JP2003218138A - Hot bonding method, bonding device, and calibration method in hot bonding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hot bonding method, a device, and a calibration method for the same in hot bonding, wherein works as objects of bonding are bonded together with high accuracy without causing misalignment attendant on thermal expansion. <P>SOLUTION: In this hot bonding method, a first work as an object of bonding is held and heated on a holding means equipped with a heater, and a second work as an object of bonding is bonded to the heated first work. The hot bonding method is characterized by it that the heating center of the holding surface of the holding means, which hardly moves with thermal expansion caused by heating, is substantially aligned with the bonding center of the first work to be bonded to the second work, and then the two works are bonded together. A hot bonding device and a calibration method in hot bonding are provided. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating joining method and apparatus, and a calibration method in heating joining, capable of performing heating joining with higher accuracy when joining objects to be joined while applying heat. .

[0002]

2. Description of the Related Art In order to bond objects to be bonded together, for example, when mounting a chip on a substrate, the relative positions of the two must be accurately aligned. In particular, when joining objects to be joined while heating, even if the objects to be joined are held with high accuracy, the objects to be joined are held when they are heated after the alignment or after the alignment and the objects to be joined are in contact with each other. A holding means, for example, a tool holding a chip or a stage holding a substrate may be thermally expanded, and the holding position of the chip or the substrate may be displaced accordingly. If they are joined with the positional deviation occurring, high-precision mounting cannot be expected.

For example, as shown in FIG. 6, a substrate 102 held on a substrate holding stage 101 having a built-in heater.
When the chip 104 held by the tool 103 is mounted on the substrate 103, after the relative positions of the both are adjusted within a predetermined accuracy, for example, the chip 104 is grounded to the substrate 102 and the substrate holding stage 101 is heated, And tip 1
04 is bonded to the substrate 102.

However, in such a mounting apparatus,
When the substrate holding stage 101 is heated, the substrate holding stage 101 is more or less thermally expanded, and this thermal expansion occurs so as to extend to both sides with respect to a certain reference point 105 as shown by a broken line. If the substrate 102 is held at a position displaced from the reference point 105, the position of the substrate 102 will also be displaced due to the thermal expansion during heating. For example, as shown in FIG.
2 shifts from the position A before heating shown by the solid line to the position B after heating shown by the broken line. When such a state occurs, an error occurs in the relative position with the chip 104.
Even if you perform high-precision alignment in advance,
High-precision implementation cannot be expected. The same problem occurs when a heater is built in the tool 103 side that holds the chip 104. If the temperature difference between before heating and after heating is set to about 300 ° C., the error caused by the thermal expansion reaches several microns.

The substrate 10 associated with the above thermal expansion
The shift in the relative position between the chip 2 and the chip 104 may adversely affect during or immediately after the bonding. For example, in the case of solder bonding between the two, even if the holding of the chip 104 is released after the chip 104 is grounded to the substrate 102, or even if the chip 104 is separated and the substrate holding stage 101 side is heated, the surface tension of the solder is By chip 1
There is a case where 04 is pulled in the direction of the position shift, and an unstable position shift occurs.

[0006]

Therefore, an object of the present invention is to heat the objects to be bonded, which can be heated and bonded with high accuracy without causing a positional deviation, paying attention to the above problems. A bonding method and apparatus, and a calibration method in the heating bonding.

[0007]

In order to solve the above-mentioned problems, a heating and bonding method according to the present invention comprises a first object to be bonded,
A method for joining a second article to a first article to be held while heating it by holding it on a holding means provided with a heater, wherein heat generated by heating the article holding surface of the holding means. It is characterized in that after substantially aligning the joining center of the first object to be joined with the second object to be joined to the heating center whose position does not change due to expansion, both objects are joined. Consist of way.

The first object to be joined is, for example, a substrate, and the second object to be joined is, for example, a chip. However, in the present invention, the chip refers to all forms such as an IC chip, a semiconductor chip, an optical element, a surface mount component, a wafer, etc. on the side to be bonded to the substrate regardless of the type or size. Further, in the present invention, the above-mentioned substrate refers to all forms such as a resin substrate, a glass substrate, a film substrate, a chip, a wafer, etc. on the side to be joined to the chip regardless of the type and size.

Further, as the holding means provided with a heater,
For example, it can be composed of a substrate holding stage that holds a substrate, a heater built-in stage, or a tool that holds a chip and has a built-in heater. Good.

