in parallel. Similarly, in the separation process, each pad electrode It is very important to separate the bump electrodes from each other in parallel and uniformly.

  Furthermore, in recent years, a glass material is used as a material constituting the wiring board 13 in the probe card 6 in order to reduce the manufacturing cost of the inspection board 5 or to increase the current for inspection applied to the semiconductor chip. Instead, resin materials are being used.

  Here, the flatness of the wiring board 13 is determined by the material constituting the wiring board 13. Specifically, the flatness of the wiring board 13 is determined by the flatness accuracy of the material constituting the wiring board 13. The degree of error that occurs is different. Furthermore, the frequency of bending or distortion occurring in the wiring board 13 varies depending on the mechanical strength of the material constituting the wiring board 13.

  Generally, resin materials have poor flatness accuracy compared to glass materials. For this reason, when a resin material is used as the material constituting the wiring board 13, an error occurs in the flatness of the wiring board 13, and when the degree of error is large, the wiring board 13 appears as an inclination. . In general, resin materials have lower mechanical strength than glass materials. For this reason, when a resin material is used as a material constituting the wiring board 13, the wiring board 13 is bent or distorted due to internal stress generated in the wiring board 13.

  For this reason, as shown in FIG. 15A, in the state where the inspection board 5 is regulated by the pressing force by the horizontal direction cylinder 21 and the vertical direction cylinder 22, the flatness error of the wiring board 13 or the wiring Due to the inclination of the substrate 13, internal stress is generated in the wiring substrate 13 in the probe card 6 constituting the inspection board 5. Furthermore, the wiring board 13 is bent or distorted due to the magnitude of internal stress generated in the wiring board 13 and the mechanical strength of the resin material constituting the wiring board 13.

  For this reason, in the separation method according to the conventional example in the burn-in inspection, when a resin material is used as the material constituting the wiring substrate 13, the wiring substrate 13 is bent or distorted due to internal stress during the separation step. Since the separation between the pad electrodes and the bump electrodes cannot be performed uniformly, a significant difference occurs in the timing of performing the separation between the pad electrodes and the bump electrodes.

  For this reason, the surface which each pad electrode and each bump electrode contact with each other by the internal stress which generate | occur | produces in the wiring board 13 between each pad electrode and each bump electrode which remain in the bonded state in the step of separating Since a force is applied in a horizontal direction, there is a problem that a dragging impression by the bump electrode is remarkably generated on the surface of the pad electrode. Thus, in the separation method according to the conventional example in the burn-in inspection, due to the material constituting the wiring board 13, specifically, due to the flatness accuracy or mechanical strength of the material, the pad electrode A dragging impression due to the bump electrode is generated on the surface.

  In view of the above, the object of the present invention is to perform the separation of each pad electrode and each bump electrode in a parallel and uniform manner without being affected by the material constituting the wiring substrate. Another object of the present invention is to provide a separation method in a burn-in inspection and an alignment apparatus used for the burn-in inspection, which can prevent the generation of a drag impression due to a bump electrode.

  In order to solve the above-described problems, in the separation method according to the present invention, each inspection electrode of a plurality of semiconductor integrated circuit elements formed on a semiconductor wafer installed on the upper surface of a wafer tray is supported by a cradle. After inspecting the electrical characteristics of a plurality of semiconductor integrated circuit elements at once by contacting each probe electrode provided on the wiring board of the inspection substrate, the stage is adsorbed on the lower surface of the wafer tray for each inspection. A separation method in burn-in inspection including a series of steps of separating the electrodes and the probe electrodes, the step (a) of releasing the position fixing in the horizontal direction with respect to the inspection substrate immediately before the stage is attracted to the lower surface of the wafer tray; With the position of the inspection substrate being released, the stage is attracted to the lower surface of the wafer tray, and each inspection electrode and each probe electrode is pulled. Characterized in that it comprises a step (b) away.

  According to the separation method of the present invention, immediately before the stage is attracted to the wafer tray, for example, a step of releasing the position fixing in the horizontal direction with respect to the inspection substrate by the horizontal cylinder is performed.

  Thereby, in the separation process, the pressing force due to the position fixing in the horizontal direction is not applied to the inspection substrate supported by the cradle, so that the material constituting the wiring substrate of the inspection substrate can be reduced. Even if a slight inclination occurs in the wiring board due to the flatness accuracy, internal stress can be prevented from being generated in the wiring board of the inspection board.

  For this reason, during the separation process, the internal stress generated in the wiring board does not cause bending or distortion in the wiring board, so that each inspection electrode and each probe electrode are uniformly separated, and each It is possible to prevent a force from acting in a horizontal direction with respect to a surface where each inspection electrode and each probe electrode are in contact between the inspection electrode and each probe electrode due to internal stress generated in the wiring board. Therefore, it is possible to prevent the occurrence of a dragging impression due to the probe electrode on the surface of the inspection electrode.

  Further, according to the pulling method according to the present invention, immediately before the stage is attracted to the wafer tray, for example, in order to release the position fixing in the horizontal direction with respect to the inspection substrate by the horizontal cylinder, immediately before the stage is attracted to the wafer tray. For example, the stage can be attracted to the wafer tray while recognizing the position of the wafer tray using a recognition camera, so that the stage can be attracted to the wafer tray with high accuracy.

  Thus, in the separation method according to the present invention, as in the conventional example, due to the flatness accuracy of the material constituting the wiring substrate of the inspection substrate, the wiring substrate may be inclined, The internal stress is generated in the wiring board due to the inclination of the wiring board because the pressing force due to the fixed position in the horizontal direction with respect to the inspection board is not applied to the inspection board on which the semiconductor wafer is mounted. Can be prevented.

  In the separation method according to the present invention, the step (a) of releasing the position fixing of the inspection substrate includes a step of further releasing the position fixing in the vertical direction with respect to the inspection substrate. The separating step (b) is performed for each inspection in a state in which the position of the inspection substrate is released, the stage is adsorbed on the lower surface of the wafer tray, and then the inspection substrate is lifted from the cradle using the stage. It is preferable to include a step of separating the electrode and each probe electrode.

  In this way, immediately after the stage is adsorbed to the lower surface of the wafer tray immediately before the stage is adsorbed to the wafer tray, for example, in a state where the vertical position fixing with respect to the inspection substrate by the vertical direction cylinder is further released, By pushing up the stage, each inspection electrode and each probe electrode can be separated while the inspection substrate on which the semiconductor wafer is mounted is lifted from the cradle.

  Thereby, the inspection substrate on which the semiconductor wafer is mounted is supported on the stage without receiving any external force, and the material constituting the wiring substrate of the inspection substrate is removed during the separation process. Even if a slight inclination occurs in the wiring substrate due to the flatness accuracy, it is possible to further prevent the internal stress from being generated in the wiring substrate of the inspection substrate.

  For this reason, during the separation process, the internal stress generated in the wiring board does not cause bending or distortion in the wiring board, so that each inspection electrode and each probe electrode are uniformly separated, and each Further preventing the force from acting in a horizontal direction with respect to the surface where each inspection electrode and each probe electrode are in contact with each other by the internal stress generated in the wiring board between the inspection electrode and each probe electrode. Therefore, it is possible to further prevent the occurrence of a dragging impression trace due to the probe electrode on the surface of the inspection electrode.

