JP2002043506A - Wiring circuit board and its manufacturing method and semiconductor integrated circuit device and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve productivity, to easily thin a wiring circuit board and its wiring film, furthermore, to fine and highly integrate the wiring film, or the like by providing sufficient strength even if a part that becomes a base is thin in the wiring circuit board. SOLUTION: The wiring film 22 is provided, where the wiring film 22 is made of third metal being at least different from second metal at least including a part that is connected to a bump 28 made of the first metal for composing an external terminal via an etching stop layer 21b made of the second metal as one portion. On the wiring film 22, the wiring film 25 having a bump 24 for interlayer connection that is connected to the wiring film 22 is laminated via an interlayer insulating film 27. The outermost surface of the wiring film 25 other than an electrode connection part where the electrode of the electronic device 31 is connected with an insulating film 27.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a printed circuit board for mounting an electronic device, a method of manufacturing the same, a semiconductor integrated circuit device in which a plurality of printed circuit boards on which semiconductor chips and other electronic devices are mounted are stacked, and a method of manufacturing the same. Things.

[0002]

2. Description of the Related Art FIGS. 9A to 9E are cross-sectional views showing one example of a conventional method of manufacturing a printed circuit board in the order of steps. (A) Resin film made of polyimide (thickness of 75 to 1)
25 μm) 1 is prepared, and a copper film (0.2 μm thick) is formed on both main surfaces of the film 1 for conductivity by, for example, sputtering, and then, between the upper and lower wirings using a drill or pressing. Forming a through hole 2 for connection,
Thereafter, electroless plating of copper is performed to reduce the electric resistance of the copper film. FIG. 9 (B) shows a state after the electroless plating, and reference numeral 3 denotes a copper film (5 μm thick) after the electroless plating.

(B) A resist film 4 having a negative pattern with respect to a wiring film to be formed is formed on both main surfaces of the film 1, and copper is electrolytically plated using the resist film 4 as a mask. Wiring film made of copper (thickness 3
0 μm) 5. FIG. 9B shows a state after the wiring film 5 is formed.

(C) The resist film 4 is removed, and then copper is lightly etched to form a copper film formed by sputtering for conductivity and a copper film formed by electroless plating, which is a base of the wiring film 5. Is removed. As a result, the wiring films 5 become independent and separated from each other in a state where they are electrically short-circuited by the underlying copper film. FIG. 9 (C)
Indicates the state after the light etching.

(D) An insulating film 6 made of resist is formed on one main surface of the resin film 1 except for a portion of the wiring film 5 to which a device electrode is to be connected, and the main surface is protected. Reference numeral 7 denotes an electrode connection opening of the insulating film 6, and the opening 7
Then, the surface of the wiring film 5 is exposed. FIG. 9D shows the insulating film 6.
This shows the state after formation. (E) Thereafter, the resin film 1 is selectively etched from the other main surface side using the wiring film 5 made of copper as a mask, thereby exposing the back surface of the wiring film 5 on the one main surface side. The exposed portion 8 is a solder ball forming portion on which a solder ball described later is formed. 9 is a printed circuit board thus formed.

FIGS. 10A to 10C show an electronic device such as an LSI chip mounted on the printed circuit board 9.
It is sectional drawing which shows the method of forming a solder ball in order of a process. As shown in FIG. 10A, the LSI chip 10 is exposed to the printed circuit board 9 so that the electrode 11 and the corresponding opening 7 are aligned with each other, and as shown in FIG. Is connected to a portion of the wiring film 6 exposed to the opening 7.

Next, as shown in FIG. 10C, a solder ball 12 is formed on a portion 8 of the one main surface of the printed circuit board 9 where the back surface of the wiring film 5 is exposed.

FIGS. 11A to 11E are sectional views showing another conventional example of a method of manufacturing a printed circuit board in the order of steps. (A) A resin film made of a polyimide resin with an adhesive having an adhesive on one main surface (film thickness of 75 to 125 μm)
1a is prepared, and thereafter, a through-hole 2 for connecting the upper and lower wirings is formed by using a drill or by press working. Then, a copper foil (18 μm) 5 for forming a wiring film is formed on the resin film 1a via the adhesive. Adheres to the main surface of Specifically, they are bonded by thermocompression bonding, and then heat-treated for heat curing to cure the adhesive. FIG. 11A shows a state after bonding.

(B) Next, a resist film 4 is applied to the surface of the copper foil 5, and the wiring film to be formed by exposing and developing the resist film 4 is patterned into a negative pattern. Thereafter, a resist film 4 is applied to the other main surface of the resin film 1a.
Is exposed and developed to pattern only the through holes 2. FIG. 11B shows a state after the formation of the resist film 6 filling the through hole 2.

(C) Next, the wiring film 5 is formed by selectively etching the copper foil 5 using the resist film 6 as a mask. During this etching, the through holes 2 of the copper foil 5
Is masked by the resist film 4 and is not etched. After that, the resist film 4 is removed. FIG. 11C shows a state after the resist film 4 is removed.

(D) Next, an insulating film 6 made of a resist is selectively formed on one main surface of the resin film 1. Thereafter, an electroless nickel plating process is performed, and thereafter, an electroless gold plating process is performed. FIG. 11D shows this insulating film 6.
Shows the state after selective formation of. Reference numeral 7 denotes an opening for selectively exposing the wiring film 5 of the insulating film 6. 9a is a printed circuit board made. (E) Next, the semiconductor chip 10 is mounted on the printed circuit board 9a by connecting the bump electrodes 11 of the semiconductor chip 10 to the portions of the wiring film 5 exposed to the openings 7, and thereafter, A solder ball 11 is formed on the back surface of the portion exposed to the through hole 2. FIG. 11E shows a state after the formation of the solder ball 11.

[0012]

As described above, according to the prior art, since a printed circuit board is manufactured on the basis of a polyimide film, a certain level of mechanical strength is required due to transportation and handling. Since it is necessary, there is a limit in reducing the thickness of the wiring film and the thickness of the insulating film, and usually about 100 μm is required. Therefore, there is a problem that there is a limit in thinning.

Further, when a plurality of printed circuit boards are stacked for three-dimensional mounting, it is necessary to connect the printed circuit boards with solder balls interposed therebetween. There is also a problem that the solder is easily deformed due to the melting and pressurization due to heat, and the LSI chip is likely to be damaged. Of course, the above-mentioned problem that it is difficult to reduce the thickness of one printed circuit board is a problem that, when a plurality of printed circuit boards are stacked and three-dimensionally mounted, the larger the number of printed circuit boards, the more the three-dimensional package This is a factor that significantly increases the thickness of the substrate.

When the wiring layers of the printed circuit board are multi-layered, mechanical drilling of the film is indispensable for the interlayer connection between the wiring films on both sides, but in order to ensure the reliability of the interlayer connection. In addition, it is indispensable to make the diameter of the hole more than a certain level, and reduction in the diameter is restricted. However, when the hole diameter is increased, elongation and deformation of the film, displacement of each portion of the wiring film, and the like are caused, and adverse effects on the wiring film such as elongation, deformation, and displacement are increased as the wiring film becomes finer. Therefore, there is a problem that the miniaturization of the wiring film is limited.

For this reason, drilling is a very important technique. As one of the drilling techniques, there is a technique of drilling with a laser beam using a laser device. There are problems such as the generation of foreign matter and a long time. Furthermore, since the wiring film made of copper constituting the circuit is formed on the insulating layer by the electrolytic plating method, electroless plating for conducting treatment is required as a base treatment for plating, and the insulating film and the plating film are formed. There is also a problem that the bonding strength cannot be sufficiently increased, which has also been a factor that hinders miniaturization of the wiring film. Further, performing both the electroless plating and the electrolytic plating complicates the process, and has been a factor in causing an increase in the price of the printed circuit board.

When a plurality of printed circuit boards are stacked for three-dimensional arrangement of LSI chips, it is necessary to mount solder balls or the like in order to form terminal portions in a bump shape. It is necessary to perform the process, which involves a problem that the process becomes complicated. In addition, variations in the height of the balls are likely to occur, and the variation in the height has been a factor preventing the printed circuit boards from being properly stacked.

For forming the solder balls, a jig for determining the ball mounting position is used.
(5 mm or less), which hinders good mounting due to static electricity. Also, the jig cost (6 million yen) is not inexpensive at all, and has become a cost-increasing factor that cannot be ignored.

