JP4392201B2 - Electronic device and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electronic device having a multilayer wiring board structure incorporating a semiconductor chip such as a semiconductor integrated circuit or a large-scale integrated circuit, and a manufacturing method thereof.
[0002]
[Prior art]
As a conventional multilayer wiring board, a semiconductor chip is mounted on the surface, and in order to connect the electrodes of the semiconductor chip, and further to lead out the electrodes of the semiconductor chip to the outside, an interlayer insulating film is interposed. There has been a configuration in which a plurality of laminated wiring films are formed and electrical connection is made between the respective wiring films by bumps or the like (see Japanese Patent Application Laid-Open No. 2002-043506).
[0003]
The semiconductor chip generally has a thickness of, for example, 100 μm or more, and therefore has rigidity. Thus, since the semiconductor chip has rigidity, the multilayer wiring board on which the semiconductor chip is mounted has rigidity as a matter of course.
[0004]
[Problems to be solved by the invention]
By the way, an electronic device including an electronic circuit made of a multilayer wiring board on which a semiconductor chip is mounted is increasingly required to have flexibility. In particular, this tendency is strong for an endoscope, a pacemaker, a sphygmomanometer, or the like that is inserted into, embedded in, or along the human body.
However, the fact was that it did not meet such demands.
[0005]
Therefore, as a result of repeated experiments and researches, the inventor of the present application has obtained flexibility if the thickness of the semiconductor chip is reduced to 50 μm or less, and the multilayer wiring board alone is flexible. Since some have been developed, by mounting a flexible semiconductor chip on the flexible multilayer wiring board, even when the semiconductor chip is mounted, the multilayer wiring board structure with the built-in flexible semiconductor chip is provided. The idea was that an electronic device could be provided.
The present invention has been made based on such an idea, and an object thereof is to provide an electronic device having a flexible multilayer wiring board structure incorporating a semiconductor chip and a method for manufacturing the same.
[0007]
[Means for Solving the Problems]
The electronic device according to claim 1 is flexible on the one surface of the first metal base member in which the wiring film is formed on one surface and the terminal bump is formed on the back surface of at least a part of the wiring film. A semiconductor chip formed in a thin film having a thickness is flip-chip bonded with its electrodes connected to the wiring film, and connected to the wiring film on the one surface of the first metal base member . A second metal base member having a chip housing space for accommodating the bump and the semiconductor chip on the same surface, and having a wiring film formed on the opposite side, accommodates the semiconductor chip in the chip housing space and the interlayer connection. The bumps are overlaid on the first metal base member so that the bumps are connected to the corresponding wiring films, and between the bumps and between the wiring films of the first and second metal base members. Insulate During insulating film is formed, characterized by having a multi-layer wiring board structure.
[0008]
According to a second aspect of the present invention, in the electronic device according to the first aspect , the thickness of the semiconductor chip is 50 μm or less.
The electronic device according to claim 3 is the electronic device according to claim 1 , wherein the electrode of the semiconductor chip and the wiring film are made of a conductive material selectively formed on a surface portion of the wiring film. It is characterized by being connected through a bump for use.
[0009]
The electronic device according to claim 4 is the electronic device according to claims 1 to 3 , wherein the interlayer insulating film is made of an insulating film made of polyimide, liquid crystal polymer, glass cloth-impregnated B-stage resin, or BCB film. It is characterized by that.