  Thus, in the separation method according to the present invention, as in the conventional example, due to the flatness accuracy of the material constituting the wiring substrate of the inspection substrate, the wiring substrate may be inclined, The inspection substrate on which the semiconductor wafer is mounted is supported on the stage without receiving any external force, so that internal stress is surely generated in the wiring substrate due to the inclination of the wiring substrate. Can be prevented.

  In the separation method according to the present invention, in the step (b) of separating each inspection electrode and each probe electrode, the semiconductor wafer is mounted on the inspection substrate in a state where each inspection electrode and each probe electrode are in contact with each other. It is preferable that the annular sealing member provided on the upper surface of the wafer tray includes a step of introducing high-pressure air into a space formed by closely contacting the inspection substrate.

  In this way, the atmosphere in the space can be adjusted to a high pressure state by introducing high-pressure air into the space formed by the annular seal member being in close contact with the inspection substrate. A force is instantaneously and evenly applied in a direction perpendicular to the surface where each inspection electrode and each probe electrode contact so that each inspection electrode and each probe electrode are separated from each other between the electrode and each probe electrode. Therefore, the inspection electrodes and the probe electrodes can be separated from each other in a parallel and uniform manner.

  As described above, in the separation method according to the present invention, an error may occur in the flatness of the wiring board due to the flatness accuracy of the material constituting the wiring board of the inspection board as in the conventional example. However, by adjusting the atmosphere in the space to a high-pressure state, each inspection electrode and each probe electrode can be separated in a parallel and uniform manner. Since no force is applied in the horizontal direction with respect to the surface where each inspection electrode and each probe electrode are in contact, it is possible to reliably prevent the occurrence of dragging impressions caused by the probe electrode on the surface of the inspection electrode. can do.

  In this case, as described above, for example, since the position fixing of the inspection substrate by the horizontal direction cylinder and the vertical direction cylinder is released in advance, the annular seal member is in close contact with the inspection substrate. By introducing high-pressure air into the space formed by this, each inspection electrode and each probe electrode are separated from each other, and the relative positional relationship between the semiconductor wafer and the inspection substrate is prevented from changing. Therefore, high-pressure air can be effectively introduced into the space.

  Further, in this way, the inspection electrode and the probe electrode are separated in parallel and uniformly without being affected by the material constituting the wiring board, so that the inspection electrode can be used in the separation step. Since it is possible to reliably prevent the occurrence of drag impressions due to the probe electrode on the surface of the substrate, the range of options for the material constituting the wiring board can be expanded. For example, as a material constituting the wiring board By using the resin material, it is possible to reduce the manufacturing cost of the inspection substrate and increase the inspection current applied to the semiconductor chip during the burn-in inspection.

  In the alignment apparatus according to the present invention, each inspection electrode of a plurality of semiconductor integrated circuit elements formed on a semiconductor wafer installed on an upper surface of a wafer tray is provided on a wiring substrate of an inspection substrate supported by a cradle. A series of inspecting the electrical characteristics of a plurality of semiconductor integrated circuit elements by bringing them into contact with each of the probe electrodes, and then attracting the stage to the lower surface of the wafer tray to separate each inspection electrode from each probe electrode The alignment apparatus used for the burn-in inspection including the above-described process is provided on the upper surface of a wafer tray that can mount a semiconductor wafer on an inspection substrate in a state where each inspection electrode and each probe electrode are in contact with each other. The ring-shaped sealing member is formed in close contact with the substrate for inspection, adjusts the atmosphere in the space to a high pressure state, and increases the atmosphere in the space. Wherein the first solenoid valve can be adjusted to a state, that the atmosphere in the space and a tunable second solenoid valve to a vacuum state.

  According to the alignment apparatus of the present invention, the atmosphere in the space formed by the annular seal member in close contact with the inspection substrate using the first solenoid valve and the second solenoid valve is changed to a high pressure state / atmosphere. The state / vacuum state can be appropriately adjusted.

  Thus, for example, during the separation process, by adjusting the atmosphere in the space from a vacuum state to a high pressure state, each inspection electrode and each probe electrode are placed between each inspection electrode and each probe electrode. Since the force can be applied instantaneously and uniformly in the direction perpendicular to the surface where each inspection electrode and each probe electrode are in contact with each other, the separation between each inspection electrode and each probe electrode is parallel. And uniform.

  In addition, by this, for example, in the bonding process, by adjusting the atmosphere in the space from the atmospheric state to the vacuum state, between each inspection electrode and each probe electrode, each inspection electrode and each probe Since the force can be applied instantaneously and uniformly in the direction perpendicular to the surface where each inspection electrode and each probe electrode are in contact with each other, the inspection electrode and each probe electrode Can be bonded in parallel and uniformly.

  As described above, in the burn-in inspection, by using the alignment apparatus according to the present invention, in the bonding process, the inspection electrodes and the probe electrodes are bonded in parallel and uniformly, and in the separation process. In addition, the inspection electrodes and the probe electrodes can be separated in parallel and uniformly.

  Furthermore, according to the alignment apparatus according to the present invention, by using the first solenoid valve and the second solenoid valve capable of switching the atmosphere in the space, the atmosphere in the space is changed during the bonding process. Provided is an alignment apparatus having both a bonding function and a separation function because the atmosphere in the space can be adjusted from a vacuum state to a high pressure state during the separation step while adjusting from the atmospheric state to the vacuum state. Therefore, the alignment apparatus can be used effectively.

  According to the separation method according to the present invention in the burn-in inspection, each pad electrode and each bump electrode are separated by adjusting the atmosphere in the space to a high pressure state in a state where the restriction of the inspection board is released.

  In this way, by releasing the restriction on the inspection board, even if a slight inclination occurs in the wiring board due to the flatness accuracy of the material constituting the wiring board, the internal stress is applied to the wiring board. Since it is possible to reliably prevent the occurrence of occurrence, there is no occurrence of bending or distortion in the wiring board due to the mechanical strength of the material constituting the wiring board. Can be evenly separated.

  Furthermore, by adjusting the atmosphere in the space to a high pressure state, even if an error may occur in the flatness of the wiring board due to the flatness accuracy of the material constituting the wiring board, each pad electrode Between each bump electrode and each bump electrode so that each pad electrode and each bump electrode are separated from each other, and a force is applied instantaneously and uniformly in a direction perpendicular to the surface where each pad electrode and each bump electrode are in contact with each other. Therefore, the pad electrodes and the bump electrodes can be separated from each other in parallel and uniformly.

  Thus, even if a slight inclination occurs in the wiring board due to the flatness accuracy of the material constituting the wiring board or an error occurs in the flatness of the wiring board, each pad electrode and By separating the bump electrodes from each bump in parallel and evenly, the internal stress generated on the wiring board between each pad electrode and each bump electrode causes the pad electrode and each bump electrode to contact each other. Since no force is applied in the horizontal direction, it is possible to reliably prevent the occurrence of drag impressions caused by bump electrodes on the surface of the pad electrode. Can be expanded.

