JP2005329274A - Film forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a film forming apparatus in which the control accuracy of film thickness is better than that in the conventional art in the film forming apparatus for forming the film of a viscous material having a prescribed film thickness and slope on the surface of a transfer pan. <P>SOLUTION: A plurality of displacement sensors S1, S2, S3 are attached to a bracket 10 to fix the position so as to measure the film thickness in a plurality of points each having different film surface of the viscous material formed on the surface of the transfer pan 2 and the attitude of a blade 3 is controlled by a film thickness control part 6 to bring the film thickness close to a required value on the basis of the measured values of a plurality of the displacement sensors S1, S2, S3. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a film forming apparatus for forming a film of a viscous material having a desired film thickness and inclination on the surface of a transfer dish.

  This type of film forming apparatus is used to apply an appropriate amount of viscous material to the chip. Specifically, the apparatus shown in (Patent Document 1) for attaching a conductive paste to a chip to be mounted in the flip chip mounting method can be given as an example.

This conventional film forming apparatus is configured as shown in FIG.
Non-contact for measuring the film thickness of a transfer tray 2 that is rotationally driven by a motor 1, a blade 3 that can adjust the gap and inclination with respect to the surface of the transfer plate 2, and a conductive paste 4 formed on the surface of the transfer plate 2. The displacement sensor 5 and a film thickness controller 6 that relatively controls the posture of the transfer plate 2 and the blade 3 so that the film thickness measured by the non-contact displacement sensor 5 approaches a specified value. ing. R is the rotation direction of the transfer plate 2.

  Specifically, a laser displacement meter is used for the non-contact type displacement sensor 5, and the film thickness distribution is obtained by moving the non-contact type displacement sensor 5 in the radial direction of the transfer plate 2 while the transfer plate 2 is stopped rotating. When the film thickness controller 6 changes the posture of the blade 3 so that the film thickness distribution has a desired film thickness and inclination, and the transfer plate 2 is rotated by the motor 1 after the posture change, The conductive paste 4 scraped by the blade 3 has a desired film thickness and inclination.

As a means for driving the non-contact type displacement sensor 5 in the radial direction of the transfer plate 2, a ball screw (not shown) for laterally feeding the non-contact type displacement sensor 5 is used.
JP 2001-102412 A

  In this conventional technique, the non-contact type displacement sensor 5 is moved in the radial direction of the transfer plate 2 and a ball screw or the like is used as a driving means thereof. When moving the non-contact type displacement sensor 5, a slight amount of rattling is accompanied by the movement of the non-contact type displacement sensor 5. Further, since it is affected by the reproduction accuracy of the scanning trajectory, it is difficult to sufficiently improve the film thickness control accuracy.

9 (a) to 9 (d) show the necessity of high film thickness control accuracy.
(A) shows a state immediately before the chip 7 is pressed against the conductive paste 4 on the transfer tray 2 whose film thickness is controlled, and the electrode portion 8 of the chip 7 is transferred as shown in (b) and (c). By pressing the plate 2 and lifting it, an appropriate amount of the thermosetting conductive paste 4 is transferred to the electrode portion 8 of the chip 7. Further, the chip 7 on which the conductive paste 4 is transferred to the electrode portion 8 is pressed and set to the mounting position of the printed board 9 as shown in FIG. The printed circuit board 9 on which the chip 7 has been set is partially or entirely heated and cured.

  At this time, when the film thickness control of the conductive paste 4 in the step of FIG. 9A is insufficient and the film thickness of the conductive paste 4 is thin, the target soldering strength cannot be obtained. If it is too thick, a solder bridge is generated between the printed circuit board 9 and an adjacent wiring pattern in the step of FIG. 9D. Therefore, it is necessary to control the film thickness of the conductive paste 4 with high accuracy in the process of FIG.

  It is an object of the present invention to provide a film forming apparatus with better film thickness control accuracy than before.

  The film forming apparatus of the present invention includes a transfer plate, a blade that scrapes the viscous material on the surface of the transfer plate, a non-contact displacement sensor that measures the film thickness of the viscous material formed on the surface of the transfer plate, A film thickness controller for relatively controlling the posture of the blade and the blade is provided so that the film thickness measured by the non-contact displacement sensor approaches a specified value, and the non-contact displacement sensor is transferred. A plurality of displacement sensors fixed to each other and spaced from each other so as to measure a plurality of different points on the surface of the viscous material formed on the surface of the dish, and the film thickness control unit, The film thickness is controlled to be the specified value based on the measurement values of a plurality of displacement sensors.

