JPH01176679A - Mounting method for semiconductor element - Google Patents

Abstract

PURPOSE:To make the construction strong against the stress resulting from the difference between coefficients of thermal expansions so as to exactly prevents such phenomena that the connection pert breaks by making the shapes of the pad patterns of a printed board and the output terminals on the element chip side in rectangles arranged along radial lines streatching outward from the center of an element chip. CONSTITUTION:The shapes of pad patterns 12 on the printed board 20 side and output terminals 2 on the element chip 1 side are formed in rectangles which have the centers on the lattice lines in the checker shape and are arranged along the radial lines K stretching outward from the center O of the formation of the output terminals 2. By arranging the output terminals 2 and the pad patterns 12 like this, even if difference of coefficient of thermal expansion has arised between the printed board 20 and the element chip 1 at the time of bonding or element heat generation, a metal pipe connecting both works its bonding force effectively in the direction of the stress and remarkably high limit can be obtained.

Description

[Detailed Description of the Invention] [Summary] The present invention relates to a method for mounting a semiconductor element or an element chip (hereinafter referred to as an element chip) on which a semiconductor element is mounted on a printed circuit board using a bump bonding method, and particularly relates to The purpose of this study was to develop a method for preventing bond failure when strain stress is applied to bumps due to the difference in thermal expansion coefficient between the semiconductor element and the printed circuit board.The pad pattern on the printed board side and the shape of the output terminal on the element chip side , is formed into an oval shape along a radial line extending outward from the center of the element chip.

[Industrial application field]

The present invention relates to a semiconductor element mounting method that is applied when mounting an element chip on a printed board.

[Conventional technology]

Figure 2 (al and middle) is a perspective view and side sectional view of the main part for explaining the mounting method of the element chip, and Figure 3 (al and (b)
FIG. 1 is a plan view of main parts showing the shapes of conventional output terminals and pad patterns.

Figure 2 (a), (b) and Figure 3 (a), (b)
As shown in D, the conventional element chip 1 is equipped with a plurality of output terminals 2 arranged in a matrix. Further, the printed board 20 is equipped with a pad pattern 12 at a position corresponding to the output terminal 2. Note that the metal bump 11 is usually attached to the output terminal 2 using a soldering method or the like. and is deposited on the pad pattern 12. When mounting the element chip 1 on the printed board 20, after positioning the output terminals 2 of the element chip 1 on the pad pattern 12 of the printed board 20, the metal bumps 11 are bonded using, for example, a flow bonding method. Melt and bond.

Note that the conventional output terminal 2 and pad pattern 12 are
As shown in Figures (al and b), they are arranged in a matrix.

[Problem that the invention seeks to solve]

However, the conventional output terminal 2. The pad patterns 12 are each formed in a circular shape as shown in FIGS. 2 and 3. Therefore, stress due to thermal distortion caused by element heat generation during bonding or energization may be applied between the output terminal 2 and the pad pattern 12, leading to bond breakdown. Since bond failure due to this stress is caused by the difference in coefficient of thermal expansion between the printed board 20 and the element chip 1, it has been considered impossible to avoid this unless both are made of the same material. That is, in the past, this was the biggest constraint that prevented the size of the element chip 1 from being increased, that is, the degree of integration could not be increased.

The present invention has been made to solve this problem.

[Means for solving problems]

As shown in the embodiment diagram of FIG.
The shapes of the pad pattern 12 on the 0 side and the output terminal 2 on the element chip 1 side have a center point on a grid line in a checkerboard shape,
The output terminal 2 is formed in an oval shape along a radial line k extending outward from the formation center 0 of the output terminal 2.

[For production]

By arranging the output terminal 2 and the pad pattern 12 in this way, even if a difference in coefficient of thermal expansion occurs between the printed circuit board 20 and the element chip 1 during bonding or when the element heats up, the metal bump 11 that connects the two can be The bonding force is effectively applied in the direction of stress, resulting in a significantly higher limit.

〔Example〕

EMBODIMENT OF THE INVENTION The present invention will be described in detail below based on embodiment figures.

FIG. 1 (al and 'b) is a schematic plan view of an element chip showing an embodiment of the present invention, and a plan view of essential parts showing an example of the shape of a pad pattern formed on the element chip and a printed board. However, the same parts as in FIGS. 2 and 3 are given the same reference numerals.

As shown in FIG. 1(a), the method for mounting a semiconductor element according to the present invention is to form an elliptical shape (width: The bonding method is such that an element chip 1 on which an output terminal 2 of W and length L) is formed and a printed board 20 provided with a band pattern 12 corresponding to the output terminal 2 are faced to each other and bonded. .

In this case, the center 0 of the element chip 1 shown in FIG. 1(a) and the corresponding center on the printed board 20 side (not shown)
It goes without saying that these should match.

If the element chip 1 is mounted on the printed circuit board 20 in this manner, the structure becomes extremely strong against stress caused by the difference in the coefficient of thermal expansion, and phenomena such as damage to the bonded parts can be accurately prevented. Ru.

Note that the width W and length of the pad pattern 12 are determined as appropriate, taking into consideration the size of the element chip 1, the difference in coefficient of thermal expansion between the element chip 1 and the printed board 20, and the like.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, damage accidents between the element chip and the printed board caused by the difference in coefficient of thermal expansion between the element chip (semiconductor element) and the printed board on which it is mounted can be prevented, and reliability can be improved. This has significant industrial effects, such as the ability to perform printed board mounting with high performance.

[Brief explanation of the drawing]

FIGS. 1A and 1B are schematic plan views showing an embodiment of the present invention; FIGS. 2A and 2B are a perspective view of a main part and a side sectional view of a main part showing a method of mounting an element chip; FIG. 3 is a schematic plan view of main parts showing an example of the shape of a conventional output terminal and pad pattern. In the figure, 1 is an element chip, 2 is an output terminal, 11 is a metal bump, 12 is a pad pattern, and 20 is a Printed board, L is the longitudinal dimension of the pad pattern, W is the width dimension of the pad pattern, k is the center line of the pad pattern, and O is the center of the element chip. (Q) tl)> Hand-invented sea oil Side view Figure 1 O ↑5chi 7°, 7° tomojo! Figure 11 Meiji Figure 2 Saikaku, +I71 Shiriki' Ishiriko 86~.p-Yada Renai length 11 Figure 3

Claims (1)

[Claims] Output terminal (2) of a semiconductor element or a component (1) on which it is mounted and a pad pattern (12) of a printed board (20)
In a method for mounting a semiconductor element, the semiconductor element or a component (1) having the semiconductor element mounted thereon is mounted by bonding the pad pattern (12) on the printed board (20) side with the semiconductor element using metal bumps (11). The shape of the output terminal (2) on the side of the element or the component (1) on which it is mounted is such that the center point is on the grid line of a checkerboard, and the shape extends outward from the formation center (o) of the output terminal (2). A method for mounting a semiconductor element, characterized in that the semiconductor element is formed into an oval shape along a radial line (k) extending toward the direction of the semiconductor element.