In the heating and joining method according to the present invention, the heating center is determined as follows, for example. That is,
2 separated from each other on the object holding surface of the holding means.
By providing the above marks, the position movement of the marks caused by the thermal expansion of the holding means due to heating can be measured in advance for joining at two temperatures or more, and the position of the heating center can be obtained based on the measurement result. It is preferable that the marks are installed at positions on opposite sides of the center of the holding means on the article holding surface, and in such a form, at least a total of 4 in at least two vertical and horizontal directions.
It is more preferable to provide individual marks. However, in principle, if two or more marks are provided at positions other than the center of heating, the position of the center of heating can be determined from the position movement due to thermal expansion at two or more temperatures.

As a method of setting the mark, a method may be used in which the mark is directly attached on the object holding surface of the holding means, or a jig having a mark is held on the object holding surface. It may be a method.

Further, when a plurality of second objects to be joined are joined to the first object to be joined, the holding position of the first article to be joined is changed and the joining center is set to the heating center for each joining. Are preferably aligned, which allows the bonding center to be aligned with the heating center in all of the bonding operations.

The heating and bonding apparatus according to the present invention holds the first object to be bonded on the holding means having a heater, and bonds the second object to be bonded to the first object to be bonded while heating. In the device, two or more marks spaced from each other are provided on the object holding surface of the holding means, and the positional movement of the marks caused by thermal expansion of the holding means due to heating is performed.
Recognizing means for measuring the temperature or higher, means for obtaining the position of the heating center on the object holding surface whose position does not change due to thermal expansion caused by heating based on the measurement result, And a control means for substantially aligning a joining center of the one article to be joined with the second article to be joined. The means for holding the second object to be bonded may or may not include the heater.

When a plurality of second objects to be joined are joined to the first object to be joined, the above-mentioned control means, each time the joining is carried out,
It is preferable to change the holding position of the first object to be joined so that the joining center is aligned with the heating center. Further, it is preferable that the holding means for holding the first object to be joined is formed in a convex shape near the heating center.

As the recognizing means, the recognizing means used for normal alignment can be used also, but a dedicated recognizing means for measuring the position movement of the mark can be separately provided. As a form of the recognizing means, any device such as a CCD camera, an infrared camera, an X-ray camera, a sensor, or the like can be used as long as the mark can be recognized (or imaged).

According to the calibration method for heating and bonding according to the present invention, the first object to be bonded is held on the holding means having a heater, and the first object to be bonded is heated to the second object to be bonded. Before joining, the position of the heating center of the object holding surface of the holding means, which does not change due to the thermal expansion caused by heating, is set on the object holding surface by two or more spaced apart from each other. A mark is provided, and the position movement of the mark caused by the thermal expansion of the holding means by heating is prevented.
The method is characterized in that the position of the heating center obtained from the result of measurement for the temperature or higher is set as the position of the joining center of the first object to be joined to the second object to be joined.

By performing such a calibration and obtaining the position of the heating center prior to the actual joining, the above-described heating joining method and apparatus according to the present invention can be carried out and realized.

In the heating joining method and apparatus and the calibration method in the heating joining according to the present invention as described above, after the joining center is aligned with the heating center of the object holding surface of the holding means, both joining objects are joined. The articles are heated and joined. At the heating center of the object-to-be-bonded holding surface and its vicinity, the position of the object to be bonded does not substantially fluctuate even when heated, so that the object to be bonded held on the object-to-be-bonded holding surface is not displaced. Since joining is performed in this state,
Even in the case of joining with heating, a relative positional shift does not occur between the objects to be joined, and a highly accurate joined state is secured.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings. 1 to 3 show a heating and bonding apparatus according to an embodiment of the present invention. In this embodiment, the heating and bonding apparatus 1 is configured to mount a chip on a substrate by heating and bonding. That is, the chip 2 as the second object to be bonded is aligned with the substrate 3 as the first object to be bonded which is arranged below, and is then configured to be mounted by heat bonding.

As shown in FIG. 1, the tip 2 has a tool 4
Is held on the lower surface of, for example, by adsorption. The suction is performed by, for example, air suction through a suction hole (not shown) provided in the tool 4 and opened on the lower surface of the tool 4. However, this chip holding means is not limited to adsorption holding means, electrostatic holding means by static electricity, magnetic holding means by magnets or magnetic fields, mechanical means for holding the chip by a plurality of movable claws, and a single movable claw for holding the chip. Any means such as a pressing means may be used. Also,
The tool 4 may have a built-in heater.

In the present embodiment, the tool 4 can be moved in the Z direction (vertical direction) by a drive control mechanism (not shown). With this movement control in the vertical direction (Z direction), the chip 2 is grounded and pressed against the substrate 3. In this embodiment, the position control on the tool 4 side is performed only in the vertical direction (Z direction), but the position control may be performed also in the rotation direction θ and the parallel movement directions X and Y.

