JPH02239636A - Diebonding device - Google Patents

Abstract

PURPOSE:To prevent development of bubbles in a bonding section by providing a rotating mechanism to rotate a die collet which sucks and holds a die and by die-bonding the die after adhesive is uniformly applied to a rear side of the die. CONSTITUTION:A die collet 1 lowers and attracts a die 3 on a die tray 4 in vacuum. The die collet 1 with the die sucked rotates by 180 deg. upward around a rotating axle 2, and brings the die 3 into contact with a surface of a screen mask 5 of a screen printer. Then, successively, adhesive 6 on the mask 5 is stenciled to a rear side of the die 3 with a squeegee 7. The die collet 1 rotates by 180 deg. downward around the rotating axle 2 to set the die 3 onto a die junction surface of a package 8, then, the die collet 1 is depressed by applying a load a little thereto, and the die 3 is bonded to a die bonding section of the package 8 for die bonding. The package 8 is heated in an oven, and the adhesive 6 which bonds the die 3 to the package 8 is hardened to finish a diebonding process. Thereby, an appropriate and uniform film thickness of adhesive without bubbles can be secured.

Description

[Detailed Description of the Invention] [Summary] The present invention is applicable to the assembly of semiconductor devices. Regarding the die bonding equipment used to fix semiconductor devices to packages with adhesive, it is possible to ensure uniform and appropriate film thickness without leaving bubbles even for large semiconductor devices, and it is compatible with the diversification of pan cages. The purpose of the present invention is to provide a die bonding apparatus that includes an element feeding part that supplies a semiconductor element, an element suction part that sucks and holds a semiconductor element placed on the element feeding part, and mounts the semiconductor element on the element mounting part. a holding part; a rotation mechanism for rotating the element suction holding part so that the back side of the semiconductor element held in the element suction holding part faces upward; and a back surface of the semiconductor element held so that the back side faces upward; The die bonding apparatus is configured by a die bonding apparatus characterized in that it has an adhesive application section for applying an adhesive to the die bonding apparatus.

[Industrial application field]

The present invention relates to a die bonding apparatus used for fixing a semiconductor element (die) to a package with an adhesive in the assembly of a semiconductor device.

In recent years, there has been a remarkable increase in the size of die bonding devices and the diversification of the packages they are mounted on. For large dies, it is important to ensure that no air bubbles remain, to ensure a uniform and appropriate adhesive film thickness, and to develop die bonding equipment that can accommodate the diversification of packages. Development is strongly required.

In die bonding using adhesives, the reliability is closely related to the adhesive film thickness, and it is important to control the film thickness within an appropriate range, and also to prevent air bubbles from remaining at the bottom of the die. It is necessary to

[Conventional technology]

FIG. 3 shows a general conventional example of die bonding.

In the figure, l8 is the package, 19 is the adhesive, 2
0 is die.

Conventionally, in the method of die bonding using a conductive adhesive, as shown in FIG. 3(a), after applying the adhesive 19 to the die bonding part of the package 18, as shown in FIG. 3(b), , the die 20 is placed on the adhesive l9, and an appropriate load is applied to the die 20 and scraped so that the adhesive l9 spreads uniformly over the back surface of the die 20, and the die 20 is bonded to the package l8.

Next, in order to harden the adhesive l9, the package l8 is baked in an oven, and the die 20 is fixed.

In this type of die bonding equipment, the adhesive application method is important. Conventional methods include dispensing, screen printing, and damping, but in all cases adhesive is applied to the package. On the other hand, in die bonding using 8 adhesives, the reliability is closely related to the adhesive film thickness. It is important to control the film thickness within an appropriate range, and in addition, it must be ensured that no air bubbles remain at the bottom of the die.

However, in recent years, die sizes have become larger and the packages they are mounted on have become more diverse. There is a strong demand for the development of die bonding equipment that can ensure a uniform and appropriate adhesive film thickness without leaving any air bubbles, and that can accommodate the diversification of packages.

[Problem to be solved by the invention]

Therefore, as a method for applying conductive adhesive. With the conventional dispenser method. As shown in Figure 4, in the case of single-point dispensing, the adhesive does not spread uniformly at the bottom of the die with a large goo, and in the case of multi-point dispensing, as shown in Figure 5, the adhesive does not spread evenly at the bottom of the die. Since there is always a gap between the dispensing point and the next dispense point, the problem arises that air bubbles remain at the bottom of the die. Furthermore, in the stamping method. Only a thin film thickness of about 10 μm can be applied. This causes the problem that the adhesive dries during the work.

