JPH03238834A - Method and device for coating of paste - Google Patents

Abstract

PURPOSE:To achieve a uniform coating and enable a corner of a packaging semiconductor chip to be securely adhered by coating a position on a substrate where the corner of the semiconductor chip is to be adhered with a certain amount of paste and by applying the paste in dot shape in a region which is set on the inside from that position. CONSTITUTION:A certain amount of paste is applied to a position on a packaging substrate where a corner of a semiconductor chip is to be adhered and a paste is applied to a region which is set to the inner side as compared with a position on the packaging substrate where the semiconductor chip is to be adhered, thus enabling paste to be applied to a position corresponding to the corner of the semiconductor chip which is located on the outer side as compared with a normal paste coating region. Therefore, the corner of the semiconductor chip can be securely adhered and a fixed amount of paste which is not extremely excessive projects from the corner, thus obtaining a highly reliable adhesion.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a method for applying paste using a multi-nozzle to a tie bond area formed on a resin substrate for mounting semiconductor chips such as ICs and LSIs. The present invention relates to a paste application method and an apparatus therefor.

[Conventional technology] The manufacturing process of semiconductors such as ICs and LSIs includes a die bonding process in which a semiconductor chip separated from a wafer is die-bonded onto a resin substrate using a conductive paste.

Conventionally, there was a method to perform this die bonding by stamp printing, but this method is difficult to control the amount of paste applied, and sometimes the paste may not be applied in some areas.Currently, a paste application device called a dispenser is generally used. Die bonding is performed using

This paste applicator basically seals the paste in a storage container (syringe) that has a hollow part, and by applying pressure from the base end into the hollow part, conducts electricity from a nozzle installed at the tip of the storage container. The process involves discharging a paste.

By the way, conventional paste application devices have a configuration that discharges conductive paste from a single nozzle hole, but since it is difficult to apply conductive paste uniformly within a certain area with such a configuration, it has been developed in recent years. , a paste coating device equipped with a large number of pores called a multi-nozzle has been developed (see, for example, Japanese Utility Model Application Publication No. 1-174926).

In a conventional multi-nozzle, for example, assuming that the semiconductor chip to be die-bonded is formed in a rectangular shape, the nozzle holes 101 are arranged at regular intervals within the rectangular outline 102, as shown in FIG. 6(a). It was well placed. The paste P discharged from such a multi-nozzle 100 is applied within the die bond area 51 on the mounting board 50, as shown in FIG. 2(b). Then, the same figure (C
), a semiconductor chip 60 was placed on the paste P, and the semiconductor chip 60 was pressed from above and shaken vertically and horizontally so that the paste P was evenly applied to the bottom surface of the chip and bonded.

[Problem to be solved by the invention] However, when the paste is discharged according to the shape of the semiconductor chip and shaken vertically and horizontally as described above,
As shown in FIG. 6(c), the paste P gathers at the center of the ridge line of the semiconductor chip 60, and as a result, a large amount of paste P leaks out from the area, causing so-called paste fogging, which may cause dielectric breakdown. . On the other hand, the paste P does not penetrate through the corner portions, resulting in non-adhesion, which may result in poor conductivity.

Recently, users have high quality requirements for semiconductors such as ICs and LSIs, and there is a demand for high-quality semiconductors that are free from the paste, loose parts, and poor contact parts as described above. In other words, the best condition is that a certain amount of paste, which is not very large, uniformly protrudes from the entire outer edge of the die-bonded semiconductor chip.

There has always been a demand for die bonding technology like this.

The present invention has been made based on the above circumstances, and has a common purpose of manufacturing high quality semiconductor chips. The invention of claim 2 further aims to provide a paste application method that can adhere to the paste, and the invention of claim 2 further aims to provide a paste application method that can prevent paste fogging, and claims 3 and 4.
The purpose of the invention is to provide a paste application device that can smoothly carry out these methods and has a reasonable construction.
It is an object of the present invention to provide a paste coating device that can apply paste to a predetermined position on a semiconductor chip mounting substrate with high positioning accuracy.

