JPS63127541A - Method of bonding chip - Google Patents

Abstract

PURPOSE:To ensure mechanical and electrical connections by joining a chip to a substrate by hardening adhesives under the condition that an electrical connection is secured by pressing. CONSTITUTION:Adhesives 36 are applied on the upper surface of a chip 1, the chip 1 is pressed on a substrate 3 and the bump contact 2 of the chip 1 is pressed and jointed to the lead 4 of the substrate 3. In this case, the adhesives 36 are perfectly removed from between the bump contact 2 and the lead 4 by pressing power and the bump contact 2 is elastically pressed on the surface of the lead 4 as if encroaching in the surface, an electrical connection is secured, simultaneously a worktable 14 is moved transversely and an ultraviolet rays irradiating device 17 is positioned directly upon the chip 1 facing to the chip, the adhesives 36 are hardened by being irradiated with ultraviolet rays via the through hole 13 of the substrate 3 and the transparent substrate 3 and the chip 1 is fixed on the substrate 3. These maintain a state of pressed jointing and the electrical connection of the bump contact 2 and the lead 4 is surely maintained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for bonding chips, and in particular to a method for bonding chips, in particular a method for electrically connecting a bump contact formed on one side of a chip, such as a 7-rib chip, to a lead on a substrate and simultaneously bonding the chip. The present invention relates to a method for bonding a chip to a substrate.

2. Description of the Related Art Conventionally, various joining methods using metal-to-metal bonding have been proposed as methods for joining chips having bump contacts. For example, the present applicant has previously proposed a joining method as shown in FIG. That is, the chip 41 is held with an adhesive film 42 with its seven bump contact points facing upward, and the adhesive film 42 is positioned by a positioning device 44 via a wafer ring 43. The chip is transferred onto the mounting surface 46 of the pressing body 45, which can be raised and lowered and is configured to vacuum-adsorb the chip, using a transporter tWl equipped with a suction collet, and the chip position on the mounting surface 46 is adjusted. The position of the pressing body 45 is detected by the position detection device 47 disposed above, and the position of the pressing body 45 is corrected by the positioning device 48 according to the detected position, and further the substrate positioning device 5
2, the substrate 51 is moved on the horizontal plane above the pressing body 45, and the substrate position detection device 53 detects the position of the substrate 51 to determine the chip bonding position of the substrate 51 between the chips 41 on the mounting surface 46. , and then press the pressing body 4
proposed a method of joining the bump contacts of the chip 41 to the leads of the substrate 51 by raising the chip 41 to press the chip 41 against the substrate 51 and applying heat or ultrasonic waves.

Problem to be solved by the invention α By the way, in the above chip joining method, metal-to-metal joining is performed by applying heat, ultrasonic waves, or sound waves while applying pressure to the joining surface, and fixing of the chip and electrical joining are simultaneously performed. As a result, there is a problem in that heat or ultrasonic waves must be applied to the substrate or chip, and there is also a problem in that reliable bonding may not be possible even due to slight differences in conditions.

In view of the above-mentioned conventional problems, the present invention provides a chip bonding method that can reliably fix the chip to the substrate while the bump contacts and leads are electrically connected by pressing the chip against the substrate. The purpose is to

Means for Solving the Problems In order to achieve the above object, the present invention includes a step of applying an ultraviolet curable adhesive to one side of a chip on which a bump contact is formed or a chip bonding surface of a substrate, and There is a step of pressurizing the chip and the board so that the contacts are pressed against the leads of the board, and in this pressurized state, the adhesive is irradiated with ultraviolet rays to harden the adhesive, and the bump contacts and the leads are pressed together to form an electrical connection. and fixing the chip to the substrate in a state where the chip is connected to the substrate.