[0010]
According to a fifth aspect of the present invention, there is provided an electronic device manufacturing method comprising: a first metal base member having a wiring film formed on a surface of a terminal bump-forming metal layer; and a semiconductor chip formed in a thin thickness with flexibility; One surface of the metal layer for forming the wiring film has an interlayer connection bump connected to the wiring film of the first metal base member and a chip storage space for housing the semiconductor chip on the same surface, And a second metal base member laminated with an interlayer insulating film so that the interlayer connection bumps are penetrated and do not occupy the chip housing space, and the wiring film of the first metal base member The semiconductor chip is flip-chip bonded to one surface on the formation side so that the electrode is connected to the wiring film, and the second metal is applied to the one surface of the first metal base member. the base member, the It said semiconductor chip is accommodated in the serial chip accommodation space, by connecting the top surface exposed from the interlayer insulating film of the interlayer connection bumps to the wiring layer of the first metal base member, an interlayer insulating film And forming a wiring film by selectively etching the metal layer for forming the wiring film of the second metal base member , and for forming the terminal bumps of the first metal base member Terminal bumps are formed by selectively etching the metal layer.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail according to embodiments shown in the drawings. 1A to 1C are cross-sectional views showing a first embodiment of the electronic device of the present invention. FIG. 1A shows an electronic device in a normal state, and FIG. 1B shows a bent state. The electronic device is shown deformed, and (C) shows the deformed state of the built-in semiconductor chip.
This electronic device is used as a medical device that requires flexibility, such as an endoscope or a cardiac pacemaker.
[0012]
11 is a wiring film formed in a predetermined pattern by selectively plating, for example, nickel (thickness, for example, 0.5 to 2 μm) and copper (thickness, for example, 3 to 18 μm), and on the wiring film 11, A plurality of bumps 12 for electrode connection are formed by gold plating, for example, which are connected to the electrodes of a semiconductor chip (20) such as a semiconductor integrated circuit chip or a large scale integrated circuit chip. A semiconductor chip 20 has a main surface facing the surface on which the bump 12 is formed, and each electrode thereof is connected to the corresponding electrode connection bump 12 to be flip-chip connected.
[0013]
Reference numeral 30 denotes an insulating layer that covers the main surface of the semiconductor chip 20 and insulates between the semiconductor chip 20 and the wiring film 11, and is a flexible insulating material such as an underfill resin such as ACF, ACP, NCF, or NCP, or a film. Made of material.
In order to provide flexibility, the semiconductor chip 20 is polished on the surface opposite to the main surface on which the integrated circuit is formed, that is, the back surface of the semiconductor substrate (after being formed into a semiconductor chip or in a wafer state). The thickness is adjusted so as to be 10 to 50 μm, and one side is cut into chips of about 20 mm, for example. As described above, the semiconductor chip 20 having one side having a rectangular shape of about 20 mm and a thickness of 50 μm or less bends as shown in FIG.
[0014]
Reference numeral 13 denotes a terminal bump, which is formed of copper on the side opposite to the semiconductor chip 20 side of the wiring film 11 and leads out the electrodes of the semiconductor chip 20 to the outside. Reference numeral 15 denotes solder balls formed so as to cover the entire terminal bumps 13 and have heights and diameters of 50 to 200 μm and 50 to 250 μm, respectively, and are arranged at a pitch of 300 to 800 μm.
[0015]
40 is an interlayer insulating film, for example, made of an insulating film made of polyimide, liquid crystal polymer, glass cloth impregnated B-stage resin or the like, and performs interlayer insulation between the wiring film 11 and a wiring film (51) described later. A chip storage space 42 for escaping the semiconductor chip 20 is provided. The interlayer insulating film 40 is penetrated by interlayer connection bumps (52) described later.
Reference numeral 51 denotes a wiring film made of, for example, copper, and a plurality of interlayer connection bumps 52 having a diameter of about 50 to 100 μm are formed on the back surface thereof, and the wiring film 11 and the wiring are connected via the interlayer connection bumps 52. The film 51 is electrically connected at a predetermined position. An insulating protective film 60 is provided on the surface of the wiring film 51. The total thickness of the wiring film 11 to the protective film 60 is about 50 to 100 μm.
[0016]
Such an electronic device has sufficient flexibility in a state where it only has a multilayer wiring board structure without the semiconductor chip 40. If the thickness of the semiconductor chip 40 is 50 μm or less, FIG. Therefore, even when the semiconductor chip 20 is mounted, it has flexibility as shown in FIG.
Therefore, when this electronic device is used for an endoscope, pacemaker, sphygmomanometer, etc. that is inserted into, embedded in, or along the human body, it can match the human body due to its flexibility. Thus, the influence of the electronic device on the human body can be reduced.
