JP4935491B2 - Die bonding apparatus and die bonding method thereof - Google Patents

Description

  The present invention relates to a die bonding apparatus and a die bonding method thereof, and more particularly to a die bonding apparatus suitable for improving throughput and a die bonding method thereof.

  Die bonding refers to mounting a semiconductor chip at a predetermined position. In general, die bonding of an optical semiconductor chip is performed by mounting the optical semiconductor chip on a metal member called a stem. Actually, in order to actually mount the optical semiconductor chip on the stem, the solder attached to the stem is melted, and the semiconductor chip is pressed against it and cooled. An apparatus for performing die bonding is called a die bonding apparatus.

A die bonding apparatus and a die bonding method using solder as described above are described in Patent Document 1. The die bonding apparatus and the die bonding method disclosed in Patent Document 1 employ a method using an alignment jig. This method includes a step of correcting the position using a laser device recognition device. In addition, there is a step of correcting the mounting position by actually emitting light from a laser element to be mounted on the stem or the like. As described above, the method using the alignment jig has an advantage that the semiconductor chip can be die-bonded with high accuracy although the processing steps are somewhat complicated.
Japanese Unexamined Patent Publication No. Hei 6-282819 JP 2003-273139 A Japanese Patent Laid-Open No. Sho 62-190891

  In DVD optical semiconductor elements and the like, it is required to improve die bonding throughput without reducing yield in order to reduce manufacturing costs. However, in the die bonding apparatus and the die bonding method disclosed in Patent Document 1, it is difficult to increase the throughput because the processing is complicated and there are many processing steps. Therefore, there is a problem that sufficient throughput cannot be realized.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a die bonding apparatus and a die bonding method thereof that can shorten the time required for die bonding.

A die bonding apparatus according to the present invention includes a collet that holds and positions a semiconductor chip, a stem on which the semiconductor chip is mounted, a heat block that contacts the stem and supplies heat to the stem, and the semiconductor An abutment claw for adjusting the angle of the semiconductor chip with respect to the stem by contacting one end of the chip, and the abutment claw is not in contact with the stem and the abutment claw The first feature is that it touches a place where the relative position with respect to the stem is fixed.

The die bonding apparatus according to the present invention includes a heat sink on which a semiconductor chip is mounted, a collet that holds the above-described semiconductor chip or the above-described heat sink and positions each of the semiconductor chip, a stem on which the above-mentioned heat sink is mounted, and the above-described stem A heat block that contacts the stem and contacts one end of the semiconductor chip and the one end of the heat sink so that the angle of the semiconductor chip and the heat sink is adjusted with respect to the stem. The above-mentioned abutment claw has a second feature in that the abutment claw is in contact with a place where the relative position between the abutment claw and the stem is fixed without contacting the stem.

In addition, the die bonding method according to the present invention includes a heat block contact step in which the heat block is brought into contact with the stem, and an abutment claw contact step in which the abutment claw is brought into contact with the heat block without being brought into contact with the stem. after the aforementioned heat block contacting step above abutting claws contacting step, aligning angle foregoing semiconductor chip to be mounted on the aforementioned stem by utilizing one surface abutting the nail described above with respect to the aforementioned stem Third feature is that it has an angle adjusting step, a positioning step for determining the mounting position of the semiconductor chip, and a stem heating step for heating the stem with the heat block after the heat block contact step. To do.

  According to the present invention, die bonding can be performed at high speed.

Embodiment 1
FIG. 1 is a diagram for explaining the configuration of the present embodiment. FIG. 1 is a front view. FIG. 2 is an AA arrow view of FIG. The components of this embodiment include a semiconductor element on which a semiconductor chip is to be mounted and a die bonding apparatus. The configurations of the semiconductor element and the die bonding apparatus will be described below.

  The aforementioned semiconductor element has a stem base 10. The stem base 10 is a metal member and may have a flat plate shape, but the stem base 10 of the present embodiment has a circular flat plate shape. The semiconductor element further has a stem block 12. The stem block 12 is also a metal member. At least one surface of the stem block 12 is fixed to the stem base 10. The stem block 12 has a surface coated with solder. The surface to which the solder is applied is a surface on which the semiconductor chip 18 is mounted in the die bonding process. The shape of the stem block 12 may be a portion fixed to the stem base 10 and a flat surface on which the semiconductor chip 18 on which the solder is applied is to be mounted. In some cases, the stem base 10 and the stem block 12 are integrated from the beginning. In this embodiment, for convenience of explanation, the stem base 10 and the stem block 12 may be collectively referred to as a stem. The stem is made of Ni / Au plated metal with good heat dissipation. The metal used for the stem is often Cu or Fe, but is not limited as long as the heat dissipation is good.