Further, in a temperature cycle test after mounting the substrate, a large area area of a land on which the ball is mounted is required to improve the ball drop due to stress caused by a difference in expansion coefficient between the substrate and the chip. Therefore, there is a problem that the number of wirings between the balls is limited, and there is a limit to miniaturization and high density of the wiring film. Furthermore, in bonding the printed circuit board and the LSI chip, it is necessary to form expensive bumps such as gold balls on the LSI chip side, and there has been a problem that the material cost is increased and the cost is increased.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is possible to provide a printed circuit board having sufficient strength even when a base portion of the printed circuit board is thin, thereby improving productivity. The purpose of the present invention is to improve the quality of the printed circuit board and to facilitate the thinning of the wiring film, and furthermore, to achieve the finer and higher integration of the wiring film. Another object of the present invention is to solve various problems caused by stacking circuit boards, and eliminate the need to make a laser beam or press working on a base for interlayer connection. Another object of the present invention is to avoid the problem that the base is extended or displaced, thereby eliminating the need for electroless plating, which is a prerequisite for forming a wiring film by electrolytic plating. Still another object is to reduce the number, eliminate the need to use expensive materials such as gold balls, and reduce the cost of a printed circuit board or a laminate thereof. .

[0020]

According to a first aspect of the present invention, there is provided a printed circuit board including a part connected to a bump made of a first metal and forming an external terminal via an etching stop layer made of a second metal. A wiring film made of a third metal that is different from at least the second metal that includes at least;
On the wiring film, another one or more wiring films having bumps for interlayer connection to be connected thereto are laminated via an interlayer insulating film, and the uppermost wiring film among the wiring films is formed on the wiring film. And an electrode connecting portion to which an electronic device electrode is connected, and covered with an insulating film.

According to a second aspect of the present invention, there is provided the wired circuit board according to the first aspect, wherein the bumps forming the external terminals are covered with solder.

According to a third aspect of the present invention, there is provided the wired circuit board according to the first or second aspect, wherein a surface of the electrode connection portion of the outermost wiring film is covered with gold.

According to a fourth aspect of the present invention, there is provided a printed circuit board comprising: a metal film for forming a bump made of a first metal; an etching stop layer made of a second metal having an etching selectivity with respect to the first metal; Forming a wiring film by patterning the metal film for forming a wiring film on a metal substrate having a three-layer structure in which a metal film for forming a wiring film formed of a third metal different from the third metal is stacked; On the main surface of the metal substrate on which the wiring film is formed, a metal foil for forming a wiring film having a bump for interlayer connection on one surface is insulated by connecting the bump to the wiring film. Bonding with an adhesive, and forming a wiring film of one or more layers including at least a step of forming a wiring film by selectively etching the wiring film forming metal foil having the bump, The wiring A step of covering the wiring film with an insulating film on the surface on which the uppermost wiring film is formed, leaving an electrode connecting portion to which an electronic device electrode is connected; and forming a bump forming metal of the three-layer metal substrate. Forming a bump forming an external terminal by selectively etching the film.

According to a fifth aspect of the present invention, there is provided a method of manufacturing a printed circuit board according to the fourth aspect, wherein the bump forming an external terminal is formed by selectively etching the metal film for forming a bump. The method is characterized in that a surface of the bump is covered with solder by using a solder layer selectively formed on the surface of the metal film and performing a reflow process on the solder layer after the selective etching is completed.

According to a sixth aspect of the present invention, there is provided the printed circuit board having at least a part including at least a part connected via a first metal interconnect bump and a second metal via an etching stop layer. A bump made of a third metal different from the second metal and separated from each other by an insulating layer, and connected to a bump forming the external terminal among the bumps for the interlayer connection The bumps that are not formed are used as bumps for connecting electronic device electrodes, and at least a portion of the insulating layer that is connected to the bumps for interlayer connection on the surface of the insulating layer opposite to the side on which the bumps for wiring circuit board connection are formed is provided. One or more wiring films are formed, and the surface of the wiring film on which the outermost wiring film is formed is formed between the electrode connection portion to which the electronic device electrode is connected and the wiring circuit board. Characterized by comprising covered with an insulating film leaving the wiring circuit board interconnection bump connection unit connection bumps are connected.

According to a seventh aspect of the present invention, in the wired circuit board according to the sixth aspect, the surface of the bump for connection between the wired circuit boards is covered with solder.

According to an eighth aspect of the present invention, in the wired circuit board according to the sixth or seventh aspect, the surface of the electrode connection portion of the outermost wiring film is covered with gold.

According to a ninth aspect of the present invention, there is provided a method of manufacturing a printed circuit board, comprising the steps of: forming a metal film made of a first metal for forming a bump between wiring circuit boards; and a second metal having an etching selectivity with the first metal. Etching stop layer and at least a second
The bumps are connected to the wiring circuit board connection bumps by patterning the bump formation metal films of a three-layer metal substrate in which a bump formation metal film made of a third metal different from the third metal is laminated. Forming bumps to be connected and bumps for connecting unconnected electronic device electrodes, and insulates and separates the respective bumps on the main surface of the metal substrate on which the bumps made of the third metal are formed. A step of laminating a metal foil for forming a wiring film via an insulating layer, and a step of forming a single or multiple-layer wiring film including at least a step of forming a wiring film by selectively etching the metal foil. On the surface of the wiring film on which the uppermost wiring film is formed, an insulating film covering a portion other than a portion to which the electronic device electrode of the wiring film is connected and a portion to which the wiring circuit board connection bump is connected is connected. Forming a bump for wiring circuit board connection by selectively etching the metal film for forming a wiring circuit board connection bump of the three-layer structure metal substrate. And

According to a tenth aspect of the present invention, there is provided a method of manufacturing a wired circuit board according to the ninth aspect, wherein bumps forming external terminals are formed by selectively etching a metal film for forming a bump for connecting the wired circuit boards. A solder layer selectively formed on the surface of the metal film as an etching mask, and performing a reflow process on the solder layer after completion of the selective etching, so that the surface of the bump is covered with solder. It is characterized by.

The semiconductor integrated circuit device according to the eleventh aspect is characterized in that:
A third metal that is different from at least the second metal, at least including at least a portion connected via a bump for wiring circuit board connection made of the metal and an etching stop layer made of the second metal And bumps that are not connected to the bumps that form the external terminals of the bumps are used as electronic device electrode connection bumps, and the external terminals of the insulating layer A wiring layer of one or more layers having at least a portion connected to the bump for interlayer connection is formed on the surface opposite to the side on which the bumps are formed, and the outermost surface of the wiring film A plurality of wiring circuit bases covered with an insulating film, leaving an electrode connection portion to which an electronic device electrode is connected and a bump connection portion to which a bump for connection between wiring circuit boards is connected on the wiring film. And a plurality of semiconductors having electrodes connected to electrode connection portions of the wiring film of each of the wiring circuit boards or to bumps made of the third metal, which are not connected to the wiring circuit board connection bumps. A chip or other electronic device, and having the plurality of wiring circuit boards connected to the electronic device on both sides or one side in the same direction, and connecting wiring circuit board connection bumps of one wiring circuit board, It is characterized in that a plurality of wiring circuit boards are stacked by connecting to a bump connection portion of a wiring film of another wiring circuit board.

According to a twelfth aspect of the present invention, there is provided a method of manufacturing a semiconductor integrated circuit device, wherein a part connected via an interconnecting bump made of a first metal and an etching stop layer made of a second metal is partially included. A third metal, which is a metal different from at least the second metal, including at least a bump for interlayer connection which is insulated and separated from each other by an insulating layer; Unconnected bumps are used as electronic device electrode connection bumps,
On the surface of the insulating layer opposite to the side on which the bumps forming the external terminals are formed, one or more layers of wiring films having at least a portion connected to the bump for interlayer connection are formed. On the surface of the wiring film, prepare a plurality of wiring circuit boards covered with an insulating film, leaving an electrode connection portion to which the electronic device electrode is connected and a bump connection portion to which the wiring circuit board connection bump is connected. Connect the electronic device electrode to the electrode connection portion of the wiring film of the wiring circuit board and the bump made of the third metal, which is not connected to the bump for connection between the wiring circuit boards, on both surfaces or one surface. A semiconductor chip or other electronic device is mounted, the plurality of wiring circuit boards are stacked in the same direction, and the bumps for connecting the wiring circuit boards of one wiring circuit board are connected to the bumps of the wiring film of another wiring circuit board. By connecting the connecting portion, characterized by stacking a plurality of printed circuit board.