  In addition, the film forming apparatus of the present invention includes a transfer plate that is rotationally driven, a blade that is attached so that the clearance and parallelism with respect to the surface of the transfer plate can be adjusted, and scrapes the viscous material on the surface of the transfer plate, and the transfer plate A non-contact displacement sensor for measuring the film thickness of the viscous material formed on the surface of the transfer plate, and the posture of the transfer plate and the blade so that the film thickness measured by the non-contact displacement sensor approaches a specified value. And a non-contact type displacement sensor that is fixed in position so as to measure a plurality of different points on the film surface of the viscous material formed on the surface of the transfer dish. The film thickness control unit is configured to control the film thickness control unit so that the film thickness becomes the specified value based on the measurement values of the plurality of displacement sensors. Characterized by composition .

  The film forming apparatus of the present invention further includes a third displacement sensor for detecting the surface of the transfer dish, and the film thickness control unit is based on the measured values of the first, second, and third displacement sensors. The film thickness is controlled so as to be the specified value.

  The first, second, and third displacement sensors may be laser displacement meters or capacitive displacement sensors.

  According to the film forming apparatus of the present invention, there are provided a plurality of displacement sensors which are fixed in position and spaced from each other so as to measure a plurality of different points on the film surface of the viscous material formed on the surface of the transfer dish. Therefore, the film thickness distribution can be measured without moving the non-contact displacement sensor and scanning as in the conventional film thickness control unit, and the film thickness control accuracy is improved as compared with the conventional film thickness control unit.

The film forming apparatus of the present invention will be described below with reference to FIGS.
In addition, the same code | symbol is attached | subjected and demonstrated to what has the effect | action similar to FIG. 8 which showed the prior art example.

(Embodiment 1)
1 and 2 show the main part of the film forming apparatus of (Embodiment 1).
In the film forming apparatus shown in FIG. 1, in place of the laser displacement meter as the non-contact type displacement sensor 5 scanned in the radial direction of the transfer plate 2 in the conventional example, a plurality of stationary positions are fixed and the movement is not performed. Non-contact displacement sensors S1, S2, S3 are provided.

  Specifically, capacitance sensors are used as the non-contact type displacement sensors S1, S2, and S3. The non-contact type displacement sensors S1, S2, and S3 are fixedly attached to the bracket 10 that is fixedly attached at the base end to the fixed side with a space therebetween. As shown in FIG. 2, the non-contact displacement sensor S <b> 1 is fixed so as to measure the position of the radius L <b> 1 from the rotation center of the transfer plate 2. The non-contact type displacement sensor S2 is fixed so as to measure the position of the radius L2 from the rotation center of the transfer plate 2. The non-contact type displacement sensor S3 is fixed so as to measure the position of the radius L3 from the rotation center of the transfer plate 2.

L2 <L1 <L3
It is.
The radius position of the distance L1 and the radius position of the distance L2 are located within the range of the conductive paste 4 developed on the transfer plate 2 by scratching with the blade 3, and the radius position of the distance L3. Is located outside the range of the conductive paste 4.

When the detection distances of the non-contact displacement sensors S1, S2, S3 while the rotation of the transfer plate 2 is stopped are d1, d2, and d3, respectively, a film thickness control that is configured with a microcomputer as a main part and controls the posture of the blade 3 is performed. Part 6
d3-d1 = a 1st formula d3-d2 = b When using the 2nd formula, "(a + b) / 2" is the detected film thickness, and the blade 3 is moved so that this approaches the target film thickness value. Move to adjust the gap with the surface of the transfer dish 2. Further, the film thickness controller 6 treats “(a−b)” as a function of the inclination, and moves the blade 3 so as to approach a similar function in the case of the target inclination value. Adjust the tilt.

Note that the control of the inclination θ of the blade 3 by the film thickness controller 6 is the interval (L1-L2) between the non-contact displacement sensors S1, S2, so
θ = tan ⁻¹ (ab) / (L1-L2)
However, the same control can be performed by moving the blade 3 so as to approach the target tilt angle and adjusting the tilt with the surface of the transfer plate 2.

  In this way, the film thickness distribution of the conductive paste 4 can be detected based on the detection values of the non-contact displacement sensors S1, S2, S3 fixedly attached. Further, since it is not necessary to scan and move the single non-contact type displacement sensor 5 in the radial direction of the transfer plate 2 as in the prior art, there is no influence of backlash and trajectory reproduction accuracy due to the scanning movement, and control of the film thickness. The accuracy can be made better than before.

