JPH0476930A - Semiconductor chip mounter - Google Patents

Abstract

PURPOSE:To enable coping with micronization following increases in density by providing a means to detect the state of contact between a conductive pin fitted on a bonding tool and a conductive division fitted on the substrate hold division. CONSTITUTION:An electric detective division 4 provided to correspond with a pair of a conductive pin 9 and a conductive division 13 is equipped with a power supply division 16 and a current detector 17 which are connected in series: one end of the division 16 is connected to one end of the pin 9, and one of the device 17 to the division 13. When the tip 9a of the pin 9 comes in contact with the division 13 to make continuity, the device 17 detects current. When the bonding tool 2 is lowered to the substrate hold division 12, the pin 9 close to the lowest side of the inclined plane contacts the division 13 in the case of inclination of the chip suction plane 2a of the tool 2 to the substrate hold plane of the division 12 with the result that the device 16 corresponding to this pair detects. This process allows high-accuracy detection of the parallelism between a chip l and a board 3 and exact face-down bonding in a chip 1 having fine bumps.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a semiconductor element mounting apparatus, and more particularly to a semiconductor element mounting apparatus for mounting a semiconductor element on a substrate by face-down bonding.

[Prior art]

In recent years, when mounting semiconductor elements on a substrate, flip-chip mounting technology has been attracting attention as a face-down method from the viewpoint of mounting density and workability. This method is described in a document entitled "Technical Trends in Free-Nopchi-Tsub Mounting" published in the December 1989 issue of "Electronic Backpacking Technology." When a flip chip is mounted on a substrate using a face-down method, the flip chip must be mounted face-down while being kept parallel to the surface of the substrate on which the semiconductor element is mounted. However, conventionally, during the first adjustment of the mounting apparatus, after adjusting the parallelism between the bonding head and the substrate surface, face-down bonding was performed without making any adjustment. With such a method, there are cases where the semiconductor element cannot be reliably bonded to the substrate surface. Therefore,
During face-down bonding, the semiconductor element was observed with a TV camera or the like placed right next to the tool holding the semiconductor element by suction, and face-down was performed while observing the parallelism between the tool and the substrate.

[Problem to be solved by the invention]

However, in the conventional method as described above, parallelism of only a few μm per 10 mm can be achieved between the semiconductor element provided with the bump and the substrate to which it is bonded. Height is 10μm
It was not possible to adequately respond to the miniaturization that accompanies higher density as described below.

An object of the present invention is to solve the above problems and provide a semiconductor element mounting apparatus that can cope with miniaturization as the density increases.

[Means to solve the problem]

The semiconductor element mounting apparatus of the present invention includes a bonding tool that has a suction surface and holds a semiconductor element having a bump electrode formed on one side by adsorbing it to the suction surface on the other side, and a substrate on which the semiconductor element is mounted. a holding member to be held; a moving mechanism for moving the bonding tool relative to the holding member; At least three or more conductive pins provided around the surface, conductive parts provided around the substrate holding surface of the holding member at positions corresponding to the conductive pins, and pairs of the conductive pin and the conductive part, respectively. It is characterized by comprising an electrical detection means for electrically detecting the contact state between the conductive pin and the conductive part.

Furthermore, the semiconductor element mounting apparatus is provided with an inclination adjustment mechanism that allows the bonding tool to adjust the inclination of its suction surface with respect to the substrate holding surface, and a storage mechanism that stores the conductive pins,
Furthermore, it is also preferable to provide a control means for controlling the inclination adjustment mechanism, storage mechanism, and movement mechanism based on detection by the electric detection means so as to automatically perform face-down bonding.