Further, a second aspect of the present invention is that, prior to the step of pressurizing the chip and the substrate, the method includes a step of adjusting parallelism between one side of the chip on which the bump contact is formed and the chip bonding surface of the substrate. It is characterized by

Function: Since the present invention has the above configuration, the chip having bump contacts is bonded to the substrate using an adhesive, and there is no need to apply heat or ultrasonic waves, which simplifies the device. The chip can be easily and reliably fixed to the board, and since the bump contacts are pressure-contacted to the leads to ensure electrical connection, the adhesive is cured and bonded. After completion of mechanical bonding due to hardening, even if the pressure is removed, the bump contacts are pressed against the leads due to their elastic restoring force, and electrical connection is maintained, so that mechanical and electrical bonding can be reliably obtained.

Further, by adjusting the parallelism between the chip and the substrate when pressurizing them, the bonding surfaces can be reliably pressed against each other, and a highly reliable electrical bonding state can be obtained.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 6.

In Fig. 5, 1 is a chip such as an IC chip, and its -
A bump contact 2 is provided protruding from the side surface, and this bump contact 2 is formed on the chip mounting surface of the board 3.
It is electrically connected to the card 4.

The chips 1 are transferred from the chip supply section onto the pressure table 5a at the upper end of the chip table 5 by a transfer device (not shown). The chip table 5 includes an X table 6 that moves from below in the X-axis direction and a Y-table that moves in the Y-axis direction perpendicular to the X-axis.
The table 7, the θ table 8 that rotates around the Z axis perpendicular to the X and Y axes, the Z table 9 that moves in the Z axis direction, and can swing around an axis parallel to the X pongee and Y glaze. It is composed of a parallel adjustment table 10. On the other hand, the substrate 3 is made of a transparent positive substrate, and a reference mark (not shown) for positioning is placed at an appropriate position on the chip mounting surface.
is provided. This substrate 3 is held by a substrate moving device 11 disposed above the chip table 5 with a holder 12 with the chip mounting surface facing downward. This substrate moving device 11 is movable between a position above the chip table 5 and a position retracted to the side thereof, and moves the held substrate 3 to an arbitrary position at the center position of the pressurizing table 5a of the chip table 5. When the substrate moving device 11 is in the retracted position, the substrate 3 is supplied by a substrate supply/takeout device (not shown) and the substrate 3 on which the chip 1 is mounted is taken out. It is configured as follows. Further, the back side of the substrate 3 of the substrate moving device 11 comes into contact with the support plate 11+z, and there are through holes 13 corresponding to the placement positions of the reference marks provided on the substrate and the chip mounting positions.
but! ? ! It is set up. 14 is the substrate moving device 11
A microscope 15 with a focus detection device equipped with a CCTV camera, an adhesive applicator 16 consisting of a dispenser that drips adhesive, and an ultraviolet irradiator 1 are installed on a workbench located above.
7 are arranged in parallel, and are configured to be movable in the Z-axis direction and movable in the arrangement direction of each of the above devices. The ultraviolet irradiation tool 17 includes a mercury lamp i4 having a shutter:
Ultraviolet rays are guided from 18 through a light 7 eyeper 19.

Further, the microscope 15 with a focus detection device is arranged on the workbench 1.
It is attached to a movable base 20 that is movable in the Z-axis direction with respect to 4.

The movable table 20 and the microscope 15 with a focus detection device are constructed as shown in FIG. The image of the mark ah4 on the top surface of the chip 1 and the chip mounting surface of the substrate 3 illuminated by the illumination device ra21 is captured by the CCTV camera 2 through the objective lens 22.
A part of the light is taken out laterally by a beam splitter 24, and then a combination of a beam splitter and a total reflection prism 25.
27 is a focus determination device that determines the focus position direction from the contrast difference between the two images on the CCD line sensor 26. , a motor 29 is driven by a motor driver 28, and a ball screw 30 drives a movable base 20 to move. The height position of the movable base 20 is monitored by a displacement detector 31 and a counter 32 by a central device (hereinafter abbreviated as CPU). The image signal of the CCTV camera 23 is sent to the camera control unit 33.
The position reading result is then sent to the pattern matching type position reading device 34 and the monitor television 35, and the position reading result is transmitted to the CPU.