(Embodiment 2)
3A and 3B show the main part of the film forming apparatus of (Embodiment 2).
In (Embodiment 1), non-contact type displacement sensors S1, S2, S3 are used, but in this (Embodiment 2), non-contact type displacement sensors S1, S2 that have fixed mounting positions and do not move are used. Although provided, the non-contact displacement sensor S3 is not provided. Instead of the non-contact displacement sensor S3 being provided, the film thickness controller 6 of this (Embodiment 2) is configured as follows.

In the first step, the film thickness controller 6 sets the detection distances d10 and d20 of the non-contact displacement sensors S1 and S2 in a state where the conductive paste 4 is not present on the surface of the transfer dish 2 as shown in FIG. Remember each one. In the second step, as shown in FIG. 3B, the detection distances d1 of the non-contact type displacement sensors S1, S2 while the rotation of the transfer plate 2 is stopped in a state where the conductive paste 4 is spread on the surface of the transfer plate 2. detect d2,
d10−d1 = a 3rd formula d20−d2 = b When the 4th formula is established, the detected film thickness “(a + b) / 2” is set so that the blade 3 approaches the target film thickness value. Move to adjust the gap with the surface of the transfer dish 2. Further, the film thickness controller 6 treats “(a−b)” as a function of the inclination, and moves the blade 3 so as to approach a similar function in the case of the target inclination value. Adjust the tilt.

Note that the control of the inclination θ of the blade 3 by the film thickness controller 6 is the interval (L1-L2) between the non-contact displacement sensors S1, S2, so
θ = tan ⁻¹ (ab) / (L1-L2)
However, the same control can be performed by moving the blade 3 so as to approach the target tilt angle and adjusting the tilt with the surface of the transfer plate 2.

  In this manner, the film thickness distribution of the conductive paste 4 can be detected based on the detection values of the non-contact displacement sensors S1 and S2 that are fixedly attached. Further, since it is not necessary to scan and move the single non-contact type displacement sensor 5 in the radial direction of the transfer plate 2 as in the prior art, there is no influence of backlash and trajectory reproduction accuracy due to the scanning movement, and control of the film thickness. The accuracy can be made better than before.

(Embodiment 3)
4 to 6 show the main part of the film forming apparatus of (Embodiment 3).
The non-contact displacement sensors S1, S2 and S3 of (Embodiment 1) and the non-contact displacement sensors S1 and S2 of (Embodiment 2) are all capacitive sensors. In the third embodiment, laser displacement meters fixed in position and spaced apart from each other are used as the non-contact displacement sensors S1, S2 and S3 so as to measure a plurality of different points on the film surface of the viscous material. Only the difference is from (Embodiment 1).

  Specifically, the non-contact displacement sensors S1, S2, and S3 of the laser displacement meter are fixedly attached at an interval so as not to move with respect to the transfer plate 2. As shown in FIGS. 5 and 6, the non-contact displacement sensors S1, S2, and S3 are fixed so as to measure the positions of the radii of the distances L1, L2, and L3 from the rotation center of the transfer plate 2, respectively. <L1 <L3.

  Note that the positions of the radii of the distances L1 and L2 are located within the range of the conductive paste 4 scraped by the blade 3 and spread on the transfer plate 2, and the positions of the radii of the distance L3 are the positions of the conductive paste 4. It is located outside the range.

  When the detection distances of the non-contact displacement sensors S1, S2, S3 while the rotation of the transfer plate 2 is stopped are d1, d2, and d3, respectively, the film thickness control unit 6 that controls the posture of the blade 3 is (Embodiment 1). ), The blade 3 is moved so that the detected film thickness and gap approach the target film thickness value and the target gap value, and the gap between the transfer dish 2 and the surface of the transfer dish 2. Adjust the tilt with the surface.

  In this way, the film thickness distribution of the conductive paste 4 can be detected based on the detection values of the non-contact displacement sensors S1, S2, S3 fixedly attached. Further, since it is not necessary to scan and move the single non-contact type displacement sensor 5 in the radial direction of the transfer plate 2 as in the prior art, there is no influence of backlash and trajectory reproduction accuracy due to the scanning movement, and control of the film thickness. The accuracy can be made better than before.

