JP2006303151A - Bonding method of semiconductor chip, adsorption jig, and bonding apparatus of semiconductor chip - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the occurrence of any void by restraining air from entering between a semiconductor chip and a lead frame at the time of mounting of the semiconductor chip. <P>SOLUTION: In a bonding method of a semiconductor chip in which a semiconductor chip 7 is mounted on a lead frame 14 via a die bond agent, the semiconductor chip is adsorbed and held by a first air vent formed in a circumferential region of a flat collet 16, and the central region of the semiconductor chip is deformed into a protruded shape with respect to the lead frame for bonding thereafter by blowing air from a second air vent formed in a central region of the flat collet. <P>COPYRIGHT: (C)2007,JPO&amp;INPIT

Description

  The present invention relates to a semiconductor chip bonding method, a suction jig, and a semiconductor chip bonding apparatus. More specifically, the present invention relates to a semiconductor chip bonding method in which a semiconductor chip is mounted on a substrate such as a lead frame via a die bonding agent, an adsorption jig used in such a semiconductor chip bonding method, and a semiconductor chip bonding apparatus.

  As one of the semiconductor manufacturing processes, there is a process of bonding a semiconductor chip to a substrate such as a lead frame. In this process, the semiconductor chip is cut and separated into pieces by a dicing process as shown in FIG. The semiconductor chips 101 are pushed up one by one from the lower surface of the dicing sheet 102 by the pushing device 103 to peel off the semiconductor chips from the dicing sheet and pick up by the suction force of the suction device 104 (see FIG. 6B). In this state, after being transported to the bonding position (see FIG. 6C), bonding is performed on the substrate 105 such as a lead frame (see FIG. 6D). Note that a die bond agent 106 is applied in advance on the substrate, and the semiconductor chip is bonded to the substrate through the die bond agent (see, for example, Patent Document 1).

  Here, as an example of a generally used adsorption apparatus, FIG. 7A (FIG. 7A-1 is a schematic perspective view, and FIG. 7A-2 is a schematic cross-sectional view. 7 (a-3) shows a schematic plan view), and has a pyramid collet 107a made of metal, and the pyramid collet has a pyramidal semiconductor chip contact portion 108 and a semiconductor chip. An intake hole 109 formed inside the contact portion is provided. When the semiconductor chip is actually held by suction, the semiconductor chip is attached to the four sides of the semiconductor chip without contacting the surface of the semiconductor chip while sucking air through the suction holes by the operation of a vacuum device (not shown). Touch the contact part.

  Moreover, as another example of the adsorption device generally used, FIG. 7B (FIG. 7B-1 is a schematic perspective view, FIG. 7B-2 is a schematic cross-sectional view, As shown in FIG. 7B-3, a schematic plan view is provided. As shown in FIG. 7B, a flat collet 107b made of resin is provided. The flat collet has a semiconductor chip contact portion 108 and the semiconductor chip contact portion. An intake hole 109 formed inside is provided. When actually holding the semiconductor chip by suction, the semiconductor chip contact portion is brought into direct contact with the surface of the semiconductor chip while sucking air through the intake holes by the operation of a vacuum device (not shown).

Japanese Patent Application Laid-Open No. 2004-241685

  By the way, the thickness of the conventional semiconductor chip is about 100 μm to 250 μm. However, in recent years, with the miniaturization of electronic products, for example, in a semiconductor chip embedded in an IC card, the thickness is about 30 μm to 50 μm. Very thin ones are being adopted.

  In the case of a semiconductor chip as thin as several tens of μm in this way, when sucked and held by an adsorption collet, the semiconductor chip is concave as shown in FIG. 8A (recessed with respect to the substrate on which the semiconductor chip is mounted). ) Is bent or warped, and air 110 enters between the semiconductor chip and the substrate when mounted on the substrate 105 via the die bond agent as shown in FIG. This contributes to the generation of cracks and leads to a decrease in the heat resistance of the product. FIG. 8B-1 shows the case where the die bond paste 111 is used as the die bond agent, and FIG. 8B-2 shows the case where the die attach film 112 is used as the die bond agent.

  It is also conceivable to adjust the suction force acting on the suction holes to such a pressure that the semiconductor chip is not bent or warped when the semiconductor chip is sucked and held. However, the suction leakage between the suction surface of the suction collet and the top surface of the semiconductor chip due to the top surface of the semiconductor chip bonded to the dicing sheet being inclined or the uneven state of the semiconductor chip surface being slightly different for each semiconductor chip. Considering the difference between the above, the suction force acting on the suction hole is increased so that the semiconductor chip can be picked up and transported by the suction collet even in such a state. The current situation is to keep it constant during the operation until bonding. Therefore, in the case of an extremely thin semiconductor chip, the above-described bending and warping of the semiconductor chip is currently occurring.

