JPH05326633A - Method and apparatus for mounting semiconductor chip - Google Patents

Abstract

PURPOSE:To adjust parallelism between a board and a chip by measuring cubic profile of the surface of the board and measuring the distance between a semiconductor chip and the board at three points in a region on the board. CONSTITUTION:Surface of a board 12 is scanned by means of a spot light projected from a distance sensor 14 and positional variation of spot image due to irregularities on the surface of the board 1 is measured through a semiconductor position sensor thus determining cubic profile of the surface of the board 12. Distance between a semiconductor chip and a region 12a on the board for mounting a semiconductor chip having square mounting surface is then measured at three points 12b-12d in the region 12a by means of the distance sensor 14. Measurements at respective points are fed to a controller where parallelism is examined. When angular adjustment is required, commands are delivered to actuators 11c, 11d. When angular adjustment is required for the board 12, commands are delivered from the controller to actuators 13c, 13d at a board mounting part 13.

Description

Detailed Description of the Invention

[0001]

The present invention relates to Si-LSI and GaA.
The present invention relates to a mounting method and a mounting device for a large semiconductor chip such as an s-LSI and a liquid crystal display (LCD).

[0002]

2. Description of the Related Art A flip chip mounting method is performed by connecting all bumps provided on a semiconductor chip to pads on a substrate. For this reason, the technique of maintaining the parallelism between the semiconductor chip and the substrate is extremely important. As a conventional technique for keeping the semiconductor chip and the substrate parallel to each other as described above, there is a method using an optical probe, for example. In this method, the semiconductor chip and the substrate are irradiated with probe light, and the reflected light is measured to adjust the parallelism between them.

[0003]

However, due to the recent increase in the size of the semiconductor chip and the substrate, it has become difficult to keep the semiconductor chip and the substrate parallel to each other by the conventional adjusting method. The following two points can be considered as the cause. First, in the conventional method, the deviation of the parallelism was detected by the deviation of the angle of the reflected light, but the error in this detection method became large. That is, even if the angle deviation at a certain measurement point is slight, the angle deviation at a portion distant from the measurement point becomes very large as the semiconductor chip and the substrate become larger. Secondly, when the substrate is a ceramic, there are warps and undulations as characteristics of the baked product, but these warpages and undulations cannot be ignored as the size of the substrate increases.

The present invention provides a semiconductor chip mounting method and a semiconductor chip mounting apparatus which can keep the semiconductor chip and the substrate sufficiently parallel to each other even when the size of the semiconductor chip and the substrate is increased, and ensure a high mounting yield. With the goal.

[0005]

In order to solve the above problems, the semiconductor mounting method of the present invention comprises a first step of measuring a three-dimensional shape of a substrate surface, and a substrate and a semiconductor chip based on the measurement result. A second step of adjusting the parallelism, a third step of measuring the distance between the semiconductor chip and the substrate at at least three measuring points in a region on the substrate on which the semiconductor chip is mounted, and the measured distance The fourth step of adjusting the parallelism between the substrate and the semiconductor chip and the fifth step of bringing the substrate mounting means and the semiconductor chip holding means close to each other to mount the semiconductor chip on the substrate.

Further, the semiconductor mounting apparatus of the present invention measures the three-dimensional shape of the substrate surface and measures the distance between the semiconductor chip and the substrate at at least three measurement points within the region on the substrate on which the semiconductor chip is mounted. And a adjusting means for adjusting the parallelism between the substrate and the semiconductor chip based on the measurement result of the measuring means.

[0007]

According to the semiconductor mounting method of the present invention, the three-dimensional shape of the substrate surface is measured, and the parallelism between the substrate and the semiconductor chip is adjusted based on the measurement result. Next, the distance between the semiconductor chip and the substrate is measured at at least three measuring points in the area on the substrate on which the semiconductor chip is mounted. The parallelism between the substrate and the semiconductor chip is readjusted based on this measurement result. After the above adjustment is completed, the board mounting means and the semiconductor chip holding means are brought close to each other to mount the semiconductor chip on the board.