[Means for Solving the Problem] In order to achieve the above object, the invention of claim 1 provides a paste coating method for bonding a polygonal semiconductor chip to a predetermined position on a semiconductor chip mounting board. , at a corner of the semiconductor chip at a position on the mounting board to be bonded,
A method is provided in which a certain amount of paste is applied to each of the above, and the paste is applied in a dotted manner to an area set inside an area on the mounting board to which the semiconductor chip is to be bonded, and the invention further provides The amount of paste per unit area is reduced or no paste is applied around the center of each ridge line forming a region set inside the region on the mounting substrate to which the semiconductor chip is to be bonded.

The invention according to claim 3 provides a paste application device for applying paste using a multi-nozzle in order to adhere a polygonal semiconductor chip to a predetermined position on a semiconductor chip mounting board, wherein the multi-nozzle is configured to apply a paste to the semiconductor chip. and a plurality of nozzle holes are provided at a portion corresponding to an area within an arbitrary dimension from the outer edge of the bonding surface of the semiconductor chip, and a plurality of nozzle holes are provided at positions corresponding to corners of the semiconductor chip, In the invention, the multi-nozzle has a nozzle hole at a position corresponding to a corner of the semiconductor chip, and a portion corresponding to an area within an arbitrary dimension from an outer edge of the bonding surface of the semiconductor chip,
In addition, a plurality of nozzle holes are provided in a portion other than the center portion of each ridgeline forming the portion.

Further, the invention of claim 5 provides a multi-nozzle having a plurality of nozzle holes, a cylindrical syringe which encloses paste and whose tip portion is detachably connected to the multi-nozzle, and which corresponds to the external shape of the syringe. The syringe holding member has a syringe holding portion having an inner surface shape, and a holding member having a fixing portion for the multi-nozzle at the distal end thereof.

[Function] In the paste application method of claim 1, the paste is also applied to positions corresponding to the corners of the semiconductor chip, which are outside the normal paste application area, so that the corners of the semiconductor chip can also be bonded securely. Moreover, a certain amount of paste, not too much, protrudes from the corners, resulting in a highly reliable bond.

Furthermore, in the paste application method of claim 2, in addition to the effect of claim 1, the amount of paste applied to the periphery of the center of each ridgeline at the outer edge of the bonded portion of the semiconductor chip is smaller than that to other parts. Even if the semiconductor chip is shaken vertically and horizontally after coating to make the coating amount uniform, the amount of paste protruding from around the center of the ridge line is maintained at an appropriate amount.

In addition, in the paste application apparatus of claim 3, an appropriate amount of paste is discharged from the nozzle hole provided in the multi-nozzle at a position corresponding to the corner of the semiconductor chip to the corner adhesive part of the semiconductor chip on the mounting board, thereby Adhere each part of the chip securely.

Furthermore, in addition to the effect of the third aspect, the paste application device according to the fourth aspect does not discharge paste around the central part of each ridge line forming the outer edge of the paste area on the mounting board,
As a result, the amount of paste applied around the center of each ridge line at the outer edge of the bonded area of the semiconductor chip is adjusted so that it is smaller than other parts, and as a result, after application, the semiconductor chip is shaken vertically and horizontally to ensure an even amount of paste applied. Even when this is achieved, the amount of paste protruding from the periphery of the center of each ridgeline at the outer edge of the vi-arrival area is kept at an appropriate amount.

In the paste application 2V device of claim q45, the syringe is positioned and fixed in surface contact with the inner surface of the syringe holding part formed on the holding member, so there is no stiffness, and the multi-nozzle is also fixed on the holding member. The mounting positions of the syringe and multi-nozzle are determined based on the holding member, and as a result, high positioning accuracy can be achieved.

[Embodiment 1] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First, 1 [Z(a), FIG. 2, and FIG. 3(a),
An embodiment of the invention of the first paste application device will be described with reference to (b). Here, FIG. 1(a) is a bottom view showing the multi-nozzle of the same device.

Figure 2 is a front view of the device, Figure 3 (a) is an exploded front sectional view of the multi-nozzle of the device, and Figure 3 (b) is a front view of the connected state of the multi-nozzle and syringe. FIG.