  The present invention has been devised in view of the above points, and is a semiconductor chip bonding method and suction jig that suppresses the entry of air when mounting a semiconductor chip and reduces the generation of voids. An object is to provide a bonding apparatus.

  In order to achieve the above object, a semiconductor chip bonding method according to the present invention is a semiconductor chip bonding method in which a semiconductor chip is mounted on a substrate via a die bonding agent, wherein the semiconductor chip is a central region of the semiconductor chip. After the contact with the die bond agent, the semiconductor chip is mounted so that the peripheral region of the semiconductor chip is in contact with the die bond agent.

Here, after mounting the semiconductor chip so that the central region of the semiconductor chip is in contact with the die bond agent, and the peripheral region of the semiconductor chip is in contact with the die bond agent, as shown in FIG. Air intervening between the semiconductor chip and the substrate can be excluded in the outward direction. 8C-1 shows a case where a die bond paste is used as the die bond agent, and FIG. 8C-2 shows a case where a die attach film is used as the die bond agent.
For example, by deforming the semiconductor chip so that the central region of the semiconductor chip is convex with respect to the substrate, the peripheral region of the semiconductor chip is die bonded after the central region of the semiconductor chip is in contact with the die bond agent. A semiconductor chip can be mounted so as to come into contact with the agent.

  In the semiconductor chip bonding method according to the present invention, the die bonding agent is applied to the substrate using an adsorption jig having a first vent hole formed in the peripheral region and a second vent hole formed in the central region. A semiconductor chip bonding method of mounting a semiconductor chip via a step of picking up a semiconductor chip disposed at a predetermined position by adsorbing a peripheral area of the semiconductor chip by at least the suction force of the first air hole; The semiconductor chip is mounted on the substrate in a state where a peripheral region of the semiconductor chip is adsorbed by the suction force of the first air hole and a predetermined gas is discharged from the second air hole to the central region of the semiconductor chip. A process.

  Here, the peripheral area of the semiconductor chip is adsorbed by the suction force of the first vent hole, and the semiconductor chip is mounted on the substrate in a state where a predetermined gas is discharged from the second vent hole to the central area of the semiconductor chip. That is, by mounting the semiconductor chip on the substrate with the suction jig deformed so that the central region of the semiconductor chip is convex with respect to the substrate, the air interposed between the semiconductor chip and the substrate is removed. It can be eliminated in the outward direction.

  In order to achieve the above object, the suction jig according to the present invention picks up a semiconductor chip arranged at a predetermined position by a suction force, and the suction jig mounts the semiconductor chip on a substrate. The jig includes a first air hole formed corresponding to a peripheral region of the semiconductor chip to be adsorbed, and a second air hole formed corresponding to a central region of the semiconductor chip to be adsorbed. The first air hole is configured so that the peripheral area of the semiconductor chip can be picked up by the suction force of the first air hole so that the semiconductor chip can be taken up, and the second air hole is formed in the first air hole. A structure in which the central region of the semiconductor chip can be deformed into a convex shape with respect to the substrate by discharging a predetermined gas from the second vent hole in a state where the peripheral region of the semiconductor chip is adsorbed by the suction force of the pores Been That.

  Here, in the state where the second vent hole adsorbs the peripheral area of the semiconductor chip by the suction force of the first vent hole, a predetermined gas is discharged from the second vent hole so that the central area of the semiconductor chip is By being configured so that it can be deformed in a convex shape with respect to the substrate, the air interposed between the semiconductor chip and the substrate can be excluded in the outward direction.

  In order to achieve the above object, a semiconductor chip bonding apparatus according to the present invention has a first vent hole formed in a peripheral region and a second vent hole formed in a central region. In a semiconductor chip bonding apparatus that picks up a semiconductor chip disposed at a predetermined position by a suction force of a jig and mounts the semiconductor chip adsorbed on the adsorption jig on a substrate, at least the first of the semiconductor chips is picked up. A suction force generating means for generating a suction force in the air hole, and the second force in the state where the suction force is generated in the first air hole by the suction force generating means when the semiconductor chip is mounted on the substrate. Gas discharge means for discharging a predetermined gas from the vent hole.