The substrate 3 is held on the substrate holding stage 5 from its lower surface side. As the means for holding the substrate 3 by the substrate holding stage 5, any means such as a suction holding means, an electrostatic holding means, a magnetic holding means, a plurality of movable claws or a mechanical means with a single movable claw may be used. Good. In this embodiment, the substrate holding stage 5 is configured as a heat stage having a built-in heater 6, and when the substrate 2 is bonded to the chip 2, the substrate 3 is heated to a predetermined temperature, and the substrate 2 is connected to the chip 2 through the heating. The joint can be heated to a predetermined temperature. The substrate holding stage 5 is mounted on a movable table (not shown), and the position of the substrate holding stage 5 can be controlled in the parallel movement directions X and Y and the rotation direction θ by the control of the movable table in this embodiment. The position control is performed based on a command from the control device 7.

A recognizing means 8 is arranged above the substrate holding stage 5 so as to be able to move forward and backward (insertable and retractable). The recognizing means 8 is configured to be capable of reading the moving position of the mark 9 on the substrate holding stage 5 in order to specify the position of the heating center described later. In the present embodiment, the recognition means 8 also functions as an alignment recognition means for reading the positions of the chip 2 and the substrate 3 and adjusting and controlling the relative positional relationship between the two within a predetermined accuracy range. It is possible to read both positions on the board and the board 3 side.
It is configured as a visual field recognition means.

A mark 9 is attached to an object holding surface 10 for holding the substrate 3 of the substrate holding stage 5. However, the mark 9 may be provided by holding a jig or the like with the mark on the article holding surface 10. In the present embodiment, as shown in FIG. 2, the marks 9 are provided on the both sides of the center position of the substrate holding stage 5 so as to be spaced from each other, and two marks are provided vertically and horizontally (that is, as a pair of marks). There is.

When the substrate holding stage 5 is heated, the positions of the respective marks 9 move due to the expansion of the object holding surface 10 accompanying the thermal expansion thereof. This position movement is the recognition means 8
Is read for two or more temperatures. By measuring the position movements of the plurality of marks at two temperatures or higher, the position of the heating center 11 on the bonded object holding surface 10 whose position does not change due to thermal expansion caused by heating is specified.
The specification of the position of the heating center 11 is achieved by the calibration method according to the present invention, and in the present embodiment,
This is achieved by performing calculation or image analysis in the control device 7 based on the information from the recognition means 8.

After the position of the heating center 11 is specified, as shown in FIGS. 1 and 3, the tip 2 is placed on the heating center 11.
Center 12 between substrate and substrate 3 (center of joint between objects to be joined)
Are substantially aligned.

In the heating / bonding apparatus 1 thus constructed, since the positions of the heating center 11 and the bonding center 12 coincide with each other, the chip 2 and the substrate 3 are aligned,
After the chip 2 is grounded to the substrate 3, the substrate holding stage 5
When the substrate is heated to a predetermined temperature, the position of the heating center 11 does not change even if the substrate holding stage 5 thermally expands and the bonded object holding surface 10 expands due to the thermal expansion. The position of the substrate 3 does not substantially change because the substrate 3 is continuously held. Since the chip 2 is heat-bonded to the substrate 3 in a state where the bonding center 12 is aligned with the position of the heating center 11, the bonding position and the bonding state do not vary, and highly accurate bonding is performed. .

The position of the heating center 11 and the joining center 12
As a result of the coincidence of the positions, even if the chip 2 is grounded after the chip 2 is grounded, for example, even if the chip 2 is released, the relative positional relationship between the chip 2 and the substrate 3 depends on the surface tension of the solder. The force that displaces does not work. Therefore, even if there is some change in the joining step, no problem occurs and a highly accurate joining state is secured.

When a plurality of chips 2 are mounted on the substrate 3 in the heating and bonding apparatus 1, for example, as shown in FIG. 4, a plurality of (two in the illustrated example) chips 2 are mounted on the substrate 21.
In the case of heat bonding of the two, the holding position of the substrate 21 on the object holding surface 10 of the substrate holding stage 5 is changed every time the bonding is performed, and the heating center 11 is used as the bonding center 12 at that time.
Can be aligned. For example, as shown in FIG. 5, when the chip 22 arranged at the upper left of FIG. 4 is bonded to the substrate 21 by heating, the position of the heating center 11 on the bonded object holding surface 10 is set to the bonding center 12 at that time. If the substrate 21 is shifted and held so that the position comes and the chip 22 is heat-bonded to the substrate 21 in that state, the same condition as that shown in FIG. Can be created, and high-precision mounting becomes possible. When the joining at this position is completed, the holding positions of the substrate 21 on the object holding surface 10 are sequentially shifted,
Each time the heating center 11 and the joining center 12 are aligned,
It suffices to perform the heating and joining in sequence.