  The semiconductor element further has a metal lead 14. The metal lead 14 is connected to the stem by glass sealing. The lead 14 is wire-connected to a predetermined place by an Au wire or the like.

  On the other hand, the configuration of the die bonding apparatus is as follows. The die bonding apparatus of this embodiment has a collet 16 made of a ceramic material. The collet 16 is a tool for holding a semiconductor chip. The shape of the collet 16 is arbitrary, but in the present embodiment, it has an elongated cylindrical shape with a sharp tip. The collet 16 has a suction hole for sucking the semiconductor chip 18 at its tip. The collet 16 can hold the semiconductor chip 18 by applying this suction hole to one surface of the semiconductor chip 18 and vacuum-sucking it. The collet 18 can be moved to an arbitrary place while holding the semiconductor chip 18.

  The die bonding apparatus further includes a heat block 22. The heat block 22 has a heating / cooling function. The heat block 22 contacts the stem base 10 during die bonding and supplies heat to the stem base 10. Therefore, the shape of the heat block 22 is formed so as to easily come into contact with the stem base 10. The ability of the heat block 22 to raise the temperature is at least enough to melt the solder applied to the stem block 12. As can be seen from FIG. 2, the stem block 22 of this embodiment is configured to contact the stem base 10 at three locations. Each of the three locations mentioned above comes into contact with the outer periphery and the flat surface of the stem base 10. The location and area where the stem block 22 contacts the stem base 10 is appropriately determined. Further, since the heat block 22 is installed to heat the stem, it may be in contact with any part of the stem.

  The die bonding apparatus further has an abutment claw 20. The abutment claw 20 is a member for determining the mounting angle of the semiconductor chip 18 on the stem. That is, the abutment claw 20 is used for angle alignment between the stem and the semiconductor chip 18. The abutment claw 20 abuts at least a side surface of the semiconductor chip 18 to adjust the angle (hereinafter referred to as an angle determination surface), and a surface that contacts the heat block 22 (hereinafter referred to as a heat block contact surface). It has). When the above-described heat block contact surface is brought into contact with the heat block 22, the position of the above-described angle determination surface is determined. Then, the side of the semiconductor chip 18 is abutted against the angle-determined surface whose position has been determined, so that the angle with the stem of the semiconductor chip is adjusted. Further, the abutment claw 20 is configured not to contact the stem. Here, the material of the abutment claw 20 is not particularly limited, but in this embodiment, it is made of Fe.

  Next, a process for mounting the semiconductor chip 18 on the above-described semiconductor element by the above-described die bonding apparatus will be described. First, the heat block 22 is brought into contact with the stem. As shown in FIGS. 1 and 2, the heat block 22 comes into contact with three locations on the outer periphery of the stem base 10 by this process. Next, the heat block contact surface of the abutment claw 20 is brought into contact with the heat block 22. When the heat block contact surface of the abutment claw 20 comes into contact with the heat block, the location of the angle determination surface of the abutment claw 20 is determined. Then, the side surface of the semiconductor chip 18 is abutted against the angle-determined surface whose location is determined. The semiconductor chip 18 is vacuum-sucked by the collet 16. The collet 16 that vacuum-sucks the semiconductor chip 18 moves in the X direction, so that the semiconductor chip 18 is abutted against the angle determination plane.

  In addition, in this embodiment, after the contact of the heat block 22 to the stem, the heat block contact surface of the abutment claw 20 is contacted with the heat block 22, but each contact may be performed in the reverse order.

  Thus, the mounting position of the semiconductor chip 18 that has been subjected to the angle adjustment to be mounted on the semiconductor element is determined by the movement of the collet 16. Here, the collet 16 performs positioning for mounting the semiconductor chip 18 at a predetermined position. Then, the semiconductor chip 18 that has undergone the angle alignment and positioning is mounted on the stem block 12. Mounting of the semiconductor chip 18 on the stem block 12 is performed by melting the solder applied to the stem block 12 and pressing the semiconductor chip 18 with the collet 16 there. The solder applied to the stem block 12 is melted by the heat supplied from the heat block 22 being conducted to the stem block 12. In order for the semiconductor chip to be firmly fixed to the stem block 12, it is desirable that the stem is heated to a temperature as low as possible.