A semiconductor integrated circuit device according to a thirteenth aspect is characterized in that:
A third metal that is different from at least the second metal, at least including at least a portion connected via a bump for wiring circuit board connection made of the metal and an etching stop layer made of the second metal And bumps that are not connected to the bumps that form the external terminals of the bumps are used as electronic device electrode connection bumps, and the external terminals of the insulating layer A wiring layer of one or more layers having at least a portion connected to the bump for interlayer connection is formed on the surface opposite to the side on which the bumps are formed, and the outermost surface of the wiring film The wiring film is covered with an insulating film except for an electrode connection portion to which an electronic device electrode is connected and a bump connection portion to which a wiring circuit board connection bump is connected. A plurality of wiring circuit boards which are formed so as to protrude from the other and have a heat sink connection part on one surface of the protruding part, and the electrode connection part of the wiring film of each of the wiring circuit boards or the third A plurality of semiconductor chips or other electronic devices in which electrodes are connected to bumps made of a metal which are not connected to the wiring circuit board connection bumps, and are widely formed of the plurality of wiring circuit boards. A concave heat sink that covers a wiring circuit board other than the one wiring circuit board including the electronic device connected thereto, and the other wiring circuit board having the electronic device connected to both sides or one side thereof has another The printed circuit boards of the one printed circuit board are stacked in the same direction, and the connection bump between the printed circuit boards of the one printed circuit board is connected to the bump connection portion of the wiring film of the other printed circuit board. By stacking a plurality of printed circuit boards, the upper edge of the heat sink is connected to the heat sink connecting portion of the one printed circuit board protruding from the other printed circuit board, and the other heat sink is connected to the other portion by the heat sink. Characterized in that the printed circuit board is covered with the electronic device connected thereto.

According to a fourteenth aspect of the present invention, at least a second circuit board includes at least a part of a bump connected to an external terminal made of a first metal and connected via an etching stop layer made of a second metal. A third metal, which is a different metal from the metal, having an interlayer connection bump which is insulated and separated from each other by an insulating layer; and an interlayer connection bump made of at least the third metal on the insulating layer. A wiring film of one or more layers having a part connected is formed, and an insulating film covering the wiring film other than the electronic device electrode connection portion of the wiring film is formed on the uppermost wiring film forming surface of the wiring film. It is characterized by having been formed.

According to a fifteenth aspect of the present invention, the electronic device electrode connection portion of the outermost wiring film is covered with gold.

According to a sixteenth aspect of the present invention, there is provided the wired circuit board according to the fourteenth aspect.
Alternatively, in the wired circuit board according to 15, the surface of the bump forming the external terminal is covered with solder.

A method for manufacturing a printed circuit board according to claim 17 is as follows.
A bump-forming metal film forming an external terminal made of a first metal, an etching stop layer made of a second metal having an etching selectivity with respect to the first metal, and a third metal layer different from at least the second metal; Forming the interlayer connection bumps by patterning the interlayer connection bump formation metal film of a three-layer structure metal substrate in which an interlayer connection bump formation metal film made of a metal is laminated; A step of adhering a metal foil via an insulating layer to the side of the metal substrate on which the interlayer connection bumps are formed, and a step of forming a wiring film by patterning the metal foil. Forming a wiring film, and forming a bump-forming metal film by selectively etching the bump-forming metal film forming the external terminal of the metal substrate having the three-layer structure. Characterized in that it.

The method of manufacturing a printed circuit board according to claim 18 is
18. The method for manufacturing a printed circuit board according to claim 17, wherein the bumps for connecting the electronic device electrodes are selectively formed on the surface of the metal film when the bumps for connecting the electronic device electrodes are formed by selectively etching the bump-forming metal film forming the external terminals. It is characterized in that a solder layer is used.

A printed circuit board according to a nineteenth aspect of the present invention includes at least a second circuit board including at least a part connected to an electronic device electrode connection bump made of a first metal via an etching stop layer made of a second metal. A wiring film made of a third metal, which is another metal different from the metal of the above, and one or more wiring films laminated on the surface on which the wiring film is formed or with an insulating film interposed therebetween. An insulating film is formed on the surface on which the wiring film is formed to cover portions other than the external terminal connection portion.

According to a twentieth aspect of the present invention, there is provided the wired circuit board according to the nineteenth aspect.
In the printed circuit board described above, a gold film is formed on a surface of the external terminal connection portion of the outermost wiring film.

According to a twenty-first aspect of the present invention, there is provided the printed circuit board according to the nineteenth aspect.
Wherein the surface of the electronic device electrode connection bump is covered with gold.

The method of manufacturing a printed circuit board according to claim 22 is
A metal film for forming an electronic device electrode connection bump formed of a first metal, an etching stop layer of a second metal having an etching selectivity with respect to the first metal, and at least a second metal different from the second metal; Forming a wiring film by patterning the metal film for forming a wiring film on a three-layer metal substrate in which a metal film for forming a wiring film made of the metal of No. 3 is laminated; and forming the wiring film or the wiring film. An insulating film covering the outermost surface of the one or more wiring films formed on the uppermost surface of the one or more wiring films formed with an insulating film therebetween, except for the external terminal connection portion of the uppermost wiring film. Forming an electronic device electrode connection bump by selectively etching the electronic device electrode connection bump formation metal film of the three-layer metal substrate; and forming the electronic device electrode connection bump. As a mask, and having a selectively etching the etch stop layer.

According to a twenty-third aspect of the present invention, there is provided a method for manufacturing a printed circuit board.
In the method for manufacturing a printed circuit board according to the present invention, a gold film is used as an etching mask when the metal film for forming bumps for connecting electronic device electrodes is selectively etched.

According to a twenty-fourth aspect of the present invention, there is provided a semiconductor integrated circuit device according to the first to third aspects of the present invention.
One or more semiconductor chips are mounted on the printed circuit board described in 19, 20, or 21.

[0044]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to illustrated embodiments. 1A to 1F are sectional views showing a first embodiment of a method of manufacturing a wired circuit board according to the present invention in the order of steps. In the present embodiment, the present invention is applied to a printed circuit board of a type in which electronic chips such as ICs are not three-dimensionally arranged and, therefore, a plurality of electronic chips are not stacked.

(A) A metal substrate 21 having a three-layer structure shown in FIG. 1A is prepared. Reference numeral 21a denotes a metal film having a thickness of, for example, about 80 to 150 μm which forms a base of the copper foil 21 and 21b is an etching stop layer on the surface of the metal film 21a. Any material can be used as long as it has a sufficient etching selectivity with respect to the copper or copper alloy in, for example, etching using a hydrochloric acid-based etching solution), but nickel or a nickel alloy is preferable. When this nickel or nickel alloy is used as the etching stop layer 21b, the thickness is preferably, for example, about 0.1 to 2 μm. The nickel-based etching stop layer 21b can be removed with an alkaline-based etching solution.

21c is the etching stop layer 21b
Is a thin metal film made of copper laminated on the surface of the substrate, and later becomes a wiring film, and its thickness is set in consideration of the wiring width and the electrical characteristics. For example, the thickness is preferably about 1 to 20 μm.

(B) Next, the three-layer metal substrate 21
The wiring film 22 is formed by patterning the metal film 21c by photo-etching. Thereafter, a circuit-forming substrate 23 having bumps is prepared, and the circuit-forming substrate 23 is aligned with the metal substrate 21. . Specifically, each bump 2 made of copper or the like of the circuit forming substrate 23 is used.
4 is positioned so as to be located on a portion of the wiring film 22 to be connected to the bump 24. FIG. 1B shows a state where the alignment is performed.

The circuit forming substrate 23 is formed, for example, by forming a copper foil 24 on a copper foil (thickness, for example, 1 to 20 μm) 25 via a nickel-based metal film (thickness, for example, 0.1 to 2 μm) 26. A laminate is prepared, and the copper foil 24 is selectively etched to form a bump 24 made of the copper foil. Thereafter, the nickel-based metal film 2 serving as an etching stop layer at the time of the etching is formed.
6 is removed using the bumps 24 as a mask, and thereafter,
Insulating layer having adhesiveness (thickness, for example, 10 to 35 μm) 2
7 is laminated on the main surface of the circuit-forming substrate 23 on the side where the bumps 24 are formed so that the bumps 24 pierce and protrude the tips. The insulating layer 27 is made of, for example, a resin such as glass epoxy, liquid crystal polymer, or thermoplastic polyimide.

A circuit forming substrate of this type and a method for manufacturing the same have already been proposed by the present applicant in a patent application (application number: Japanese Patent Application No. 2000-142856). According to the patent application, a metal foil such as a single-layer copper foil (ie, a metal foil without an etching stop layer) is prepared.
A technique for forming a bump by half etching has also been proposed, and the technique can be used in the present invention.

