JPH11354579A - Mounting structure for semiconductor chip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform face down bonding of semiconductor chip without using any bump electrode. SOLUTION: A terminal electrode 2 is disposed on a substrate through a conductive adhesive while facing the electrode pad 4 of a semiconductor chip 3 and the gap is filled with anisotropic conductive adhesive 6. The semiconductor chip 3 is provided with a passivation having an opening at a position corresponding to the electrode pad 4. The terminal electrode 2 on the substrate 1 is smaller than the opening of the passivation and the distance from the electrode pad 4 to the terminal electrode 2 is shorter than the distance from the passivation to the substrate 1. According to the structure, bump electrode can be eliminated without causing defective contact.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor chip mounting structure for making an electrical connection between a semiconductor chip and terminal electrodes on a circuit board, and more particularly, to a connection structure by face-down bonding using an anisotropic conductive adhesive. The present invention relates to a mounting structure of a semiconductor chip to be performed.

[0002]

2. Description of the Related Art In conventional face-down mounting using an anisotropic conductive adhesive, a bump electrode made of Au (gold) or the like is formed in advance on an electrode pad formed on a semiconductor chip. An anisotropic conductive adhesive is inserted between the bump electrodes and the terminal electrodes on the circuit board, and the conduction between the electrode pads of the semiconductor chip and the terminal electrodes on the circuit board is ensured by heating and pressing. .

[0003]

However, in a conventional mounting structure of a semiconductor chip, it is necessary to form bump electrodes on the semiconductor chip, which increases the cost. In addition, when a plurality of bump electrodes are formed, if the height of the bump electrodes varies, there is a problem that a connection failure is caused.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention connects an electrode pad of a semiconductor chip to a terminal electrode provided on a substrate by using a conductive adhesive. In the mounting structure of the semiconductor chip fixed to the substrate, a passivation having an opening at a position corresponding to the electrode pad is provided between the conductive adhesive and the semiconductor chip, and faces the electrode pad. The size of the opposing surface of the terminal electrode is smaller than the size of the opening, and the distance from the electrode pad to the terminal electrode is shorter than the distance from the passivation to the substrate.

According to the present invention having the above structure, the connection between the terminal electrode on the substrate and the electrode pad of the semiconductor chip can be secured without forming a bump electrode.
The cost of the bump electrode can be reduced, and connection failure due to variation in the height of the bump electrode is eliminated.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. Elements common to the drawings are denoted by the same reference numerals. FIG. 1 is a sectional view showing a mounting structure of a semiconductor chip according to an embodiment of the present invention.

In FIG. 1, terminal electrodes 2 are formed on a substrate (printed wiring board) 1, and electrode pads 4 are provided on a semiconductor chip 3. The semiconductor chip 3 is mounted face-down, and a passivation 5 is formed below the semiconductor chip 3 in the figure. Semiconductor chip 3
An anisotropic conductive adhesive 6 is injected between the substrate and the substrate 1. The passivation 5 protects the surface of the semiconductor chip 3 and is made of glass or the like. Further, a through hole 7 is formed in the substrate 1, and the terminal electrode 2 is connected to the conductor pattern 1.
0 is connected. Insulating resin 11 is embedded in through hole 7.

The method of mounting the above structure will be described. First, the electrode pads 4 on the semiconductor chip 3 and the terminal electrodes 2 on the substrate 1
And an anisotropic conductive adhesive 6 is put between them. At this time, no bump electrode is formed on the electrode pad 4. Next, the electrode pads 4 and the terminal electrodes 2 are aligned, and then the semiconductor chip 3 is mounted face down on the substrate 1 by applying heat and pressure.

FIG. 2 is a plan view showing the semiconductor chip of the embodiment, and is a view of the semiconductor chip in FIG. 1 as viewed from below. In FIG. 2, the passivation 5 is formed over almost the entire surface of the semiconductor chip 3, and the passivation 5 is formed.
An opening 5a is formed in a portion facing the electrode pad 4.

In FIG. 1 and FIG. 2, the area S1 of the opening 5a of the passivation 5 is
Is larger than the area of the surface opposed to. That is, the entire upper surface of the terminal electrode 2 is covered with the opening 5 a of the passivation 5.
The size is included in the. With this configuration,
The conductive particles 6a on the terminal electrode 2 in FIG.
Contact only with the electrode pad 4 through the
Does not contact with The anisotropic conductive adhesive 6 contains conductive particles 6a, and the conductive particles 6a are crushed from above and below by the terminal electrode 2 and the electrode pad 4, so that the conductive particles 6a are formed between the terminal electrode 2 and the electrode pad 4. It will be in a state where it can be energized.
The size of the conductive particles 6a is about several to 20 μm, and the distance between the terminal electrode 2 and the electrode pad 4 is several to 20 μm in order for the conductive particles 6a to be crushed and become energized.
Approach until it is below.