[0017]
2A to 2F are cross-sectional views showing an example of the method for manufacturing the electronic device shown in FIG. 1 (first embodiment of the electronic device of the present invention) in the order of steps.
(A) As shown in FIG. 2A, first, a first metal base member 16, a semiconductor chip 20 that has been adjusted to have a thickness of 10 to 50 μm in advance and have flexibility, and a second metal A base member 56 is prepared.
The first metal base member 16, which is one of the members to be prepared, has a thickness made of, for example, nickel and copper on one surface of the copper layer 10 having a thickness of about 50 μm to be the terminal forming bumps 13 made of copper. A wiring film 11 having a thickness of about 12 μm is formed by, for example, a selective plating method. Further, for example, a nickel film and gold (or copper), or a nickel film and a copper film and a gold film are selectively formed on the surface portion of the wiring film 11. The electrode connection bumps 12 are formed by, for example, a selective plating method. The selective plating method can be formed, for example, by forming a resist film having a negative pattern with respect to a pattern to be formed and plating using the resist film as a mask.
[0018]
Another member to be prepared, the semiconductor chip 20, is adjusted in advance to have a thickness of 10 to 50 μm and have flexibility as described above.
The remaining one member to be prepared, the second metal base member 56, is a wiring film forming copper layer 50 having a thickness of about 3 to 18 μm and an interlayer connection having a thickness of about 30 to 100 μm. A metal member having a three-layer structure in which a bump forming copper layer to be used as a bump 52 is laminated with a nickel film having a thickness of about 0.5 to 2 μm is prepared, and the bump forming copper layer is photoetched An interlayer connection bump 52 is formed by processing to expose the surface of the nickel film, and a base material obtained by etching the nickel film using the remaining interlayer connection bump 52 as an etching mask is used.
[0019]
The metal base member 56 is not formed with the interlayer connection bumps 52 in the portion where the semiconductor chip 20 escapes when the semiconductor chip 20 is laminated on the first metal base member 16 which is flip-chip connected. A chip storage space 42 for escaping the chips is provided.
The second metal base member 56 is laminated with an interlayer insulating film 40 having a pattern (pattern having a device hole) through which the interlayer connection bumps 52 penetrate and the chip housing space 42 is not occupied.
[0020]
The interlayer insulating film 40 is made of an insulating film made of polyimide, liquid crystal polymer, glass cloth-impregnated B-stage resin, or BCB film, and has a chip storage space 42 that can be said to be a device hole of about 20 mm in length and width for placing the semiconductor chip 20. It ’s open. The thickness of the insulating film 40 is set to be substantially the same as the thickness of the semiconductor chip 20 or about 1 to 5 μm thicker than the semiconductor chip 20.
Furthermore, in other words, the space filling resin 58 is applied on the chip storage space 42 at the place where the semiconductor chip 20 is mounted. This is to prevent a gap from being generated between the chip 20 and the second metal base member 56.
[0021]
(B) Next, an insulating material made of an underfill resin such as ACF, ACP, NCF, or NCP, or a film is applied as an insulating layer 30 to the place where the semiconductor chip 20 of the first metal base member 16 is mounted. The semiconductor chip 20 is flip-chip connected to the first metal base member 16 so that each electrode thereof is connected to the corresponding electrode connection bump 12 on the wiring film 11. In that case, the insulating layer 30 is interposed between the semiconductor chip 20 and the first metal base member 16. FIG. 2B shows a state after the flip chip connection.
[0022]
(C) Next, as shown in FIG. 2C, a second metal base member 56 is laminated on the first metal base member 16 on which the semiconductor chip 20 is mounted. More specifically, the semiconductor chip 20 is housed in the chip storage space 42, and stacking is performed so that the top surfaces of the interlayer connection bumps 52 penetrating the interlayer insulating film 40 are connected to the wiring film 11.
(D) Next, as shown in FIG. 2D, a wiring film 51 is formed by selectively etching the wiring film forming copper layer 50 of the second metal base member 56, and then a cover is formed. A ray 60 is formed.
