JPH02130862A - Semiconductor assembly material - Google Patents

Abstract

PURPOSE:To increase the strength of a die pad itself, to alleviate a deformation due to thermal stress, and to simultaneously reduce an internal crack by dispersing the influence (stress) of outer resin by providing protrusions at the lower part of the pad. CONSTITUTION:Protrusions 2 are provided at the lower part of a die pad 1. Thus, the strength of the pad 1 itself is increased, stress received from sealing resin 6 is dispersed to alleviate the deformation of the pad 1 due to resin stress, and an internal crack is resultantly suppressed. The protrusion may not be square post but be conical or columnar. The protrusions may be regularly disposed or irregularly located.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a semiconductor assembly material suitable for use as a die pad material in a semiconductor assembly process, which is a manufacturing process of semiconductor integrated circuits.

[Prior art] Conventionally, there is a package O, which has a package form as shown in Fig. 1.
As a die pad material for fixing elements such as LSI, the thickness is about 150 μr! A flat metal plate of about L size was used.

Here, the die pad is used to fix a semiconductor element, and is a metal that enables assembly work (wire bonding) and resin sealing work for electrically connecting the semiconductor element to the outside. It is a sexual plate-like thing.

This is used for all semiconductor devices that are sealed with resin.

Therefore, the die pad and the element are bonded together with an adhesive called a Guibond material (for example, silver paste), and the area of the die pad can cover the area of the semiconductor element.

[Problems to be Solved by the Invention] Plastic resins, silicone resins, and the like are generally used for resin encapsulation of semiconductor elements. Taking the case of plastic resin as an example, there are differences in physical properties (coefficient of thermal expansion, etc.) between the resin-sealed die pad and the sealing tree itself.
If the package is subjected to thermal stress (the imbalance of cold and heat) due to such reasons, the die pad will deform and internal cracks will occur at the corners of the die pad.

In addition, this crank may reach the outside, causing deterioration and damage to the elements and significantly impairing the reliability of the workpiece.

As is well known, ICs are used in all kinds of fields, including industrial and consumer applications, and are often used in places where they can be subjected to heat stress as described above, which poses a very big problem in practical terms.

[Means for solving problems] The present invention has been made to solve the above-mentioned problems, and by providing a protrusion at the bottom of the die pad,
This increases the strength of the die pad itself and alleviates deformation caused by thermal stress, while at the same time dispersing the influence (stress) of the external resin and reducing internal cracks.

Note that the desired protrusions can be easily obtained by pressing etched circles during molding of the Gui frame.

[Example] This example is shown in FIG. 1 (1, (,c)).

FIG. 1Cb) is a cross section of the IC package, and FIG. 1C is a downward perspective view of the die pad.

When a die pad having such a structure was used, no defects due to cracks occurred in tests under the same conditions as conventional ones.

This is because the strength of the die pad itself has been increased by providing a protrusion at the bottom of the die pad, and the stress received from the sealing resin has been dispersed, so that the deformation of the die pad due to resin stress as seen in the past has been avoided. As a result, the occurrence of internal cracks is suppressed.

In this embodiment, a quadrangular prism-shaped protrusion is provided at the bottom of the die pad, but this protrusion may be conical (or cylindrical) instead of a quadrangular prism.

That is, the shape of the protrusions does not matter, as long as the metal surface has a plurality of protrusions.

Further, the protrusions may be arranged regularly or irregularly.

5...--Lead, lead frame 4...
・・・・・・Semiconductor element (chip) 5・・・・・・・・・
・Au wire 6・・・・・・・・・Sealing resin [Effects of the invention According to the present invention, deformation of the die pad due to thermal stress of the resin is suppressed 5, so that excessive thermal stress is not applied. No cracks will occur in the package even in the case of
A more reliable semiconductor integrated circuit can be provided.

[Brief explanation of drawings]

Fig. 1 (α) is an external view of the package of a typical machine C used in this example, Fig. 1 (b) is a sectional view of the machine C, and Fig. 1 CC) is a package appearance diagram of a typical machine C used in this example. ) Die pad parts 1 and 2 in the figure
FIG. Figure 1 (b) Description of each part 1...Die pad 2...Die pad protrusion or more

Claims (1)

[Claims] In the semiconductor element assembly process, an element fixing plate (made of metal) used for fixing the semiconductor element (
Hereinafter, it will be referred to as a die pad. ) on the back side, the shape, size,
A semiconductor assembly material characterized by having protrusions regardless of the regularity of their positions.