(C) From the state shown in FIG.
As shown in (C), the circuit forming substrate 23 is laminated on the metal substrate 21 by connecting the bumps 24 to the wiring film 22 by thermocompression bonding. The portions other than the bumps 24 of the circuit forming substrate 23 and the metal substrate 21 are bonded via the insulating layer 27. (D) Next, the wiring film 25 is formed by photo-etching the copper foil 25 of the circuit forming substrate 23, and then the surface on which the wiring film 25 is formed including the surface on the wiring film 25 is formed. It is selectively covered with an insulating film 27a, and thereafter, nickel plating (thickness, for example, 2 μm) and gold plating (thickness, for example, 0.3 μm) are formed.
The connectivity with the electrodes of the I chip is improved. Reference numeral 27b denotes an opening for partially exposing the wiring film 25 of the insulating film 27a, and an electrode of a semiconductor chip described later is connected to the wiring film 25 in the opening 27b.

(E) Next, the bumps 28 and the reinforcing portions 29 are formed by selectively etching the metal film 21a made of copper on the metal substrate 21 from the back side. Reference numeral 30 denotes a solder film (thickness, for example, 10 to 50 μm) used as an etching mask in the selective etching, and is formed by plating. Since the solder film 30 can be patterned by being selectively removed by alkali etching using a resist film or the like as a mask, the solder film 30 can be used as an etching mask in the etching for forming the bumps 28 and the reinforcing portions 29 forming the external terminals. FIG. 1E shows a state in which etching of the metal film 21a made of copper using the solder film 30 as a mask has been completed.

(F) Next, the surface of the bump 28 forming the connection terminal is covered with the solder 30 by performing a reflow process on the solder film 30. This bump 2
8 covered with solder 30 serves as external terminals of the printed circuit board 32, and connection between the printed circuit board 32 and a printed circuit board (not shown) is made through the external terminals. Then, the LSI chip 31a (logic LSI chip), 3
1b (memory LSI chip) is mounted on the main surface of the printed circuit board 32 on the side opposite to the bumps 28. Specifically, the bump electrodes 33 whose surfaces are covered with gold of the chips 31a and 31b are mounted on the surface of the wiring film 22 exposed in the opening 27 by bonding.

According to the printed circuit board according to the embodiment shown in FIG. 1, since it can be manufactured based on the metal substrate 21 having a three-layer structure, the mechanical strength necessary for transport and other handling can be ensured even if it is thin. In addition, the wiring film on the substrate can be made thinner than before, and the wiring film can be made thinner, so that high integration can be easily achieved.

Further, unlike the case where the external terminals are formed of the bumps 28 and the solder balls are used, there is no danger of the solder balls falling, deformation due to the melting of the solder, and poor connection due to the change in thickness. Further, the problem that a special expensive alignment jig is required for the alignment of the solder balls can be avoided. Further, since the bumps 24 are used for the interlayer connection, it is not necessary to form a hole for the interlayer connection as in the related art. Therefore, the limit of reducing the diameter of the hole, which occurred when the hole was drilled by the laser beam,
Various problems such as deformation of the film due to the holes, generation of foreign matter due to heat treatment, and time required for heat treatment, and a decrease in productivity do not occur.

Since the metal substrate 21 is used as a base and before the metal film 21a is patterned, a nickel-based metal film and a gold layer are formed in portions of the wiring film 25 where the electrodes of the electronic devices 31a and 31b are connected. These layers can be formed by electrolytic plating, and there is no need for electroless plating. Therefore, a high-quality plating layer can be easily formed. This is because the metal film 21a of the metal substrate 21 can be used for transmitting a potential to each plating portion necessary for electrolytic plating, and therefore, the electroless plating process is not required.

FIGS. 2A to 2E are sectional views showing a second embodiment of the method of manufacturing a printed circuit board according to the present invention in the order of steps.
In this embodiment, a printed circuit board (here, a plurality of the present invention can be stacked and electronic devices such as LSI chips can be arranged three-dimensionally).
In the present embodiment, when a plurality of printed circuit boards are stacked, they are already mounted on each printed circuit board, and a semiconductor chip and other electronic devices are already mounted at the stage of stacking. I can say. ) Is applied to the configuration.

(A) A metal substrate 21 having a three-layer structure as shown in FIG. 1A is prepared. However, the metal substrate 21 in the present embodiment is different from that shown in FIG. 1A only in that the thickness of the metal film 21c made of copper is different and is 40 to 70 μm. Then, a bump 35 for interlayer connection is formed by photoetching the metal film 21c. The bump 35 has a thickness (height) of about 60 μm and a diameter of about 50 μm. FIG. 2A shows a state after the bump 35 is formed, and thereafter, a resist film used as an etching mask in the selective etching of the bump 35 is removed.

(B) Next, as shown in FIG. 2 (B), an insulating layer (thickness: 25 to 35 μm) 36 having adhesiveness is formed on the surface of the metal substrate 21 on which the bumps 35 are formed. The bump 35 is adhered so as to be penetrated by 35 so that the tip of the bump 35 protrudes from the surface. The material may be the same as, for example, the insulating layer 27 of the first embodiment. (C) Next, as shown in FIG.
A copper foil 37 (thickness: 12 to 35 μm) serving as a wiring film is laminated by thermocompression bonding on the surface on which the one bump 35 is formed and the insulating layer 27 is bonded. The processing conditions of this lamination processing are, for example, a heating temperature of 300 ° C., a pressure of 50 kg / cm ₂ , and a pressing time of 10 minutes.

(D) Next, a wiring film 37 is formed by photo-etching the laminated copper foil (37), and then an insulating layer 38 made of, for example, a resist is selectively formed on the surface on which the wiring film 37 is formed. Further, nickel plating and gold plating are sequentially performed on the surface of the wiring film 37 to ensure connectivity, and thereafter, the metal film 2 of the metal substrate 21 is formed.
1a is etched using a solder layer selectively formed on the surface thereof as a mask to form bumps 39 and reinforcing portions 40.
Is formed, and then the solder layer is reflowed.
1 to cover the bump 39. Thus, the printed circuit board 44 is completed.

Thereafter, the semiconductor chips 31, 31 are made to face both surfaces of the metal substrate 21. Specifically, the metal substrate 21
On the wiring film 37 forming side, the bump electrode 43 of the semiconductor chip 31 faces the portion of the wiring film 37 exposed to the insulating layer 38 opening 42, and on the metal film 21 a side of the metal substrate 21, the bump of the semiconductor chip 31 Electrode 43 is bump 3
Face 5. FIG. 2 (D) shows the state in which it is seen.
The processes from the formation of the wiring film by the selective etching of the copper foil 37 to the formation of the bumps 39 and the reflow of the solder layer used as a mask are the same as those of the first embodiment shown in FIG.

In the present embodiment, the semiconductor chips 31, 31,... Are mounted on both sides of each metal substrate 21, but it is not indispensable to do so. For example, the semiconductor chips 31, 31,... May be mounted only on the surface on which the bump 39 is formed. Also, semiconductor chips 31, 31,... Are mounted on both sides of a part of the plurality of stacked metal substrates 21, 21,. Semiconductor chips 31, 31, ...
May be mounted. Further, not all of the components mounted on the metal substrate 31 need to be the semiconductor chips 31, and some of them may be resistors, capacitors, inductive elements, or other conductive devices. There may be variations.

(E) Thereafter, the semiconductor chip 31 is connected to the wiring film 37 of the wiring circuit board 44 by the bump electrode 43.
Is mounted on the printed circuit board 44 by pressure bonding or thermocompression bonding to the exposed portion of the opening 42 and the bump 35. Then, as described above, the printed circuit board 4 having the semiconductor chips 31 mounted on both sides thereof
4 and a plurality of bumps 39 on one printed circuit board 44.
Is located on a portion of another wiring circuit board 44 exposed to the opening 42 of the wiring film 37. By reflowing the solder 30 covering the surface of the bump 39 in such a state, the bump 39 is connected to the exposed portion of the wiring film 37 via the solder 30, and thus the plurality of wiring circuit boards 44.
4 are laminated. FIG. 2E shows a state after the lamination. In FIG. 2E, two printed circuit boards 44 are used.
Are shown, but the number of stacked printed circuit boards is not limited to two, and three or more, for example, ten or more printed circuit boards can be stacked. is there.

The printed circuit board according to the present embodiment also has the same advantages as the printed circuit board according to the first embodiment shown in FIG. That is, first, the metal substrate 21 having a three-layer structure can be used as a base, so that even if it is thin, the mechanical strength necessary for transportation and handling can be secured, the substrate can be made thinner, and the wiring film can be made thinner. Therefore, there is an advantage that high integration can be easily achieved. Further, since the bumps 39 are used for the connection between the printed circuit boards, unlike the case of using the solder balls, there is no danger of the solder balls falling, deformation due to melting of the solder, connection failure due to a change in thickness, and the like, and In addition, the problem that a special and expensive positioning jig is required for positioning the solder ball can be avoided. Further, since the bumps 35 are used for interlayer connection, a hole is not required for interlayer connection as in the related art, and therefore, a reduction in the diameter of the hole, which has occurred when the hole was drilled by a laser beam. There is also an advantage that various problems such as limitations, deformation of the film due to holes, generation of foreign substances due to heat treatment, and time required for heat treatment are not caused, and productivity is reduced.