[0023]
(E) Next, as shown in FIG. 2 (E), the copper layer for forming terminal bumps is formed by selectively etching the terminal bump forming copper layer 10 of the first metal base member 16. A resist film 64 serving as an etching mask is selectively formed on 10.
(F) Next, as shown in FIG. 2F, the copper bumps 10 are etched by using the resist film 64 as a mask, thereby forming terminal bumps 13.
Thereafter, although not shown in FIG. 2, the nickel film is removed by etching using the terminal bumps 13 as a mask, and solder 15 is formed around the terminal bumps 13.
[0024]
As described above, in the electronic device of this embodiment, the semiconductor chip 20 is embedded between the two wiring films 11 and 51, and the periphery thereof is protected by the insulating layer 30, the insulating film 40, or the like. The semiconductor chip 20 can have a thickness of 50 μm or less such that the semiconductor chip 20 exhibits flexibility, and an electronic device having a flexible multilayer wiring board structure as a whole can be configured.
[0025]
In addition, this invention is not limited to the said embodiment, A various deformation | transformation is possible. Examples of this modification include the following.
(1) Although the two-layer structure has been described, the number of layers is arbitrary.
(2) The number of semiconductor chips 20 provided in each layer is arbitrary. In addition to the semiconductor chip 20, passive functional elements such as resistors and capacitors can be incorporated.
[0026]
(3) The thickness of the copper foil etc. which comprises the wiring films 11 and 51, and the thickness and material of the insulating layer 30 and the insulating film 40 are not limited to what was illustrated.
(4) The wiring film 51 is formed using a three-layer metal member having an etching stopper made of a nickel film. However, the formation method and material are not limited to those exemplified.
[0027]
(5) In the above-described embodiment shown in FIGS. 1 and 2, the wiring film 11 is formed by selectively plating nickel and copper on the surface of the copper base member 10, and further, at a predetermined portion of the wiring film 11. Although the plurality of bumps 12 for mounting the semiconductor chip are formed, the formation of the wiring film 11 is not limited to this method. For example, a copper foil used as the wiring film 11 is used, a plurality of bumps 12 for mounting a semiconductor chip are formed at predetermined locations on the copper foil, and the wiring film 11 is formed by etching the copper foil. Also good.
[0028]
(6) In the above embodiment, the plurality of bumps 12 for mounting the semiconductor chip 20 are formed at predetermined locations on the wiring film 11, but connection bumps are formed on the semiconductor chip 20 side. If it is, this bump 12 is not necessary.
(7) In the above embodiment, the thickness of the insulating film 40 is set to be substantially the same as the thickness of the semiconductor chip 20 or about 1 to 5 μm thicker than the semiconductor chip 20. You may set to the thickness of 1/3-2/3 of the 2nd copper foil in the metal member 56 used.
As a reference example, an electronic device includes a multilayer wiring board in which interlayer connection of a plurality of wiring films interlayer-insulated by a plurality of interlayer insulating layers is made by an interlayer connection conductive layer penetrating the interlayer insulating layer. In any one of the interlayer insulating layers, an electrode is formed so as to be connected to the wiring film, and the semiconductor chip is formed in a thin thickness having flexibility. .
[0030]
【The invention's effect】
According to the electronic device of claim 1 , a semiconductor chip formed on a thin surface having flexibility on the surface of the first metal base member on which the wiring film is formed, and an electrode thereof on the wiring film and flip-chip bonding the connected state, the second metal base member, wiring layer of the first metal base member in which the semiconductor chip is fit and a second interlayer connection bumps correspond to those of the chip accommodation space An interlayer insulating film that insulates between the bumps and between the bump films and between the wiring films of the first and second metal base members is formed so as to be connected to the first metal base member . Therefore, the entire electronic device having the multilayer wiring board structure can be made flexible.
[0031]
According to a second aspect of the present invention, in the electronic device according to the first aspect , since the thickness of the semiconductor chip is 50 μm or less, the semiconductor chip is flexible and has a multilayer wiring board structure incorporating the semiconductor chip. The electronic device as a whole can be flexible.