[Effect]

In the semiconductor element mounting apparatus of the present invention, a plurality of conductive pins whose tips define a plane parallel to the element attraction surface are provided protruding from the attraction surface, and a plurality of conductive pins are provided on the substrate holding surface corresponding to the conductive pins. A conductive part is provided. Therefore, by moving the bonding tool toward the holding member and observing the contact state between this conductive pin and the conductive part provided on the bonding tool in correspondence with the conductive pin, the inclination state of the adsorption surface of the bonding tool can be accurately determined. can be detected. Based on this detected result, the tilted state of the bonding tool can be corrected to make the surface of the semiconductor element on the bonding tool parallel to the element mounting surface of the substrate.

〔Example〕

Embodiments according to the present invention will be described below with reference to the drawings.

As shown in FIG. 1, the semiconductor element mounting apparatus includes a bonding tool 2 on which a semiconductor element 1 is mounted, a substrate holder 12 that holds a semiconductor substrate on which the semiconductor element is mounted, and a bonding tool 2 and a substrate holder 12. and an electrical detection section 4 that detects the parallelism between the two.

The tip of this bonding tool 2 has a semiconductor element 1 attached thereto.
A flat surface 2a (suction surface) for suctioning and fixing is formed.

A through hole 2b connected to the vacuum pump 20 is formed in the center of this plane 2a. Furthermore, this bonding tool 2 includes, as shown in FIG. 2(a),
Three bin mechanisms 5.6.7 are provided at positions separated by an angle of 120 degrees around the center of the through-hole 2b. Since these bottle mechanisms 5 and the like all have the same structure, the bottle mechanism 5 will be described as an example.

As shown in FIG. 1, the bottle mechanism 5 includes a cylindrical cylinder portion 5a and a drive mechanism (not shown) connected to the cylinder portion 5a and housed within the holding member 2. Further, in this cylinder portion 5a, a compression spring 8 abuts against the bottom of the conductive pin 9 so that the conductive bottle 9 made of a conductive material and the tip 9a of the conductive pin 9 protrude from the suction surface of the bonding tool. It is arranged as follows.

The cylinder portion 5a is a rod 5c extending from the drive mechanism.
is combined with This drive mechanism is configured to move the cylinder portion 5a in a direction perpendicular to the tool surface,
The tip end 9a of the conductive pin 9 can be stored inside the tool surface. Three pairs of the drive mechanism, cylinder section, and conductive pin configured as described above are provided. The tips of these three conductive pins 9, 10, and 11 define a plane parallel to the suction surface 2a in an unloaded state. Furthermore,
The bonding tool 2 is a substrate 3 mounted on a mounting device.
When the semiconductor element mounting surface 3a of is an XY plane, this
It is movable in the direction Z orthogonal to the Y plane, and further has a rotation angle θ , θy force direction is adjustable.

The substrate holding section 12 of this semiconductor element mounting apparatus supports the substrate 3 on its entire lower surface and includes a fixing mechanism (not shown) for holding and fixing the substrate 3 in a predetermined position. Conductive parts 13, 14, and 15 are provided in areas of the substrate holding part 12 outside the substrate holding area. These conductive parts 13, etc. are provided at positions corresponding to the conductive pins 9, 10, 11, and are sufficiently arranged so that even if the bonding tool 2 is tilted to some extent, they can abut on the conductive pins 9, 10, 11, respectively. The bonding tool 2 has an area such that its upper surface is parallel to the substrate holding surface 12a of the bonding tool 2.

The electric detection section 4 is provided for each pair of the conductive pin and the conductive section described above, and they have the same structure. Therefore, the electric detection section 4 provided for the pair of the conductive pin 9 and the conductive section 13 will be explained. This electric detection section 4 includes a power supply section 16 and a current detector 17 that are connected in series with each other.As shown in FIG. One end of is connected to the conductive part 13. When the tip end 9a of the conductive pin 9 contacts the conductive part 13 and becomes conductive, the current detector 17 is configured to detect the current flowing there and indicate that the contact has been made. . Such an electrical detection part is connected to the conductive pin 9.10.11 and the conductive part 13.1.
4.15 and are provided independently.