Further, based on the metal substrate 21, before patterning the metal film 21 a, a nickel-based metal film or a gold layer is formed on a portion of the wiring film 25 where the electrodes of the semiconductor chips (electronic devices) 31 a and 31 b are connected. So that
At that time, the metal film 21a in an unpatterned state can be used as a potential transmission path, and these layers (a nickel layer and a gold layer) can be formed by electrolytic plating.
There is also an advantage that there is no need for electroless plating.

Further, the printed circuit board according to the present embodiment has a great advantage that the electronic devices can be three-dimensionally mounted at a very high density by stacking a plurality of them. FIG.
3A and 3B are cross-sectional views showing dimensions of a printed circuit board according to a second embodiment of the present invention shown in FIG. 2 and a conventional example, respectively, and FIG. FIG. 7B is a cross-sectional view showing the dimensions of a memory card to which the second embodiment of the present invention is applied, in which FIG. When the second embodiment is compared with the conventional example according to FIG. 3, the thickness is about 275 μm in the conventional case, whereas the thickness is 210 μm in the second embodiment. So that one step of the printed circuit board,
It can be as thin as about 65 μm. Therefore, the number of stages of the printed circuit board that can be accommodated in the same mounting space can be made larger in the case of the present invention than in the conventional case.

In the case where a memory card is manufactured, in one case, a printed circuit board must be laminated within a thickness of 1.3 mm as shown in FIG. In the conventional case, only four printed circuit boards can be stacked. In the present invention, six printed circuit boards can be stacked. Of course, the printed circuit board according to the present invention still has the possibility of being made thinner, so that there is a possibility that ten or more printed circuit boards can be stacked.

In the conventional case, the solder balls are used for the connection between the printed circuit boards, so that the connection failure due to the falling off of the solder balls is large.
Is used for the connection between the printed circuit boards, and it goes without saying that there is no room for such troubles such as falling off.

FIGS. 4A to 4D are sectional views showing a third embodiment of the method of manufacturing a printed circuit board according to the present invention in the order of steps. In the present embodiment, the present invention is applied to a printed circuit board of a type in which electronic chips such as ICs are not three-dimensionally arranged and, therefore, a plurality of electronic chips are not stacked. (A) After the bumps 35 for interlayer connection are formed by selectively etching the metal film 21c of the metal substrate 21 having a three-layer structure in the same steps as FIGS. 2 (A) to 2 (C),
The insulating layer 36 having adhesiveness is formed on the bump 35 of the metal substrate 21.
The copper foil 37 is laminated on the metal substrate 21 via the insulating layer 36, and thereafter, the wiring film 37 is formed by selectively etching the copper foil 37. . FIG. 4A shows a state after the wiring film 37 is formed.

(B) Next, as shown in FIG. 4B, the circuit forming substrate 23 is exposed to the main surface of the metal substrate 21 on the side where the wiring film 37 is formed. The circuit forming substrate 23 is formed in exactly the same manner as the circuit forming substrate 23 shown in FIG. It is needless to say that a substrate without the nickel or nickel alloy layer 26 (having the bumps 24 formed by half etching) may be used as the circuit forming substrate 23. Specifically, the bump 24 of the circuit-forming substrate 23 is made to face the bump connection portion 37a of the wiring film 37. Then, the circuit forming substrate 23 is replaced with the metal substrate 2.
1. Adhesively bond to 1.

(C) Next, a wiring film 25 is formed by patterning the copper foil 25 of the circuit forming substrate 23, and thereafter, an insulating layer 38 made of, for example, a resist is selectively formed to form a semiconductor layer to be described later. Chips (31a, 31b)
Opening 42 only in the portion to which bump electrode (43) is to be connected.
Is formed. Then, a portion of the wiring film 25 exposed to the opening 42 is a portion to which the bump electrode of the semiconductor chip is connected. FIG. 4C shows a state after the formation of the insulating layer 38.

(D) Next, the metal film 2 on the metal substrate 21
The bump 39 and the reinforcing portion 40 are formed by selective etching using the solder layer selectively formed on the reinforcing portion 1a as a mask, and then the solder layer on the reinforcing portion 40 is removed. Apply. as a result,
The bump 39 is covered with the solder 30. The method of forming the bumps 39 and the reinforcing portions 40 and the reflow process are the same as those in the embodiment shown in FIGS. Thus, the printed circuit board 46 is completed. Thereafter, the semiconductor chips 31a and 31b are mounted on the surface of the printed circuit board 46 on the side opposite to the bump 39 as in the first embodiment shown in FIG.

The printed circuit board according to this embodiment has substantially the same advantages as the printed circuit board according to the first embodiment shown in FIG.

FIGS. 5A to 5E are sectional views showing a fourth embodiment of the printed circuit board of the present invention in the order of steps. In the present embodiment, the present invention is applied to a printed circuit board of a type in which electronic chips such as ICs are not three-dimensionally arranged and, therefore, a plurality of electronic chips are not stacked. (A) The same substrate as the metal substrate 21 having the three-layer structure shown in FIG. 1A is prepared, and the wiring film 22 is formed by selectively etching the metal film 21c. The thickness of the metal film 21c is set to an optimum value based on the fineness (width) of the wiring film 22 to be formed and the electrical characteristics. In the present embodiment, the thickness is, for example, 1 to 20 μm. Is the same as Incidentally, when the line / space is 8 μm / 8 μm, the thickness of the metal film 21 c is preferably about 10 μm. Next, the surface on the side of the metal substrate 21 where the wiring film 22 is formed is an insulating layer (for example, a thickness of 20 μm) made of, for example, a polyimide resist except for a portion of the wiring film 22 on which a later-described solder ball (12) is mounted. Cover with 50. Reference numeral 51 denotes an opening in the insulating layer 50 for exposing the wiring film 22 and has a thickness of 250 μm.
m, and the opening 51 is a solder ball mounting portion. FIG. 5A shows a state after the formation of the insulating layer 50.

(B) Next, as shown in FIG. 5B, a mask film 52 made of resist or gold is selectively formed on the surface of the metal film 21a of the metal substrate 21. When a material made of gold is used as the mask film 52, the gold also plays a role in enhancing the connectivity between the bumps to be formed later and the bumps of the semiconductor chip connected to the bumps. Thereafter, in order to enhance the adhesion of the surface of the wiring film 22 to the solder balls, nickel plating is performed, and then gold plating is performed.

(C) Next, the metal film 21a is etched using the mask film 52 as a mask to form the bump 5
Then, the etching stop layer 21b made of a nickel-based metal is selectively etched using the bumps 53 as a mask to separate the bumps 53 from each other. FIG. 5C shows a state after the selective etching of the etching stop layer 21b. Thereby, the printed circuit board 54
Can be.

(D) Next, when a resist is used as the mask film 52, the mask film 52 is removed, and when gold is used as the mask film 52, the bump 52 is left with the mask 52 left. LSI chips 31a and 31b at 53
The LSI chips 31 a and 31 b are bonded to the printed circuit board 54 via, for example, an anisotropic conductive film 55 by aligning the positions of the electrodes. After that, each LSI chip 3
The space between 1a and 31b is sealed with resin 56. FIG. 5D shows a state after sealing with the resin 56.

(E) Thereafter, as shown in FIG.
The solder ball 12 is mounted on a portion of the wiring film 22 exposed at the opening 51 of the insulating layer 50.

The printed circuit board 54 according to this embodiment is
The bumps 53 formed by the selective etching of the metal film 21a are connected to LSI chips 31a and 31b as electronic devices.
This is different from the printed circuit boards according to the first to third embodiments in that the solder balls 12 formed in portions exposed to the openings 51 of the wiring film 22 are used as external terminals. There is no fundamental difference except for
Advantages required for the printed circuit board according to the third embodiment are also generally recognized in the printed circuit board 54 according to the present embodiment.

FIGS. 6A to 6E and FIGS. 7F to 7F
(I) is sectional drawing which shows 5th Embodiment of the manufacturing method of the printed circuit board of this invention in order of process (A)-(I). In the present embodiment, the present invention is also applied to a printed circuit board of a type in which electronic chips such as ICs are not three-dimensionally arranged, and thus a plurality of electronic chips are not stacked.

