JP2001358171A - Structure for semiconductor element mounting - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure for semiconductor element mounting, capable of mounting at a high density, without short-circuiting connecting metal bumps in mounting semiconductor elements by a flip-chip type facedown mounting system. SOLUTION: In the structure for semiconductor element mounting, comprising a metal layer 8 on connecting terminals 9 of a semiconductor element 7 and metal bumps 2 on the metal layer 8 with respect to wirings 3 and connecting terminals 4, formed on a wiring board 5 and an anisotropically conductive adhesive 6 or anisotropically conductive film for bonding one side of the wiring board 5, having the wirings 3 and the connecting terminals 4 to one side of the semiconductor element 7 which has the metal bumps 2 with electrical connections made between the connecting terminals in the facedown mounting system, and insulative material-made walls 1 are provided between the adjacent connecting terminals.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor element mounting structure in which a semiconductor element is mounted by a flip-chip type face-down mounting method.

[0002]

2. Description of the Related Art In information processing apparatuses such as video cameras, digital cameras, and printers, miniaturization, thinning, low power consumption, high definition, and colorization are progressing. The screen is planned. The semiconductor elements to be mounted along with this are also highly integrated, larger, faster,
Power consumption is reduced, and the number of input / output points tends to increase.

[0003] Accordingly, it has been required to increase the mounting density of the semiconductor element and the wiring board. Conventionally, a mounting technique of bonding a semiconductor element on a lead frame, connecting terminals of the semiconductor element and terminals of the lead frame by wire bonding, and sealing the periphery of the semiconductor element with a resin or the like has been frequently used. However, in order to realize high-density mounting, multiple connection metal projections are provided on the semiconductor element, and the surface is connected to the surface on which the connection terminals of the wiring board are provided with the connection terminals by heat and pressure to connect them in a flip-chip manner In other words, a so-called face-down mounting method has been used.

[0004] In the face-down mounting method using the flip chip method, instead of wire bonding, the semiconductor element and the wiring board are connected by anisotropic conductive resin such as a film or an adhesive, solder bumps, conductive paste, or gold-gold connection. Etc. are used. As a result, the pitch between connection terminals in face-down mounting is 100 μm to 60 μm.
m, bump (metal projection for connection) size is 60 × 60 μm
~ 40 × 50μm, space between connecting terminals is 40 ~
Fine pitches such as 20 μm have progressed, and some of them have several hundred connection terminals.

[0005] In the face-down mounting method of connection by heat compression, the relationship between the pressing force and the connection resistance between the wiring board and the semiconductor element is such that as the pressing force increases, the connection resistance decreases and the resistance varies. Become smaller. However, the metal projection for connection collapses and expands in the lateral direction due to the pressure during connection. Therefore, as the pressing force increases, the amount of crushing of the metal protrusion (bump) increases, and the lateral spread also increases.

[0006]

The tendency for high-density mounting will tend to increase further in the future. As an example of high-density mounting,
Connection terminal pitch 40μm, bump size 25μm × 8
0 μm, connection space 15 μm, A for connection terminal
1 and a glass substrate on which an ITO (Indium Tin Oxide) film has been formed, a semiconductor element having a 14 μm-high gold-plated bump formed as a connection projection using an anisotropic conductive adhesive, and a heating temperature of 200 ° C. for the purpose of low resistance connection FIG. 2 is a schematic diagram of a mounting structure when face-down mounting is performed at 30 kg / mm ² .
(A) and (B) show.

FIG. 2A is a cross-sectional view of a conventional face-down mounting method, and FIG. 2B is a view of the mounting state of FIG.

Reference numeral 5 denotes a glass wiring board on which Al wiring 3 and connection terminals 4 are provided. On the other hand, the semiconductor element 7 has a metal layer 8 and a gold-plated bump 2 as a metal projection on a connection terminal 9. The surface of the glass substrate 5 on which the Al wirings 3 and the connection terminals 4 are provided and the surface of the semiconductor element 7 on which the gold-plated bumps 2 are formed face each other, and are electrically bonded by pressure using an anisotropic conductive adhesive 6. The connection is intended to be established. 2 (A) and FIG. 2 (B).
As can be seen from the view of the glass substrate seen through the glass substrate from above, the gold plating bumps 2 are crushed by the pressing force and adjacent gold plating bumps are short-circuited, and the electrical connection between the semiconductor element and the wiring board becomes poor. The short-circuit phenomenon due to the crushing of the bump is more likely to occur as the fine pitch progresses and the distance between the connection terminals becomes shorter.

The problem to be solved by the present invention is that in a semiconductor element mounting structure in which a semiconductor element is mounted by face-down mounting of a flip chip type, high-density mounting is possible without short-circuiting between connection metal projections. It is to provide a semiconductor element mounting structure.

[0010]

According to the semiconductor device mounting structure of the present invention, a metal layer and a metal layer are formed on a connection terminal on a semiconductor device side with respect to a wiring and a connection terminal formed on a wiring board. A metal projection is provided, and an anisotropic conductive adhesive or an anisotropic conductive adhesive film is used to bond the surface of the wiring substrate on which the wiring and connection terminals are provided and the surface of the semiconductor element on which the metal protrusion is provided, and simultaneously In a semiconductor element mounting structure connected by a face-down mounting method for making electrical connection between connection terminals, a wall made of an insulating material is provided between the adjacent connection terminals. .

In the above embodiment of the present invention, the insulating wall may be provided between the connection terminals on the wiring board side.
It may be between the connection terminals on the semiconductor element side.

In the above embodiment of the present invention,
The insulating wall is made of an organic material such as a dry film or a resist, or a silicon oxide film, NSG (Non-doped Silicate G).
a non-conductive film such as a glass film or a silicon nitride film.

