JPH0476931A - 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 division 13, and one of the device 17 to the pin 9. 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 1 and a board 3 and exact face-down bonding in a chip l 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 "Technological Trends in Flip Chip Mounting" published in the December 1989 issue of Electronic Packaging Technology J.

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 tool 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, we installed a TV left camera right next to the sole that holds the semiconductor element by suction during face-down bonding, and use this camera to observe the semiconductor element and perform face-down bonding while observing the parallelism between the tool and the substrate. Ta.

[Problem to be solved by the invention]

However, with the above-mentioned conventional equipment, it is only possible to achieve parallelism of only a few μm per 10 mm between the semiconductor element provided with bumps and the substrate to which it is bonded, and as a result, the bump height of the flip chip is reduced. Vertical 10μm
It has not been 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 pumping tool that has a suction surface and holds a semiconductor element having bump electrodes formed on one side by adsorbing it to the suction surface on the opposite side, and a substrate on which the semiconductor element is mounted. a holding member that holds the bonding tool; a moving mechanism that moves the bonding tool relative to the holding member;
At least three or more conductive pins that are provided around the substrate holding surface of the holding member, can be stored in the holding member, and whose tips define a plane parallel to the substrate holding surface, and around the suction surface. a conductive part provided at a position corresponding to the conductive pin; and a conductive part provided in each pair of the conductive pin and the conductive part,
The present invention is characterized by comprising an electrical detection means for electrically detecting the contact state between the conductive pin and the conductive part.

[Effect]

In the semiconductor element mounting apparatus of the present invention, a plurality of conductive pins whose tips define a plane parallel to the substrate holding surface are provided to protrude from the substrate holding surface, and the tip of the bonding tool corresponding to the conductive pins in the parentheses is is provided with a plurality of conductive parts forming a plane parallel to the suction surface. Then, by moving the bonding vine toward the holding member and observing the contact state between the conductive pin and the conductive part provided on the bonding tool in correspondence with the conductive pin, the slope of the adsorption surface of the bonding tool can be determined. can be detected accurately. 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.

FIG. 1 is a block diagram of an embodiment of a semiconductor element mounting apparatus according to the present invention.

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),
Conductive parts 13, 14, . 15 are provided. These conductive parts 13 and the like are provided at positions corresponding to conductive pins 9, 10, 11, which will be described later, so that even if this bonding tool 2 is tilted to some extent, the conductive pins 13, 14, 15, etc.
The upper surface is parallel to the adsorption surface 2a of the bonding tool 2.

Furthermore, when the semiconductor element mounting surface 3a of the substrate 3 mounted on the mounting apparatus is an XY plane, the bonding tool 2
It is movable in the direction Z perpendicular to this XY plane, and furthermore, it is parallel to this XY plane and is movable in the through hole 2a on the plane 2a.
It is held so that the rotation angles θX and θy can be adjusted in the force direction with respect to both the X and Y axes that define a plane passing through the center of b.

- The substrate holding section 12 of this semiconductor element mounting apparatus is attached to the substrate 3.
A fixing mechanism (not shown) is provided to support the substrate 3 on its entire lower surface and to hold and fix the substrate 3 in a predetermined position. Three bin mechanisms 5, 6, and 7 are provided outside the substrate holding area of the substrate holding section 12. Since all of these pin mechanisms have the same structure, the pin machine 1'5
This will be explained using an example. As shown in FIG. 1, the bin mechanism 5 includes a cylindrical cylinder portion 5a and a drive mechanism (not shown) that is connected to the cylinder and portion 5a and housed in the holding member 12. . Furthermore, this cylinder part 5
a shows a conductive pin 9 made of a conductive material and a tip end 9a of the conductive pin 9 attached to the substrate holding surface 1 of the substrate holding section 12.
A compression spring 8 is arranged to press the bottom of the conductive pin 9 so as to protrude from the conductive pin 2a.

The cylinder portion 5a is coupled to a rond 5c extending from the drive mechanism. This drive mechanism is configured to move the cylinder portion 5a in a direction perpendicular to the substrate holding surface 12a, and allows the tip portion 9a of the conductive pin 9 to be stored inside the substrate holding portion 12. The drive mechanism configured in this manner, the cylinder portion, and the conductive pins are provided in three pairs on the substrate holding portion 12. And these three conductive pins 9.10.11
In an unloaded state, the tip end defines a plane parallel to the substrate holding surface 12a.