The distance T1 between the terminal electrode 2 and the electrode pad 6 is set smaller than the distance T2 from the substrate 1 to the passivation 5. With this configuration, the conductive particles 6 a on the terminal electrode 2 in FIG. 1 contact the electrode pad 4 before the conductive particles 6 a on the substrate 1 contact the passivation 5. Accordingly, it is possible to prevent an electrical connection failure or breakage of the passivation 5 due to the conductive particles 6a on the substrate 1 coming into contact with the passivation 5 first.

FIG. 3 is a sectional view showing a mounting structure of another semiconductor chip. In FIG. 3, a terminal electrode 2 is provided on a substrate 1.
In addition, patterns 8a and 8b are mounted. These patterns 8a and 8b correspond to the mounting area T3 of the semiconductor chip 3.
It is formed more outside. That is, the gap T4 is provided between the mounting area T3 of the semiconductor chip 3 and the patterns 8a and 8b. Assuming that the patterns 8a and 8b are provided in the mounting area T3 of the semiconductor chip 3, the distance between the patterns 8a and 8b and the passivation 5 is determined by the terminal electrode 2 and the electrode pad 4.
If the distance is smaller than the distance between the conductive particles 6a on the terminal electrodes 2, the conductive particles 6a on the patterns 8a and 8b contact the passivation 5 before the conductive particles 6a contact the electrode pad 4, and A poor connection or destruction of the passivation 5 will occur. These problems can be solved by setting the inside of the mounting area T3 of the semiconductor chip 3 as the pattern non-forming portion.

If the patterns 8a and 8b are temporarily
No problem occurs if the distance between the patterns 8a and 8b and the passivation 5 is larger than the distance between the terminal electrode 2 and the electrode pad 4 even if they are provided in the mounting region T3. Pattern 8 with such height
Since it is extremely difficult to manufacture the patterns 8a, 8b, the patterns 8a, 8b are entirely formed in the mounting region T3 of the semiconductor chip 3.
It is easier to manufacture without providing 8b. However, the pattern 8 having a height satisfying the above condition
a and 8b can be manufactured, the semiconductor chip 3 of the substrate 1
May be provided in the mounting area T3 on the side.

As described above, in face-down bonding of a semiconductor chip using an anisotropic conductive adhesive, connection can be secured without forming a bump electrode, so that the cost of the bump electrode can be reduced and the bump electrode can be cut. Since there is no need to consider variations in electrode height,
Connection quality can be improved.

[0015]

As described above in detail, according to the present invention, the electrode pads of the semiconductor chip are connected to the terminal electrodes provided on the substrate by the conductive adhesive, and the semiconductor chip is connected to the substrate. In the semiconductor chip mounting structure to be fixed to the semiconductor chip, a passivation having an opening at a position corresponding to the electrode pad is provided between the conductive adhesive and the semiconductor chip, and the terminal facing the electrode pad is provided. The size of the opposing surface of the electrode was smaller than the size of the opening, and the distance from the electrode pad to the terminal electrode was shorter than the distance from the passivation to the substrate, so that the bump electrode was not formed on the substrate. The connection between the terminal electrode of the semiconductor chip and the electrode pad of the semiconductor chip can be secured, so that the cost of the bump electrode can be reduced and Poor connection due to variation in the pole height is eliminated.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a mounting structure of a semiconductor chip according to an embodiment.

FIG. 2 is a plan view showing a semiconductor chip of the embodiment.

FIG. 3 is a cross-sectional view illustrating a mounting structure of another semiconductor chip.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Terminal electrode 3 Semiconductor chip 4 Electrode pad 5 Passivation 6 Anisotropic conductive adhesive 8a, 8b Pattern

Claims (2)

[Claims] In a semiconductor chip mounting structure, an electrode pad of a semiconductor chip is connected to a terminal electrode provided on a substrate by an anisotropic conductive adhesive, and the semiconductor chip is fixed to the substrate. A passivation having an opening at a position corresponding to the electrode pad is provided between the anisotropic conductive adhesive and the semiconductor chip. A mounting structure for a semiconductor chip, wherein the distance from the electrode pad to the terminal electrode is shorter than the distance from the passivation to the substrate side, the size being smaller than the size of the opening. 2. The semiconductor chip mounting structure according to claim 1, wherein a pattern non-forming portion is provided in a mounting area of said semiconductor chip.