In the above configuration, the operation of mounting the chip 1 at a predetermined position on the substrate 3 will be explained with reference to FIG. 1 and FIG. first,
A substrate supply/takeout device (not shown) supplies the substrate 3 to the substrate moving device 11 which has been moved to the retracted position in advance, and a chip 1 is transferred onto the pressure table 5a of the chip table 5 by a transfer device (not shown). First, move the board! ! Place 1
1 to a position above the chip table 5, and lower the workbench 14 to a predetermined position.
As shown in a), the three reference marks provided on the substrate 3 are sequentially positioned directly below the microscope fi 15 with a focus detection device, and the movable table 20 is moved to perform an automatic focusing operation, and when the focus point is The height position of the movable base 20 is read by the displacement detector 31 and the counter 32, and the height of each of the three points on the board 3 is detected. This allows board 3
The position and inclination of the chip mounting surface can be detected.

Next, after moving the substrate moving device W111 to the retreat position,
As shown in FIG. 1(b), the workbench 14 is further lowered to a predetermined position, the chip 1 on the chip table 5 is placed in the field of view of the microscope fi 15 with a focus detection device, and the position of the chip 1 is detected from the image. Then, set X table 6, Y table 7,
The θ table 8 is operated, the center of the chip 1 is positioned at a predetermined position, and then 3. α is sequentially positioned directly below the microscope 15 with a focus detection device, and the movable base 20 is moved to perform an automatic focusing operation, and the height position of the movable base 20 at the time of focusing is read in the same manner as above,
The heights of three points on the top surface of the chip 1 are detected, and the top surface position and inclination of the chip 1 are detected. Next, based on the above detection results, the parallel adjustment table 10 is operated so that the top surface of the chip 1 is parallel to the chip mounting surface of the substrate 3. Next, as shown in FIG. Move the stand 14 laterally to position the adhesive coating @f116 on the chip 1,
By discharging the adhesive 36, the adhesive 36 is applied to the upper surface of the chip 1, as shown in FIG. 3(a). Subsequently, after raising the workbench 14, the substrate moving device 11 is moved to a position above the chip table 5, the position where the chip 1 is to be bonded is positioned directly above the chip 1, and the Z table 9 is moved up. Figure 1(d)
As shown in FIG. 3(b), the chip 1 is pressed against the substrate 3, and the bump contacts 2 of the chip 1 are brought into pressure contact with the leads 4 of the substrate 3. At this time, each bump contact 2 has, for example, 1
Since the sides are generally small, about 0.1 mm, the adhesive 36 is completely removed from between the bump contact 2 and the lead 4 by the pressurizing force, and the bump contact
is pressed against the surface of the lead 4 so as to bite into it and elastically, thereby ensuring electrical connection. At the same time, the workbench 14 moves laterally so that the ultraviolet ray irradiator 17 is located directly above the chip 1, and the workbench 14 is lowered, and as shown in FIG. The adhesive 36 is irradiated with ultraviolet rays through the through hole 13 and the transparent substrate 3 to cure it, and the chip 1 is fixed to the substrate 3. During this time,
By maintaining the pressure contact state between the bump contact 2 and the lead 4, when the adhesive 36 hardens, the pressure contact state is maintained even when the pressure on the chip 1 is released, and the bump contact 2
The electrical connection between the lead 4 and the lead 4 is reliably maintained.

In this way, when the bonding of one chip 1 is completed, the substrate moving device! 11 is evacuated, and thereafter, new chips 1 are sequentially transferred onto the pressurizing table 5a of the chip table 5, and mounted and fixed on the substrate 3 in the same manner as above, and all the chips 1 are removed! ! When the substrate is fixed, the substrate moving device 11 retreats to the retracted position and is taken out by the substrate supply/takeout device, and a new substrate 3 is supplied, and the above operation is repeated.