As a countermeasure for this. No air bubbles remain. One possibility is to apply the adhesive by screen printing, which can ensure a uniform and appropriate film thickness, as shown in Figure 6. Generally, in a package 22 having a cavity 2l, the wall of the cavity 21 where the sticky adhesive part 23 is located becomes an obstacle, and screen printing
This method could not be used because the adhesive 25 could not be applied to the goo adhesive portion 23 through the screen mask 24 with a squeegee 26. The present invention is. The purpose of this invention is to provide a die bonding device that can ensure a uniform and appropriate film thickness without leaving any bubbles even for large dies in die bonding using adhesives, and that is compatible with the diversification of packages.

[Means to solve the problem] FIG. 1 is a diagram explaining the principle of the present invention.

In the figure, l is an element adsorption holding part (guicolet). 2
is the rotating shaft, 3 is the guide, 4 is the die tray 5 is the screen mask, and 6 is the adhesive. 7 is a squeegee. 8 is a package.

The guicolet 1 is connected to a rotating mechanism that rotates around a rotating shaft 2, rotates 180 degrees vertically around the rotating shaft 2, and rotates the die tray 1 supplied to the element feeding section.
Adsorption of the upper die 3, set on the screen printing machine as an adhesive application part, package 8 set in the element mounting part
Adhesion of die 3 to the parts is carried out one after another.

First, as shown in Figure 1(a), the dicolent l falls downward. The die 3 on the die tray 4 is vacuum-adsorbed.

Next, as shown in Figure 1(b). Daicollet I is
While holding the die 3, rotate it 180 degrees around the rotating shaft 2.
The die 3 is then rotated upward to bring the die 3 into contact with the surface of the screen mask 5 of the screen printing machine.

Next, apply the adhesive 6 on the screen mask 5 with a squeegee 7.
Then, print on the back of die 3.

next. As shown in Fig. 1(C), Guicolette l is .
The die 3 is set on the die bonding surface of the package 8 by rotating 180 degrees downward about the rotation axis 2.

Next, as shown in Figure 1(d), a light load was applied to Guicoret 1. Press down and glue die 3 to the die attachment part of package 8. Die bonding. After this. The package 8 is heated in an oven to harden the adhesive 6 bonding the die 3 and the package 8.

[Function] In the present invention, a rotation mechanism is provided to rotate the die collet that holds the die by suction, and the die can be bonded after the adhesive is evenly applied to the back surface of the die, thereby preventing air bubbles from forming in the bonded area. Can be done.

Therefore, according to the present invention: (1). Using a screen printing method or the like, it is possible to apply a flat adhesive with a constant thickness to the entire back surface of the die.

(2). Since adhesive is applied to the back of the die, die bonding can be performed by simply pressing the die into any shape of package.

etc. The problems of the prior art are solved.

〔Example〕

FIG. 2 is an explanatory diagram of an apparatus according to an embodiment of the present invention.

In the figure, 1 is Guicolette, 2 is the rotating shaft, 3 is the die, 4 is the die tray, 5 is the screen mask, 6 is the adhesive, 7 is the squeegee, 8 is the package, 9 is the feed table of the element feeding section, 10 is the rotary feed Mechanism feeding table, 11
is the feed axis. 12 is a feed table vertical mechanism, 13 is a feed shaft, 14 is a screen printing mechanism, 15 is a vertical mechanism of the screen printing mechanism, 16 is a feed table of the element feeding section,
17 is a device stand.

First, the configuration of an embodiment of the die bonding apparatus of the present invention will be described.

The equipment is provided by the elementary supply department. Element suction holding section, rotational feeding mechanism. It consists of five mechanisms: an adhesive application section and an element mounting section.

The names of the mechanisms that make up the device are shown in Figure 2.
Display within. In addition, Guikorent 1, rotation axis 2. The movement of the screen printing mechanism 14 and the feed table IO is the second
It is shown by a dashed line in the figure.

■The element feeding section consists of a die feeding table 9 and a die tray 4. It has a mechanism in which a die feeding table 9 is automatically moved in the X and Y directions on a horizontal plane, and a die 3 to be die bonded in a die tray 4 set on the feeding table 9 is fed directly below the guicollet 1. The die tray 4 generally accommodates several dozen dies 3, although it depends on the size of the dies 3.

■The element suction holding part is usually called a die collet 1, and has a square mouth slightly larger than the die 3, and it vacuum-adsorbs the die 3 in the die tray 4, and applies the adhesive 6 as it is. Up to adhesion of die 3 to package 8. Holds by adsorption.

