JPH07326643A - Bonding head structure - Google Patents

Abstract

PURPOSE:To prevent adhesive agent used for reinforcing a semiconductor chip from flowing out and protruding, regarding bonding head structure for sucking, pressing, heating, and bonding a semiconductor chip when it is mounted on pads formed on a board. CONSTITUTION:In bonding head structure wherein a semiconductor chip 2 is sucked, pressed, heated, and bonded to a board 1 on which pads 7 are formed, refrigerant channels 4b, 4c for cooling reinforcing agent 10 which is used for the purpose of reinforcement when the semiconductor chip 2 is bonded to the board 1 are layed in the bonding head.

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 semiconductor chip is mounted on a pad formed on a substrate, the semiconductor chip is pressed while being pressed,
The present invention relates to a bonding head structure for heating and bonding and bonding.

In recent years, bare chip mounting technology has been developed along with miniaturization and high density of electronic devices. In this bare chip mounting, a semiconductor chip is not mounted on a substrate in a package, but the semiconductor chip is directly mounted on the substrate. In addition, there are two types of bare chip mounting, a flip chip type that uses bumps to join the substrate and the semiconductor chip, and a one-way bonding type that uses wires to join the substrate and the semiconductor chip. It is appropriately selected and adopted according to 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, a predetermined number of stud bumps (hereinafter referred to as bumps) 32 are formed on the pads of the semiconductor chip 30 using wires (for example, aluminum, copper, gold, etc.) by the wire bonding mounting technique using the capillaries 31.

Since the height of each bump 32 has a variation of about 20 μm, the bumps 32 of the semiconductor chip 30 are different.
Are pressed against the glass flat plate 33 to perform leveling so that the bumps 32 have the same height.

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, a thermosetting insulating adhesive 36 for reinforcement is applied by screen printing on a substrate 38 on which mounting pads 37 are formed corresponding to the number of bumps 32 of the semiconductor chip 30 to be mounted. To be done. The semiconductor chip 30 attracted 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 semiconductor chip 30 are aligned, and the semiconductor chip 30 is pressurized and heated by the bonding head.
The flip chip bonding and the mounting are simultaneously performed on the substrate 38. 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.

A conventional example of this bonding head will be described with reference to FIG. The bonding head has a vacuum path 47 for sucking the semiconductor chip 41 and a vacuum path 46 for sucking the adapter 42 that covers the size difference between the bonding head and the semiconductor chip 41. Further, the bonding head is provided with a heater 44, and the heater 44 is for curing a thermosetting insulating adhesive 48 which serves as a reinforcement when the semiconductor chip 41 is bonded to the substrate 40. .

When the insulative adhesive 48 is cured, the fluidity of the adhesive increases, and the adhesive does not flow smoothly. Since the fluidity of the adhesive decreases when cooled, the nozzle 45 blows cold air from the outside of the bonding head to directly cool the adhesive to prevent its flow.

[0011]

However, if the insulative adhesive is directly cooled by the nozzle for blowing cold air, the adhesive may stick out as shown in FIG. 3 and may be scattered on the board pad of the adjacent component. .

Therefore, it is an object of the present invention to prevent the adhesive used for reinforcing the semiconductor chip from flowing out due to the outflow.

[0013]

The above-described object is to provide a bonding head structure in which a semiconductor chip 2 is adsorbed onto a substrate 1 on which a pad 7 is formed while being pressed and heated to bond the semiconductor chip 2 to the substrate 1. A substrate having a bonding head structure characterized in that coolant flow paths 4b and 4c for cooling a reinforcing agent 10 used for reinforcement when joining two are embedded in the bonding head, or a pad 7 is formed. Reinforcing agent 1 used for reinforcing when bonding the semiconductor chip 2 to the substrate 1 in a bonding head structure for bonding and bonding the semiconductor chip 2 to the substrate 1 while applying pressure and heat.
This is achieved by a bonding head structure characterized in that a protective wall 8c for preventing zero flow is provided on the bonding head.

[0014]

That is, according to the first aspect, the adhesive is not directly cooled by the cold air, but can be cooled by the indirect cold air by forming the cooling medium flow path in the bonding head. Runoff can be prevented.

According to the second aspect of the invention, the protective wall provided on the bonding head mechanically protects the adhesive from flowing out, so that the adhesive does not flow out to the adjacent parts.

