JPH07326642A - Bonding head structure - Google Patents

Abstract

PURPOSE:To enable bonding by controlling height and heating and pressing each chip individually, by moving a plurality of adaptors with the respective motors, on the basis of a control part which changes and controls the travel distances as far as a plurality of the chips individually for each of the adaptors. CONSTITUTION:A board on which pads 4 are formed is coated with reinforcing agent 5 for increasing the bonding strength of a chip 2. Bumps 3 are bonded to a chip 2 to be mounted on the board 1, and aligned to the formation positions of pads 4. The chip 2 is transferred with a bonding head 10. The bonding head 10 is equipped with two adaptors 6 having heaters 7, in order to bond collectively a plurality of the chips 2. The adaptor 6 is moved with a motor 8, on the basis of a control part 9. Thereby the number of heads to be pressed and controlled is reduced, and the coping with high density mounting is enabled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bonding head structure, and in particular, when a plurality of chips are mounted on a pad formed on a substrate, the plurality of chips are pressed and heated to collectively bond them together. The present invention relates to a bonding head structure.

In recent years, bare chip mounting technology has been developed along with miniaturization and high density of electronic devices. In this bare chip mounting, the chip is not mounted on the substrate in a package but directly mounted on the substrate. In addition, there are two types of bare chip mounting, a flip chip type that uses bumps to bond the substrate and chip, and a one-way bonding type that uses wires to bond the substrate and chip. It is appropriately selected and adopted depending on the situation. The present invention particularly relates to this flip chip type bare chip mounting.

[0003]

2. Description of the Related Art First, a flip chip type semiconductor chip mounting process will be described with reference to FIG.

First, the capillary 3 is placed on the pad of the chip 30.
A predetermined number of stud bumps (hereinafter referred to as bumps) 32 are formed by using a wire (for example, aluminum, copper, gold, etc.) by the wire bonding mounting technique using 1.

Since the height of each bump 32 has a variation of about 20 μm, the bumps 32 of the chip 30 are pressed against the glass flat plate 33 to perform leveling, and the bumps 32 are
Align the height of.

Subsequently, a conductive adhesive 34 is thinly squeezed on a glass flat plate 35 (which may be the same as the above-mentioned glass flat plate 33) in advance, and each bump is attached to the conductive adhesive 34. Transfer is performed by pressing 32 to attach.

On the other hand, the bump 32 of the mounted chip 30
The thermosetting insulative adhesive 36 for reinforcement is applied on the substrate 38 on which the mounting pads 37 are formed by a number corresponding to the above number by the screen printing method. The chip 30 adsorbed by a bonding head (not shown) is transferred above the substrate 38.

Then, the mounting pads 37 of the substrate 38 and the bumps 32 of the chip 30 are aligned, and the semiconductor chip 30 is flip-chip bonded and mounted on the substrate 38 at the same time by applying pressure and heating by the bonding head. . In this case, the bonding head is equipped with a heat source, and the insulating adhesive is thermally cured by heating to reinforce the flip chip bonding.

[0009]

When the adhesive is heat-cured in a so-called multi-chip in which a plurality of chips are mounted in a lump, the chip thickness varies due to the difference between wafer lots and multi-benders. There is a drawback that it is difficult to heat-harden the chips all together.

It suffices if the multi-chips can be individually heated and controlled by the bonding head, but the equipment is expensive and the multi-chip mounting cannot be carried out in the high-density mounting area because the bonding head with pressure control has a space. Due to this, there is a drawback that the mounting area is limited.

Therefore, it is an object of the present invention to control the height of each of a plurality of chips so that they can be bonded by heating and pressing.

[0012]

The above object is to provide a bonding head structure in which a plurality of chips 2a and 2b are pressed and heated on a substrate 1 on which a pad 4 is formed to bond them together in a batch. 2a, 2b, a plurality of adapters 6 having a heater 7 for supplying heat to the plurality of chips 2a, 2b, and a chip thickness for each of the plurality of chips 2a, 2b mounted on the substrate 1 in advance. A control unit 9 that variably controls the moving distance to the plurality of chips 2a and 2b for each of the plurality of adapters 6 based on the measured value, and the plurality of adapters 6 based on the control of the control unit 9. And a plurality of chips 2a and 2b are pressed and heated together on a substrate 1 having a pad 4 formed thereon by a bonding head structure characterized by having a motor 8 for moving them respectively. In the bonding head structure for bonding and joining, a different thickness is measured for each of the plurality of chips 2a, 2b based on the measurement value obtained by measuring the chip thickness for each of the plurality of chips 2a, 2b mounted on the substrate 1 in advance. Adapters 11a and 11b that are determined and are joined to the plurality of chips 2a and 2b and the plurality of chips 2a and 2
and a head 12 having a heater 7 for supplying heat to the plurality of chips 2a, 2b, and the bonding head structure.