As shown in FIG. 2, the paste coating device of this embodiment has the following features:
The device includes a main body 10, a syringe 20, and a multi-nozzle 30. The syringe 20 is formed into a cylindrical shape, and is fixedly attached to the device main body 10 with a paste enclosed in a hollow part.

Therefore, the device body 10 is provided with screws 11.12 facing each other for fixing the syringe at two locations, one at the center of the side surface and the other at the lower end. , the syringe 20 is fixed by tightening the screws 11 and 12.

Note that the syringe 20 fixed in this way has a base end 20
A pressure regulating pipe 21 is connected to the side a, and when applying the paste, a constant pressure is applied to the hollow part from a pressure regulating device (not shown), the paste is discharged under this pressure, and after discharging a fixed amount, the liquid is immediately subjected to suction Prevent sagging. Therefore, in the normal state, it is in a state where it receives an attractive force.

As shown in FIG. 3(a), the multi-nozzle 30 is constructed by screwing a nozzle hole forming member 32 onto a nozzle main body 31, and has a large number of nozzle holes 33 on the bottom surface. This multi-nozzle 30 is attached by screwing the proximal end 34 to the threaded part 22 provided at the distal end 20b (which has a small diameter) of the syringe 20, as shown in FIG. It communicates with the hollow part 21 of.

Incidentally, the shape of the semiconductor to be die-bonded may be any polygonal shape, but in this example, a semiconductor chip having a rectangular bonding surface is die-bonded. In this case, the nozzle holes 33 of the multi-nozzle 30 are arranged as follows (see FIG. 1(a)).

That is, a rectangular region 30a corresponding to the bonding surface of the semiconductor chip is set on the bottom surface of the multi-nozzle 30, and a nozzle hole 33a is provided at each corner of the region. Further, a portion 30b corresponding to an area within an arbitrary dimension (for example, a dimension slightly longer than the outer diameter of the nozzle hole) is set by the outer edge of the bonding surface of the semiconductor chip, and a large number of nozzle holes 33b are arranged in that portion. It is. These nozzle holes 33b
are arranged at regular intervals vertically and horizontally, except at least those located at the outermost edge. Then, at least at the outermost edge, the nozzle hole 33 except for the central part 30c of each ridgeline
b is arranged.

In this embodiment, all the nozzle holes 33 are formed to have the same diameter, and the diameter is small enough to prevent paste from leaking, for example, 0.29 mm to 0.6 mm.
φ, preferably set to about 0.5 mm.

FIG. 4 is a partially sectional front view showing an embodiment of the second paste application device according to the invention.

The paste application device of this embodiment has a holding member 40 fixed to the device main body 10, and the holding member 40 holds the syringe 2.
0 and the multi-nozzle 30 are held.

The holding member 40 has a hollow part (syringe holding part) 41 having a shape corresponding to the syringe 20, and this syringe holding part 4
Hold the syringe 2o inside the syringe 1.

That is, the syringe holding part 41 holds the syringe 20 with its entire inner surface without wobbling.

In the case of the paste application device shown in Fig. 2, the syringe 20
Because it has a structure in which the two places are fixed with screws 11 and 12,
There is a risk that the screws may loosen and become stiff during work.
Further, each time the syringe 20 is attached or detached, the attachment requires position adjustment, which is complicated, and the repeatability is poor.

The device of this embodiment eliminates these drawbacks, and as long as the syringe 20 is housed in the syringe holding portion 41, it can always be attached to the same position, and there is no fear of rattling during operation. Further, the multi-nozzle 30 is fixed to the tip of the holding member 40 using a screw 42.

in this way.

Since the syringe 20 and multi-nozzle 30 are attached to the holding member 40, the positioning of each member is based on one standard (
It is only necessary to perform the positioning on the holding member 40), so that the positioning between each member can be easily and highly accurately performed. The multi-nozzle 3o and the syringe 20 are connected to each other by screwing together the threaded portion 22 formed at the tip of the syringe 20 and the proximal end 34 of the multi-nozzle 30, as in the previous embodiment (see Fig. 3(b)). )>.The holding member 4o may be integrally formed with the main body 1O of the device, but in order to be replaceable depending on the type of syringe 2o, it is preferably attached removably using a fixing member such as a screw. Next, we will explain the first embodiment of the paste application method of the present invention.
This will be explained based on FIGS. (a) to (c).