<About Burn-In Inspection as a Premise of the Present Invention>
Hereinafter, the burn-in inspection as a premise of the present invention will be described in detail.
<About semiconductor wafers>
1 (a) and 1 (b) are top views showing the structure of a semiconductor wafer. Specifically, FIG. 1 (a) is an overall view, and FIG. 1 (b) is an enlarged view (in particular, It is an enlarged view of a semiconductor chip formation region. As shown in FIG. 1A, a plurality of semiconductor chips are formed in the semiconductor chip forming region 2 of the semiconductor wafer 1. As shown in FIG. 1B, a plurality of pad electrodes (inspection electrodes) 4 are formed on the peripheral edge of each of the plurality of semiconductor chips 3 formed on the semiconductor wafer 1.
<About inspection board>
2 (a) and 2 (b) are diagrams showing the configuration of the inspection board. Specifically, FIG. 2 (a) is a perspective view showing the configuration of the inspection board, and FIG. It is sectional drawing which shows the structure of an inspection board. As shown in FIGS. 2 (a) and 2 (b), the inspection board (inspection board) 5 includes, as shown in FIGS. 2 (a) and 2 (b), a probe card 6, a multilayer wiring board 7, a connector 8, a wiring board cradle 9, a pressing rubber 10, a presser 11, and a frame 12, and as will be described later, the probe card 6 includes a wiring substrate 13, a localized anisotropic conductive rubber 14, and a contact probe 15 (see the drawings described later). 3).

  As shown in FIG. 2 (a), a probe card 6 is provided on the multilayer wiring board 7, and the side of the multilayer wiring board 7 opposite to the surface on which the probe card 6 is provided. A connector 8 is provided on the surface. Moreover, the material which comprises the multilayer wiring board 7 is a resin material, and the shape of the multilayer wiring board 7 is a square shape whose film thickness is about 3 [mm] and one side is about 450 [mm]. As shown in FIG. 2B, a wiring board 13, a localized anisotropic conductive rubber (not shown), and a contact probe 15 are provided on the multilayer wiring board 7 from below through a wiring board cradle 9. A probe card 6 arranged in order is provided.

--- About the wiring board cradle ---
As shown in FIG. 2 (b), the wiring board cradle 9 is arranged at eight positions on the peripheral edge of the wiring board 13, and the multilayer wiring board 7 is placed on the multilayer wiring board 7 via the wiring board cradle 9. A wiring board 13 is provided. As a result, the multilayer wiring board 7 and the wiring board 13 are not in direct contact with each other. Therefore, when the semiconductor chip is inspected by burn-in, the wiring board 13 is exposed to a high temperature (for example, a temperature of about 125 ° C.). When heat is conducted from the substrate 13 to the multilayer wiring substrate 7, it is possible to prevent the multilayer wiring substrate 7 made of a resin material from being distorted.

--- Presser and presser rubber ---
As shown in FIG. 2 (b), the surface of the wiring board 13 on the side opposite to the side on which the wiring board cradle 9 is provided is silicon so as to correspond to the wiring board cradle 9. A pressing rubber 10 made of rubber is provided, and the pressing rubber 10 is fixed by a pressing 11 provided on the multilayer wiring board 7. In this way, the wiring board 13 is fixed on the multilayer wiring board 7 by the presser 11, and the presser rubber 10 is interposed between the wiring board 13 and the presser 11, whereby the wiring board 13 by the presser 11. Since the pressure on the wiring board 13 can be relaxed, it is possible to prevent the wiring board 13 from being cracked.

--About the frame--
As shown in FIG. 2B, a frame 12 is attached to the corner of the multilayer wiring board 7, and the rigidity of the entire inspection board 5 is enhanced by the frame 12.
<About probe card>
Hereinafter, the configuration of the probe card will be described in detail with reference to FIGS. 3, 4 (a) and (b), and FIGS. 5 (a) and 5 (b).
-About probe card (cross section)-
FIG. 3 is a cross-sectional view showing the configuration of the probe card, specifically, a cross-sectional view showing the configuration of the probe card in a state where each pad electrode and each bump electrode are bonded together. 4 (a) and 4 (b) are enlarged views showing the structure of the probe card (particularly, an enlarged view of the periphery of the bump electrode), and FIG. 4 (a) is a sectional view. (b) is a top view (specifically, a top view as seen from the bump electrode side). As shown in FIG. 3, the probe card 6 includes a wiring board 13, a localized anisotropic conductive rubber 14, and a contact probe 15. As shown in FIG. 3, a wiring board 13 is provided on a multilayer wiring board (not shown) via a wiring board cradle (not shown). A type anisotropic conductive rubber 14 and a contact probe 15 are provided in order from the bottom.

-Contact probe-
As shown in FIG. 3, the contact probe 15 constituting the probe card 6 includes a thin film 15a, a bump electrode (probe electrode) 15b, a copper thin film 15c, and a ceramic ring 15d. As shown in FIG. 3, a plurality of hemispherical bump electrodes 15b are formed on the thin film 15a by plating, and the surface of the thin film 15a is relatively opposite to the surface on which the bump electrodes 15b are formed. Each of the plurality of copper thin films 15c is provided on the surface on the side corresponding to each of the plurality of bump electrodes 15b. Further, as shown in FIG. 3, a ceramic ring 15d is provided on the peripheral portion of the surface of the thin film 15a where the bump electrodes 15b are formed, and the bumps 15b are formed by the ceramic rings 15d. And the thin film 15a in which the several copper thin film 15c was formed is hold | maintained. As shown in FIGS. 4A and 4B, a thin film 15a having an opening is formed on the copper thin film 15c. On the thin film 15a, the interior of the opening is embedded. A bump electrode 15b made of copper is formed. Thus, the copper thin film 15c serves as a seed layer when the bump electrode 15b is formed by a plating method.

--Localized anisotropic conductive rubber--
As shown in FIG. 3, the localized anisotropic conductive rubber 14 constituting the probe card 6 is composed of the pad electrodes 4 in the semiconductor chip 3 formed on the semiconductor wafer 1 and the bump electrodes 15 b in the contact probe 15. The contact probe 15 and the wiring board 13 are connected to each other while serving as a cushion that absorbs the variation in height. Further, as shown in FIG. 3, a copper thin film 15c is interposed between the localized anisotropic conductive rubber 14 and the thin film 15a, and as shown in FIG. The copper thin film 15c and the bump electrode 15b exposed to each other are in direct contact with each other. For this reason, the copper thin film 15 c also plays a role of improving the conduction between the contact probe 15 and the localized anisotropic conductive rubber 14.

-Electrical connection method-
Thus, the electrical connection between each of the plurality of bump electrodes 15 b in the contact probe 15 and each of the plurality of pad electrodes 4 in the semiconductor chip 3 is performed between the wiring substrate 13 and the multilayer wiring substrate 7 by the wiring substrate 13. Is electrically connected to the multilayer wiring board 7 via a flexible board (not shown) provided on the board, and further via the connector 8 (see FIG. 2 (a)) by the multilayer wiring board 7. , Electrically connected to a burn-in inspection device (not shown).
-Probe card (top view)-
5 (a) and 5 (b) are top views showing the configuration of the probe card. Specifically, FIG. 5 (a) is a top view showing the configuration of the probe card as viewed from the contact probe side. FIG. 5B is an enlarged view (particularly, an enlarged view of a bump electrode formation region). As shown in FIG. 5 (a), a bump forming region 16 is provided at the center of the thin film 15a so as to correspond to the semiconductor chip forming region 2 (see FIG. 1 (a)) in the semiconductor wafer 1. Yes. Further, as shown in FIG. 5 (a), an alignment mark (17a to 17d) serving as a reference for alignment between the bump electrode 15b in the contact probe 15 and the pad electrode in the semiconductor chip is provided on the peripheral portion of the thin film 15a. Is formed. As described above, the alignment marks (17a to 17d) are a combination of the alignment marks ((17a, 17d) or (17b, 17c)) that are symmetrical with respect to each other with respect to the center point in the thin film 15a. In general, two or more sets are provided.