(A) A metal substrate 21 having a three-layer structure as used in the first embodiment shown in FIG. 1 is prepared, and a resist film 60 is selectively formed on the metal film 21c.
FIG. 6A shows a state after the resist film 60 is selectively formed. (B) Next, as shown in FIG. 6A, a wiring film 61 is formed by electroplating copper on the metal film 21a using the resist film 60 as a mask.

(C) Next, as shown in FIG. 6 (C), the metal foil 6
The surface of the metal substrate 21 on which the bumps 64 are formed faces the metal film 21c side of the metal substrate 21. The metal foil 63 for forming a wiring film with a bump is formed by half-etching a single-layer metal foil made of, for example, copper using, for example, a resist film or the like selectively formed from one side as a mask. (D) Next, as shown in FIG. 6D, the metal foil 63 for forming a wiring film with bumps is bonded to the metal substrate 21 via the adhesive insulating layer 62.

(E) Next, a wiring film 63 is formed by selectively etching the metal foil 63, and thereafter,
On the surface on which the wiring film 63 is formed, an insulating layer 65 made of, for example, a resist is formed to cover a portion of the wiring film 63 other than a portion where a later-described solder ball (12) is to be formed. Reference numeral 66 denotes an opening formed in a portion of the insulating layer 65 where the solder ball (12) is to be formed. FIG. 6E shows the insulating layer 50.
This shows the state after formation.

(F) Next, the metal film 21a of the metal substrate 21
A mask film 52 made of resist or gold is selectively formed on the surface of the substrate. When a film made of gold is used as the mask film 52, the gold also plays a role of improving the connectivity between the bumps to be formed later and the bumps of the semiconductor chip connected to the bumps. FIG. 7F shows the mask film 53.
2 shows the state after formation. Thereafter, in order to increase the adhesion of the surface of the wiring film 63 to the solder balls, a nickel plating process is performed and then gold plating is performed.

(G) Next, the metal film 21a is etched using the mask film 52 as a mask to form the bump 5
Then, the bumps 53 and the reinforcing portions 67 are formed as masks, and the etching stop layer 21b made of a nickel-based metal is selectively etched using the bumps 53 and the reinforcing portions 67 as masks so that the bumps 53 are separated from each other. FIG. 7G shows a state after the selective etching of the etching stop layer 21b. Thus, the printed circuit board 68 is completed.

(H) Next, when a resist is used as the mask film 52, the mask film 52 is removed, and when gold is used as the mask film 52, the bump 52 is left with the mask 52 left. LSI chips 31a and 31b at 53
The LSI chips 31 a and 31 b are bonded to the printed circuit board 54 via, for example, an anisotropic conductive film 55 by aligning the positions of the electrodes. After that, each LSI chip 3
The space between 1a and 31b is sealed with resin 56. FIG. 7H shows a state after sealing with the resin 56.

(I) Then, as shown in FIG.
The solder ball 12 is mounted on a portion of the wiring film 22 exposed at the opening 51 of the insulating layer 50. In the printed circuit board 68 according to the present embodiment, the number of layers of the wiring film on the anti-electronic device mounting side is increased compared to the printed circuit board 54 according to the fourth embodiment shown in FIG. In this respect, it is different in that point, and it can be said that the degree of integration of the wiring is higher.

FIGS. 8A and 8B show a semiconductor integrated circuit according to the present invention in which semiconductor chips and other electronic devices are three-dimensionally arranged using a plurality of printed circuit boards, and the heat dissipation of the electronic devices is enhanced by housing them with a heat sink. 1A is a cross-sectional view showing one embodiment of a circuit device, FIG. 1A shows one printed circuit board used for the semiconductor integrated circuit device, and FIG.
Indicates a completed state of the semiconductor integrated circuit device housed by the heat sink.

Reference numeral 70 denotes one of the laminated printed circuit boards.
For example, a multilayer wiring film is formed by making full use of the technique as shown in FIG. 2 and connected to the electrodes of a semiconductor chip including a wiring circuit board connection bump 71 made of copper and an interlayer connection bump 72 on one surface. Semiconductor chip connection part to be formed.
The bump 72 is formed, for example, by the same method as the bump 35 shown in FIG. A solder layer 73 covers the surface of the bump 71.

The semiconductor integrated circuit device shown in FIG. 8A has two printed circuit boards 70, 70 on which the semiconductor chip 31 is mounted, and the printed circuit board 70 when the printed circuit board 70 is overlaid on the printed circuit board 70. As shown in FIG. 8B, the wiring circuit board 74 on which the semiconductor chip 31 is mounted is formed by using the bumps 71 for connection between the wiring circuit boards for connection between the wiring circuit boards. . This lamination is performed in the same manner as in the embodiment shown in FIG. The printed circuit board 74 is a surface on the side opposite to the bump 71 and a heat sink connection portion 75
Having.

The upper edge 77 of the concave heat sink 76 is connected to the heat sink connecting portion 75 in a state where the wiring circuit boards 70 and 70 and the wiring circuit board 74 are stacked. At this time, the uppermost semiconductor chip 31 and the bottom surface of the heat sink 76 may be brought into direct contact, or a heat transfer material may be interposed therebetween. Reference numeral 78 denotes an anisotropic conductive film interposed between the semiconductor chip 31 and the printed circuit boards 70 and 74.

According to such a semiconductor integrated circuit device,
Since the heat sink 76 houses the printed circuit boards 70, 70 and the semiconductor chips 31, 31,... Mounted thereon, the heat dissipation can be enhanced.

[0092]

According to the printed circuit board of the first aspect, since it can be manufactured based on a metal substrate having a three-layer structure, the mechanical strength required for transportation and handling can be ensured even if it is thin. Therefore, the wiring film of the substrate can be made thinner than before, and the wiring film can be made thinner.
High integration can be easily achieved.

Further, unlike the case where the external terminal is formed of a bump and a solder ball is used, there is no danger of the solder ball dropping, deformation due to melting of the solder, and connection failure due to a change in thickness. Further, the problem that a special expensive alignment jig is required for the alignment of the solder balls can be avoided. Since bumps are used for interlayer connection, it is not necessary to form a hole for interlayer connection as in the related art. Therefore, various problems such as the limitation of the diameter reduction of the hole, the deformation of the film due to the hole, the generation of foreign matter due to the heat treatment, the time required for the heat treatment, and the reduction in productivity occurred when the hole was formed by the laser beam. Does not occur.

According to the wiring circuit board of the second aspect, since the surface of the bumps forming the external terminals is covered with the solder, the solder is used as the external terminal and other parts (other than the wiring circuit board, for example, printed wiring). To improve the connectivity.

According to the printed circuit board of the third aspect, in the printed circuit board of the first or second aspect, the electrode connection portion of the uppermost wiring film is covered with gold, so that the electrode connection portion is formed. Connectivity can be improved. Then, before patterning the metal film made of the first metal, which is based on the metal substrate, a gold layer can be formed in a portion of the wiring film to which the electronic device electrode is connected. The layers can be formed by electrolytic plating, eliminating the need for electroless plating. Therefore, a high-quality gold layer can be easily formed by plating.

According to the method of manufacturing the printed circuit board of the fourth aspect, the printed circuit board of the first aspect can be obtained. According to the printed circuit board, the above-described effects can be obtained.

In the method of manufacturing a printed circuit board according to a fifth aspect of the present invention, the surface of the bump is covered with solder by a reflow process after the etching of the solder layer used as an etching mask when forming the bump. In addition, the surface of the bumps can be easily covered with solder without increasing the number of manufacturing steps, thereby improving the connectivity.

According to the printed circuit board of the sixth aspect, since the electronic device can be mounted on the electrode connecting portion to which the electronic device electrode is connected and on the bump for connecting the electronic device electrode, the electronic device is mounted on both sides. be able to. In addition, since one of the main surfaces has the bumps for connection between the wiring circuit boards and the other main surface has the bump connection portions for connection between the wiring circuit boards, the plurality of wiring circuit boards are stacked in the same direction, and one By connecting the wiring circuit board connection bumps of the wiring circuit board to the wiring circuit board connection bump connection portion thereunder, a large number of wiring circuit boards are stacked,
It is possible to provide a highly integrated laminated wiring board in which electronic devices are three-dimensionally arranged.