As described above, even when a plurality of objects to be joined are heated and joined to one object to be joined, the influence of thermal expansion in the heating and joining can be eliminated, and the joining state with extremely high accuracy can be obtained. Can be realized efficiently.

The holding means for holding the first object to be welded is formed in a convex shape in the vicinity of the heating center, and the convex portion of the holding means holds the first object to be welded. By doing so, it is possible to suppress the displacement of the first object to be bonded due to the extension of the holding means as much as possible, which is desirable.

[0032]

As described above, according to the heating joining method and apparatus and the calibration method in the heating joining according to the present invention, the influence of the positional deviation due to the thermal expansion of the object holding means due to the heating is applied. The objects to be joined can be heated and joined with high accuracy without affecting the objects.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a heating and bonding apparatus according to an embodiment of the present invention.

2 is an enlarged plan view of a substrate elbow stage of the apparatus of FIG.

FIG. 3 is a plan view showing a positional relationship between a heating center and a joining center on the substrate elbow stage of FIG.

FIG. 4 is a plan view of a substrate and chips showing an example of mounting a plurality of chips.

5 is a plan view showing an example of changing a holding position on a substrate elbow stage in the mounting shown in FIG.

FIG. 6 is a schematic configuration diagram showing a preferable aspect of a first object holding means.

FIG. 7 is an enlarged plan view of a substrate elbow stage showing a problem in the conventional apparatus.

[Explanation of symbols]

1 Heat bonding equipment 2 Chip as the second object 3 Substrate as the first object to be bonded 4 tools 5 Substrate holding stage 6 heater 7 Control device 8 recognition means 9 mark 10 Object holding surface 11 heating center 12 Junction center 21 board 22 chips

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Claims (7)

[Claims] 1. A method for holding a first object to be bonded on a holding means equipped with a heater and bonding a second object to be bonded to the first object to be bonded while heating the holding object. After substantially aligning the joining center of the first article to be joined with the second article to the heating center of the object holding surface of the means, the position of which does not change due to thermal expansion caused by heating. A method for heating and joining, wherein both objects to be joined are joined. 2. Two or more marks spaced apart from each other are provided on the object holding surface of the holding means, and the positional movement of the mark caused by thermal expansion of the holding means due to heating is performed by two temperatures prior to the joining. The heating and joining method according to claim 1, wherein the above-mentioned measurement is performed, and the position of the heating center is obtained based on the measurement result. 3. When bonding a plurality of second objects to be bonded to the first object to be bonded, the holding position of the first object to be bonded is changed for each bonding so that the heating center becomes the heating center. The heat-bonding method according to claim 1 or 2, wherein the positions are aligned. 4. An apparatus for holding a first article to be joined on a holding means provided with a heater and joining the second article to the first article to be joined while heating the holding means. Two or more marks spaced apart from each other are provided on the object holding surface of the means, and the recognizing means measures the positional movement of the marks caused by thermal expansion of the holding means due to heating at two or more temperatures. Means for determining the position of the heating center on the object holding surface whose position does not change due to thermal expansion caused by heating based on the measurement result, and a second object of the first object to be bonded to the heating center. A heating and bonding apparatus comprising: a control unit that substantially aligns a bonding center with a bonded object. 5. The control means, when joining a plurality of second objects to be joined to the first object to be joined, each time the joining is performed.
The heating and bonding apparatus according to claim 4, wherein the holding position of the first object to be bonded is changed to align the bonding center with the heating center. 6. The heating and bonding apparatus according to claim 4, wherein the holding means for holding the first object to be bonded is formed in a convex shape near the heating center. 7. The first object to be bonded is held on a holding means provided with a heater, and when the second object to be bonded to the first object to be bonded while being heated, before the bonding, The position of the heating center of the holding member holding surface of the holding means, the position of which does not change due to thermal expansion caused by heating, is provided with two or more marks separated from each other on the holding object holding surface, and the heat of the holding means due to heating is increased. The position movement of the mark caused by expansion is obtained from the result of measurement at two temperatures or more, and the obtained position of the heating center is set as the position of the joining center of the first object to be joined with the second object to be joined. A method for calibration in heating and bonding, comprising: