JPH0837209A - Method of mounting electronic part with bump - Google Patents

Abstract

PURPOSE:To provide a method of mounting an electronic part with a bump capable of positioning the bump of the electronic part with the bump such as a flip-ship etc., in alignment with electrodes of a board with high precision to mount. CONSTITUTION:A flip-chip 1 is observed by a camera to acquire coordinate values of a first corner part and a second corner part and an x coordinate value and a y coordinate value with respect to these coordinate values of an arbitrary bump 2. Next, after flux is applied to the bump 2, it is observed again by a camera to acquire the coordinate values of the first corner part and second corner part and to acquire a presumed coordinate value of the bump 2 from these coordinate values, the x coordinate value and y coordinate value. Next, based upon this presumed coordinate value, the bump 2 is positioned in an electrode 11 of a substrate 10 to mount the flip-chip 1 to the board 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for mounting an electronic component with bumps, in which the bumps of the electronic component with bumps are aligned and mounted on the electrodes of the substrate.

[0002]

2. Description of the Related Art Electronic parts with bumps (protruding electrodes) such as flip chips are mounted by aligning the bumps with the electrodes on the substrate. In recent years, the number of bumps has been increasing and their size has increased. Since it is also extremely miniaturized, high mounting accuracy is required for bumped electronic components. Hereinafter, a conventional method for mounting electronic components with bumps will be described.

FIG. 8 is an explanatory view of a conventional mounting process of a bumped electronic component. In FIG. 8A, 1 is a flip chip as an electronic component with bumps, and a large number (9 in this embodiment) of bumps 2 are formed in a matrix on the bottom surface thereof. Reference numeral 3 denotes a nozzle for vacuum-sucking the flip chip 1, which is held by the head 4. The head 4 is driven by a moving table (not shown) to move in the X direction and Y direction.
Move horizontally in the direction.

The nozzle 3 is driven by an elevating mechanism (not shown) to move up and down. Now, the flip chip 1 is provided on the tray 5, and the nozzle 1 vertically moves to pick up the flip chip 1 by vacuum suction. In this example, the supply unit of the flip chip 1 is the tray 5, but the supply unit may be of another type such as a wafer.

The nozzle 3 picking up the flip chip 1 moves to above the camera 6a as shown in FIG. 8B, and the flip chip 1 is observed from below by this camera 6a to obtain the position of the bump 2. . This position can be easily obtained by analyzing the image data captured by the camera 6a by known image processing using a computer.

Next, as shown in FIG.
Moves above the container 9 in which the flux 8 is stored, and moves up and down there to cause the bumps 2 to land on the flux 8 and attach the flux 8 to the bumps 2.

Next, as shown in FIG. 8D, the nozzle 3 moves above the substrate 10. The substrate 10 is the X table section 12
It is mounted on the Y table 13 and can be moved horizontally in the X and Y directions. An electrode 11 is formed on the upper surface of the substrate 10. The electrode 11 is attached to the camera 6 in advance.
By observing with c, the coordinate value of this electrode 11 is obtained. Therefore, the substrate 10 or the nozzle 3 is set to X.
The bump 2 and the electrode 11 are aligned by moving in the direction Y or the direction Y, and then the nozzle 3 is moved up and down to mount the flip chip 1 on the substrate 10.
The substrate 10 on which the flip chip 1 is mounted is sent to a heating furnace and heated there, whereby the bumps 2 are melted and solidified, and the flip chip 1 is fixed to the substrate 10.

[0008]

In the above-mentioned conventional example, as shown in FIG.
As shown in (b), the flip chip 1 is observed by the camera 6a to find the position of the bump 2, and then the flux 8 is attached to the bump 2 as shown in FIG. 8 (c). Was mounted on the substrate 10. That is, in this conventional example, between the step of detecting the position of the bump 2 by the camera 6a and the step of mounting the flip chip 1 on the substrate 10,
Since the step of adhering the flux 8 to the bump 2 is interposed, a new positional deviation is likely to occur in the bump 2 during this time, which causes a problem that the mounting accuracy of the flip chip 1 is not improved. Further, after the position detecting process by the head 4 and the camera 6a, the head 4 moves to the substrate 10 via the container 9, so that the moving distance of the head 4 becomes long, and the influence of the moving error of the head 4 becomes large, and the mounting accuracy becomes large. There is also a problem that it lowers.

In order to improve the mounting accuracy, immediately before mounting the flip chip 1 on the substrate 10, that is, in FIG.
It is desirable to obtain the position of the bump 2 by observing the bump 2 with a camera between the flux applying step shown in FIG. 8C and the mounting step shown in FIG. 8A. Even when observed with a camera, the flux 2 becomes noise and the bump 2 cannot be clearly observed. Therefore, in the conventional example, the bump 2 is unavoidable.
The position of the bump 2 was obtained by observing with the camera 6a before attaching the flux 8 to the.

Therefore, an object of the present invention is to provide a mounting method for an electronic component with bumps, in which the bumps and the electrodes on the substrate can be accurately aligned to improve the mounting accuracy.

[0011]

To this end, according to the present invention, a step of picking up a bumped electronic component provided in a supply unit by vacuum suction on a nozzle and picking up the bumped electronic component from below with a camera. Then, the step of obtaining the relative position of the arbitrary bump with respect to the characteristic part of the bumped electronic component, the step of applying flux to the bump of the bumped electronic component, and the camera of the bumped electronic component are again observed from below. The step of obtaining the position of the characteristic part and the estimated position of an arbitrary bump from the position of the characteristic part and the relative position, the estimated position, and the position of the substrate obtained by observing the substrate in advance with a camera Based on the above, the bump and the electrode of this substrate are aligned with each other, and the bumped electronic component is mounted on this substrate.

[0012]

According to the above construction, after the flux is attached to the bumps and immediately before the electronic component with bumps is mounted on the substrate,
The electronic parts with bumps are observed with a camera to find the positions of their characteristic parts, and the estimated positions of the bumps are found based on this.Therefore, the electronic parts with bumps are not displaced while the flux is attached to the bumps. Even if it occurs, the bumps and the electrodes of the substrate can be accurately aligned and the electronic component with bumps can be mounted on the substrate with high accuracy regardless of this positional deviation.

[0013]

Embodiments of the present invention will now be described with reference to the drawings. 1 to 5 are explanatory views of a mounting process of an electronic component with bumps according to an embodiment of the present invention, and show a series of operations in the order of operations. 6 and 7 are bottom views of the flip chip in the mounting process of the electronic component with bumps. In each figure, the same parts as those of the conventional example shown in FIG. The operation will be described below with reference to the drawings.

First, as shown in FIG. 1, the nozzle 3 vertically moves above the tray 5 so that the flip chip 1 provided on the tray 5 is vacuum-sucked and picked up. Next, as shown in FIG. 2, the nozzle 3 moves to above the camera 6a, and the flip chip 1 is observed from below with the camera 6a.

FIG. 6 shows the bottom surface of the flip chip 1 observed by the camera 6a. First, the field of view of the camera 6a is aligned with the first corner K1 which is a characteristic part of the flip chip 1. A is a check area set in the field of view,
The coordinate value of the first corner K1 in the check area A (x1,
y1) and x with respect to the first corner K1 of the bump 2a closest to the first corner K1 in the check area A.
The coordinate value xa and the y coordinate value ya are calculated. The bumps for obtaining the x-coordinate value and the y-coordinate value can be arbitrarily determined, but as in the present embodiment, the bumps in the same check area A as the first corner portion K1, more preferably the first corner portion K1. It is more advantageous to select the bump 2a closest to, and the bump 2 and the substrate 10 can be aligned with high accuracy.

Next, the nozzle 3 is moved in the X and Y directions to position the second corner K2 in the check area A, and similarly, the coordinate value (x2, y2) of the second corner K2 is set.
Then, the x-coordinate value xb and the y-coordinate value yb of the closest bump 2b to this are obtained. Here, it is preferable that the first corner K1 and the second corner K2 are on the same diagonal line N, that is, the ones that are the farthest in terms of distance and angle are selected. It is easy to accurately align with and.

Next, as shown in FIG. 3, the nozzle 3 is moved above the container 9 and the nozzle 3 is moved up and down there to cause the bump 2 to land on the flux 8 and the flux 8 to the bump 2. Attach it. Next, as shown in FIG. 4, the nozzle 3 is moved above the camera 6b, and the bottom surface of the flip chip 1 is observed from below. As shown in the figure, the flux 8 is attached to the bump 2. The camera 6b may be the same camera as the camera 6a.

FIG. 7 shows the bottom surface of the flip chip 1 observed by the camera 6b. First, the check area A in the visual field of the camera 6b is aligned with the first corner K1 and the coordinate value (x1 ′, y1 ′) thereof is obtained. Next, the check area A is aligned with the second corner K2, and its coordinate value (x2 ', y
2 ').

Now, the first corner K of each bump 2a, 2b
The coordinates for the first and second corners K2 are already determined and known, as shown in FIG. Therefore, in FIG. 7, the estimated coordinate value (x1 ′ + xa, y1′− of the bump 2a is obtained.
ya) and the estimated coordinate value of the bump 2b (x2'-xb, y
2 ′ + yb) can be easily calculated. This calculation is performed by the CPU of the computer or the like.
As described in the section of the prior art, the bumps 2a, 2
Since the flux 8 adheres to b, the flux 8 becomes noise and the bumps 2a and 2b are attached to the camera 6b.
It is impossible to observe it clearly and detect its exact position.

Next, as shown in FIG.
Move above. The substrate 10 has an X table 12 and a Y
It is mounted on the table portion 13 and therefore the nozzle 3
Before the substrate moves above the substrate 10, the X table portion 12 and the Y table portion 13 are driven to move the substrate 10 below the camera 6c, and the bumps 2a and 2b are moved by the camera 6c. Observe the mounted electrode 11,
The coordinate value is obtained in advance. So bumps 2a, 2b
X table part 1 so that these electrodes 11 and
2 and the Y table portion 13 to drive the electrode 11 to the bump 2
After aligning with a and 2b, the nozzle 3 is moved up and down, and the flip chip 1 is mounted on the substrate 10. The substrate 10 on which the flip chip 1 is mounted as described above
Are sent to a heating furnace and heated, the bumps 2 are melted and solidified, and the flip chips 1 are fixed to the substrate 10.

[0021]

As described above, according to the present invention, after the flux is attached to the bumps, and immediately before the electronic component with bumps is mounted on the substrate, the electronic component with bumps is observed by the camera and the coordinates of the characteristic part are observed. Since the values are calculated and the estimated coordinate values of the bumps are calculated based on these values, even if the electronic components with bumps are misaligned while the flux is attached to the bumps, the bumps will be irrespective of this misalignment. The electronic components with bumps can be mounted on the substrate with high accuracy by accurately aligning the electrodes on the substrate. Further, since the position of the bump of the electronic component with bump can be detected immediately before mounting on the substrate, it is possible to mount the electronic component with bump with high accuracy by reducing the influence of head movement error and the like.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a mounting process of an electronic component with bumps according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a mounting process of the bumped electronic component according to the embodiment of the present invention.

FIG. 3 is an explanatory diagram of a mounting process of the bumped electronic component according to the embodiment of the present invention.

FIG. 4 is an explanatory diagram of a mounting process of an electronic component with bumps according to an embodiment of the present invention.

FIG. 5 is an explanatory view of a mounting process of an electronic component with bumps according to an embodiment of the present invention.

FIG. 6 is a bottom view of the flip chip in the mounting process of the bumped electronic component according to the embodiment of the present invention.

FIG. 7 is a bottom view of the flip chip in the mounting process of the electronic component with bump according to the embodiment of the present invention.

FIG. 8 is an explanatory diagram of a conventional mounting process of electronic components with bumps.

[Explanation of symbols]

 1 Flip Chip 2 Bump 3 Nozzle 5 Tray 6a, 6b, 6c Camera 8 Flux 10 Substrate 11 Electrode A Check Area K1 First Corner K2 Second Corner

Claims (2)

[Claims] 1. A step of vacuum picking up an electronic component with bumps provided in a supply unit by a nozzle to pick up the electronic component with bumps, and observing the picked up electronic component with bumps from a lower side with a camera to characterize the electronic component with bumps. The relative position of any bump with respect to the part, the step of attaching flux to the bump of the electronic component with bump, the electronic component with bump is observed again from below with a camera to determine the position of the characteristic portion. Obtained, the step of obtaining the estimated position of the arbitrary bump from the position of the characteristic portion and the relative position, the estimated position, based on the position of the substrate obtained by observing the substrate in advance with a camera, A method of mounting the bumped electronic component on the substrate by aligning the bump with the electrode of the substrate, and mounting the bumped electronic component on the substrate. 2. The characteristic portion is two corner portions on a diagonal of the bumped electronic component, and the arbitrary bump is
2. The method of mounting an electronic component with bumps according to claim 1, wherein the bumps are located in the same check area of the camera and located closest to the corner.