  More specifically, as shown in FIG. 5B, the bump formation region 16 corresponds to each of the plurality of semiconductor chips 3 (see FIG. 1B) formed in the semiconductor chip formation region 2. As shown in FIG. 5 (b), a plurality of pad electrodes 4 (FIG. 1 (b) formed on the periphery of the semiconductor chip 3 are formed on the periphery of the bump area 18 as shown in FIG. A plurality of bump electrodes 15b are arranged so as to correspond to each of the above).

Hereinafter, the configuration of the alignment apparatus will be described with reference to FIGS. 6 and 7.
<About alignment device>
6 and 7 are diagrams showing the configuration of the alignment apparatus. Specifically, FIG. 6 is a perspective view showing the configuration of the alignment apparatus in a state where the inspection board and the semiconductor wafer are installed. FIG. 7 is a cross-sectional view (particularly, an enlarged view of the periphery of the inspection board and the semiconductor wafer) showing the configuration of the alignment apparatus in a state where the inspection board and the semiconductor wafer are installed.

  As shown in FIGS. 6 and 7, the alignment apparatus includes, as main components, a unit base 19 (see FIG. 6), a roller 20 (see FIG. 6) attached to the upper surface of the unit base 19, and a horizontal cylinder. 21 (see FIG. 6), a vertical cylinder 22 (see FIG. 7), a cradle 23 (see FIG. 7) attached to the unit base 19, and a semiconductor wafer recognition camera 24 (see FIG. 7) installed on the lower surface of the unit base 19. 6), an X-axis table 25 (see FIGS. 6 and 7) disposed below the unit base 19, a Y-axis table 26 (see FIGS. 6 and 7) provided on the X-axis table 25, Y The Zθ axis table 27 (see FIGS. 6 and 7) and the inspection board recognition camera 28 (see FIGS. 6 and 7) provided on the axis table 26 and the Zθ axis table 27 are provided. Stage 29 (see FIGS. 6 and 7). Note that the directions of the arrows shown in the X-axis table 25, the Y-axis table 26, the Zθ-axis table 27, and the inspection board recognition camera 28 are directions in which they can move.

--- Fixing method of inspection board in alignment device ---
As shown in FIG. 7, each of a plurality of frames 12 provided at the corners of the multilayer wiring board 7 in the inspection board 5 is provided with a parallel adjusting screw 12a so as to penetrate the inside. Since the parallel adjusting screw 12a penetrating through the inside 12 is disposed on the cradle 23, the inspection board 5 is supported by the cradle 23 attached to the unit base 19 (see FIG. 6). As shown in FIG. 6, the unit base 19 is provided with a roller 20 that can move in the horizontal direction and a cylinder 21 for horizontal direction that can be pressurized in the horizontal direction. 5 is positioned in the horizontal direction by the roller 20 and the cylinder 21 for the horizontal direction, and the displacement of the inspection board 5 is prevented. Furthermore, as shown in FIG. 7, a vertical cylinder 22 that can be pressurized in the vertical direction is provided on the frame 12, and the inspection board 5 is moved vertically by the vertical cylinder 22. The positioning of the inspection board 5 is prevented.

-Fixing method of semiconductor wafer in alignment device-
As shown in FIG. 7, the semiconductor wafer 1 installed in the wafer tray 30 is supported on the stage 29, and the wafer tray 30 is configured such that the upper surface of the stage 29 is attracted to the lower surface of the wafer tray 30. 29 is held on. As shown in FIG. 7, a seal ring 31 that can be in close contact with the upper surface of the contact probe 15 is provided at the peripheral portion of the wafer tray 30. Further, as shown in FIG. 7, on the side surface of the wafer tray 30, a high-vacuum coupler capable of maintaining the atmosphere in the space formed by the seal ring 31 being in close contact with the contact probe 15 in a vacuum state. 32 is provided, and a evacuation nozzle (not shown) is connected to the high vacuum coupler 32. Here, the high vacuum coupler 32 employs an automatic closing type coupler capable of maintaining the atmospheric state in the space when the vacuuming nozzle is removed from the high vacuum coupler 32. .

Hereinafter, the burn-in inspection will be described in detail with reference to FIGS. 14 (a) and 14 (b) and FIGS. 15 (a) and 15 (b).
<Bonding process by alignment device>
--- Adjustment step of inspection board parallelism--
As shown in FIG. 14A, in a state where the inspection board 5 is supported on the cradle 23, the parallelism of the inspection board 5 with respect to the semiconductor wafer 1 is set using the parallel adjustment screw 12a penetrating through the frame 12. adjust. As described above, in the bonding method in the burn-in inspection, the adjustment step of the parallelism of the inspection board 5 with respect to the semiconductor wafer 1 is performed before the alignment step, so that the subsequent bonding step can be accurately performed. it can.

-Semiconductor wafer alignment step-
Next, each of a plurality of pad electrodes (not shown) on the semiconductor wafer 1 is obtained from images taken by the respective recognition cameras (24 and 28) subjected to image processing using an image recognition device (not shown). The position and the position of each of a plurality of bump electrodes (not shown) in the contact probe 15 constituting the probe card 6 are recognized, and the optimum contact position is calculated. Based on the optimum contact position, each of the bump electrodes is controlled by, for example, a control motor (not shown) using the X-axis, Y-axis, Z-axis, and θ-axis in each XYZθ table (25, 26, and 27). Alignment of the semiconductor wafer 1 with respect to the inspection board 5 is performed so that the pad electrode and each of the pad electrodes correspond to each other. As described above, in the bonding method in the burn-in inspection, the alignment step of the semiconductor wafer 1 with respect to the inspection board 5 is performed before the bonding step, so that the subsequent bonding step can be performed with high accuracy.

--Raising step of semiconductor wafer by stage--
Next, as shown in FIG. 14B, the semiconductor wafer 1 installed in the wafer tray 30 is raised to the optimum contact position by using the Z axis in the Zθ table 27. At this time, a vacuuming nozzle (not shown) connected to the high vacuum coupler 32 provided on the side surface of the wafer tray 30 is released to the atmosphere. As a result, the seal ring 31 is in close contact with the contact probe 15 to prevent the atmosphere in the space from being sealed, and the atmosphere in the space is sealed, so that each pad electrode is attached to each bump electrode. The center part of the inspection board 5 is prevented from being lifted without being brought into contact.