  The semiconductor chip 18 is mounted on the stem block 12 after the mounting angle and mounting position are determined as described above. A front view of the semiconductor element after the semiconductor chip 18 is mounted is shown in FIG. FIG. 4 is a view taken along the line BB in FIG.

  Subsequently, before describing the features of the present invention, a die bonding apparatus and a die bonding method thereof shown in FIGS. 5 and 6 will be described as comparative examples of the present invention. FIG. 5 is a front view of a comparative example. FIG. 6 is a CC arrow view of FIG. The configuration of the comparative example is shown in FIG. 1 and FIG. 2 in that the abutment claw 24 does not have a heat block contact surface but has a surface in contact with the stem (hereinafter referred to as a stem contact surface). The configuration is different. The heat block 22 of the comparative example is configured to be in contact with the stem base at four locations, and to secure a portion where the stem contact surface of the abutting claw 24 is in contact with the stem base 10. As described above, in the comparative example, the position of the angle determination surface is determined by the contact of the stem contact surface of the abutment claw 24 with the stem. Furthermore, the collet 16 of the present embodiment is made of a ceramic material, while the collet 30 of the comparative example is made of metal. The die bonding method after the location of the angle determination surface in the abutting claw 24 is determined is the same as the method of the present embodiment shown in FIGS.

  When die bonding is performed by the configuration and method shown in the comparative example, the stem may not be sufficiently heated by the heat block. This is because the heat supplied from the heat block to the stem for the purpose of overheating the stem escapes to the abutment claw 24 via the stem contact surface of the abutment claw 24 of the comparative example. Further, since the collet of the comparative example is made of metal, heat may escape through the collet when the semiconductor chip is pressed against the stem and welded. This sometimes required additional overheating after the semiconductor chip was pressed against the stem.

  In the comparative example, as a result of the heat loss described above, there is a problem that it takes time to melt the solder applied to the stem block and it is difficult to shorten the time required for die bonding (hereinafter referred to as tact time). It was. Similarly, as a result of this heat loss, due to insufficient melting of the solder, the fixing of the semiconductor chip to the stem becomes fragile, which has been a factor in reducing the product yield. In general, in die bonding, a high yield and a high throughput are required in which the takt time is shortened while maintaining a high level of yield. However, it is difficult for the die bonding apparatus and the die bonding method as in the comparative example to satisfy this requirement for the reasons described above.

  According to the die bonding apparatus and the die bonding method of the present embodiment, high yield and high throughput die bonding can be performed. Since the abutment claw 20 of this embodiment determines the location of the angle determination surface without contacting the stem, heat loss via the abutment claw as in the comparative example is suppressed. Therefore, the temperature of the stem in the configuration of the present invention rises quickly due to the heating from the heat block 22. As a result, the solder applied to the stem block 12 is quickly and sufficiently melted. Further, since the collet 16 of the present embodiment is made of a ceramic material, heat loss via the collet 16 can be suppressed when the semiconductor chip 18 is pressed against the stem. According to the configuration of this embodiment, the semiconductor chip 18 can be mounted on the stem in a state where the solder is melted at high speed and sufficiently, so that high yield and high throughput die bonding can be achieved.

  In the comparative example, a space for the stem base 10 to come into contact with the stem contact surface of the abutment claw 24 is essential. This space requirement hinders miniaturization of the semiconductor element. According to the configuration of the present embodiment, the abutment claw 20 has a heat block contact surface instead of the stem contact surface and does not contact the stem, so that the aforementioned space is not required. Therefore, the semiconductor element can be reduced in size.

  Although the abutment claw 20 of this embodiment has a heat block contact surface, it is not an essential constituent requirement in the present invention. In other words, since the effect of the present invention can be obtained if the abutment claw is not in contact with the stem, a contact surface that does not contact the other stem is used instead of the heat block contact surface as long as the angle determination surface can be fixed. Also good.

Embodiment 2
The present embodiment relates to a die bonding apparatus and a die bonding method for the same that have a high yield, a high throughput, and an easy die bonding. FIG. 7 and FIG. 8 are diagrams for explaining the die bonding apparatus and the die bonding method of the present embodiment. FIG. 7 is a front view. FIG. 8 is a DD arrow view of FIG. The configuration of the semiconductor element and the die bonding apparatus of the present embodiment is different from the first embodiment in that the semiconductor element of the present embodiment includes a heat sink 26. The heat sink 26 is formed of a metal material with good heat dissipation. In the present embodiment, the heat sink 26 is made of AlN or SiC. The surface of the heat sink 26 includes a metal electrode made of Ti, Pt, or Au. The stem block 32 is also different from the stem block 12 of the first embodiment in that solder is not applied.