[0013]

That is, according to claim 1 of the present invention, the chip thickness is measured in advance for each of a plurality of chips mounted on the substrate, and the moving distance of the adapter to the chip is calculated based on the measured value. Since they are controlled, the chips to be mounted can be collectively bonded.

According to a second aspect of the present invention, the chip thickness is measured in advance for each of a plurality of chips mounted on the substrate, and an adapter having a different thickness is selected and used based on the measured value. Bonding can be performed collectively for each chip to be mounted.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will now be described with reference to FIG.
And it demonstrates using FIG. The same reference numerals in FIGS. 1 and 2 denote the same objects.

First, the first embodiment will be described with reference to FIG. The substrate 1 on which the pads 4 are formed is coated with a reinforcing agent 5 which is a thermosetting insulating adhesive for enhancing the bonding strength of the chip 2.

Bumps 3 are bonded to the chip 2 mounted on the substrate 1 by the process described in the prior art, and the chip 2 is transferred by the bonding head 10 in alignment with the formation position of the pad 4 of the substrate 1. Come on.

The bonding head 10 is equipped with two adapters 6 corresponding to the plurality of chips 2 so that the plurality of chips 2 can be bonded and bonded together.
This adapter 6 is in direct contact with the chip and has a heater 7 for pressurizing and heating the chip 2.

As described above, since the plurality of chips 2 have different chip thicknesses due to the difference in wafer lot and multi-bender, in order to collectively bond the plurality of chips 2 to each other, it is necessary to individually bond each chip. It is necessary to recognize the chip mounting height (chip thickness). This chip thickness can be recognized by measuring the chip thickness for each of a plurality of chips mounted on the substrate in advance by a known method.

The bonding head 10 has a controller 9 and two motors 8. The controller 9 controls the moving distance of the adapter 8 to the chip 2 based on the above-mentioned measured value of the chip thickness. The motor 8 moves based on the signal from the control unit.

Therefore, by making the moving distance of the adapter 6 variable, a plurality of chips 2 can be heated and pressed together. Next, a second embodiment will be described with reference to FIG.

In the second embodiment, a plurality of chips having different chip thicknesses are mechanically allowed to collectively pressurize and heat. That is, although the description has been given assuming that the adapter 11 is bonded to the chip 2, the thickness of the adapter 11 is set in advance by the same method as in the first embodiment for each chip mounting height (chip thickness). ) Is selected based on the measured value.

Since the distance between the head 12 of the bonding head 10 and the chip 2 is fixed, for example, in FIG. 2, a thick adapter 11a is selected for a thin chip 2a and, conversely, a thick chip 2b. However, the adapter 11b having a small thickness is selected.

Also in the second embodiment, two chips 2 are used.
Since a and 2b are collectively bonded and bonded, the head 12 has an adapter 11a for the chip 2a.
Is formed, and a recess 12b for installing the adapter 11b for the chip 2b is formed.

Incidentally, since the respective parts having the same reference numerals as those in the first embodiment are the same as those in the first embodiment, detailed description thereof will be omitted.

[0026]

As described above, according to the present invention, the number of heads for pressure control is reduced, the cost of equipment is reduced, and high density mounting can be achieved.

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention.

FIG. 2 is a diagram showing a second embodiment of the present invention.

FIG. 3 is a diagram showing a chip mounting process.

[Explanation of symbols]

 1 substrate, 2 chips, 3 bumps, 4 pads, 5 reinforcing agents, 6 adapters, 7 heaters, 8 motors, 9 controllers, 10 bonding heads,

Claims (2)

[Claims] 1. A bonding head structure in which a plurality of chips (2a, 2b) are pressed and heated on a substrate (1) on which pads (4) are formed to perform bonding bonding at one time. , 2b) and a plurality of adapters (6) having heaters (7) for supplying heat to the plurality of chips (2a, 2b), and the plurality of chips (8) mounted on the substrate (1) in advance. Two
a, 2b), the chip thickness is measured for each of the plurality of chips (2) for each of the plurality of adapters (6).
Control unit (9) for variably controlling the moving distance to a, 2b)
And a motor (8) for moving each of the plurality of adapters (6) under the control of the control unit (9). 2. A bonding head structure in which a plurality of chips (2a, 2b) are pressed and heated on a substrate (1) on which a pad (4) is formed to perform bonding bonding at one time, the substrate (1) being previously prepared. Mounted on the chip (2a, 2
Based on the measured value of the chip thickness for each b), a different thickness is determined for each chip (2a, 2b), and the adapter (11a, 11a,
11b) and a head (12) having a heater (7) joined to the chip (2) and supplying heat to the chip (2).