JPH02113528A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To cancel mechanical stress created when a semiconductor chip is sealed in a package by adjusting a thickness of an insulating protective film formed on the surface of the semiconductor chip or laminating such insulating protective films to provide a multiple layer. CONSTITUTION:Stress created by bonding a semiconductor chip 1 to a metallic substrate 3 acts such that the top face of the semiconductor chip 1 is extended and the bonded face is contracted. On the other hand, stress created by an insulating protective film 2 on the surface of the semiconductor chip 1 acts such that the top face of the chip 1 is contracted and the rear face is extended, Since these stresses act opposite to each other, the stress of the insulating protective film 2 can be controlled by selecting a type and thickness of the film 2 appropriately or by combining several such films to provide a multiple layer. In this manner, the stress created by bonding the semiconductor chip 1 to the metallic substrate 3 can be cancelled.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is applicable to silicon (Si) and gallium arsenide (GaAs).
The present invention relates to a method for manufacturing a semiconductor device that cancels warpage that occurs when a semiconductor chip, which is a semiconductor substrate such as a semiconductor substrate with circuit elements integrated therein, is sealed in a plastic or ceramic container.

Conventional technology An oxide film or nitride film is applied to the surface of a semiconductor chip, which has a large number of circuit elements integrated on a semiconductor substrate such as Si or GaAs, to protect it from electrical contact with the outside, mechanical damage, moisture, etc. Form an insulating protective film such as

The semiconductor chip on which the insulating protective film has been formed is adhered to the pad portion of a lead frame made of metal, and then sealed with resin to form a semiconductor device.

Problems to be Solved by the Invention As shown in FIG. 2, when the insulating protective film 2 is formed on the surface of the semiconductor substrate 1, the semiconductor substrate 1 is damaged by the insulating protective film 2 due to stress.
Warpage occurs on the sides. On the other hand, as shown in FIG. 3, when the semiconductor substrate 1 is bonded onto a metal substrate 3 such as a lead frame or a metal container, warpage occurs on the back side of the semiconductor substrate 1 due to thermal stress.

As described above, there is a problem in that the characteristics of integrated circuit elements and electric circuits change due to warping of the semiconductor substrate due to stress.

An object of the present invention is to provide a semiconductor device that is less affected by these stresses.

Means for Solving the Problems The method for manufacturing a semiconductor device of the present invention includes encapsulating a semiconductor chip in a package by adjusting the thickness of an insulating protective film formed on the surface of a semiconductor chip or by forming multiple layers of insulating protective films. This offsets the mechanical stress that occurs when

Effect: According to the method of manufacturing a semiconductor device of the present invention, it is possible to suppress warping of the semiconductor chip due to stress.

Examples of large stress applied to the semiconductor chip are due to bonding the semiconductor chip to a metal substrate as shown in Figure 3, and due to depositing an insulating protective film on the surface of the semiconductor chip as shown in Figure 2. There are some things that occur due to The stress caused by bonding to a metal substrate is such that the surface of the semiconductor chip stretches and the bonding surface side contracts. On the other hand, the stress caused by the insulating protective film on the surface of the semiconductor chip is such that the front surface of the semiconductor chip contracts and the back surface stretches. Since the directions of these two stresses are opposite to each other, the stress of the insulating protective film can be controlled by changing the type and thickness of the insulating protective film, and by combining these into multiple layers.
Stress caused by bonding a semiconductor chip to a metal substrate can be offset. It is also possible to control the stress caused by adhesion to the container substrate by adjusting the adhesive, adhesion temperature, substrate material, etc.

For a certain semiconductor chip bonding process, a silicon nitride film is deposited on the surface of a silicon semiconductor as an insulating protective film, and the resistance value of a resistor, which is a circuit element, is measured against this film thickness. Figure 1 shows the results. show.

As shown in FIG. 1, by changing the film thickness, the stress changes and the resistance value changes. When the above two stresses cancel each other out, the resistance change is minimized.

Therefore, the thickness of the silicon nitride film is optimized to minimize the resistance change.

Effects of the Invention According to the method for manufacturing a semiconductor device of the present invention, in response to the step of adhering a semiconductor chip to a substrate when encapsulating it in a container,
Stress can be offset by controlling the type of insulating protective film, the film thickness, and the multilayer structure based on a combination thereof. As a result, changes in the characteristics of semiconductor elements and circuits can be avoided.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the change in resistance value within an integrated circuit when the thickness of the insulating protective film is changed while the bonding process of the semiconductor chip is kept constant according to the present invention. FIG. 3 shows a deformation of the semiconductor chip due to the deposition of a protective film. FIG. 3 shows a deformation of the semiconductor chip when the semiconductor chip is bonded to a metal substrate. 1... Semiconductor chip, 2... Insulating protective film, 3... Metal substrate. Name of agent: Patent attorney Shigetaka Awano and one other person Figure 1 Figure 2 Figure 3

Claims (2)

[Claims] (1) A method for manufacturing a semiconductor device, which comprises adjusting the thickness of an insulating protective film formed on the surface of the semiconductor chip to offset mechanical stress generated when bonding the semiconductor chip to a metal substrate. (2) A method for manufacturing a semiconductor device, characterized in that mechanical stress generated when bonding a semiconductor chip to a metal substrate is offset by forming a multilayer insulating protective film on the surface of the semiconductor chip.