JPH0471243A - Die bonding equipment for semiconductor device - Google Patents

Abstract

PURPOSE:To uniformly and quickly spread adhesive agent on semiconductor pellets different in size, by setting the area of contact surface with the rear of a semiconductor pellet so as to be larger than the semiconductor pellet, in an adhesive agent coater. CONSTITUTION:The surface 8a of an impregnation body 8 of an adhesive agent coater 3 is formed in a spherical shape having a constant curvature. An adhesive agent transfer layer 9 for uniformly forming an adhesive agent layer 10 is installed on the surface 8a. A semiconductor pellet 1 which has been conveyed above the adhesive agent transfer layer 9 is vertically conveyed downward, in order that adhesive agent may be transferred on the rear 1a of the pellet 1, and the adhesive agent is transferred. When the area of the semiconductor pellet 1 is comparatively large, the pellet is vertically moved downward with a constant loard, until the adhesive agent is transferred on the whole rear of the pellet. Then the adhesive agent transfer layer 9 composed of flexible material is deformed by the load at the time of descending of the pellet. That is, the adhesive agent on the transfer part can uniformly come into contact with the rear of the semiconductor pellet, and very uniform transfer can be realized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a die bonding device used in the manufacturing process of semiconductor devices, and particularly to the structure of a supply device for a die bonding adhesive.

[Prior art] Conventionally, in die bonding equipment used in the manufacturing process of semiconductor devices, adhesive is supplied in advance to the semiconductor pellet mounting area (island) of the lead frame, and then the semiconductor pellet is placed on top of the island. The mainstream method is to apply a constant load and bond. According to this method, the die bonding device uses a certain pressure such as air pressure to force the die bonding adhesive in the syringe from one or more nozzles at the tip of the syringe to the island of the lead frame. It has a dispensing device for supplying adhesive. In addition, the die has a stamp transfer device that applies a die bonding adhesive that maintains a uniform surface condition to a stamp rubber with approximately the same area as the semiconductor pellet, and then transfers it to the island of the lead frame. There is a bonding device.

In semiconductor devices, it is important to closely bond the semiconductor pellet and the island of the lead frame with the die bonding adhesive, and in the die bonding process, it is important to ensure the wettability between the adhesive and the semiconductor pellet and island. That is the purpose. Therefore, in the conventional die bonding equipment described above, the former is the size (area) of the semiconductor pellet to be die bonded.
Use multiple dispense nozzles adapted to
The latter uses stamp rubber that matches the size (area) of the semiconductor pellet. Further, in some cases, higher wettability is ensured by simultaneously performing die bonding and scrubbing the semiconductor pellet in the X direction or Y direction via an adhesive. In addition, in recent years, in view of the wettability mentioned above, an adhesive layer of a certain thickness is made on the surface of a rotating roller, and the back surface of the semiconductor pellet is moved on top of the adhesive layer so that the back surface of the semiconductor pellet is in contact with the adhesive layer. A method for transferring images has been put into practical use.

[Problem to be solved by the invention]

The die bonding equipment used in the conventional semiconductor device manufacturing process described above each uses a dispenser that injects die bonding adhesive from one or more nozzles to ensure wettability between the semiconductor pellet and the island. This was done by changing the nozzle tip diameter and the number of nozzles depending on the size of the semiconductor pellet. That is, the nozzle must be replaced each time pellets of different pellet sizes are die-bonded, which requires a huge amount of man-hours in the recent high-mix, low-volume production. Further, even if a dispensing nozzle adapted to the pellet size is used, the injected adhesive is supplied at a point, so the larger the pellet size, the greater the number of dispensing nozzles must be used.

In this case, air is trapped between the dots of adhesive injected from each nozzle and remains as air bubbles, which hinders ensuring wettability. Similarly, the transfer method using stamp rubber has similar drawbacks.

The fact that wettability between the semiconductor pellet and the island and the adhesive cannot be ensured means that the adhesive strength between the semiconductor pellet and the lead frame is low, and there is a possibility that the semiconductor pellet and the lead frame will peel off. Furthermore, the fact that the back surface of the semiconductor pellet is not uniformly wetted indicates that there is a difference in the thickness of the adhesive layer, which may cause problems such as non-adhesion during subsequent wire bonding. In order to solve them,
There is a problem in that a huge amount of man-hours are required for adjusting and inspecting the equipment.

In order to ensure uniform wettability of the adhesive on the back side of the semiconductor pellets described above, in recent years, by rotating a roller, an adhesive layer of uniform thickness is created on the surface of the rotating roller, and the adhesive layer is adsorbed and conveyed on the surface of the rotating roller. A roller transfer method has been put into practical use in which a semiconductor pellet is moved in a tangential direction to bring it into contact with an adhesive layer on the surface of a roller, and the adhesive is transferred to the back surface of the pellet. However, while it is possible to ensure uniform wettability, it is necessary to make extremely precise adjustments such as the clearance and height when the back surface of the semiconductor pellet contacts the adhesive layer of the rotating roller, and in order to transfer the adhesive uniformly, There are problems such as not being able to increase the pellet movement speed.

An object of the present invention is to provide a die bonding apparatus for semiconductor devices that can uniformly and quickly apply adhesive to semiconductor pellets of different sizes.

[Means for Solving the Problems] In order to achieve the above object, a die bonding apparatus for semiconductor devices according to the present invention includes an adhesive applicator,
A die bonding device for semiconductor devices that die-bonds a semiconductor pellet onto a lead frame, and an adhesive applicator applies a die bonding adhesive to the back side of the semiconductor pellet, and a die bonding machine that applies die bonding adhesive to the back side of the semiconductor pellet. The bonding adhesive application surface has a large application area that can accommodate multiple types of semiconductor pellets, and the application surface is formed in a spherical shape and is made of a material that is elastically deformed by the pressing force of the semiconductor pellets. It is something that

[Function] The adhesive applicator 3 has a contact surface with the back surface of the semiconductor pellet set to be larger than that of the semiconductor pellet, and can handle semiconductor pellets of different sizes.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing an embodiment of the present invention, and FIG. 2 is a sectional view showing an adhesive applicator in the present invention.