According to the above configuration of the present invention, by providing an insulating wall between the connection terminals of the semiconductor element or the wiring board, it is possible to prevent an adjacent short circuit due to a crushed bump at the time of thermocompression bonding. Enables high-density mounting in face-down mounting.

[0014]

An embodiment of the present invention will be described below with reference to FIG.

FIG. 1A is a connection sectional view at a pitch of 40 μm in which a semiconductor element is mounted face-down by a flip chip method on a wiring board provided with a wall for preventing adjacent short circuit.

FIG. 1B is a connection state diagram of the semiconductor element mounted face-down in FIG. 1A viewed from above the glass substrate through the glass.

1 (A) and 1 (B), reference numeral 1 denotes a wall formed of an insulating material for preventing adjacent short-circuit, 2 denotes a gold-plated bump, 3 denotes an Al wiring, 4 denotes a connection terminal (substrate side),
5 is a glass wiring board, 6 is an anisotropic conductive adhesive, 7 is a semiconductor element, 8 is a metal layer, 9 is a connection terminal (semiconductor element side).
It is.

In order to obtain the semiconductor element mounting structure of the present invention shown in FIGS. 1A and 1B, first, an insulating wall 1 is formed between connection terminals 4 of a glass wiring board 5. Next, in order to mount the semiconductor element 7 on the glass wiring board 5, the semiconductor element 7 may be mounted according to a normal face-down mounting method. That is,
The surface of the glass wiring board 5 on which the connection terminals 4 are formed and the surface of the semiconductor element 7 on which the gold-plated bumps 2 are formed face each other, and the predetermined connection terminals 4 of the glass wiring board 5 and the predetermined gold-plated bumps of the semiconductor element 7 are formed. What is necessary is just to heat-press using the anisotropic conductive adhesive 6 so that 2 may adhere | attach.

As shown in FIGS. 1 (A) and 1 (B), the gold-plated bump 2 crushed by heat compression does not come into contact with the adjacent gold-plated bump due to the insulating wall for short-circuit prevention. The connection with the connection terminal of the opposing wiring board can be performed without causing the problem.

In the above embodiment, the example in which the wall for preventing short circuit is provided on the wiring board side is shown, but the wall for preventing short circuit may be provided on the semiconductor element side. Further, in the above embodiment, an example using an anisotropic conductive adhesive is shown, but an anisotropic conductive adhesive film may be used.

In the present invention, the material of the wall for preventing short circuit is not particularly limited as long as it is an insulating material. For example, an organic material such as a dry film or a resist,
Non-conductive films such as an oxide film, an NSG film, and a silicon nitride film can be given.

Next, an embodiment of a method for forming a wall for preventing a short circuit adjacent to a wiring board or a semiconductor element will be described.
The method of forming the short prevention wall on the semiconductor element or the wiring board is the same. That is, when a short-circuit preventing wall is formed on a wiring board, a wiring layer is formed and a protective film is formed, and when a short-circuit preventing wall is formed on a semiconductor element, after the process step is completed, the following ( It may be performed by the method of 1) or 2).

(1) A non-conductive film for preventing short circuit is formed on a wiring board or a semiconductor element by sputtering or CVD, followed by patterning after resist coating and etching to form a wall for preventing short circuit.

(2) After the dry film is thermocompression-bonded to a wiring board or a semiconductor element, patterning is performed. Next, development is performed and then heating is performed to complete the preparation. In addition,
In the case of a semiconductor device, a bump is formed after a short prevention wall is formed.

[0025]

As described above, by providing insulating walls between the connection terminals for preventing the connection terminals from being short-circuited, the connection pitch can be reduced, and high-density and low-resistance connection can be achieved.

[Brief description of the drawings]

FIG. 1 (A) shows a case where a wall for preventing adjacent short circuit is provided.
Sectional view of mounting in a face-down mounting method at a pitch of μm, (B): 40 μm provided with a wall for preventing adjacent short circuit
FIG. 3 is a view showing a mounting state in a face-down mounting method at a pitch, which is transmitted from the upper surface of the glass.

FIG. 2A is a cross-sectional view of mounting at a pitch of 40 μm mounted by a conventional face-down method, and FIG. 2B is a view of the mounting state at a pitch of 40 μm mounted by a conventional face-down method, which is transmitted through the upper surface of a glass substrate. .

FIG. 3 is a graph showing a relationship between connection resistance and pressurized pressure in a face-down system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wall for prevention of adjacent short-circuit 2 Gold-plated bump 3 Al wiring 4 Wiring board side connection terminal 5 Glass wiring board 6 Anisotropic conductive adhesive 7 Semiconductor element 8 Metal layer 9 Semiconductor element side connection terminal

Claims (5)

[Claims] 1. A semiconductor device comprising a metal layer on a connection terminal on a semiconductor element side and a metal projection on the metal layer. Face-down mounting, in which an isotropic conductive adhesive film is used to bond the surface of the wiring substrate on which the wiring and connection terminals are provided and the surface of the semiconductor element on which the metal projections are provided, and simultaneously establish electrical connection between the connection terminals. In a semiconductor device mounting structure connected in a system, a wall made of an insulating material is provided between the adjacent connection terminals. 2. The semiconductor element mounting structure according to claim 1, wherein said wall is provided between connection terminals on a wiring board. 3. The semiconductor element mounting structure according to claim 1, wherein the wall is provided between connection terminals on the semiconductor element. 4. The semiconductor device mounting structure according to claim 1, wherein the material of the wall is an organic material such as a dry film or a resist. 5. The device according to claim 1, wherein the wall is a non-conductive film such as a Si oxide film, an NSG film, and a silicon nitride film.
4. The semiconductor element mounting structure according to any one of items 3 to 3.