According to the printed circuit board, similar to the printed circuit boards of the first and second aspects, the above-described various effects can be obtained because the manufacturing can be performed based on the metal substrate having the three-layer structure. Since the bumps are used as the connection means between the wiring circuit boards, there is no danger of occurrence of solder balls falling, deformation due to melting of solder, connection failure due to change in thickness, etc., as in the case of using solder balls, The problem that a special expensive positioning jig is required for positioning the solder ball can also be avoided. Since bumps are also used for interlayer connection, it is not necessary to form holes for interlayer connection as in the related art. Therefore, various problems such as the limitation of the diameter reduction of the hole, the deformation of the film due to the hole, the generation of foreign matter due to the heat treatment, the time required for the heat treatment, and the reduction in productivity occurred when the hole was formed by the laser beam. Also, there is an effect that no occurrence occurs.

According to the printed circuit board of the present invention, since the surface of the bump for connecting the printed circuit boards is covered with the solder, the connection between the solder and the bump connection portion for connecting the printed circuit boards is improved. Can be

In the printed circuit board according to the present invention, since the surfaces of the electronic device electrode connection section and the bump connection section for connection between the wiring circuit boards are covered with gold, the connectivity of the connection section can be enhanced.

According to the method of manufacturing a printed circuit board of claim 9, the printed circuit board of claim 6 can be obtained. According to the printed circuit board of the sixth aspect, the various effects described above can be obtained.

According to the tenth aspect of the present invention, the solder layer used as an etching mask when forming the bumps is subjected to a reflow process after completion of the etching so that the surfaces of the bumps are covered with the solder. Therefore, it is possible to easily cover the surface of the bump with solder without increasing the number of manufacturing steps, thereby improving the connectivity.

According to the semiconductor integrated circuit device of the eleventh aspect, the electronic device is three-dimensionally formed by laminating a plurality of wiring circuit boards each having an electronic device mounted on both surfaces thereof (the wiring circuit board of the sixth aspect) in the same direction. It is possible to provide an electronic device with a very high degree of integration, for example, a memory card or the like. The laminated printed circuit board uses a plurality of the printed circuit boards according to claim 6.
The advantages of the printed circuit board can be enjoyed.

According to the method of manufacturing a semiconductor integrated circuit device of claim 12, the semiconductor integrated circuit device of claim 11 can be obtained. According to the semiconductor integrated circuit device, it goes without saying that the above-described effects can be obtained.

According to the semiconductor integrated circuit device of the thirteenth aspect, since the printed circuit board and the semiconductor chip and other electronic devices mounted thereon are housed by the heat sink, the heat dissipation can be enhanced.

According to the wiring circuit board of the present invention, the number of wiring films can be increased, and the integration density of the wiring films can be significantly increased. Since bumps are used as interlayer connection means, the reliability can be improved and the number of manufacturing steps can be reduced as compared with the case where holes are formed and interlayer connection is performed. In addition, since the external terminals are formed by the bumps made of the first metal, the connection work is improved in comparison with the case where solder balls are used, and there are various advantages such as the need for a special jig. In addition, the present wired circuit board has various advantages enjoyed by the wired circuit boards according to Claims 1 and 6 because they are manufactured using the metal substrate having the three-layer structure.

According to the fifteenth aspect of the present invention, since the electronic device electrode connection portion of the outermost wiring film is covered with gold, the connectivity of the electronic device electrode connection portion can be made higher than that of gold. it can.

According to the sixteenth aspect of the present invention, since the surfaces of the bumps forming the external terminals are covered with the solder, the connectivity of the bumps can be enhanced by the solder.

According to the method of manufacturing a printed circuit board of claim 17, the printed circuit board of claim 13 can be obtained.
As described above, according to the printed circuit board, the various effects described above are exhibited.

According to the method of manufacturing a printed circuit board of the eighteenth aspect, a solder layer is used as an etching mask when a bump forming an external terminal is formed by selective etching of the bump forming metal film forming an external terminal. The solder layer can be left as it is and used for improving electrical connectivity with other bumps.

According to the nineteenth aspect of the present invention, since the bump made of the first metal is used for connecting the electrode of the electronic device,
It is possible to avoid the above-mentioned various problems caused when the solder ball is used for connecting the electrode of the electronic device, and to obtain the above-mentioned various advantages of the printed circuit board according to claim 1, 6, 13 or the like. You can enjoy.

According to the twentieth aspect of the present invention, since the gold film is formed on the surface of the external terminal connection portion of the outermost wiring film, the connectivity of the external terminal connection portion can be improved. .

According to the printed circuit board of the present invention, since the surface of the electronic device electrode connection bump is covered with gold, the bump connectivity can be improved by the gold.

According to the method of manufacturing a printed circuit board of claim 22, the printed circuit board of claim 19 can be obtained.
As described above, according to the printed circuit board of the eighteenth aspect, the various effects described above can be enjoyed.

According to the twenty-third aspect of the present invention, a gold film is used as an etching mask when the metal film for forming bumps for connecting electronic device electrodes is selectively etched, so that the gold film used as the mask after the etching is used. Can be utilized for improving the connectivity of the bumps, and the improvement in the connectivity of the bumps can be realized without increasing the number of steps.

According to the semiconductor integrated circuit device of claim 24, claims 1, 2, 3, 6, 7, 8, 14, 15, 1
Since one or a plurality of semiconductor chips are mounted on the printed circuit board described in claim 6, 17, 19, 20, or 21,
2, 3, 6, 7, 8, 14, 15, 16, 17, 19,
It is possible to provide a semiconductor integrated circuit device that has enjoyed the effects of the printed circuit board described in 20 or 21.

[Brief description of the drawings]

FIGS. 1A to 1F are cross-sectional views showing a first embodiment of a method of manufacturing a printed circuit board according to the present invention in the order of steps.

FIGS. 2A to 2E are cross-sectional views showing a second embodiment of the method of manufacturing the wired circuit board (semiconductor integrated circuit device) of the present invention in the order of steps.

FIGS. 3A and 3B are cross-sectional views showing dimensions of a printed circuit board according to the second embodiment of the present invention shown in FIG. 2 in comparison with a conventional example. FIG. 4B shows the case of the second embodiment, FIG. 4B shows the case of the conventional example, and FIG. 5C shows the cross section showing the dimensions of the memory card to which the wired circuit board according to the second embodiment of the present invention is applied. FIG.

FIGS. 4A to 4D are cross-sectional views showing a third embodiment of the method of manufacturing a printed circuit board according to the present invention in the order of steps.

5A to 5E are cross-sectional views showing a fourth embodiment of the printed circuit board of the present invention in the order of steps.

FIGS. 6A to 6E are cross-sectional views sequentially showing steps (A) to (E) of a fifth embodiment of the method of manufacturing a wired circuit board according to the present invention.

FIGS. 7 (F) to 7 (I) are cross-sectional views sequentially showing steps (F) to (I) of a fifth embodiment of the method of manufacturing a wired circuit board according to the present invention.

FIGS. 8A and 8B are cross-sectional views for explaining one embodiment of the semiconductor integrated circuit device of the present invention. FIG. 8A is a cross-sectional view of one printed circuit board constituting the semiconductor integrated circuit device. FIG. 1B is a cross-sectional view showing the completed semiconductor integrated circuit device.

FIGS. 9A to 9E are cross-sectional views illustrating a conventional example of a method of manufacturing a printed circuit board in the order of steps.

10A to 10C are cross-sectional views showing a method of mounting an electronic device, for example, an LSI chip on the printed circuit board of FIG. 9 and further forming a solder ball in the order of steps.

11A to 11E are cross-sectional views illustrating another conventional example of a method of manufacturing a printed circuit board in the order of steps.

[Explanation of symbols]

Reference numeral 21: a three-layer metal substrate, 21a: a metal layer made of a first metal, 21b: an etching stop layer, 21c: a metal layer made of a third metal, 22: wiring Film, 24 bump, 25 wiring film, 27 insulating film, 28 protrusion, 30 solder (solder layer), 31 (31a, 31b) electronic device ( LSI chip), 35 ... bump, 36 ... insulating film, 37 ... wiring film, 39 ... bump, 70 ... wiring circuit board, 71 ...
· Bump for interlayer connection, 72 ... Bump for interlayer connection, 7
4 ... one printed circuit board wider than the others, 75 ... heat sink connection part, 76 ... heat sink.