(Embodiment 4)
FIG. 7 shows the main part of the film forming apparatus of (Embodiment 4).
In (Embodiment 3), non-contact type displacement sensors S1, S2, and S3 are used. In (Embodiment 4), a non-contact type displacement sensor of a laser displacement meter that does not move because the mounting position is fixed. S1 and S2 are provided, but the non-contact displacement sensor S3 is not provided. Instead of the non-contact type displacement sensor S3 being provided, the film thickness controller 6 of this (Embodiment 4) is in a state in which there is no conductive paste 4 on the surface of the transfer dish 2 as shown in FIG. The detection distances of the non-contact displacement sensors S1 and S2 at d10 and d20 are d10 and d20, and the rotation of the transfer plate 2 is stopped when the conductive paste 4 is spread on the surface of the transfer plate 2 as shown in FIG. Assuming the detection distances d1 and d2 of the non-contact displacement sensors S1 and S2, the film thickness and gap detected in the same manner as the film thickness control unit 6 in (Embodiment 2) become the target film thickness value and the target gap value. The blade 3 is moved so as to approach, and the gap with the surface of the transfer plate 2 and the inclination with the surface of the transfer plate 2 are adjusted.

  In this manner, the film thickness distribution of the conductive paste 4 can be detected based on the detection values of the non-contact displacement sensors S1 and S2 that are fixedly attached. Further, since it is not necessary to scan and move the single non-contact type displacement sensor 5 in the radial direction of the transfer plate 2 as in the prior art, there is no influence of backlash and trajectory reproduction accuracy due to the scanning movement, and control of the film thickness. The accuracy can be made better than before.

  In each of the above-described embodiments, the case where the viscous material is a conductive paste has been described as an example. However, a viscous material such as an adhesive having viscosity is spread on the transfer dish 2, and the thickness and inclination thereof are determined. The same can be done for control.

The film thickness controller 6 in the first embodiment (third embodiment) provided with three non-contact type displacement sensors is a non-contact type displacement sensor S 1, S 2, S 3 when the transfer tray 2 is stopped rotating. Although the attitude of the blade 3 is controlled based on the detected value of the non-contact displacement sensor S3 that detects the distance to the surface of the transfer plate 2, the film thickness control unit 6 is rotating the transfer plate 2. Specifically, a plurality of pieces of occasional data of the non-contact displacement sensor S3 during one rotation of the rotating dish 2 are collected, and this average value is set as a distance d3A to the surface of the transfer dish 2, and this distance d3A and the transfer Based on the detection distances d1 and d2 of the non-contact displacement sensors S1 and S2 when the rotation of the pan 2 is stopped,
d3A−d1 = a Fifth Formula d3A−d2 = b As the sixth formula, the film thickness controller 6 may be configured to control the posture of the blade 3.

  The film thickness controller 6 in the second embodiment (fourth embodiment) provided with two non-contact displacement sensors is a non-contact displacement in a state where the conductive paste 4 is not present on the surface of the transfer dish 2. The detection distances d10 and d20 of the sensors S1 and S2 are stored and processed, respectively. As a specific method of collecting the detection distances d10 and d20, the transfer dish 2 is stopped and the transfer dish 2 is stopped. In the state where there is no conductive paste 4 on the surface of 2, only a plurality of occasional data of the non-contact type displacement sensors S 1 and S 2 are collected while the rotating dish 2 makes one rotation, and this average value is the distance to the surface of the transfer dish 2. Either d10A or d20A is adopted.

In addition to the above-described control based on the detection distances d10, d20 and d1, d2 in the film thickness controller 6, the control is performed as described above based on the detection distances d10A, d20A, d1, d2, Average value of detection distances d10A and d20A (d10A + d20A) / 2 = d1020A
And based on d1020A and d1, d2,
d1020A−d1 = a seventh equation d1020A−d2 = b The same control can be performed as the eighth equation.

  In each of the above embodiments, the case where the transfer plate 2 rotates with respect to the blade 3 and the viscous material is developed has been described as an example. However, the blade 3 rotates with respect to the transfer plate 2 and the viscous material is removed. It can also be developed, and can be carried out when the transfer plate 2 and the blade 3 move relatively to develop the viscous material. Similarly, the posture of the blade 3 with respect to the transfer plate 2 is changed to adjust the gap and the inclination. However, the posture of the transfer plate 2 with respect to the blade 3 can be changed to adjust the gap and the inclination. This can be implemented when the relative posture of 2 is changed to adjust the gap and inclination.