  The heat sink 26 has a shape having at least a surface in contact with the stem block 32 and a surface on which the semiconductor chip 18 is to be mounted. Solder is applied to the surface of the heat sink 26 that contacts the stem block 32 and the surface on which the semiconductor chip 18 is to be mounted. What is necessary is just to determine suitably the shape of the other part of the heat sink 26 by the ease of manufacture. The shape of the heat sink 26 of this embodiment is a rectangular parallelepiped.

  Next, the die bonding method of this embodiment will be described. The heat block contact surface of the abutment claw 20 is brought into contact with the heat block 22. This determines the location of the angle determination plane. Then, one end of the heat sink 26 held by the collet 16 is pressed against the angle determination surface, and the angle of the heat sink 26 is adjusted. Next, the mounting position of the heat sink 26 is determined by a collet. The heat sink whose mounting angle and mounting position are determined is mounted at a predetermined position of the stem block 32. Thereafter, the mounting angle and the mounting position are determined while the semiconductor chip 18 is also held by the collet 16 like the heat sink. The semiconductor chip 18 whose mounting angle and mounting position are determined is mounted on the surface of the heat sink 26 where the semiconductor chip 18 is to be mounted. The mounting of the heat sink 26 on the stem and the mounting of the semiconductor chip 18 on the heat sink 26 are performed by melting the solder applied to the heat sink 26 described above. The die bonding method of the present embodiment is different from the first embodiment in the above-described points because the present embodiment has the heat sink 26, but is the same as the first embodiment in other points.

According to the configuration including the heat sink 26 as in the present embodiment, the man-hour for applying solder directly to the stem block can be omitted. By omitting this process, it is necessary to install a heat block, but the operation becomes simpler than the process of applying solder directly to the stem block.
Therefore, according to the configuration of the present embodiment, die bonding can be facilitated.

The figure for demonstrating the die-bonding apparatus of Embodiment 1, and its die-bonding method. FIG. 2 is an AA arrow view of FIG. 1. FIG. 4 illustrates a semiconductor element after die bonding according to the first embodiment. The BB arrow directional view of FIG. The figure for demonstrating the die-bonding apparatus of the comparative example, and its die-bonding method. CC arrow figure of FIG. The figure for demonstrating the die-bonding apparatus of Embodiment 2, and its die-bonding method. DD arrow figure of FIG.

Explanation of symbols

10 stem base
12 stem block 16 collet 18 semiconductor chip 20 abutment claw 22 heat block 26 heat sink

Claims (5)

A collet that holds and positions the semiconductor chip;
A stem on which the semiconductor chip is mounted;
A heat block for contacting the stem and supplying heat to the stem;
An abutment claw for bringing one end of the semiconductor chip into contact with each other and adjusting the angle of the semiconductor chip with respect to the stem ;
The abutment nail is
A die-bonding apparatus that contacts a place for fixing a relative position between the abutment claw and the stem without contacting the stem. A heat sink to which a semiconductor chip is mounted;
A collet that holds the semiconductor chip or the heat sink and positions each of them;
A stem on which the heat sink is mounted;
A heat block for contacting the stem and supplying heat to the stem;
An abutting claw for bringing the one end of the semiconductor chip and one end of the heat sink into contact with each other and performing angle alignment of the semiconductor chip and the heat sink with respect to the stem ;
The abutment nail is
A die-bonding apparatus that contacts a place for fixing a relative position between the abutment claw and the stem without contacting the stem.   The die bonding apparatus according to claim 1, wherein the abutting claw is in contact with the heat block.   The die-bonding apparatus according to claim 1, wherein the collet is formed of a ceramic material. A heat block contact process for bringing the heat block into contact with the stem;
An abutment claw contact step of contacting the heat block without contacting the abutment claw with the stem;
After the heat block contact step and the abutting claw contact step, an angle adjusting step for adjusting the angle of the semiconductor chip to be mounted on the stem with respect to the stem using one surface of the abutting claw;
A positioning step for determining a mounting position of the semiconductor chip;
A stem heating step of heating the stem with the heat block after the heat block contact step;
A die bonding method characterized by comprising:

Images