JPH02116149A - Semiconductor device - Google Patents

Abstract

PURPOSE:To provide a buffer against an external force applied to a semiconductor element and avoid the deformation of the element and facilitate extra-thin mounting by a method wherein a trench is provided in the circumference of the element when the element is mounted on a substrate. CONSTITUTION:When an element 4 such as a chip capacitor is mounted on the surface of a substrate 5, a trench 6 is provided in the circumference of the element 4. At that time, the trench 6 may be provided so as to surround the element 4 or may be provided partially. When a chip capacitor 7 is mounted on a substrate 8, for instance, trenches 9 for restriction relief are provided around the capacitor 7 except two bridging parts 10 along two directions in the circumference of the capacitor 7. With this constitution, even if an external force is applied along the direction of arrows 11 and deformation is created, the bridging parts 10 are mainly deformed elastically and the stress is not applied to the capacitor 7.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to the structure of a substrate of a semiconductor device.

[Conventional technology] As a result of the demand for thinner electronic devices, such as those seen in card-type devices, restrictions on the height of the board mounting portion have become stricter. [Problem to be Solved by the Invention] The thickness has been reduced [Problem to be Solved by the Invention] However, in the above-mentioned conventional technology, since the substrate thickness has to be significantly reduced, a decrease in bending rigidity is unavoidable, which poses a problem. Therefore, during actual use, the deformation caused by external force increases significantly, and the stress caused in the mounting bonding area also increases significantly, resulting in frequent peeling of the soldering area and IO bonding area, and sometimes the mounting The device itself may even be destroyed.

The present invention is intended to solve these problems, and its purpose is to realize a highly reliable and thin mounting structure and to provide a small, thin, and lightweight semiconductor device.

[Means for Solving the Problems] A semiconductor device of the present invention includes a substrate on which a mounted element is disposed, wherein the substrate has a groove formed around the mounted element on which it is disposed. Features.

[Example] FIG. 3 is a perspective view showing the structure of a substrate according to the present invention, which will be described in detail below. Reference numeral 4 denotes an element mounted on the substrate, and in this figure, a chip capacitor is taken as an example. 5 is a substrate;
Reference numeral 6 denotes a groove provided around the mounted element on the substrate 5. When an external force is applied to this board and deformation occurs, especially bending deformation, most of the deformation will occur inside the groove 5 because the groove 5 according to the embodiment of the present invention extremely relaxes the restraint around the chip capacitor 4. Therefore, the stress generated in the soldering portion of the chip capacitor 4 can be sufficiently suppressed within the permissible limits.

FIG. 4 is an overview diagram of another embodiment of the present invention which is effective when the main direction of deformation is determined, in which 7 corresponds to the chip capacitor 1 in FIG. The groove is configured to surround the chip capacitor 7 with narrow border portions 10 in two directions left. When a force is applied in the direction of the arrow 11 and deformation occurs, the bridging portion 10 whose rigidity is sufficiently lower than that of the chip capacitor 7 and its surroundings is mainly elastically deformed, causing the chip capacitor 7 and its soldering to deform. It is possible to reduce the stress generated in Furthermore, even when a bending moment acts as shown by arrow 12, the generation of stress can be suppressed by the looseness of the restraint, and the structure shown in FIG. 4 is also effective when twisting occurs.

Even in cases where the narrow border section shown in FIG. 4 and 10 cannot be provided due to the presence of a large number of inputs and outputs, such as in an XC, it is important to reduce the restraint around the mounting part as much as possible, such as card-type semiconductor devices that are subject to large deformations. This is effective for improving the reliability of thin products, and FIG. 5 is an overview diagram when an IC is selected as the mounting element of the present invention. 16 is flat package E C11
4 is a circuit board, and 15 is a groove for relaxing restraint. According to this structure, when a bending moment occurs as shown by the arrow 16, there is a sufficient effect as seen in Figs. 6 and 4. Therefore, considering the main deformation direction of the product, bending is The direction of the groove 15 may be determined so that the groove 15 occurs as shown in 16. Further, it goes without saying that the mounting elements and the mounting form in this structure are not limited at all. As an example, FIG. 6 is an overview diagram when the present invention is applied to the conventional technology for keeping the height low as shown in FIG. 2, and FIG. It is an overview diagram when the board 17 is replaced.

There is no doubt that the deformation and stress occurring in mounted elements can be significantly reduced, thereby making a significant contribution to improving the reliability of thin board mounting and realizing even more ultra-thin mounting.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a first embodiment of the prior art. FIG. 2 is a perspective view showing a second embodiment of the prior art. FIG. 3 is a perspective view showing the first embodiment of the present invention. FIG. 4 is a perspective view showing a second embodiment of the invention. FIG. 5 is a perspective view showing a third embodiment of the present invention. FIG. 6 is a perspective view showing a fourth embodiment of the present invention. FIG. 7 is a perspective view showing a fifth embodiment of the present invention. 4.7, 13.17... Element 5.8, 14
... Board 6.9, 15, ...
...Groove [Effect of the Invention] According to the present invention, the substrate has a mechanism for buffering the external force applied to the mounted elements, and the mounting board is subject to large deformation.Applicant: Seiko Epson Co., Ltd. Agent Patent Attorney Kizo Suzuki Department (1 other person) Figure 3' Figure 4

Claims (1)

[Claims] A semiconductor device having a substrate on which a mounted element is arranged, wherein the substrate has a groove formed around the mounted element.