■The rotary feed mechanism is a rotating mechanism that rotates up and down by 180 degrees around the rotating shaft 2 connected to the Guicolette 1.
It has a feed shaft 11 in the X-axis direction that moves the Guicolet 1 laterally from the rotating shaft 2. Also, the feeding table 10
The entire table itself can be moved up and down by a feed table up and down mechanism 12.

■The adhesive application section is a screen printing mechanism 14 consisting of a squeegee 7 and a screen mask 5 for applying adhesive 6 onto the die 3. The squeegee 7 is moved back and forth by a feed shaft l3 of the screen printing mechanism 14, and the screen printing mechanism 14 itself is moved by a screen printing mechanism up and down mechanism 15. Move up and down. (2) The element mounting section is composed of a feeding table l6 mechanism that supplies and removes the package 8, and a package holder l5 that fixes the package.

Next, let's talk about the die bonding method using the device of the present invention. The steps will be explained in order with reference to FIG. The order of the steps is indicated by a number at the position of guicolet l in Figure 2. ■Feed the die 3 to be die bonded in the die tray 4 directly below the Guicolet 1 by operating the feed table 9, and lower the Guicolette 1. Hold die 3 under vacuum. ■Guicolet 1 holds the die 3 by suction, and rotates around the rotating shaft 2. Rotate 180 degrees up to top dead center.

At this time, it is necessary that the back surface of the die 3 is horizontal.

(2) Next, lower the screen printing mechanism 14 and gently bring the screen mask 5 into close contact with the back surface of the die 3. By moving the squeegee 7, the adhesive 6 made of conductive epoxy silver paste placed in front of the squeegee 7 can be applied to the back surface of the die 3 to a thickness of 30 μm through the screen mask 5.

■Next, move the screen printing mechanism 14 upward to remove the screen mask 5 from the back side of the die 3, and leave the Guicolette l holding the die 3 and lifting it upward.
The feed table IO is moved by the feed shaft 11 to above the element mounting section.

■Guicolet l rotates 180 degrees downwards around rotation axis 2 and lowers to the lowest point.

- Operate the feed table up/down mechanism 12 to lower the goo collet 1, place the die 3 on the package 8 on the package holder l5, and then apply a load to adhere the die 3 to the goo adhesive part of the package 8. Die bonding.

continue. The package 8 is baked in an oven at 3150° C. for 2 hours to harden the adhesive 6 and complete the die bonding process.

In the above example. The element feeding section, the element mounting section, the vertical mechanism of the screen printing mechanism, and the vertical mechanism of the feed table are all fixed to the apparatus stand 17. Although the Guicoret l of the element suction holding part moves up and down, the element feeding part and the element mounting part may also move up and down. Regarding the movement of the guicolet l in the X direction, the element feeding section and the element mounting section may also be moved.

〔Effect of the invention〕

As explained above, according to the present invention, no air bubbles remain even for large dies in die bonding using adhesive. Enables ensuring an appropriate and uniform adhesive film thickness,
Furthermore, it is possible to provide a die bonding apparatus that is compatible with the diversification of packages.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the principle of the present invention, Fig. 2 is an explanatory diagram of an apparatus according to an embodiment of the present invention, Figs. 3 to 5 are explanatory diagrams of a conventional example, and Fig. 6 is an example of application to screen printing. be. In the figure, l is Gui Colette, 2 is the rotation axis, 3 is Gui,
4 is a die tray 5 is a screen mask, 6
is the adhesive, 7 is the squeegee, and 8 is the package. 9 is a feed table, 10 is a feed table, and 11 is a feed axis. 12 is a feed table up/down mechanism, l3 is a feed shaft, l4 is a screen printing mechanism, and l5 is a package holder. 16 is the feeding table, 47 is the equipment stand (CL) Zukaimei/) Kakuzu Setsu Sail Zu Da I 2 Seishinkyo no Sekishu Mi (!f) 1: Issetkenj) Note (2 of 2: -J, i-year-old class O, 4-
Kisakiraike 1/') Shukurozu (!n3: Rejection f8 Dispens θ 嘱合 p7 5 Figure

Claims (1)

[Claims] An element supply section that supplies a semiconductor element (3). an element suction holding part (1) that suction-holds a semiconductor element (3) to be placed on the element feeding part and mounts the semiconductor element (3) on the element mounting part; The semiconductor element to be held (3)
Place the element suction holding part (1) so that the back side faces upward.
and a semiconductor element (3) held with its back surface facing upward.
) and an adhesive application section for applying an adhesive (6) to the back surface of the die bonding device.