With the above configuration, when the bonding tool 2 is lowered relative to the substrate holder 12, if the element suction surface 2a of the bonding tool 2 touches the substrate holder surface 12a of the substrate holder 12, If the slope is inclined, the conductive pin closest to the bottom of the slope comes into contact with the conductive part, and the electrical detector corresponding to this pair detects the contact. With this, it is possible to know which part is the lowest, that is, in which direction it is inclined, depending on which electric detector detects the current first.

In addition, after the first current detection, the bonding tool 2
By lowering the bonding tool 2 and checking which electric detector detects the current, the direction and degree of inclination of the bonding tool 2 can be determined more accurately.

When all the electric detectors detect the current at the same time, the adsorption surface of the bonding tool 2 is connected to the substrate holding part 12.
It is parallel to the holding surface 12a of. Here, the lower surface of the substrate 3 is configured parallel to the upper surface 3a of the substrate 3;
The plane formed by the tip of the conductive pin is parallel to the face-down bonding surface of the semiconductor element 1 mounted on the bonding tool 2.

Therefore, when current is detected simultaneously by the three electric detectors, the bonding surface of the semiconductor element 1 and the upper surface 3a of the substrate 3 are parallel to each other.

Next, a method of face-down bonding the semiconductor element 1 onto the semiconductor element mounting surface 3a of the substrate 3 using the above-mentioned apparatus will be described with reference to FIG.

First, the substrate 3 is fixed at a predetermined position on the substrate holding part 12. Next, drive the drive mechanism such as the cylinder part 5a, store the conductive pin in the bonding boule 2, and after the tip of the conductive pin is stored in the bonding tool, the opposite side of the surface where the bump electrode is formed. The semiconductor element 1 is set so that the surface thereof covers the through hole 2b of the bonding tool 2, and the inside of the through hole 2b is vacuumed with the vacuum pump 20, and the semiconductor element 1 is removed.
to the tip of bonding tool 2 (3rd
(See figure (a)).

Next, the drive mechanism is activated to cause the conductive pins 9 and the like to protrude from the bonding tool 2.

Next, the bonding tool 2 is gradually lowered in the -Z direction. During the descent, observe at which electrical detector the current is detected. FIG. 3(b) shows a state in which - of the three conductive pins is in contact with the corresponding conductive part. In this state, the current detector corresponding to the pair of the conductive pin and the conductive part that are in contact detects the current and indicates that they have made contact.

Therefore, next, after raising the bonding tool 2 in the Z direction and separating the contacting conductive pin and conductive part,
X of the bonding tool 2 so that the part where the conductive pin corresponding to the current detector that detected the current is located is at the same height as the position where the other two conductive pins are provided
Axial rotation angle θxSY Finely adjust the axial rotation angle θy. Then, the bonding tool 2 is moved in the −Z direction again, and the current detection state of the current detector is observed.

The above-mentioned up/down and tilt adjustment of the bonding tool 2 is repeated until all the current detectors detect current at the same time. Then, the inclination of the bonding crane 2 is fixed with all the current detectors simultaneously detecting current. This state is shown in FIG. 3(c).

After that, after operating the drive mechanism and storing the conductive bottle 9 etc. in the bonding tool 2, the bonding tool 2 is moved to -Z.
direction, and the semiconductor element 1 is face-down bonded onto the upper surface 3a of the substrate 3.

In this way, the parallelism between the surface of the semiconductor element 1 on which the bump electrode is formed and the semiconductor element mounting surface 3a of the substrate can be easily and accurately detected, and based on this detection result, the bonding tool 2 is adjusted. By adjusting the slope,
Highly accurate face-down bonding can be performed.

The present invention is not limited to the above embodiments, and various modifications may be made.

Specifically, the device used in the above embodiment is provided with three pairs of conductive pins and conductive parts, but if there are three or more pairs,
Any number is fine. By increasing the number of combinations of conductive pins and conductive parts, the tilted state of the bonding tool 2 can be known in more detail.