-Bonding step for each pad electrode and each bump electrode-
Next, as shown in FIG. 14 (b), each of the plurality of pad electrodes in the semiconductor wafer 1 is brought into contact with each of the plurality of bump electrodes in the contact probe 15 constituting the probe card 6, and then for high vacuum. Using the vacuuming nozzle connected to the coupler 32, vacuuming is performed in the space formed when the seal ring 31 is in close contact with the contact probe 15.

  In this way, by adjusting the atmosphere in the space from the atmospheric state to the vacuum state, using the atmospheric pressure outside the space, between each pad electrode and each bump electrode, each pad electrode and each bump electrode Force can be applied instantaneously and uniformly in a direction perpendicular to the surface where each pad electrode and each bump electrode are in contact with each other, so that each bump electrode and each pad electrode are parallel and Can be bonded evenly. Here, the pressure in the space is adjusted by the number of bump electrodes in the contact probe 15 constituting the probe card 6. For example, the pressure in the space is usually about −50 [kPa] to about −80 [ kPa], and the pressure is adjusted so that a pressure of about 10 [g] is applied to each bump electrode.

As described above, the bonding process by the alignment apparatus is performed.
<Inspection process with burn-in inspection equipment>
After the bonding process of each pad electrode and each bump electrode, the inspection board 5 on which the semiconductor wafer 1 is mounted is taken out from the alignment apparatus and conveyed into the burn-in inspection apparatus. In the burn-in inspection apparatus, a voltage is simultaneously applied to each semiconductor chip using each bump electrode bonded to each pad electrode at a high temperature (for example, a temperature of 125 ° C.), and each semiconductor chip is simultaneously applied. Operate and test for electrical characteristics in each of the semiconductor chips.
<Drawing process by alignment device>
After the semiconductor chip inspection process by burn-in, the inspection board 5 on which the semiconductor wafer 1 is mounted is taken out from the burn-in inspection apparatus and transferred into the alignment apparatus. In the alignment apparatus, a step of separating each pad electrode from each bump electrode is performed.

  Here, as described above, the problem to be solved by the present invention is that, in the separation step, a drag impression due to the bump electrode is generated on the surface of the pad electrode due to the material constituting the wiring substrate 13. As described later, the present invention solves the problems of the present invention by devising a separation method. Therefore, in the following description, in order to facilitate understanding of the present invention, the separation method according to the conventional example will be described in detail, and then the separation method according to the present invention will be described in detail.

-Drawing method according to conventional example-
-Positional relationship between stage and wafer tray-
Here, in the following description, a separation method according to a conventional example will be described by taking as an example a case where a resin material is used as a material constituting the wiring board 13.

  FIG. 8 is a cross-sectional view showing the positional relationship between the inspection board and the stage on which the semiconductor wafer is mounted before performing the separation step. Here, for easy understanding, FIG. 8 shows the wiring board 13 tilted extremely, but actually, the wiring board 13 is slightly tilted or there is an error in the flatness of the wiring board 13 (˜˜). About 50 [μm]). As described above, when the resin material is used as the material constituting the wiring board 13, the wiring board 13 is slightly inclined due to the flatness accuracy of the material constituting the wiring board 13, or as described above. An error occurs in the flatness of the wiring board 13.

-Stage alignment step for wafer tray-
As shown in FIG. 15A, the position of the stage 29 relative to the wafer tray 30 in a state where the inspection board 5 on which the semiconductor wafer 1 is mounted is regulated by the pressing force by the horizontal cylinder 21 and the vertical cylinder 22. Align. At this time, the state shown in FIG. 15A is a state in which the inspection board 5 is regulated by the horizontal direction cylinder 21 and the vertical direction cylinder 22 and the flatness accuracy of the material constituting the wiring board 13 is improved. Due to the slight inclination (see FIG. 8) in the wiring board 13 or an error in the flatness of the wiring board 13, the wiring board 13 is subject to internal stress that causes bending or distortion. appear.

-Stage adsorption step to wafer tray-
In this state, when the stage 29 is raised and the upper surface of the stage 29 is attracted to the lower surface of the wafer tray 30, since the rigidity of the stage 29 is high, the lower surface of the wafer tray 30 is attracted along the upper surface of the stage 29. As a result, the wafer tray 30 is pulled toward the stage 29, and internal stress is further generated on the wiring substrate 13 that causes bending or distortion.

--- Separation step between each pad electrode and each bump electrode--
Next, as shown in FIG. 15 (b), the stage 29 is lowered while releasing the atmosphere in the space formed by the seal ring 31 closely contacting the contact probe 15 from the vacuum state to the atmospheric state, By separating each pad electrode on the semiconductor wafer 1 from each bump electrode on the contact probe 15 constituting the probe card 6, the inspection board 5 and the semiconductor wafer 1 are separated from each other.

  At this time, in the separation method according to the conventional example, the wiring substrate 13 is bent or distorted due to the internal stress generated in the wiring substrate 13 due to the inclination of the wiring substrate 13 (see FIG. 8). There is a difference in the timing at which the electrodes are separated from the bump electrodes. Further, due to an error in the flatness of the wiring board 13, a difference occurs in the timing of separating the pad electrodes and the bump electrodes. As described above, when a resin material is used as the material constituting the wiring board 13, each pad electrode and each bump electrode is caused by the inclination of the wiring board 13 (see FIG. 8) or the flatness error of the wiring board 13. Since there is a difference in the timing at which the pad electrode and the bump electrode are separated from each other, the pad electrode and the bump electrode cannot be evenly separated from each other, resulting in the following problems.

Hereinafter, a process in which the problem of the present invention occurs will be described in detail.
<About the process in which dragging impressions are generated>
As each pad electrode and each bump electrode is separated, the pad electrode and each bump electrode remaining in the bonded state remain in a state in which the bump electrode is stuck so as to bite into the pad electrode. Therefore, a force is generated between each pad electrode and each bump electrode in a horizontal direction with respect to the surface where each pad electrode and each bump electrode are contacted by internal stress generated in the wiring board. Even in such a case, no dragging impression due to the bump electrode is generated on the surface of the pad electrode.

  However, as the separation between the pad electrodes and the bump electrodes further progresses, the pad electrodes and the bump electrodes remaining in a state where the bump electrodes are stuck so as to bite into the pad electrodes are reduced, so that each pad electrode And the bump electrode cannot withstand the force acting in the horizontal direction with respect to the surface where each pad electrode and each bump electrode are in contact, and there is a drag impression by the bump electrode on the surface of the pad electrode. There is a problem that occurs.

  As described above, the drag impression due to the bump electrode does not occur on the surface of all the pad electrodes among the plurality of pad electrodes formed on the peripheral portion of the semiconductor chip, but on the surface of some pad electrodes. This often occurs, and due to the inclination of the wiring board (see FIG. 8) or the error in the flatness of the wiring board, it remains in a region where the timing of separation of the bump electrode and the pad electrode is late, that is, in a bonded state. In the region where the pad electrode and the bump electrode to be present are present, drag impression marks are generated by the bump electrode.

  As described above, the present invention performs bonding / separation between each pad electrode (inspection electrode) on a semiconductor wafer and each bump electrode (probe electrode) on an inspection board (inspection substrate) in burn-in inspection. The problem to be solved by the present invention is that the bump electrode is formed on the surface of the pad electrode due to the material constituting the wiring board during the separation process in the burn-in inspection. This is to prevent the occurrence of dragging impressions. Therefore, in the present invention, the problem of the present invention is solved by devising a separation method in burn-in inspection. In the description of this embodiment, the separation method according to the present invention will be described in detail.