FIG. 1(b) is a plan view showing a state in which a paste is applied to a substrate for mounting a semiconductor chip, and FIG. 1(c) is a plan view showing a state in which a semiconductor chip is adhered to the same substrate.

The paste coating method of this embodiment is carried out using the above-mentioned paste coating device. That is, paste is sealed in the syringe 20 of the paste application device shown in FIG. 2 or 4, and the paste is attached to the device main body 10 or the holding member 40. Below the multi-nozzle 30 is a semiconductor chip mounting board 5.
Place 0.

Here, as the paste, for example, a known thermosetting silver paste made by mixing silver particles into an epoxy adhesive is used. Moreover, as the semiconductor chip mounting board 50,
A resin substrate having a wiring pattern and a lead frame, a counterbore in the center, and a die bonding area 51 formed by the counterbore is used. The die bond area 51 has an area somewhat larger than the semiconductor chip to be bonded. Then, within this die bond area 51, there is a region (semiconductor area) where a semiconductor chip is bonded.
52, and a region (paste area) 53 which is an arbitrary dimension inside the semiconductor area 52.

The multi-nozzle 30 is lowered together with the device main body 10 to bring the tip of the nozzle hole 33 into contact with the inside of the die bond area 51 of the semiconductor chip mounting substrate 50, and at the same time, the nozzle hole 3
Dispense the paste from step 3. Then, as shown in FIG. 1(b), paste P is formed in the die bond area 51.
or coated. Among the applied pastes P, the paste P8 located at the corner is applied on the corner of the semiconductor area 52, and the other paste P2 is placed on the outer edge of the paste area 53 and inside thereof in a fixed manner. Arranged by interval. However, the paste is not applied to the vicinity of the center 53a of the ridgeline forming the paste area 53.

Next, the semiconductor chip 60 is placed on the semiconductor area 52 of the semiconductor chip mounting substrate 50 coated with the paste P as described above, and is shaken vertically and horizontally while applying a certain pressing force, so that the entire lower surface of the semiconductor chip 60 is Make sure that the paste P is applied evenly. With this operation, the paste P leaks out from the outer edge of the semiconductor chip 60, but the paste P leaks out from the outer edge of the semiconductor chip 60, but the paste P leaks out from the center part 5 of the ridge line forming the paste area
Since paste is not applied to 3a (FIG. 1(b)), a large amount of paste will not collect in the same area even after shaking, and therefore there is no worry about paste fogging in the same area. On the other hand, since the paste PL is applied to the corners of the semiconductor chip 6o, there is no need to worry about the amount of paste being insufficient in those areas, and a certain amount of paste leaks out from the corners, which is suitable for maintaining reliability. A mounting state is realized (FIG. 1(c)).

It should be noted that the present invention is not limited to the embodiments described above, and various modifications and applications including the following modifications are possible.

■ A paste application method in which the paste area is set to a polygonal shape that is different from the shape of the bonding surface of the semiconductor chip, and the paste is arranged in that area. For example, the paste coating device 0 has nozzle holes arranged in areas set in different polygonal shapes.

As shown in FIG. 5(a), at least the nozzle holes 33d located at the outermost edge may be arranged so as to curve inward from the center. In this case, the nozzle hole 33e may be provided near the center of the outermost ridgeline, as shown in FIG. 2(b).

■Paste application device with different spacing between nozzle holes depending on location.

■Paste application device with different diameters depending on the position of the nozzle hole.

For example, as shown in FIG. 1W45(c), the nozzle hole 33a at the position corresponding to the corner of the semiconductor chip and the nozzle hole 33f around it may have a larger diameter than the other nozzle holes 33b. If the diameter difference is too large, the paste will be ejected only from the large-diameter nozzle holes and will not be able to be ejected from the small-diameter nozzle holes, so the diameter difference should be set to such an extent that such a phenomenon will not occur.