Further, according to the semiconductor chip mounting apparatus of the present invention, the three-dimensional shape of the substrate surface is measured by the measuring means. The adjusting means adjusts the parallelism between the substrate and the semiconductor chip based on the measurement result of the measuring means. Next, the distance between the semiconductor chip and the substrate is measured by the measuring means at at least three measuring points in the region on the substrate on which the semiconductor chip is mounted. Based on the measurement result of the measuring means, the parallelism between the substrate and the semiconductor chip is readjusted by the adjusting means. After the above adjustment is completed, the board mounting means and the semiconductor chip holding means are brought close to each other to mount the semiconductor chip on the board.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is an external view showing the configuration of the semiconductor chip mounting apparatus of this embodiment.

The semiconductor chip mounting apparatus of this embodiment includes a semiconductor chip mounting portion 11 on which the semiconductor chip 10 is mounted on the lower surface by vacuum suction and a substrate mounting portion 13 on which the substrate 12 is mounted on the upper surface by vacuum suction. The semiconductor chip mounting portion 11 is fixed to the upper portion of the frame body 100, and the substrate mounting portion 13 is fixed to the lower portion of the frame body 100. Semiconductor chip mounting part 1
A distance sensor device 14 that measures the three-dimensional shape of the surface of the substrate 12 is provided between the substrate 1 and the substrate mounting portion 13. On the two orthogonal sides of the side surface of the semiconductor chip mounting portion 11,
Actuators 11a and 11b for adjusting the direction parallel to the upper surface of the semiconductor chip 10 and actuators 11c and 11d for adjusting the inclination of the semiconductor chip 10 are provided. The distance sensor device 14 includes a sensor unit 14a that measures a distance from the surface of the substrate 12 and an arm unit 14b that moves the sensor unit 14a in a horizontal two-dimensional direction.

The semiconductor chip mounting portion 11 is the semiconductor chip 1.
It has an adsorption block 111 for adsorbing 0, an oscillating stage 112 to which the adsorption block 111 is fixed, and an oscillating stage 112, and a horizontal moving stage 113 to which the oscillating stage 112 is fixed and movable in a horizontal two-dimensional direction. ing. On the two orthogonal surfaces of the side surface of the horizontal movement stage 113,
The swing stage 1 is provided with actuators 11a and 11b for adjusting the direction parallel to the upper surface of the semiconductor chip 10.
The semiconductor chip 1 is provided on the two orthogonal surfaces of the side surface portion of the semiconductor chip 1.
Actuators 11c and 11d for adjusting the inclination of 0 are provided.

The substrate mounting portion 13 has a suction block 131 for sucking the substrate 12, a bonding mechanism section 132 for fixing the suction block 131 and moving the block up and down, and a swinging swing for fixing the bonding mechanism section 132. It has a moving stage 133 and a horizontal moving stage 134 to which the swinging stage 133 is fixed and movable in a horizontal two-dimensional direction. Actuators 13a and 13b for adjusting in a direction parallel to the upper surface of the substrate 12 are provided on the two orthogonal surfaces of the side surface of the horizontal movement stage 134, and the two orthogonal surfaces of the lateral surface of the swing stage 133 are provided. Is the substrate 12
Actuators 13c and 13d for adjusting the inclination of are provided.

Further, the semiconductor chip mounting apparatus is provided with a controller 15 for adjusting the parallelism between the semiconductor chip 10 and the substrate 12. The controller 15 inputs the data of the measurement result from the distance sensor device 14, and outputs necessary commands to the actuators 11a to 11d and the actuators 13a to 13d based on this data.

The distance sensor device 14 measures using the principle of triangulation. The measurement principle of the distance sensor device 14 is shown in FIG. The distance sensor device 14 irradiates the surface light of the semiconductor laser 21 onto the surface of the substrate 12 and forms an image of the reflected light on the observation surface 22 a of the semiconductor position detector 22. The position of the spot image formed on the observation surface 22a is proportional to the distance between the semiconductor laser 21 and the surface of the substrate 12. That is, when the distance between the semiconductor laser 21 and the surface of the substrate 12 changes by Δy, the position of the spot image on the observation surface 22a changes by Δμ.
It only changes. Therefore, the surface of the substrate 12 is scanned with the spot light from the distance sensor device 14,
2 The position change of the spot image caused by the unevenness of the surface is measured by the semiconductor position detector 22,
The three-dimensional shape of the surface can be obtained.

Next, a mounting method using this semiconductor chip mounting apparatus will be described with reference to the perspective view of FIG. First, the semiconductor chip 10 is suction mounted on the suction block 111 of the semiconductor chip mounting portion 11, and the substrate 12 is mounted on the substrate mounting portion 1.
The suction block 131 of No. 3 is attached by suction. Then, by scanning the surface of the substrate 12 using the distance sensor device 14, the three-dimensional shape of the surface of the substrate 12 can be measured. By this measurement, it can be confirmed whether the surface of the substrate 12 is flat. It is necessary to check such flatness before mounting.
Firstly, it is difficult to secure the parallelism of the entire surface due to the increase in size of the semiconductor chip 10 and the substrate 12, and secondly, when the substrate is made of ceramic, it has a warp or a swell. In particular, as shown in FIGS. 4A and 4B, a multilayer thin film 31 such as PI (polyimide) / Cu is formed.
In the case of a ceramic substrate 32 such as Al ₂ O ₃ or AlN deposited on the surface, warpage and undulation are significant.

For measuring the three-dimensional shape of the surface of the substrate 12, there are the following methods other than the method using the distance sensor device 14. First, the method using moire fringes. This method is shown in Figure 5.
As shown in FIG.
Through to project onto the surface of the substrate 12. Although the shadow of the grid is projected on the surface of the substrate 12 by the grid filter 42, since the surface of the substrate 12 has irregularities, it has a partially curved grid pattern. This grid pattern is used as a grid filter 42.
When observing with a CCD camera 43, the moire fringes in which the bending of the lattice pattern is further expanded appear in the lattice filter 42. The three-dimensional shape of the substrate 12 can be measured from the grid width of the moire fringes.

There is also a method of mechanical contact. In this method, a coordinate measuring machine 51 shown in FIG. 6 is used to scan the surface of the substrate 12 with a feeler (stylus) 52 at the tip to measure the three-dimensional shape of the substrate 12. In this case, in order to prevent the mounting surface from being damaged, the back surface of the substrate 12 is used for the measurement.

Further, there is a method of measuring the amount of inclination and integrating the value. In this method, as shown in FIG. 7, the parallelism measuring device 60 is used to scan the surface of the substrate 12 to measure the inclination of the entire surface of the substrate 12. Specifically, the irradiation light from the light source 61 is reflected by the half mirror 62 and given to the optical probe 63. The substrate 12 is irradiated with this irradiation light as probe light from the optical probe 63,
The semiconductor position detector 64 detects the reflected light from the substrate 12. When the measurement point of the substrate 12 is tilted, the reflected light is detected at the shifted position. Since this detected value is the amount of inclination of the substrate 12, the three-dimensional shape of the substrate 12 can be calculated by integrating this detected value.

The measuring principle of the optical probe 63 will be described with reference to FIG. As shown in the figure, the incident lights A ₁ and B _{1 which} are incident in parallel from the light source pass through the light guide 63a and are reflected by the reflecting mirror 63.
Reflected by b and 63c, the lower surface of the semiconductor chip 10 and the substrate 1
Irradiate the upper surface of 2. Then, these irradiation lights A ₂ , B
₂ is reflected by the lower surface of the semiconductor chip 10 and the upper surface of the substrate 12 and emitted through the reflecting mirrors 63b and 63c. By measuring the emission positions of these emission lights A ₃ and B ₃ with the semiconductor position detector 64, it is possible to determine the deviation of the angle between the lower surface of the semiconductor chip 10 and the upper surface of the substrate 12.

The result measured by the above measuring method is given to the controller 15, and the parallelism between the semiconductor chip 10 and the substrate 12 is examined. As a result of the examination process by the controller 15, when it is determined that the angle adjustment of the semiconductor chip 10 is necessary, the controller 15 sends a command to the actuators 11c and 11d of the semiconductor chip mounting portion 11 to perform the necessary angle adjustment. Be seen. On the other hand, when the controller 15 determines that the angle adjustment of the board 12 is necessary, a command is sent to the actuators 13c and 13d of the board mounting portion 13 to perform the necessary angle adjustment. Further, as a result of the examination process by the controller 15, when it is determined that the measured value of the three-dimensional shape of the substrate 12 is worse than the flatness allowable value, the mounting of the semiconductor chip 10 is stopped. Further, even if it is determined that the measured value of the area on which the semiconductor chip 10 is mounted among the measured values of the substrate 12 is worse than the allowable value, the mounting of the semiconductor chip 10 is stopped. The allowable value of the flatness here is set in advance based on the warp amount of the plurality of substrates and the change amount of the uneven portion.

By the above adjustment, the semiconductor chip 10 and the substrate 12 can be made parallel to each other. However, if more strict angle adjustment is required, one of the following angle adjustment processes may be performed. First, the first angle adjustment process is shown in FIG.
This will be described with reference to (a) and (b). In the first angle adjustment processing, the distance sensor device 14 is used to determine the distance between the region 12a on the substrate on which the semiconductor chip 10 is mounted and the semiconductor chip 10 at three predetermined measurement points 12b to 12d in the region 12a.
To measure. In the method of measuring the distance by the distance sensor device 14, first, the distance between the distance sensor device 14 and the substrate 12 is measured. Next, the distance sensor device 14 is turned upside down and the distance between the distance sensor device 14 and the semiconductor chip is measured. From the total of the two measured distances, the distance between the semiconductor chip 10 and the substrate 12 can be known. The measured value at each measurement point measured in this way is given to the controller 15, and the semiconductor chip 10
And the parallelism between the substrate 12 and the substrate 12 is examined. As a result of this examination,
When the controller 15 determines that the angle adjustment of the semiconductor chip 10 or the substrate 12 is necessary, a command is sent to the actuators 11c and 11d, and the necessary angle adjustment is performed. Further, when the controller 15 determines that the angle of the board 12 needs to be adjusted, the board mounting portion 13
A command is sent to the actuators 13c and 13d, and the necessary angle adjustment is performed.

Next, the second angle adjustment processing is shown in FIG.
This will be described with reference to (a) and (b). In the second angle adjustment process, the distance sensor device 14 is used to measure the distance between the semiconductor chip 10 and the region 12a on the substrate on which the semiconductor chip 10 having a rectangular mounting surface is mounted, at three measurement points 12b in the region 12a.
Measure at ~ 12d. Measurement points 12b to 12d are in area 1
Points are selected which are close to the predetermined three corners of the four corners of 2a. The measured value at each measurement point is given to the controller 15, and the parallelism between the semiconductor chip 10 and the substrate 12 is examined. As a result of this examination, the semiconductor chip 10 or the substrate 12
When the controller 15 determines that the angle adjustment is required, the command is sent to the actuators 11c and 11d, and the necessary angle adjustment is performed. Further, when the controller 15 determines that the angle adjustment of the board 12 is necessary, the actuators 13c and 13d of the board mounting portion 13 are provided.
Command is sent to and the necessary angle adjustment is performed.

[0023]

According to the semiconductor mounting method of the present invention, the three-dimensional shape of the substrate surface is measured, and the parallelism between the substrate and the semiconductor chip is adjusted based on the measurement result. Next, the distance between the semiconductor chip and the substrate is measured at at least three measuring points in the area on the substrate on which the semiconductor chip is mounted. The parallelism between the substrate and the semiconductor chip is readjusted based on this measurement result. After the above adjustment is completed, the board mounting means and the semiconductor chip holding means are brought close to each other to mount the semiconductor chip on the board.

In the semiconductor chip mounting apparatus of the present invention, the three-dimensional shape of the substrate surface is measured by the measuring means. The adjusting means adjusts the parallelism between the substrate and the semiconductor chip based on the measurement result of the measuring means. Next, the distance between the semiconductor chip and the substrate is measured by the measuring means at at least three measuring points in the region on the substrate on which the semiconductor chip is mounted. Based on the measurement result of the measuring means, the parallelism between the substrate and the semiconductor chip is readjusted by the adjusting means. After the above adjustment is completed, the board mounting means and the semiconductor chip holding means are brought close to each other to mount the semiconductor chip on the board.

As described above, the semiconductor mounting method and mounting apparatus of the present invention measure the three-dimensional shape of the surface of the substrate and adjust the parallelism between the substrate and the semiconductor chip based on the measurement result. All of the bumps provided and the pads provided on the substrate facing these bumps can be joined. Therefore, it is possible to prevent the contact failure between the bump and the pad and improve the yield at the time of mounting.

[Brief description of drawings]

FIG. 1 is an external view showing a configuration of a semiconductor chip mounting apparatus of this embodiment.

FIG. 2 is a perspective view showing a measurement principle of a distance sensor device.

FIG. 3 is a perspective view showing a mounting method using a semiconductor chip mounting apparatus.

FIG. 4 is a cross-sectional view showing a ceramic substrate having warpage and undulation.

