JPS598353Y2 - Surface protection agent coating equipment for semiconductor devices - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for applying a surface protective agent to improve the reliability of cylindrical semiconductor devices.

In order to prevent the influence of external charges or impurities on the semiconductor surface of a semiconductor element and improve the reliability of the semiconductor element, the surface is coated with a surface protective agent made from resin such as silicone varnish or silicone rubber, and then For example, sealing with a resin is performed.

These surface protective agents may be applied by hand to the semiconductor surface, but automatic coating equipment is used for mass production.

As shown in FIG. 1, this device carries a semiconductor element 4 supported in a support frame 3 so as to be in contact with the drum on the upper side of a drum 2 to which a surface protection agent 1 has been adhered, by a conveyor 5 in the direction of the arrow. direction, that is, clockwise in the example shown.

The element 4 passes in contact with this drum 2 while rotating counterclockwise, and since the surface protection agent needs to be applied to all sides, its shape is cylindrical, and its axis is aligned with the axis of the drum 2. It is rotatably supported by the support frame 3 so as to be parallel to each other.

As shown in FIG. 2, the cylindrical semiconductor element 4 has cylindrical electrode bodies 7 fixed to both sides of a semiconductor disk 6 made of a material such as tungsten, molybdenum, or kovar whose coefficient of thermal expansion is close to that of the semiconductor. A lead wire 8 is connected to 7.

However, when such a drum is used for coating, the thickness of the surface protective agent 9 becomes uneven as shown in Figure 3, which may cause cracks in the resin layer during resin sealing, or may cause problems in the use of the device. In some cases, cracks may occur in the protective agent layer due to thermal distortion.

An object of the present invention is to provide a coating device that enables uniform coating of such a surface protective agent.

The purpose of this is to provide a conveying means in which the coating device rotatably supports cylindrical semiconductor devices around its axis and to move the devices in a direction perpendicular to the axis, and a rotating shaft that is sequentially arranged in the direction of movement of the devices to be perpendicular to the direction of movement of the devices. The first drum for applying the surface protective agent rotates in the direction of travel, and the second drum for removing excess surface protective agent rotates at right angles to the direction of travel and opposite to the direction of travel. be done.

An embodiment of the present invention will be described below with reference to FIG.

As shown, this device is similar to drum 2 in FIG.
In addition to the drum 11, a second drum 12 is provided further forward in the direction in which the semiconductor elements 4 travel on the conveyor 5.

The first drum 11 is brought into contact with the element 4 with the surface protection agent 1 attached thereto, and its side surface is coated with the surface protection agent 9.

The semiconductor element 4 has a cylindrical shape as shown in FIG. The surface protectant 9 is coated with the surface protective agent 9 while being brought into contact with the clockwise rotating drum 11 and rotating counterclockwise.

The element 4 advances further and contacts the second drum 12.

The second drum 12 rotates in a counterclockwise direction opposite to that of the first drum 11, and rotates in the opposite direction to the advancing direction of the element 4.

When the element 4 comes into contact with this drum 12, it rotates clockwise, and the excess thickness of the surface protection agent 9 is wiped off by this drum 12, resulting in a uniform thickness.

In this case, if the surface of the second drum 12 is wetted with a solvent 13 such as xylene and then brought into contact with it, the thickness of the surface protective agent layer 9 will be more uniform.

Furthermore, in order to ensure reliable application and uniformity of the surface protective agent, it is also effective to place another pair of rolls further along the conveyor and repeat the same operation. It is.

As mentioned above, the coating device based on the present invention enables uniform automatic coating of the surface protection agent by providing a counter-rotating roll for removing excess surface protection agent in addition to the roll for applying the surface protection agent. This further improves the reliability of semiconductor devices.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a conventional surface protective agent coating device, Figure 2 is a side view of a cylindrical semiconductor device being coated, and Figure 3 shows the unevenness of the surface protective agent applied by the device shown in Figure 1. FIG. 4 is a longitudinal cross-sectional view of a semiconductor element showing the state of the semiconductor element, and FIG. 4 is a cross-sectional view of a coating apparatus according to an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1...Surface protection agent, 4...Semiconductor element, 5...Conveyor, 9...Surface protection agent layer, 11...Surface Drum for applying protective agent, 12.
...Drum for removing excess surface protection agent.

Claims (1)

[Scope of utility model registration request] A conveying means that rotatably supports a cylindrical semiconductor element around its axis and moves the element in a direction perpendicular to the axis, and a rotating shaft that is sequentially arranged in the direction of movement of the element and extends in the direction of movement perpendicular to the direction of movement of the element. A semiconductor device comprising: a rotating first drum for applying a surface protective agent; and a second drum for removing excess surface protective agent, the rotating shaft of which rotates at right angles to the traveling direction and opposite to the traveling direction. Surface protection agent coating equipment.