■A paste application method in which the amount of paste applied per unit area around the center of each ridgeline forming the paste area is smaller than that applied to other parts of the paste area.

That is, in the above example, the paste was not applied to the same part, but the effect of the present invention can also be obtained by reducing the amount of paste applied per unit area. In the paste coating Ia device used for this purpose, the diameter of the nozzle hole located at the outermost edge is smaller than that of the other nozzle hole.

[Effects of the Invention] As explained above, according to the paste application method of the present invention (claim 1), the corners of the semiconductor chip can be reliably bonded, so that high-quality semiconductor chips can be molded. .

In addition, if the paste is not applied around the central part of the ridgeline that forms the area on the semiconductor chip mounting board where the paste is to be applied (claim 2), it is possible to prevent paste fogging in the peripheral area and increase the layer height. It is possible to manufacture high quality semiconductor chips.

Furthermore, according to the paste coating apparatus of the present invention (claim 3.4), the paste coating method described above can be carried out smoothly and in a manner that is impossible due to the construction.

Furthermore, according to the invention of the paste coating apparatus of claim 5, the paste can be applied to a predetermined position on the semiconductor chip mounting substrate with high positioning accuracy, so that high quality semiconductor chips can be manufactured.

[Brief explanation of drawings]

Figure 1 (a) is a bottom view showing the multi-nozzle of the paste coating device, Figure 1 (b) is a top view showing the state of paste application on a semiconductor chip mounting board, and Figure 1 (c) is a bottom view showing the multi-nozzle of the paste coating device. A plan view showing the chip adhesion state, Figure 2 is a front view of the paste application device, Figure 3 (a) is an exploded front sectional view of the multi-nozzle, and Figure (b) is the connection between the multi-nozzle and the syringe. Front sectional view showing the condition! Figure s4 is a partially sectional front view showing another embodiment of the paste coating device, Figures 5 (a) to (C) are bottom views showing modified examples of the nozzle hole, and Figure 6
Figures (a) to (c) are diagrams for explaining conventional examples. 10: Device main body 20: Syringe 30: Multi-nozzle 33: Nozzle hole 40: Holding member 41, syringe holding part

Claims (5)

[Claims] (1) In a paste application method for adhering a polygonal semiconductor chip to a predetermined position on a semiconductor chip mounting board, a certain amount of paste is applied to each position on the mounting board where the corners of the semiconductor chip are to be bonded. A paste application method, comprising: applying the paste, and applying the paste in dots to an area set inside an area on the mounting board to which the semiconductor chip is to be bonded. (2) In the paste application method according to claim 1, the area around the center of each ridgeline forming an area set inside the area on the mounting board to which the semiconductor chip is to be bonded has a paste amount per unit area. Paste application method characterized by applying less or no paste. (3) In a paste coating device that uses multi-nozzles to apply paste in order to bond a polygonal semiconductor chip to a predetermined position on a semiconductor chip mounting board, the multi-nozzles correspond to corners of the semiconductor chip. 1. A paste coating device, comprising: a plurality of nozzle holes at respective positions, and a plurality of nozzle holes at portions corresponding to regions inside by an arbitrary dimension from the outer edge of the bonding surface of the semiconductor chip. (4) In a paste coating device that uses multi-nozzles to apply paste in order to bond a polygonal semiconductor chip to a predetermined position on a semiconductor chip mounting board, the multi-nozzles correspond to corners of the semiconductor chip. a plurality of nozzle holes at respective positions, and a plurality of nozzle holes in a portion corresponding to a region inside the adhesive surface of the semiconductor chip by an arbitrary dimension, excluding the center portion of each ridge line forming the said portion. A paste application device characterized by being equipped with a nozzle hole. (5) A paste application device for adhering a semiconductor chip to a predetermined position on a semiconductor chip mounting board, which includes a multi-nozzle having a plurality of nozzle holes, and a tip part that seals in paste and is detachable from the multi-nozzle. A paste application device comprising: a connected cylindrical syringe; and a holding member having a syringe holding part with an inner surface shape corresponding to the external shape of the syringe and having a fixing part for the multi-nozzle at its tip end. .