FIG. 5 is a plan view showing a method for measuring a three-dimensional shape.

FIG. 6 is a plan view showing a method for measuring a three-dimensional shape.

FIG. 7 is a plan view showing a method for measuring a three-dimensional shape.

FIG. 8 is a perspective view showing the measurement principle of the optical probe.

FIG. 9 is a plan view showing a first angle adjustment process.

FIG. 10 is a plan view showing a second angle adjustment process.

[Explanation of symbols]

10 ... Semiconductor chip, 11 ... Semiconductor chip mounting portion, 12
... board, 13 ... board mounting portion, 14 ... distance sensor device, 1
5 ... Controller.

Claims (8)

[Claims] 1. A semiconductor chip mounting method for mounting a semiconductor chip held on an upper portion of the substrate by a semiconductor chip holding means on a substrate fixed to the substrate mounting means, wherein a three-dimensional shape of the surface of the substrate is measured. 1 step, a second step of adjusting the parallelism between the substrate and the semiconductor chip based on the measurement result, and at least 3 measurement points in an area on the substrate where the semiconductor chip is mounted. A third step of measuring a distance between the semiconductor chip and the substrate, a fourth step of adjusting parallelism between the substrate and the semiconductor chip from the measured distance, the substrate mounting means and the semiconductor chip A fifth method for mounting the semiconductor chip on the substrate by bringing the holding means close to each other.
A semiconductor chip mounting method, comprising: 2. A semiconductor chip mounting method for mounting a semiconductor chip, the mounting surface of which is held on the upper portion of the substrate by a semiconductor chip holding means and has a rectangular mounting surface, on a substrate fixed to the substrate mounting means, wherein the three-dimensional surface of the substrate is mounted. A first step of measuring the shape; a second step of adjusting the parallelism between the substrate and the semiconductor chip based on the measurement result; and a square area 4 on the substrate on which the semiconductor chip is mounted.
The third step of measuring the distance between the semiconductor chip and the substrate at three measurement points in the area, which are close to the predetermined three corners of the corners, respectively. A fourth step of adjusting the parallelism between the substrate and the semiconductor chip from a distance, and a fifth step of mounting the semiconductor chip on the substrate by bringing the substrate mounting means and the semiconductor chip holding means close to each other.
A semiconductor chip mounting method, comprising: 3. The method according to claim 1, further comprising a step of stopping the mounting process when the flatness of the three-dimensional shape measured in the first step is worse than a predetermined allowable value. Semiconductor chip mounting method. 4. The mounting process is stopped when the flatness of the three-dimensional shape of the region on the substrate on which the semiconductor chip is mounted is worse than a predetermined allowable value based on the measurement result in the first step. The semiconductor chip mounting method according to claim 1 or 2, further comprising a step. 5. A semiconductor chip mounting apparatus for mounting a semiconductor chip held on an upper part of the substrate by a semiconductor chip holding unit on a substrate fixed to a substrate mounting unit, measuring a three-dimensional shape of the substrate surface, And, at least at three measuring points in the area on the substrate on which the semiconductor chip is mounted, measuring means for measuring the distance between the semiconductor chip and the substrate, and the measuring result by the measuring means. A semiconductor chip mounting apparatus comprising: an adjusting unit that adjusts the parallelism between a substrate and the semiconductor chip. 6. A semiconductor chip mounting apparatus for mounting a semiconductor chip held on an upper part of the substrate by a semiconductor chip holding unit on a substrate fixed to the substrate mounting unit, measuring a three-dimensional shape of the substrate surface, And among the four corners of the rectangular area on the substrate on which the semiconductor chip is mounted,
Measuring means for measuring the distance between the semiconductor chip and the substrate at three measuring points in the region respectively close to three predetermined corners, and the measuring means for measuring the distance based on the measurement result by the measuring means. A semiconductor chip mounting apparatus comprising: an adjusting unit that adjusts the parallelism between a substrate and the semiconductor chip. 7. The mounting stopping means for stopping the mounting processing when the flatness of the three-dimensional shape measured by the measuring means is worse than a predetermined allowable value, and the mounting stopping means is provided. Semiconductor chip mounting equipment. 8. Based on the measurement result by the measuring means,
7. The mounting stopping means for stopping the mounting process when the flatness of the three-dimensional shape of the area on the substrate on which the semiconductor chip is mounted is worse than a predetermined allowable value. Semiconductor chip mounting device.