  “D1” and “d2” in the first and second formulas, the third and fourth formulas, the fifth and sixth formulas, and the seventh and eighth formulas in the above embodiments are non-contact types. The case where the mounting heights of the displacement sensors S1 and S2 are the same as the mounting height of the non-contact displacement sensor S3 has been described as an example. However, the mounting height is between the mounting height of the non-contact displacement sensor S1 and the mounting height of the non-contact displacement sensor S3, and between the mounting height of the non-contact displacement sensor S2 and the mounting height of the non-contact displacement sensor S3. Since errors occur, actual “d1” and “d2” include correction terms Δ1 and Δ2 for correcting the mounting height. Specifically, immediately after the assembly is completed, the non-contact type displacement sensors S1, S2, and S3 are read in a state where the conductive paste 4 is not present on the transfer plate 2, and “d3-d1” at that time is attached and the height is corrected. The term Δ1 is preset in the memory, and similarly “d3−d2” is preset in the memory as the correction height Δ2 of the mounting height, and the correction error Δ1, Δ2 is used to correct the mounting error. The minute film thickness of the conductive paste 4 is accurately measured without being affected by the mounting height error between the sensors S1, S2 and S3.

  Further, in each of the above embodiments, the film thickness of the conductive paste 4 is determined based on the occasional d3 of the non-contact displacement sensor S3 that measures the location where the conductive paste 4 of the transfer dish 2 is not spread. However, the measured value d30 at the start of operation of the non-contact displacement sensor S3 is stored in the memory, and the occasional d3 of the non-contact displacement sensor S3 is compared with d30 stored in the memory. Therefore, if an error Δ3 occurs between them, it is assumed that distortion due to the heat of the transfer plate 2 has occurred. By correcting the d1 and d2 from time to time with this error Δ3, the film thickness of the conductive paste 4 can be reduced. The influence of distortion due to heat of the transfer tray 2 can be reduced and measured accurately, and the development of a uniform film thickness of the conductive paste 4 can be expected by controlling the inclination of the blade 3 more accurately.

  The film forming apparatus of the present invention can control the film thickness of the conductive paste or adhesive of the viscous material developed on the transfer plate to a target value with high accuracy, and can be used for mounting various parts. .

(Embodiment 1) perspective view of essential parts of the film forming apparatus of the present invention Main part front view of the same embodiment The front view of the principal part before and behind developing the viscous material of (Embodiment 2) of the film forming apparatus of this invention (Embodiment 3) perspective view of essential parts of the film forming apparatus of the present invention The principal part top view of the same embodiment Main part front view of the same embodiment The front view of the principal part before and behind developing the viscous material of (Embodiment 4) of the film forming apparatus of this invention Perspective view of main part of conventional film forming apparatus Explanatory drawing of mounting process using film forming equipment

Explanation of symbols

2 Transfer tray 3 Blade 4 Conductive paste (viscous material)
6 Film thickness controller S1, S2, S3 Non-contact displacement sensor 10 Bracket

Claims (4)

A transfer plate,
A blade that scrapes the viscous material on the surface of the transfer dish;
A non-contact displacement sensor that measures the film thickness of the viscous material formed on the surface of the transfer dish;
A film thickness control unit that relatively controls the posture of the blade and the blade so that the film thickness measured by the non-contact displacement sensor approaches a specified value;
The non-contact type displacement sensor is composed of a plurality of displacement sensors fixed in position and spaced apart from each other so as to measure a plurality of different points on the surface of the viscous material formed on the surface of the transfer dish. ,
A film forming apparatus configured to control the film thickness control unit so that the film thickness becomes the specified value based on measurement values of the plurality of displacement sensors. A transfer plate that is driven to rotate;
A blade attached to the surface of the transfer plate to adjust the gap and parallelism, and scraping the viscous material on the surface of the transfer plate;
A non-contact displacement sensor that measures the film thickness of the viscous material formed on the surface of the transfer dish;
A film thickness control unit that relatively controls the posture of the blade and the blade so that the film thickness measured by the non-contact displacement sensor approaches a specified value;
The non-contact type displacement sensor is fixed in position so as to measure a plurality of different points on the film surface of the viscous material formed on the surface of the transfer plate, and is mounted at a distance from each other. Composed of sensors,
A film forming apparatus configured to control the film thickness control unit so that the film thickness becomes the specified value based on measurement values of the plurality of displacement sensors. Providing a third displacement sensor for detecting the surface of the transfer dish;
The film forming apparatus according to claim 2, wherein the film thickness control unit is configured to control the film thickness to be the specified value based on measurement values of the first, second, and third displacement sensors. The film forming apparatus according to claim 3, wherein the first, second, and third displacement sensors are laser displacement meters or capacitance displacement sensors.

Images