[0016]

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, a first embodiment of the present invention will be described with reference to FIG. When the semiconductor chip 2 is bonded to the substrate 1 on the surface of which the pad 6 and the reinforcing agent 10 which is a conductive adhesive are applied, the semiconductor chip 2 is adsorbed by the bonding head 4 via the head adapter 3.

In particular, the head adapter 3 is for covering the bonding head 4 and the semiconductor chip 2 when they are different in size, and is appropriately selected and used according to the size of the semiconductor chip 2. , In addition,
The head adapter 3 is vacuum-sucked by a suction vacuum path 4a formed in the bonding head 4.

Further, the bonding head 4 is also formed with a vacuum path 4d for vacuum-sucking the semiconductor chip 2 in the same manner, whereby the semiconductor chip 2 is sucked to the bonding head 4 and predetermined on the substrate 1. It is transferred to the position. The head adapter 3 has a hole 3a for attracting the semiconductor chip 2.

Bonding with a heater 5 in a state where the semiconductor chip 2 is aligned at a predetermined position on the substrate 1, that is, a position where the bumps 6 of the semiconductor chip 2 are in contact with the pads 7 formed on the substrate 1. The head 4 pressurizes and heats so as to perform the frit chip bonding.

By heating with this bonding head 4, the reinforcing agent 10 which is the above-mentioned thermosetting conductive adhesive is cured. However, it is necessary to cool the flow of the reinforcing agent 10 whose fluidity is increased by the heat when the reinforcing agent 10 is heated and hardened. In this embodiment, this cooling is performed in advance in the cooling medium passage 4b in which cold air flows through the bonding head 4. 4c is embedded and formed, and indirect cooling is performed by the coolant channels 4b and 4c via the bonding head 4 and the head adapter 3.

As a result, since the reinforcing agent 10 can be cooled, the reinforcing agent 10 can be prevented from flowing out. Next, a second embodiment of the present invention will be described with reference to FIG.

In both the conventional example and the first embodiment, the reinforcement agent is cooled in order to prevent it from flowing out, but in the second embodiment, the reinforcement agent is mechanically prevented from flowing out. It is a thing.

In other words, the bonding head 8 for attracting the head adapter 3 is provided with a protective wall 8c extending toward the surface of the substrate 1 outside the head adapter 3. The protective wall 8c prevents the reinforcing agent 10 which is a thermosetting conductive adhesive from flowing out.
Since the protective wall 8c is in contact with the substrate 1, it is desirable to form the elastic body 9 on the tip 8d of the protective wall 8c in consideration of damage to the substrate 1.

A vacuum path 8a formed in the bonding head 8 is for vacuum-sucking the semiconductor chip 2, and a reference numeral 8b is for vacuum-sucking the head adapter 3. The hole 3a formed in the head adapter 3 is for vacuum-sucking the semiconductor chip 2 to the bonding head 4.

[0026]

As described above, according to the present invention, it is possible to prevent the reinforcing agent from flowing out after the semiconductor chip is mounted, so that the cleaning step immediately after mounting the semiconductor chip can be eliminated.

[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 semiconductor chip mounting process.

FIG. 4 is a diagram showing a conventional example.

[Explanation of symbols]

 1 substrate, 2 semiconductor chips, 3 head adapters, 4, 8 bonding heads, 4b, 4c coolant passage, 5 heaters, 6 bumps, 7 pads, 8c protective wall, 9 elastic body, 10 stiffener,

Claims (3)

[Claims] 1. A bonding head structure for bonding and bonding a semiconductor chip (2) to a substrate (1) on which a pad (7) is formed while adsorbing the semiconductor chip (2) by pressing and heating the semiconductor chip (2). A bonding head structure characterized in that a coolant flow path (4b, 4c) for cooling a reinforcing agent (10) used for reinforcement when joining (2) is embedded in the bonding head. 2. A bonding head structure for bonding and bonding a semiconductor chip (2) to a substrate (1) on which a pad (7) is formed by adsorbing and pressing the semiconductor chip (2), wherein the semiconductor chip is attached to the substrate (1). A bonding head structure characterized in that a protective wall (8c) for preventing the flow of a reinforcing agent (10) used for reinforcement when joining (2) is provided on the bonding head. 3. The bonding head structure according to claim 2, wherein an elastic body (9) is formed at a tip (8d) of the protective wall (8c).