-Detaching method according to the present invention-
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

(One embodiment)
Hereinafter, a separation method according to an embodiment of the present invention will be described with reference to FIGS. 9 (a) and 9 (b) and FIGS. 10 (a) and 10 (b). 9 (a) and 9 (b) and FIGS. 10 (a) and 10 (b) are principal part process sectional views showing a separation method according to an embodiment of the present invention.
<Drawing process by alignment device>
-Stage alignment step for wafer tray-
As shown in FIG. 9 (a), an image recognition device (not shown) in a state where the inspection board 5 on which the semiconductor wafer 1 is mounted is regulated by the pressing force of the horizontal cylinder 21 and the vertical cylinder 22. ) Is used to recognize the position of the wafer tray 30 with respect to the stage 29 from the captured image of the semiconductor wafer recognition camera 28 that has been subjected to image processing, and the optimum suction position (that is, the center position of each of the stage 29 and the wafer tray 30). Is calculated. Based on the optimum suction position, the stage with respect to the wafer tray 30 is set so that the wafer tray 30 and the stage 29 correspond to each other by using the X axis, Y axis, Z axis, and θ axis in each XYZθ table (25, 26, and 27). Align 29.

-Stage adsorption step to wafer tray-
Next, as shown in FIG. 9B, the stage 29 is raised to the optimum contact position by using the Z axis in the Zθ axis table 27, so that the upper surface of the stage 29 is attracted to the lower surface of the wafer tray 30.

  As a preparatory step for the separation step after the adsorption step, a vacuum-drawing nozzle (not shown) is used in order to maintain the close contact between the seal ring 31 and the contact probe 15 by the automatic closing type high-vacuum coupler 32. Is connected to the high vacuum coupler 32. A vacuuming nozzle is used to evacuate the space formed by the seal ring 31 being in close contact with the contact probe 15, whereby the pressure in the space is adjusted according to the number of bump electrodes, It is held at about −50 [kPa] to about −80 [kPa].

  At this time, in the separation method according to the embodiment of the present invention, as shown in FIG. 9B, immediately before the upper surface of the stage 29 is attracted to the lower surface of the wafer tray 30, the horizontal cylinder 21 and the vertical cylinder. 22, the restriction of the inspection board 5 is released, and the upper surface of the stage 29 is attracted to the lower surface of the wafer tray 30 in a state where the restriction of the inspection board 5 is released. In this manner, the inspection board 5 is regulated by the horizontal cylinder 21 and the vertical cylinder 22 until immediately before the upper surface of the stage 29 is attracted to the lower surface of the wafer tray 30, and the upper surface of the stage 29 is attracted to the lower surface of the wafer tray 30. When doing so, the restriction of the inspection board 5 is released.

  Furthermore, in the separation method according to the embodiment of the present invention, as shown in FIG. 9B, the stage 29 is further pushed up (for example, about 1) while the upper surface of the stage 29 is attracted to the lower surface of the wafer tray 30. By pushing up [mm], the inspection board 5 is completely lifted from the cradle 23.

  Thereby, the inspection board 5 on which the semiconductor wafer 1 is mounted can be supported on the stage 29 via the wafer tray 30 without applying any external force to the inspection board 5. Even if a slight inclination occurs in the wiring substrate 13 due to the flatness accuracy of the material constituting the substrate 13, it is possible to reliably prevent the internal stress from being generated in the wiring substrate 13. The internal stress generated in the wiring board 13 can be suppressed.

  As described above, in the separation method according to the embodiment of the present invention, the inspection board 5 is regulated by the horizontal cylinder 21 and the vertical cylinder 22 immediately before the upper surface of the stage 29 is attracted to the lower surface of the wafer tray 30. By releasing, it is possible to reliably prevent the internal stress from being generated in the wiring board 13 due to the inclination of the wiring board 13.

  For this reason, in the next separation step, the internal stress generated in the wiring board 13 does not cause bending or distortion in the wiring board 13, so that the separation between the pad electrodes and the bump electrodes is uniform. In addition, the internal stress generated in the wiring board 13 between each pad electrode and each bump electrode causes a force to act in a horizontal direction with respect to the surface where each pad electrode and each bump electrode contact. Can be suppressed. However, at this time, the generation of internal stress due to the flatness error of the wiring board 13 has not been eliminated, and the internal stress is generated in the wiring board 13 due to the flatness error of the wiring board 13. ing.

--- Separation step between each pad electrode and each bump electrode--
Next, as shown in FIG. 10A, the pad electrodes and the bump electrodes are separated from each other with the inspection board 5 completely lifted from the cradle 23.

  Here, in the separation method according to the conventional example, as described above, the stage 29 is lowered while releasing the atmosphere in the space formed by the seal ring 31 closely contacting the contact probe 15 from the vacuum state to the atmospheric state. By doing so, each pad electrode and each bump electrode are separated.

  However, when exposed to the atmosphere, the pulling force acting between each pad electrode and each bump electrode is weak, and furthermore, as described above, due to an error in the flatness of the wiring board 13, each pad There is a difference in the timing at which the electrodes are separated from the bump electrodes.

  Therefore, in the separation method according to the embodiment of the present invention, the seal ring 31 is in close contact with the contact probe 15 with the inspection board 5 completely lifted from the cradle 23 as shown in FIG. By adjusting the atmosphere in the space to a high pressure state (for example, a high pressure state of about 0.1 [MPa]) by sending high pressure air into the space formed by Pull apart.

  Accordingly, a force (that is, a direction perpendicular to the surface where each pad electrode and each bump electrode are in contact with each other so as to separate each pad electrode and each bump electrode between each pad electrode and each bump electrode (that is, , The separating force) can be applied instantaneously and uniformly, so that each pad electrode and each bump electrode can be separated in parallel and uniformly.

  For this reason, even when internal stress may occur in the wiring board 13 due to an error in the flatness of the wiring board 13 during the separation step, the separation between the pad electrodes and the bump electrodes is performed in parallel. Since it can be performed uniformly, there is no difference in the timing of separating each pad electrode and each bump electrode, and each pad electrode, each bump electrode, Since no force is generated in the horizontal direction with respect to the surface in contact with the surface of the pad electrode, it is possible to reliably prevent the occurrence of a dragging impression due to the bump electrode on the surface of the pad electrode.

  Further, as shown in FIG. 9 (b), by releasing the restriction of the inspection board 5 by the horizontal cylinder 21 and the vertical cylinder 22 in advance, high-pressure air is sent into the space during the separation step. As a result, the pad electrodes and the bump electrodes are not separated from each other, and the relative positional relationship between the semiconductor wafer 1 and the inspection board 5 is not hindered. Can be sent to.

  Next, as shown in FIG. 10 (b), the stage 29 is lowered, the inspection board 5 is installed again on the inspection board cradle 23, and the separation process is completed.

  As described above, according to the pulling method according to the embodiment of the present invention, the seal ring 31 is in contact with the contact probe 15 in a state where the restriction of the inspection board 5 by the horizontal cylinder 21 and the vertical cylinder 22 is released. Each pad electrode and each bump electrode are pulled apart by sending high-pressure air into the space formed by closely contacting with each other.