Further, in the above embodiment, the surface formed by the tip of the conductive pin is configured to be parallel to the semiconductor element surface on the bonding tool 2, and the top surface of the conductive part is configured to be parallel to the top surface of the substrate. Alternatively, it may be configured such that it does not have this configuration and contacts all the conductive pins or conductive parts at the same time while the top surface of the semiconductor element and the top surface of the substrate are in a parallel state.

Further, in the above embodiment, an electrically controlled tilt drive mechanism such as a solenoid is used so that an electrically controlled tilt drive mechanism such as a stepping motor that can adjust the tilt of the bonding tool 2 and a conductive pin can be accommodated in the bonding tool 2. By providing a drive mechanism, making the drive mechanism for moving the bonding tool 2 in the Z direction electrically controlled, and providing an electronic control device such as a microcomputer to control these, the bonding tool 2 can be automatically Face-down bonding can be performed by adjusting the surface of the semiconductor element on which the bump electrode is formed parallel to the semiconductor element mounting surface of the substrate.

Specifically, the electronic control device energizes the movement mechanism that moves the bonding tool 2 in the Z direction. This causes the bonding tool 2 to move in the -Z force direction. This electronic control device is connected to the electric detection section, and based on the detection result of the contact state between the conductive bottle and the conductive part from the electric detection section, energizes the tilt drive mechanism and adjusts the tilt of the bonding tool. . After the adjustment is completed, the electronic control device energizes the conductive pin drive mechanism to house the conductive pin in the bonding crane, and then energizes the moving mechanism to perform face-down bonding.

〔Effect of the invention〕

As described above, in the semiconductor element mounting apparatus of the present invention, the contact state between the conductive bottle provided in the bonding tool and the conductive part provided in the substrate holding part is electrically detected, and the semiconductor Since the parallelism between the element and the substrate is detected with high accuracy, reliable face-down bonding can be performed even on semiconductor elements having minute bumps.

[Brief explanation of drawings]

1 is a diagram showing the configuration of a semiconductor element mounting apparatus according to an embodiment of the present invention, FIG. 2 is a diagram showing the arrangement of conductive bins of the bonding tool shown in FIG. 1, and FIG. FIG. 3 is a diagram showing the relationship between a bonding tool and a substrate holding section when a semiconductor element is mounted using the apparatus of the example shown in the figure. 1... Semiconductor element, 2... Bonding tool, 3
... Board, 4... Electricity detection part, 5.6.7... Bin mechanism, 5a... Cylinder part, 8... Compression spring,
9.10.11... Conductive pin, 12... Board holding part, 1
3.14.15... Conductive part, 16... Power supply, 17...
・Current detector. Representative Patent Attorney Yoshiki Hasejo
Fumi Terasaki Movement (first half) Figure 3 (1) Movement (VK half) Figure 3 (2)

Claims (1)

[Claims] 1. A bonding tool that has a suction surface and holds a semiconductor element having bump electrodes formed on one side by suctioning the opposite side to the suction surface, and a substrate on which the semiconductor element is mounted. a holding member for holding; a moving mechanism for moving the bonding tool with respect to the holding member; at least three or more conductive pins provided around the suction surface; a conductive part provided around the substrate holding surface of the holding member at a position corresponding to the conductive pins; and the conductive pins and the conductive pins. provided for each pair with the section,
A semiconductor element mounting apparatus comprising: electrical detection means for electrically detecting a contact state between the conductive pin and the conductive part. 2. The bonding tool includes an inclination adjustment mechanism that can adjust the inclination of the adsorption surface with respect to the substrate holding surface, and a storage mechanism that stores the conductive pin, based on detection by the semiconductor element mounting apparatus or the electrical detection means. 2. The semiconductor device mounting apparatus according to claim 1, further comprising control means for controlling said tilt adjustment mechanism, said storage mechanism, and said moving mechanism.