  Here, when the semiconductor chip is mounted on the substrate, in a state where the suction force is generated in the first vent hole by the suction force generating means, the gas discharge means for discharging a predetermined gas from the second vent hole, that is, The gas discharge means that realizes mounting the semiconductor chip on the substrate in a state where the central region of the semiconductor chip is deformed so as to be convex with respect to the substrate by the suction jig is interposed between the semiconductor chip and the substrate. To the outside direction.

  In the semiconductor chip bonding method, the suction jig, and the semiconductor chip bonding apparatus to which the present invention is applied, the air interposed between the semiconductor chip and the substrate can be excluded in the outward direction. Intrusion of air is suppressed and void generation is reduced.

Hereinafter, embodiments of the present invention will be described with reference to the drawings to facilitate understanding of the present invention.
FIG. 1 is a schematic diagram for explaining an example of a semiconductor chip bonding apparatus to which the present invention is applied. A semiconductor chip bonding apparatus 1 shown here includes a wafer support portion 2, a lead frame transport portion 3, and a bonding portion 4. It consists of and.

The wafer support unit 2 has a wafer holder 8 for holding the semiconductor chip 7 bonded to the dicing sheet 6 and an XY table 9 for placing the wafer holder. One semiconductor chip is moved by moving the XY table. It is configured so that it can be sequentially positioned at a pickup position which is a predetermined position.
Further, a push-up device 10 is provided below the dicing sheet corresponding to the pickup position. This push-up device pushes up the semiconductor chip bonded to the dicing sheet from below, and dicing is performed on the upper surface thereof. A backup holder 11 that adsorbs the sheet, and a pin holder 13 that moves up and down in the backup holder and has a push-up pin 12 at the tip are arranged so that the push-up pin pushes up the semiconductor chip from the back surface of the dicing sheet by the upward movement of the pin holder. It is configured. The semiconductor chip pushed up by the push-up pin is picked up by a suction collet described later.

  The lead frame transport unit described above is configured so that the lead frame 14 can be transported along the transport rail 15 by a lead frame feed mechanism (not shown).

The bonding part described above has a suction jig 17 having a flat collet (suction collet) 16 at the tip. Here, as shown in FIG. 2 (FIG. 2 (a) is a schematic perspective view and FIG. 2 (b) is a schematic plan view), a semiconductor chip is formed in the peripheral area of the flat collet, that is, in the flat collet. In the region corresponding to the peripheral region of the semiconductor chip when the semiconductor chip is adsorbed, the semiconductor chip contact portion 18 formed in a convex shape with respect to the semiconductor chip is formed, and the four corners 19a of the semiconductor contact portion and the semiconductor contact portion A first vent hole 20 is formed on the four sides 19b. A second air hole 21 is formed in the central area of the flat collet, that is, the area corresponding to the central area of the semiconductor chip when the semiconductor chip is sucked by the flat collet.
Further, the first vent hole is connected to a vacuum source 23 such as a vacuum pump via a first pipe line 22, and the second vent hole is connected to a vacuum source and an air discharge via a second pipe line 24. It is connected to the device 25.
Since the semiconductor contact portion is in direct contact with the semiconductor chip, a material (such as a resin material) that can minimize the influence on the semiconductor chip when contacting the semiconductor chip is used. Configured.

  Hereinafter, a method of bonding a semiconductor chip using the semiconductor chip bonding apparatus configured as described above will be described. That is, a semiconductor chip bonding method to which the present invention is applied will be described.

  In the semiconductor chip bonding method to which the present invention is applied, first, the XY table is moved to position one of the semiconductor chips on the dicing sheet at the pickup position. Thereafter, as shown in FIG. 3A, the semiconductor chip positioned at the pickup position is sucked and held on the upper surface of the backup holder of the push-up device through the dicing sheet.

  Next, the suction jig is lowered from above the pickup position by the operation of an elevating device (not shown), and the flat collet is brought into contact with the semiconductor chip positioned at the pickup position. Subsequently, the semiconductor chip is sucked and held using the suction force generated in the first vent hole by the vacuum source (see FIG. 3B).

  Subsequently, the push-up pin is raised and the semiconductor chip is pushed up from below through the dicing sheet (see FIG. 3C). At this time, the flat collet rises together with the rise of the push-up pin with the semiconductor chip sandwiched between the push-up pins, and stops after the push-up pin rises to a predetermined position (see FIG. 3D). Thereafter, the semiconductor chip is taken out by a flat collet (see FIG. 3E).

