JP2953508B2 - Component mounting mechanism and method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a component mounting mechanism, and more particularly to a component mounting mechanism for mounting a relatively large external component such as a bare chip on a substrate by applying a small load of about several grams.

[0002]

2. Description of the Related Art A conventional component mounting mechanism for mounting a mounting target such as an electronic component on a mounting target such as a substrate is disclosed in, for example, Japanese Patent Application Laid-Open No. 57-15429. The apparatus includes a means for detecting the inclination and a mechanism for adjusting the inclination of the substrate stage holding the substrate, and adjusts the inclination of the substrate stage so that the inclination of the electronic component and the substrate becomes parallel.

[0003]

However, the above-described conventional component mounting mechanism considers only the tilt on the substrate stage side, does not have a correction function for the tilt on the mounting head side on which the electronic components are mounted, and has a relative function. The target inclination was not taken into account. Therefore, even when the inclination of the substrate stage is adjusted, the electronic component and the substrate may not be parallel.
In particular, when mounting an electronic component with a large external shape with a small load applied, the electronic component and the substrate do not become parallel enough, and only a part of the electronic component comes into contact with the substrate, resulting in poor connection. There has been a problem that sufficient connection strength may not be obtained.

[0004]

In order to solve the above-mentioned problems, a component mounting mechanism according to the present invention includes a mounting head for holding an electronic component and mounting the electronic component on a substrate, mounting head driving means for driving the mounting head, and a substrate. A substrate stage for holding the
Detecting means for detecting pressure applied to the substrate stage by the mounting head at a plurality of locations; tilt calculating means for calculating a relative tilt between the substrate stage and the mounting head based on a signal from the detecting means; And a tilting means for tilting the head, wherein the substrate stage or the mounting head is tilted in accordance with a tilt measurement result from the tilt calculating means.

[0005]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a drawing showing an example of the present invention. The apparatus shown in FIG. 1 includes a mounting head 1 that holds an electronic component and mounts the electronic component on a substrate, and a mounting head driving unit 2 that drives the mounting head 1. At the tip of the mounting head 1, a collet 1a for adsorbing an electronic component 11 such as a semiconductor chip is attached.
And moves up and down by the rotation of the motor 1d via.

On the other hand, below the mounting head 1, a substrate 12
And a substrate stage 3 for moving the substrate 12 to the mounting position of each electronic component. Substrate stage 3
At a predetermined position by the mounting head 1
Are attached. Piezoelectric elements 4, 5, and 6 for detecting the pressure applied to are mounted. The signals from the piezoelectric elements 4, 5, and 6 are sent to a tilt calculator 7, and the tilt calculator 7 calculates a relative tilt between the mounting head 1 and the substrate stage 3 based on the signals.

The substrate stage 3 is replaceably mounted on a tilt stage 8 as a tilting means. The tilt stage 8 includes a top stage 8a on which the substrate stage 3 is installed, a movable portion 8b having an arc-shaped lower portion to which the top stage 8a is attached, an attaching portion 8c to which the movable portion 8b is movably attached, and an attaching portion 8c. Movable part 8b attached to
And a motor 8d for moving the motor in the X direction. When the movable section 8b is moved in the X direction, the movable section 8b is tilted along an arc, so that the top stage 8a is also tilted in the X direction. Further, the mounting portion 8c is attached to a movable portion 8e having a lower circular arc shape, the movable portion 8e is attached to an attachment portion 8f, and the movable portion 8e is moved in the Y direction by a motor 8g. When the movable section 8e is moved in the Y direction, the movable section 8e moves along an arc, so that the mounting section 8c, the movable section 8b, and the top stage 8a placed on the movable section 8e tilt in the Y direction. The motors 8 d and 8 g are driven by the tilt stage drive unit 10 based on the tilt measurement results from the tilt calculation unit 7.

In the above example, three piezoelectric elements are used. However, the present invention is not limited to this, and the number of piezoelectric elements is determined so as to be more appropriate according to the shape and size of the substrate stage.
The tilt stage 8 is configured to drive in two directions, that is, the X direction and the Y direction.