In the figure, 5 is a pellet supply stage that supplies semiconductor pellets l, 6 is a frame supply stage that supplies lead frame 2, and between both stages 5 and 6, a pickup nozzle 4 is arranged to be able to reciprocate and move up and down. It is set up.

In addition, an adhesive applicator 3 is installed at the intermediate position between both stages 5 and 6.
is installed. Glue applicator 3 as shown in Figure 2
consists of a container 7 with an open top, an elastically deformable impregnated body 8 impregnated with a dicing adhesive that is housed between the containers 7, and a flexible material such as porous Silascon rubber that covers the surface 8a of the impregnated body 8. The surface 8a of the impregnated body 8 is formed into a spherical shape with a central height, and the adhesive transfer layer 9 follows the spherical shape. It covers the surface 8a. The adhesive transfer layer 9 that covers the surface 8a of the impregnated body 8 forms an adhesive layer lO with a uniform thickness, and the spherical surface 9a of the adhesive transfer layer 9
The adhesive coating surface 9a functions as an adhesive coating surface for contacting the back surface of the semiconductor pellet and transfer-coating the die bonding adhesive, and the coating surface 9a has a large coating area that can accommodate a plurality of types of semiconductor pellets.

In order to adhere the semiconductor pellet 1 to the lead frame 2 via a die bonding adhesive in the die bonding process, which is a semiconductor device manufacturing process, an adhesive tape 1 for semiconductor device manufacturing is installed on a pellet supply stage 5.
The semiconductor pellets 1 are attracted and picked up by a pick-up nozzle 4 of a die bonding device. The adsorbed semiconductor pellet 1 is conveyed to an adhesive coating machine 3 in order to apply adhesive to its back surface 1a. This adhesive applicator 3 coats the surface 8 of the impregnated body 8.
a is formed into a spherical shape having a certain curvature (for example, a radius of curvature of 50 M), and an adhesive transfer layer 10 is formed on the surface 8 a of the adhesive layer 10 having a uniform thickness of, for example, 15 to 2511 m. 9 is provided.

The semiconductor pellet 1 conveyed above the adhesive transfer layer 9 is conveyed vertically downward in order to transfer the adhesive to the back surface 1a thereof, and the adhesive is transferred thereto. Figure 3 is a longitudinal cross-sectional view showing the state of adhesive transfer when the area of the semiconductor pellet (pellet size) is relatively large, and Figure 4 is the state of adhesive transfer when the area of the semiconductor pellet is relatively small. FIG. If the semiconductor pellet l has a relatively large area, it is moved vertically downward under a constant load until the adhesive is transferred to the entire back surface of the semiconductor pellet. Then, as shown in FIG. 3, the adhesive transfer layer 9 made of a flexible material
causes deformation due to the load when the semiconductor pellet descends. That is, the adhesive on the transfer portion can uniformly come into contact with the back surface of the semiconductor pellet, making it possible to achieve extremely uniform and uniform transfer. In this way, by simply changing the contact load of the semiconductor pellet, it is possible to uniformly and uniformly transfer the adhesive to the semiconductor pellet of any area (size).

[Effects of the Invention] As explained above, in the present invention, when an adhesive is transferred to the back surface of a semiconductor pellet, the flexible adhesive surface is deformed by the load stamped by the semiconductor pellet, and the adhesive is uniformly distributed over the entire back surface of the pellet. Adhesive transfer can be performed. That is, for semiconductor pellets of any size, uniform application of the adhesive to the back surface of the pellet can be achieved by simply changing the contact load on the contact surface. In other words, the number of man-hours required for exchanging jigs depending on the product type can be significantly reduced. Furthermore, the fact that the adhesive is transferred in a uniform manner means that the wettability of the entire surface of the pellet can be ensured, and thereby sufficient die bonding strength can be obtained. Furthermore, since the thickness of the adhesive can be easily controlled, it is possible to eliminate the inclination of the semiconductor pellet, and it is possible to reduce problems such as non-adhesion during wire bonding. That is, by using the die bonding apparatus of the present invention, a semiconductor device with even higher reliability can be provided.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention, FIG. 2 is a sectional view showing an adhesive applicator according to the present invention, and FIG. 3 is a diagram showing adhesive transfer when the area of a semiconductor pellet is relatively large. FIG. 4 is a vertical cross-sectional view showing the state when the adhesive is transferred when the area of the semiconductor pellet is relatively small. l... Semiconductor pellet 2... Lead frame 3... Adhesive applicator 4... Pick up nozzle 5... Pellet supply stage 6... Frame supply stage 7... Container 8...
Impregnated body 9... Adhesive transfer layer 10...
・Adhesive layer 11...Adhesive tape for semiconductor device manufacturing 12...Die bonding equipment

Claims (2)

[Claims] (1) A die bonding device for semiconductor devices that has an adhesive applicator and performs die bonding of semiconductor pellets onto a lead frame, the adhesive applicator applies die bonding adhesive to the back side of the semiconductor pellet. 1. A die bonding device for a semiconductor device, characterized in that a surface coated with a die bonding adhesive that comes into contact with the back surface of a semiconductor pellet has a large coating area that can accommodate a plurality of types of semiconductor pellets. (2) The die for a semiconductor device according to claim (1), wherein the coating surface is formed in a spherical shape and is made of a material that is elastically deformed by the pressing force of the semiconductor pellet. bonding equipment.