  Next, the picked-up semiconductor chip is transported to the bonding position of the lead frame transported along the transport rail by the movement of the suction jig (see FIG. 4F). Subsequently, gas is blown from the second vent hole to the central region of the semiconductor chip by an air discharge device, thereby deforming the central region of the semiconductor chip so as to be convex with respect to the lead frame (FIG. 4G). reference.).

  In consideration of the adverse effect on the semiconductor chip due to the stress applied to the semiconductor chip, the timing of blowing the air to the central area of the semiconductor chip to deform the central area of the semiconductor chip is just before mounting the semiconductor chip on the lead frame. Is preferred.

  Further, in order to suppress scattering of the semiconductor chip by the air blown from the second ventilation hole, it is preferable to provide a hole (not shown) for allowing air to escape in the flat collet.

  Subsequently, when the flat collet is lowered by the operation of an elevating device (not shown) and the central region of the convex semiconductor chip touches the die bond agent, the lowering operation of the flat collet is stopped and the second air hole is opened. The semiconductor chip is vibrated by changing the amount of air to be blown or by sucking or discharging air from the second ventilation hole (see FIG. 4H).

  Here, it is considered that by vibrating the semiconductor chip, wettability and embeddability are improved, and the semiconductor chip and the lead frame become compatible with the die bond agent, and air inflow can be suppressed. If the air entry can be sufficiently suppressed even if it is not, it is not always necessary to vibrate the semiconductor chip.

  Thereafter, the flat collet is lowered by the operation of the lifting device, and bonding is performed at the bonding position of the lead frame (see FIG. 4I).

Here, in this embodiment, when picking up the semiconductor chip, the semiconductor chip is pushed up from below with a push-up pin, and the dicing sheet extends to reduce the adhesiveness of the dicing sheet so that the semiconductor chip is easily peeled off from the dicing sheet. Therefore, the case where the semiconductor chip is sucked and held using the suction force generated only in the first ventilation hole has been described as an example, but only the suction force generated in the first ventilation hole is used. In this method, the semiconductor chip is difficult to peel off from the dicing sheet, and it is considered that the semiconductor chip is scattered or cracked during pick-up.
Therefore, when it is considered that the semiconductor chip is difficult to peel off from the dicing sheet, a suction force is generated not only in the first ventilation hole but also in the second ventilation hole, and the first ventilation hole and the second ventilation hole are generated. It is preferable to suck and hold the semiconductor chip by using the generated suction force.

In addition, it is considered that the semiconductor chip becomes excessively concave with respect to the lead frame, as shown in FIG. When the shape is excessively deformed, a gap is formed between the first air hole and the semiconductor chip, and the semiconductor chip may be insufficiently held by suction from the first air hole. If the suction and holding of the semiconductor chip by suction from the first vent hole is insufficient, when suction from the second vent hole is stopped, that is, air is blown from the second vent hole. There is a possibility that the semiconductor chip is scattered when attaching.
Therefore, in the case where it is considered that the semiconductor chip becomes excessively concave with respect to the lead frame due to suction from the second vent hole during pick-up, as shown in FIG. It is preferable that the stopper 26 is formed in the central region of the flat collet so as not to be excessively deformed into a concave shape. In addition, the semiconductor chip at the time of attracting | sucking from the 2nd ventilation hole using the flat collet which formed the stopper is shown to Fig.5 (a-3).

  Further, in this embodiment, a case where the central region of the semiconductor chip is deformed into a convex shape with respect to the lead frame using a flat collet in which the first vent hole and the second vent hole are formed will be described as an example. However, any method may be used as long as the central region of the semiconductor chip can be deformed in a convex shape with respect to the lead frame, and the first vent hole and the second vent hole are not necessarily formed. There is no need to use a flat collet. For example, when picking up a semiconductor chip, as shown in FIG. 5 (b-1), the semiconductor chip is sucked and held as shown in FIG. 5 (b-1), and during bonding, the semiconductor is similar to the above-described embodiment shown in FIG. 5 (b-2). The central region of the semiconductor chip may be deformed so as to be convex with respect to the lead frame by blowing air to the central region of the chip. Further, as shown in FIG. 5 (c-1), the tip shape of the push-up pin and the suction collet is U-shaped, and the semiconductor chip so that the central area of the semiconductor chip is convex with respect to the lead frame from the time of pick-up. May be deformed (see FIG. 5C-2).