  Thus, even if a slight inclination may occur in the wiring board 13 due to the flatness accuracy of the material constituting the wiring board 13 by releasing the restriction of the inspection board 5, the wiring board 13. Since internal stress can be reliably prevented from occurring in the wiring board 13, the wiring board 13 is not bent or distorted due to the mechanical strength of the material constituting the wiring board 13. The electrodes and the bump electrodes can be uniformly separated.

  Further, by sending high-pressure air into the space formed by the seal ring 31 coming into close contact with the contact probe 15, the flatness of the wiring board 13 is caused by the flatness accuracy of the material constituting the wiring board 13. Even if an error may occur, the pad electrode and the bump electrode are in contact with each other so that the pad electrode and the bump electrode are separated from each other. Since the force can be applied instantaneously and uniformly in the vertical direction, each pad electrode and each bump electrode can be separated from each other in parallel and uniformly.

  Thus, even if a slight inclination occurs in the wiring board 13 due to the flatness accuracy of the material constituting the wiring board 13 or an error occurs in the flatness of the wiring board 13, By separating the pad electrode and each bump electrode in a parallel and uniform manner, a force is applied between each pad electrode and each bump electrode in a direction horizontal to the surface where each pad electrode and each bump electrode contact. Since this does not work, it is possible to reliably prevent the indentation trace caused by the bump electrode from being generated on the surface of the pad electrode.

  Furthermore, in this way, it is possible to prevent the occurrence of a dragging impression due to the bump electrode on the surface of the pad electrode due to the material constituting the wiring substrate 13, so that the wiring substrate 13 is configured. Since the range of choices of materials can be expanded, for example, by using a resin material as a material constituting the wiring board 13, the manufacturing cost of the inspection board 5 can be reduced, and the inspection current applied to the semiconductor chip can be reduced. High current can be achieved.

  In the following, in order to effectively explain the effects of the present invention, indentations caused by bump electrodes generated on the surface of the pad electrode will be described with reference to FIGS. 11 (a) and 11 (b). FIG. 11A is a top view showing indentations generated on the surface of the pad electrode when the separation method according to the present invention is used, and FIG. 11B uses the separation method according to the conventional example. It is a top view shown about the drag | tict impression trace which generate | occur | produces on the surface of a pad electrode in the case of being.

  As shown in FIG. 11B, the drag indentation 34 reaches a region other than the formation region of the pad electrode 4 in the semiconductor chip, damages the semiconductor chip, and further, a circuit formation region of the semiconductor chip (FIG. 11B). (Not shown) and damages the circuit formation region of the semiconductor chip, which may destroy the semiconductor chip. On the other hand, as shown in FIG. 11A, the indentation 33 does not reach a region other than the formation region of the pad electrode 4 in the semiconductor chip, so that the semiconductor by burn-in can be performed without damaging the semiconductor chip. Chip inspection can be performed satisfactorily.

  Hereinafter, a specific example of a solenoid valve piping method used for switching the atmosphere in the space formed by the seal ring being in close contact with the contact probe will be described with reference to FIGS. 12 (a) to 12 (c). explain. 12 (a) to 12 (c) are diagrams illustrating the piping method of the solenoid valve. Specifically, FIG. 12 (a) is a diagram illustrating the piping method of the solenoid valve in a vacuum state. 12 (b) is a diagram showing the piping method of the solenoid valve in the atmospheric state, and FIG. 12 (c) is a diagram showing the piping method of the solenoid valve in the high pressure state.

  In the alignment apparatus according to the embodiment of the present invention, the first electromagnetic valve 35a and the second electromagnetic valve 35b are used to combine the switching positions of each other, thereby allowing the gas flowing in the piping tube (not shown) to flow. By controlling the flow rate, the atmosphere in the space formed by the seal ring coming into close contact with the contact probe can be in a vacuum state (see FIG. 12 (a)), an atmospheric state (see FIG. 12 (b)), or a high pressure. The state can be adjusted (see FIG. 12C). Further, in the alignment apparatus according to the embodiment of the present invention, in order to improve the responsiveness of switching in each solenoid valve (35a and 35b), each solenoid valve (35a and 35a and 35a and 35b) is placed on the region below the vacuum coupler in the XYZθ table. 35b) is arranged, thereby minimizing the length of the piping tube in each solenoid valve (35a and 35b) and minimizing the piping tube diameter (for example, about φ4).

  Thus, it is important to improve the responsiveness of switching in each solenoid valve (35a and 35b), and in particular, the atmosphere in the space formed by the seal ring closely contacting the contact probe in the separation step. It is very important to improve the responsiveness of each solenoid valve (35a and 35b) when switching from a vacuum state to a high pressure state.

  Thus, the atmosphere in the space can be instantaneously switched from a vacuum state to a high pressure state using each electromagnetic valve (35a and 35b) at the time of the separation step, so that between each pad electrode and each bump electrode. In addition, a force can be applied instantaneously and uniformly in a direction perpendicular to the surface where each pad electrode and each bump electrode contact so as to separate each pad electrode and each bump electrode.

  Therefore, even if an error occurs in the flatness of the wiring board due to the flatness accuracy of the material constituting the wiring board, the pad electrodes and the bump electrodes are separated in parallel and uniformly. As a result, it is possible to reliably prevent the occurrence of a drag impression due to the bump electrode on the surface of the pad electrode, and to expand an allowable range (up to about 50 [μm]) in the flatness error of the wiring board. it can.

  Further, in the bonding step, the responsiveness of each solenoid valve (35a and 35b) is improved when the atmosphere in the space formed by the seal ring closely contacting the contact probe is switched from the atmospheric state to the vacuum state. It is also important.

  Thereby, in the bonding step, each electromagnetic valve (35a and 35b) is used to adjust the atmosphere in the space to the atmospheric state, and after contacting each pad electrode to each bump electrode, each electromagnetic valve (35a and 35b) can be used to instantly switch the atmosphere in the space from the atmospheric state to the vacuum state, so that each pad electrode and each bump electrode is attached between each pad electrode and each bump electrode. Since the force can be applied instantaneously and uniformly in the direction perpendicular to the surface where each pad electrode and each bump electrode are in contact with each other, the bonding between each pad electrode and each bump electrode can be performed in parallel and It can be performed uniformly.

  Further, since each pad electrode is brought into contact with each bump electrode while adjusting the atmosphere in the space to an atmospheric state by using each electromagnetic valve (35a and 35b), the seal ring comes into close contact with the contact probe, thereby The inside atmosphere is prevented from being sealed, and the atmosphere inside the space is sealed, so that each pad electrode cannot be brought into contact with each bump electrode, and the center part of the inspection board is raised. Can be prevented.

  Further, after adjusting the atmosphere in the space to the atmospheric state, each pad electrode is brought into contact with each bump electrode, and then the atmosphere in the space is changed from the atmospheric state to a vacuum state by using each electromagnetic valve (35a and 35b). Since switching is performed instantaneously, the inspection board is not pulled to the wafer tray side because the atmosphere in the space is not switched from the atmospheric state to the vacuum state before contacting each pad electrode with each bump electrode. It is possible to prevent distortion from occurring.