In the above embodiment, the three-point positions of the substrate 3 and the chip 1 were detected to perform parallel adjustment, but if the substrate 3 is reliable as a reference surface, the three-point positions of the chip 1 alone are detected and parallel adjustment is performed. Further, if the parallelism between the two is high, or if the pressure table 5a has a built-in spherical bearing or the like and has a parallel adjustment function with respect to the substrate 3, the parallel adjustment process is performed. It can also be omitted. Also, the adhesive is not the chip 111,
It may also be applied to the substrate 3 side. Furthermore, in the above embodiment, a transparent substrate is used as the substrate 3, but if the detection of three points on the substrate 3 and the V ultraviolet ray irradiation are performed from the chip mounting surface side, even an opaque substrate can be used. Applicable.

Effects of the Invention According to the chip bonding method of the present invention, a chip having a bump contact is bonded to a substrate using an adhesive as described above, and there is no need to apply heat or ultrasonic waves, so the device can be easily It is easy to fix the chip to the board easily and reliably, and since the bump contacts are pressed against the leads and the electrical connection is secured, the adhesive is cured and bonded. After completion of mechanical bonding due to hardening, even if the pressure is removed, the bump contact 5α is pressed against the lead due to its elastic restoring force and the electrical connection is maintained, making it possible to reliably obtain mechanical and electrical bonding. .

Moreover, in the second invention, when the chip and the substrate are pressed, their parallel ml! ! Because this process is carried out, all bonding surfaces are securely pressed against each other and a highly reliable electrical bonding state can be obtained, resulting in great effects.

[Brief explanation of the drawing]

FIG. 4 is an enlarged sectional view showing the state in which the adhesive is applied and the chip is in pressure contact; FIG. 4 is an enlarged sectional view showing the state in which the bump contact and the lead are in pressure contact; FIG. The figure is a diagram of the configuration principle of a microscope with a focus detection device.
The figure is a front view showing a schematic configuration of a conventional device. 1... Chip 2... Bump contact, Mount 3... Board 4... Lead 5... ...... Chip table 5a... Pressure table 10... Parallel adjustment table 15...
... Focus detection device 16...
・Adhesive coating device 17......Ultraviolet irradiation. Agent f) Drunk patent attorney Toshio Nakao (1 person) Figure 1 1 --- Dep 4 --- Lead
10--Ichigo Adjustment Defunle 2---Pembu Suiko,
5-1-di nofu't-n7/ 1s --
-4, Ichi, Hara [≧1 to Haru Okimura Samekagami 3-4-break 51-%
L stand 16-1 arrival @ 6 technique ff 117-ki/+ green closed, e fig. 2 fig. 3 fig. 4 fig. 5 fill 6 fig. fig. 7

Claims (4)

[Claims] (1) A step of applying an ultraviolet curable adhesive to one side of the chip on which bump contacts are formed or the chip bonding surface of the substrate, and then applying pressure to the chip and the substrate so that the bump contacts of the chip come into pressure contact with the leads of the substrate. and a step of curing the adhesive by irradiating the adhesive with ultraviolet rays in this pressurized state, and fixing the chip to the substrate with the bump contacts and the leads in pressure contact and electrically connected. A chip joining method characterized by: (2) A step of adjusting parallelism between one side of the chip on which a bump contact is formed and the chip bonding surface of the substrate, and a step of applying an ultraviolet curing adhesive to one side of the chip or the chip bonding surface of the substrate. , a step of pressurizing the chip and the substrate so that the bump contacts of the chip are brought into pressure contact with the leads of the board, and in this pressurized state, the adhesive is irradiated with ultraviolet rays to harden the adhesive, and the bump contacts and the leads are brought into pressure contact. and fixing the chip to a substrate in an electrically connected state. (3) The chip bonding method according to claim 2, wherein the parallel adjustment between one side of the chip and the chip bonding surface of the substrate is performed by detecting three points on one side of the chip. (4) The chip bonding according to claim 2, in which the parallel adjustment between one side of the chip and the chip bonding surface of the substrate is performed by detecting three points each on the one side of the chip and the chip bonding surface of the substrate. Method.