  In the semiconductor chip bonding apparatus to which the present invention is applied, the bonding operation can be performed with the central region of the semiconductor chip mounted on the lead frame deformed in a convex shape with respect to the lead frame. Since the peripheral area of the semiconductor chip contacts the die bond agent applied to the lead frame after the area contacts the die bond agent applied to the lead frame, the air interposed between the semiconductor chip and the lead frame is eliminated outward. Even when an extremely thin semiconductor chip is mounted on a lead frame, the entry of air when the semiconductor chip is mounted can be suppressed, the generation of voids can be reduced, and the product characteristics can be improved.

It is a schematic diagram for demonstrating an example of the bonding apparatus of the semiconductor chip to which this invention is applied. It is a schematic diagram for demonstrating a flat collet. It is a schematic diagram (1) for demonstrating the bonding method of the semiconductor chip to which this invention is applied. It is a schematic diagram (2) for demonstrating the bonding method of the semiconductor chip to which this invention is applied. It is a schematic diagram for demonstrating the modification of a present Example. It is a schematic diagram for demonstrating the bonding method of the conventional semiconductor chip. It is a schematic diagram for demonstrating an adsorption | suction collet. It is a schematic diagram for demonstrating the inflow of air by the deformation | transformation of a semiconductor chip, and the exclusion of air.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Bonding apparatus 2 Wafer support part 3 Lead frame conveyance part 4 Bonding part 6 Dicing sheet 7 Semiconductor chip 8 Wafer holder 9 XY table 10 Pushing apparatus 11 Backup holder 12 Pushing pin 13 Pin holder 14 Lead frame 15 Carrying rail 16 Flat collet 17 Adsorption treatment Tool 18 Semiconductor chip contact part 19a 4 corners 19b 4 sides 20 1st ventilation hole 21 2nd ventilation hole 22 1st pipe line 23 Vacuum source 24 2nd pipe line 25 Air discharge apparatus 26 Stopper

Claims (7)

In a semiconductor chip bonding method in which a semiconductor chip is mounted on a substrate via a die bond agent,
The semiconductor chip includes a step of mounting so that a peripheral region of the semiconductor chip is in contact with the die bond agent after a central region of the semiconductor chip is in contact with the die bond agent. . The semiconductor chip bonding method according to claim 1, further comprising a step of deforming the central region of the semiconductor chip so as to be convex with respect to the substrate. Semiconductor chip bonding method for mounting a semiconductor chip on a substrate via a die bonding agent using an adsorption jig having a first vent hole formed in a peripheral region and a second vent hole formed in a central region Because
Picking up a semiconductor chip disposed at a predetermined position by adsorbing a peripheral region of the semiconductor chip by at least the suction force of the first vent hole; and
The semiconductor chip is mounted on the substrate in a state where a peripheral region of the semiconductor chip is adsorbed by the suction force of the first air hole and a predetermined gas is discharged from the second air hole to the central region of the semiconductor chip. A semiconductor chip bonding method. The peripheral area of the semiconductor chip is adsorbed by the suction force of the first vent hole, and the semiconductor chip disposed at a predetermined position is picked up by attracting the central area of the semiconductor chip by the attraction force of the second vent hole. The semiconductor chip bonding method according to claim 3. The semiconductor chip bonding method according to claim 3, wherein after the semiconductor chip comes into contact with the die bonding agent, suction and discharge of a predetermined gas are performed from the second vent hole. While picking up the semiconductor chip arranged at a predetermined position by suction force, in the suction jig for mounting the semiconductor chip on the substrate,
The suction jig includes a first vent hole formed corresponding to a peripheral region of the semiconductor chip to be sucked, and a second vent hole formed corresponding to a central region of the semiconductor chip to be sucked,
The first vent hole is configured so that the semiconductor chip can be taken up by adsorbing a peripheral region of the semiconductor chip by the suction force of the first vent hole,
The second vent hole has a central area of the semiconductor chip formed by discharging a predetermined gas from the second vent hole in a state where the peripheral area of the semiconductor chip is adsorbed by the suction force of the first vent hole. An adsorption jig configured to be deformed in a convex shape with respect to the substrate. The semiconductor chip disposed at a predetermined position is picked up by the suction force of a suction jig having a first vent hole formed in the peripheral region and a second vent hole formed in the central region, and the suction jig In a semiconductor chip bonding apparatus for mounting a semiconductor chip adsorbed on a substrate on a substrate,
A suction force generating means for generating a suction force at least in the first vent hole when picking up the semiconductor chip;
Gas discharge means for discharging a predetermined gas from the second vent hole in a state in which a suction force is generated in the first vent hole by the suction force generating means when the semiconductor chip is mounted on the substrate. A semiconductor chip bonding apparatus.

Images