According to an electronic device of a third aspect, in the electronic device according to the first aspect , the electrode of the semiconductor chip and the wiring film are made of a conductive material selectively formed on a surface portion of the wiring film. Since the connection is made via the electrode connection bump, the semiconductor chip can be flip-chip connected with higher reliability.
[0032]
According to the electronic device of claim 4, in the electronic device of claims 1 to 3 , since the interlayer insulating film is polyimide, liquid crystal polymer, glass cloth impregnated B stage resin, or BCB film, the interlayer insulating film forming operation Is easy and more reliable interlayer insulation is possible.
According to the electronic device manufacturing method of the fifth aspect, the electronic device having the multilayer wiring board structure according to the first aspect can be obtained.
[Brief description of the drawings]
FIGS. 1A to 1C are cross-sectional views showing a first embodiment of an electronic device of the present invention, FIG. 1A shows an electronic device in a normal state, and FIG. The state electronic device is shown deformed, and (C) shows the state where the built-in semiconductor chip is bent.
2A to 2F are cross-sectional views showing an example of a method for manufacturing the electronic device shown in FIG. 1 (first embodiment of the electronic device of the present invention) in the order of steps.
[Explanation of symbols]
10 ... Metal layer for forming bumps for terminals, 11, 51 ... Wiring film,
12 ... Electrode connection bumps, 13 ... Terminal bumps,
15 ... solder balls, 16 ... first metal base member ,
20 ... Semiconductor chip, 30 ... Insulating layer,
40 ... interlayer insulating film,
42 ... Chip storage space (device hole),
50 ... metal layer, 52 ... bump for interlayer connection,
56: Second metal base member .

Claims (5)

Is wired film formed on one surface, on the one surface of the first metal base member terminal bumps are formed on the rear surface of at least a part of the wiring layer, formed on the thin with flexible The semiconductor chip is flip-chip bonded with the electrodes connected to the wiring film,
The second metal base member has an interlayer connection bump connected to the wiring film on the one surface of the first metal base member and a chip housing space for storing the semiconductor chip on the same surface, and a second wiring film formed on the opposite side. The metal base member is overlaid on the first metal base member so that the semiconductor chip is accommodated in the chip storage space and the interlayer connection bumps are connected to the corresponding wiring films. An interlayer insulating film is formed between the bumps and between the wiring films of the first and second metal base members .
Having a multilayer wiring board structure,
An electronic device characterized by that. The electronic device according to claim 1, wherein the semiconductor chip has a thickness of 50 μm or less. And the electrode of said semiconductor chip, and the wiring film, according to claim 1, characterized in that it is connected via the electrode contact bumps made of selectively forming conductive material in the surface portion of the wiring film Electronic devices. The electronic device according to claim 1 , wherein the interlayer insulating film is made of an insulating film that is polyimide, liquid crystal polymer, glass cloth-impregnated B-stage resin, or BCB film. A first metal base member having a wiring film formed on the surface of a metal layer for forming a bump for terminals, a semiconductor chip formed in a flexible thin film, and one surface of the metal layer for forming a wiring film Having a chip housing space for accommodating the semiconductor chip and an interlayer connection bump connected to the wiring film of the first metal base member on the same surface, and further, the interlayer connection bump is penetrated through the surface. Preparing a second metal base member on which an interlayer insulating film is laminated so as not to occupy the chip storage space;
The semiconductor chip is flip-chip bonded to one surface of the first metal base member on the wiring film formation side so that the electrode is connected to the wiring film,
To said one surface of the first metal base member, the second metal base member, said semiconductor chip is accommodated in the said chip receiving space, and exposed from the interlayer insulating film of the interlayer connection bumps By connecting the top surface to the wiring film of the first metal base member , it is laminated via the interlayer insulating film,
To form a wiring layer by selectively etching the metal layer for the wiring film formation of the second metal base member, selectively above the terminal bump forming metal layer of the first metal base member A method for manufacturing an electronic device, comprising: forming a bump for a terminal by etching the substrate.

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