Next, the operation of the above device will be described. The mounting head 1 driven by the mounting head driving unit 2 is pressed against a predetermined position on the substrate stage 3. This mounting head 1
Is pressed against the substrate stage 3 to move the substrate stage 3
Pressure is applied. This pressure value differs for each position of the substrate stage 3 because the substrate stage 3 tries to follow the inclination when the mounting head 1 and the substrate stage 3 have an inclination. In order to detect the pressure value of each part, the piezoelectric elements 4, 5, and 6 are arranged below the substrate stage 3. However, the mounting position of the piezoelectric element is not particularly limited, and may be any place where the pressure can be measured.
The number of the piezoelectric elements depends on the size of the contact surface of the mounting head 1 with the substrate stage 3, the size of the substrate stage 3 itself, or the required accuracy of the parallelism between the mounting head 1 and the substrate stage 3. Is determined by

The pressure at each position of the substrate stage 3 is output as a voltage value corresponding to the pressure value applied to that position by the piezoelectric elements 4, 5 and 6 mounted below the substrate stage 3. This voltage value is read by the inclination calculating unit 7 and converted into pressure values of respective parts, and then the relative inclination between the mounting head 1 and the substrate stage 3 is calculated from the difference between the pressure values at each position. Based on the calculation result, the motors 8d and 8g of the tilt stage 8 are driven by the slack stage driving unit 10 so that the mounting head 1 and the substrate stage 3 are parallel to each other. The inclination can be eliminated.

FIG. 2 is a timing chart showing the operation of the present invention. FIGS. 2A, 2B and 2C show the voltage signals of the piezoelectric elements 4 and 5 and the motor 8 of the tilt stage 8, respectively.
d shows the operation signal.

Next, a specific operation of the above apparatus will be described with reference to FIG. Here, only the operation in the X-axis direction will be described, but the same applies to the operation in the Y-axis direction. At time t1, the mounting head 1 contacts the substrate stage 3, and the piezoelectric elements 4, 5
And a voltage signal proportional to the pressure starts to be output. When there is an inclination between the mounting head 1 and the substrate stage 3, a difference occurs between the output voltages of the piezoelectric elements 4 and 5.
At time t2, the inclination calculation unit 7 causes the piezoelectric elements 4, 5
Is detected, and there is a signal for driving the motor 8d in a direction to eliminate the difference, that is, a direction in which the mounting head 1 and the substrate stage 3 are parallel to each other.
Is input to At time t3 and t4, the same operation as described above is repeated, and finally at time t5, the voltage difference between the piezoelectric elements 4 and 5 disappears (the same pressure value P), and the mounting head 1 and the substrate stage 3 become parallel. .

In the above description, the above-described adjustment is performed before the component is mounted. However, in principle, the above-described adjustment may be performed not only before the component is mounted but also during the component mounting.

Instead of tilting the substrate stage 3, the mounting head 1 may be tilted, or both may be moved. In short, it is only necessary to adjust the relative inclination between the substrate stage and the mounting head.

[0015]

According to the present invention, the relative inclination between the mounting head for mounting the electronic components and the substrate stage for holding the substrate is detected, and the substrate stage or the substrate stage is set so that the mounting head is parallel to the substrate stage. By driving the mounting head, the electronic component and the substrate can be made parallel. In particular, even when mounting a large-sized electronic component under a small load, the electronic component and the substrate are sufficiently parallel, and only a part of the electronic component comes into contact with the substrate to cause poor connection or insufficient connection. This has the effect of eliminating the problem that a high connection strength may not be obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an example of the present invention.

FIG. 2 is a timing chart showing a specific operation of the example of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Mounting head 2 Mounting head drive part 3 Substrate stage 4,5,6 Piezoelectric element 7 Tilt calculation part 8 Tilt stage 8d, 8g Motor 10 Tilt stage drive part

Claims (4)

(57) [Claims] 1. A mounting head for holding and mounting an electronic component on a substrate, a mounting head driving means for driving the mounting head, a substrate stage for holding the substrate, and a voltage applied to the substrate stage by the mounting head. Detecting means for detecting pressure at a plurality of locations, tilt calculating means for calculating a relative tilt between the substrate stage and the mounting head based on a signal from the detecting means, and tilting the substrate stage or the mounting head. A component mounting mechanism comprising: a tilting unit, wherein a relative tilt between the substrate stage and the mounting head is adjusted according to a tilt measurement result from the tilt calculating unit. 2. The method according to claim 1, wherein the tilting unit is configured to move the substrate stage by two.
2. A tilt stage which tilts in a direction.
Component mounting mechanism described in 1. 3. The component mounting device according to claim 1, wherein the calculation unit calculates a relative inclination between the substrate stage and the mounting head based on a difference between the pressures detected at the plurality of locations. mechanism. 4. A component mounting method in which an electronic component is held by a mounting head and mounted on a substrate held by a substrate stage, wherein the mounting head presses the substrate stage and detects the pressing force at a plurality of locations. Calculating a relative tilt between the substrate stage and the mounting head based on the detection result, tilting the substrate stage or the mounting head according to the tilt, and determining a relative tilt between the substrate stage and the mounting head. Component mounting method characterized by adjusting the natural inclination.