  As described above, according to the alignment apparatus according to the embodiment of the present invention, the seal ring is formed using the first electromagnetic valve 35a and the second electromagnetic valve 35b provided on the lower region of the vacuum coupler in the XYZθ table. Can be appropriately adjusted to a high pressure state / atmospheric state / vacuum state in the space formed by closely contacting the contact probe.

  For this reason, in the burn-in inspection, by using the alignment apparatus according to the present invention, in the bonding process, the pad electrodes and the bump electrodes are bonded in parallel and uniformly, and in the separation process, The pad electrodes and the bump electrodes can be separated from each other in parallel and uniformly.

  Furthermore, according to the alignment apparatus according to the present invention, by using the first electromagnetic valve 35a and the second electromagnetic valve 35b that can switch the atmosphere in the space, in the bonding process, An alignment device that has both a bonding function and a peeling function because the atmosphere in the space can be adjusted from the vacuum state to the high pressure state in the separation step while the atmosphere is adjusted from the atmospheric state to the vacuum state. Therefore, the alignment apparatus can be used effectively.

  As described above, according to the separation method according to the present invention, in the separation process in the burn-in inspection, a drag impression mark due to the bump electrode is generated on the surface of the pad electrode due to the material constituting the wiring board. Therefore, for example, by selecting a resin material as the material constituting the wiring board, the manufacturing cost of the inspection board can be reduced. In addition, the inspection current applied to the semiconductor chip during the burn-in inspection can be increased.

  In the present invention, during the burn-in inspection, each pad electrode (inspection electrode) on the semiconductor wafer and each pad electrode (inspection board) on the inspection board are not affected by the material constituting the wiring board of the inspection board (inspection substrate). The probe electrode) can be separated from the probe electrode in a parallel and uniform manner, so that the burn-in inspection can be performed satisfactorily without generating the drag indentation by the bump electrode on the surface of the pad electrode, which is useful for the burn-in inspection. .

(a) And (b) is a top view which shows the structure of a semiconductor wafer. (a) And (b) is a figure which shows the structure of an inspection board. It is sectional drawing which shows the structure of a probe card. (a) And (b) is an enlarged view (especially enlarged view of the peripheral part of a bump electrode) which shows the structure of a probe card. (a) And (b) is a top view which shows the structure of a probe card. These are perspective views which show the structure of an alignment apparatus. These are sectional drawings which show the structure of an alignment apparatus. These are sectional views showing the positional relationship between the inspection board and the stage on which the semiconductor wafer is mounted before performing the separation step. (a) And (b) is principal part process sectional drawing which shows the separation method which concerns on one Embodiment of this invention. (a) And (b) is principal part process sectional drawing which shows the separation method which concerns on one Embodiment of this invention. (a) is a top view showing an indentation generated on the surface of the pad electrode when the separation method according to the present invention is used, and (b) is a case where the separation method according to the conventional example is used. It is a top view shown about the drag | tict impression trace which generate | occur | produces on the surface of a pad electrode. (a)-(c) is a figure shown about the piping method of a solenoid valve. It is a figure shown about the apparatus used for a wafer level burn-in test | inspection. (a) And (b) is principal part process sectional drawing shown about the bonding method in a burn-in test | inspection. (a) And (b) is principal part process sectional drawing shown about the separation method concerning the prior art example in a burn-in test | inspection.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Semiconductor wafer 2 Semiconductor chip formation area 3 Semiconductor chip 4 Pad electrode (inspection electrode)
5 Inspection board (Inspection board)
6 Probe Card 7 Multilayer Wiring Board 8 Connector 9 Wiring Board Base 10 Holding Rubber 11 Holding 12 Frame 12a Parallel Adjustment Screw 13 Wiring Board 14 Localized Anisotropic Conductive Rubber 15 Contact Probe 15a Thin Film 15b Bump Electrode
15c Copper thin film 15d Ceramic ring 16 Bump forming area 17a, 17b, 17c, 17d Alignment mark 18 Bump area 19 Unit base 20 Roller 21 Horizontal cylinder 22 Vertical cylinder 23 Receiving base 24 Semiconductor wafer recognition camera 25 X axis table 26 Y-axis table 27 Zθ-axis table 28 Inspection board recognition camera 29 Stage 30 Wafer tray 31 Seal ring 32 Coupler for high vacuum 33 Pressure trace 34 Drag pressure trace 35a First solenoid valve 35b Second solenoid valve 36 Alignment device 37 Burn-in Inspection device

Claims (4)

Each inspection electrode of a plurality of semiconductor integrated circuit elements formed on a semiconductor wafer placed on the upper surface of the wafer tray is brought into contact with each probe electrode provided on the wiring substrate of the inspection substrate supported by the cradle. And a series of steps in which the electrical characteristics of the plurality of semiconductor integrated circuit elements are collectively inspected, the stage is adsorbed on the lower surface of the wafer tray, and the inspection electrodes and the probe electrodes are separated from each other. A separation method in burn-in inspection,
(A) releasing the position fixing in the horizontal direction with respect to the inspection substrate immediately before the stage is attracted to the lower surface of the wafer tray;
A step (b) in which the stage is attracted to the lower surface of the wafer tray and the inspection electrodes and the probe electrodes are separated from each other in a state where the position of the inspection substrate is released. Separation method in burn-in inspection. The step (a) of releasing the position fixing of the inspection substrate includes:
Further releasing the position fixing in the vertical direction with respect to the inspection substrate,
The step (b) of separating the inspection electrodes and the probe electrodes from each other,
In a state where the position of the inspection substrate is released, after the stage is adsorbed on the lower surface of the wafer tray, the inspection substrate is floated from the cradle using the stage, The separation method in the burn-in inspection according to claim 1, further comprising a step of separating the electrode and each probe electrode. The step (b) of separating the inspection electrodes and the probe electrodes from each other,
An annular seal member provided on the upper surface of the wafer tray, on which the semiconductor wafer can be mounted on the inspection substrate in a state where the inspection electrodes and the probe electrodes are in contact with each other, 3. The separation method in the burn-in inspection according to claim 2, further comprising a step of introducing high-pressure air into a space formed by being in close contact with the substrate for use. Each inspection electrode of a plurality of semiconductor integrated circuit elements formed on a semiconductor wafer placed on the upper surface of the wafer tray is brought into contact with each probe electrode provided on the wiring substrate of the inspection substrate supported by the cradle. And a series of steps in which the electrical characteristics of the plurality of semiconductor integrated circuit elements are collectively inspected, the stage is adsorbed on the lower surface of the wafer tray, and the inspection electrodes and the probe electrodes are separated from each other. An alignment apparatus used for burn-in inspection,
An annular seal member provided on the upper surface of the wafer tray, on which the semiconductor wafer can be mounted on the inspection substrate in a state where the inspection electrodes and the probe electrodes are in contact with each other, A first electromagnetic valve formed by adhering to the substrate for adjusting the atmosphere in the space to a high pressure state and capable of adjusting the atmosphere in the space to an atmospheric state;
An alignment apparatus comprising: a second electromagnetic valve capable of adjusting the atmosphere in the space to a vacuum state.

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