The electrical 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. 1, one end of the power supply section 16 is connected to one end of the conductive section 13, One end of the device 17 is connected to the conductive pin 12. 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 includes a conductive pin 7.8.9 and a conductive part 13.
14 and 15 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 is placed against the substrate holder surface 12a of the substrate holder 12, When the electrical detecting section 4.5.6 is tilted, the electrically conductive pin closest to the bottom of the inclined surface and the electrically conductive section come into contact, and the electrical detector corresponding to this pair Detect. With this, it is possible to know which part is the lowest, that is, in which direction it is tilted, 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, either the adsorption surface of the bonding tool 2 or the substrate holding part 12
It is parallel to the holding cloth 12a. 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 drive mechanism is activated to move the cylinder portion 5a and the like to house the conductive pins in the substrate holder 12, and then the substrate 3 is fixed at a predetermined position on the substrate holder 12. Next, the semiconductor element 1 is set so that the surface opposite to the surface on which the bump electrode is formed covers the through hole 2b of the bonding tool 2, and the inside of the through hole 2b is vacuum-suctioned with the vacuum pump 20, and the semiconductor element 1 is is suctioned and fixed to the tip of the bonding tool 2 (see FIG. 3(a)).

Next, the drive mechanism is activated to cause the conductive pins 9 and the like to protrude from the substrate holding surface.

Next, the bonding tool 2 is gradually lowered in the -Z force direction. During the descent, observe in which electrical detector the current is detected. FIG. 3(b) shows a state in which one 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 two directions and separating the contacting conductive pin and conductive part,
Adjust the bonding tool 2 with the
Axial rotation angle θxSY Finely adjust the axial rotation angle θy. Then, the bonding tool 2 is moved in the -Z force 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 tool 2 is fixed with all the current detectors simultaneously detecting current. This state is shown in FIG. 3(C).

After that, operate the drive mechanism to move the conductive pins 9 etc. to the substrate holding surface 1.
After being housed in the substrate 2a, the bonding claw 2 is moved in the -Z direction to perform face-down bonding of the semiconductor element 1 onto the upper surface 3a of the substrate 3.

2, 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 is easily and accurately detected, and based on this detection result, the bonding tool 2 By adjusting the slope of
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, instead of having this configuration, it may be configured such that all the conductive pins or conductive parts are contacted 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 tilting drive mechanism such as a solenoid is used so that an electrically controlled tilting drive mechanism such as a stepping motor that can adjust the inclination of the bonding crane 2 and a conductive pin can be accommodated in the substrate holding part 12. Furthermore, the drive mechanism for moving the bonding tool 2 in two directions is electrically controlled, and an electronic control device such as a microcomputer is provided to control the drive mechanism. By adjusting the surface of the semiconductor element on which the bump electrode is formed to be parallel to the semiconductor element mounting surface of the substrate, face-down bonding can be performed. Specifically, the electronic control device energizes a movement mechanism that moves the bonding tool 2 in the Z direction. This causes the bonding tool 2 to move in the -Z 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 pin and the conductive section from the electric detection section, energizes the tilt drive mechanism to adjust the tilt of the bonding tool. After the adjustment is completed, this electronic control device energizes the driving mechanism of the conductive pin to house the conductive pin in the substrate holding part 12, 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 pin provided on the substrate holding part and the conductive part provided on the bonding tool is electrically detected, and the semiconductor element is mounted on the semiconductor element based on the detection result. Since the parallelism between the bumps 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 the drawing]

FIG. 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 pins of the bonding tool shown in FIG. 1, and FIG. 3 is similar to FIG. 1. FIG. 3 is a diagram illustrating the relationship between a bonding tool and a substrate holder when mounting a semiconductor element using the apparatus of the illustrated embodiment. 1. Semiconductor element, 2. Bonding tool, 3.
Board, 4... Electric detection unit, 5.6.7... Pin mechanism,
5a...Cylinder part, 8...Compression spring, 9.10
．． 11... Conductive pin, 12... Board holding part, 13.1
4.15... Conductive part, 16... Power supply, 17... Current detector. Representative Patent Attorney Haseyo Hodo Fumikiro Terasaki Figure 1 Figure 2 Actions (first half) Figure 3 (1) Actions (second 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 that holds the bonding tool; a moving mechanism that moves the bonding tool relative to the holding member; a moving mechanism that is provided around a substrate holding surface of the holding member, is retractable within the holding member, and has a distal end that touches the substrate; at least three or more conductive pins defining a plane parallel to the holding surface; a conductive portion provided around the suction surface at a position corresponding to the conductive pin; and the conductive pin and the conductive portion. provided in pairs with
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, the substrate holding section includes a storage mechanism that accommodates the conductive pin, and the semiconductor element mounting apparatus or the electrical detection 2. The semiconductor element mounting apparatus according to claim 1, further comprising control means for controlling said tilt adjustment mechanism, said storage mechanism, and said moving mechanism based on detection by said means.