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] August 14, 2000 (2000.8.1)
4)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0045

[Correction method] Change

[Correction contents]

(A) A metal substrate 21 having a three-layer structure shown in FIG. 1A is prepared. Reference numeral 21a denotes a metal film having a thickness of, for example, about 80 to 150 μm which forms a base of the copper foil 21 and 21b is an etching stop layer on the surface of the metal film 21a. (For example, etching using an alkaline etching solution)
In this case, any material can be used as long as it has a sufficient etching selectivity with respect to the copper or copper alloy, but nickel or a nickel alloy is preferable. When this nickel or nickel alloy is used as the etching stop layer 21b, the thickness is preferably, for example, about 0.1 to 2 μm. The nickel-based etching stop layer 21
b can be removed by a hydrochloric acid-based etching solution or a nickel-based stripping solution.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0058

[Correction method] Change

[Correction contents]

(B) Next, as shown in FIG. 2 (B), an insulating layer (thickness: 25 to 35 μm) 36 having adhesiveness is formed on the surface of the metal substrate 21 on which the bumps 35 are formed. The bump 35 is adhered so as to be penetrated by 35 so that the tip of the bump 35 protrudes from the surface. The material may be the same as, for example, the insulating layer 27 of the first embodiment. (C) Next, FIG.
As shown in FIG. 3, a copper foil 3 serving as a wiring film is
7 (thickness: 12 to 35 μm) are laminated by thermocompression bonding. The processing conditions of this lamination processing are, for example, a heating temperature of 300 ° C., a pressure of 50 kg / cm ² , and a pressing time of 10 minutes.

[Procedure amendment 3]

[Document name to be amended] Drawing

[Correction target item name] Figure 2

[Correction method] Change

[Correction contents]

FIG. 2

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 23/12 501 H05K 3/24 B 5F044 H05K 1/09 3/40 K 1/11 3/46 N 3 / 06 Q 3/24 H01L 25/08 Z 3/40 23/12 L 3/46 F term (reference) 4E351 AA01 BB01 BB23 BB24 BB30 BB38 DD04 DD12 DD19 DD24 DD54 GG01 5E317 AA24 BB01 BB11 BB13 BB18 CC53 CC60 CD25 CD34 GG14 GG16 5E339 AD05 BC01 BD03 BD06 BD11 BE11 5E343 AA02 AA12 BB09 BB17 BB18 BB22 BB23 BB24 BB34 BB44 BB48 BB54 BB61 BB67 DD75 DD80 GG08 GG11 5E346 AA12 AA15 AA22 AA32 AA35 CC CC DD DD CC CC GG28 GG40 HH22 HH24 HH33 5F044 KK02 KK12 KK13 LL01 RR18

Claims (24)

[Claims] 1. A metal different from at least a second metal including at least part of a bump made of a first metal and forming an external terminal and connected via an etching stop layer made of a second metal. A wiring film made of a third metal, another wiring film of one or more layers having an interlayer connection bump connected thereto is laminated on the wiring film via an interlayer insulating film, A printed circuit board, wherein an uppermost wiring film of the wiring film is covered with an insulating film except for an electrode connection portion to which an electronic device electrode is connected. 2. The printed circuit board according to claim 1, wherein the surfaces of the bumps forming the external terminals are covered with solder. 3. The printed circuit board according to claim 1, wherein the surface of the electrode connection portion of the outermost wiring film is covered with gold. 4. A metal film for forming a bump made of a first metal, an etching stop layer made of a second metal having an etching selectivity with respect to the first metal, and at least a second metal different from the second metal. Forming a wiring film by patterning the metal film for forming a wiring film on a metal substrate having a three-layer structure in which a metal film for forming a wiring film made of the metal of No. 3 is laminated; and forming the wiring film on the metal substrate. A metal foil for forming a wiring film having a bump for interlayer connection on one surface is bonded to the main surface on which the bump is formed via an insulating adhesive so that the bump is connected to the wiring film. Forming a wiring film of one or more layers including at least a step of forming a wiring film by selectively etching a metal foil for forming a wiring film having the bumps; Wiring film Covering the wiring film with an insulating film while leaving an electrode connection portion to which an electronic device electrode is connected on the surface on which the electronic device electrode is connected; and selectively etching the bump-forming metal film of the three-layer metal substrate. Forming a bump forming an external terminal by the method. 5. A method for forming a bump forming an external terminal by selective etching of a bump-forming metal film, wherein a solder layer selectively formed on the surface of the metal film is used as an etching mask. 5. The method for manufacturing a printed circuit board according to claim 4, wherein a surface of the bump is covered with solder by performing a reflow process on the solder layer. 6. At least a second metal different from at least a second metal which includes at least a part connected via an etching stop layer made of a first metal and a wiring circuit board connection bump made of a first metal and a second metal. A bump made of a third metal, which is a metal, is insulated and separated from each other by an insulating layer, and the bumps that are not connected to the bumps forming the external terminals among the bumps for the interlayer connection are electronic device electrode connection. One or more layers having at least a portion connected to the interlayer connection bump on the surface of the insulating layer opposite to the side on which the wiring circuit board connection bump is formed. A wiring film is formed. On the surface of the wiring film on which the outermost wiring film is formed,
A printed circuit board characterized by being covered with an insulating film except for an electrode connection portion to which an electronic device electrode is connected and an anti-war circuit board connection bump connection portion to which a wiring circuit board connection bump is connected. 7. The printed circuit board according to claim 6, wherein a surface of the connecting bump between the printed circuit boards is covered with solder. 8. The printed circuit board according to claim 6, wherein the surface of the electrode connection portion of the outermost wiring film and the surface of the bump connection portion for connection between the printed circuit boards are covered with gold. 9. A metal film for forming bumps for connection between printed circuit boards made of a first metal, an etching stop layer made of a second metal having an etching selectivity with respect to the first metal, and at least a second metal. The bump-forming metal film of a three-layered metal substrate formed by laminating a bump-forming metal film made of a third metal different from the metal is connected to the wiring-circuit-board connection bump by patterning the bump-forming metal film. Forming bumps for connection of electronic device electrodes that are not connected to each other, and insulating the bumps on the main surface of the metal substrate on which the bumps made of the third metal are formed. Forming a wiring film of one or more layers including at least a step of laminating a metal foil for forming a wiring film via a layer, and a step of forming a wiring film by selectively etching the metal foil. That step and, on the surface where the wiring film of the outermost surface is formed of the wiring layer,
Forming an insulating film covering a portion other than a portion of the wiring film to which the electronic device electrode is connected and a portion to which the wiring circuit board connection bump is connected; and a process of connecting the three-layer metal substrate to the wiring circuit board. Forming a bump for wiring circuit board connection by selectively etching the metal film for bump formation. A method for manufacturing a wiring circuit board, comprising: 10. A solder layer selectively formed on the surface of a metal film as an etching mask when a bump forming an external terminal is formed by selective etching of a metal film for forming a bump for wiring circuit board connection. 10. The method for manufacturing a printed circuit board according to claim 9, wherein the surface of the bump is covered with solder by performing a reflow process on the solder layer after completion of the selective etching. 11. A semiconductor device according to claim 1, wherein said at least one second metal includes at least a part connected via an etching stop layer made of a second metal and a connection bump between wiring circuit boards made of a first metal. A bump made of a third metal, which is a metal, and having an interlayer connection and insulated and separated from each other by an insulating layer, and a bump that is not connected to the bump forming the external terminal is a bump for connecting an electronic device electrode. One or more wiring films having at least a portion connected to the interlayer connection bump are formed on the surface of the insulating layer opposite to the side on which the bumps forming the external terminals are formed, The uppermost wiring film of the wiring film should not be covered with an insulating film except for an electrode connection portion to which an electronic device electrode is connected and a bump connection portion to which a bump for connection between wiring circuit boards is connected. A plurality of printed circuit boards, and an electrode connected to an electrode connection portion of the wiring film of each printed circuit board or a bump made of the third metal, which is not connected to the printed circuit board connection bump. A plurality of semiconductor chips and other electronic devices connected to each other, and the plurality of wiring circuit boards connected to the electronic device on both sides or one surface thereof are stacked in the same direction, and a wiring circuit board of one wiring circuit board is provided. A semiconductor integrated circuit device comprising a plurality of wiring circuit boards stacked by connecting an inter-connection bump to a bump connection portion of a wiring film of another wiring circuit board. 12. A semiconductor device according to claim 1, wherein said at least one second metal includes at least a part connected via an etching stop layer made of a second metal and a connection bump between wiring circuit boards made of a first metal. A bump made of a third metal, which is a metal, and having an interlayer connection insulated and separated from each other by an insulating layer, wherein the bumps not connected to the wiring circuit board connection bumps are electronic device electrode connection bumps. A wiring film of one or more layers having at least a portion connected to the bump for interlayer connection is formed on the surface of the insulating layer opposite to the side on which the bumps forming the external terminals are formed, A plurality of insulating films are formed on the outermost wiring film, leaving an electrode connection portion to which an electronic device electrode is connected and a bump connection portion to which a bump for connection between wiring circuit boards is connected. A printed circuit board is prepared, and an electronic device electrode is connected to an electrode connection portion of the wiring film of each printed circuit board and a bump made of the third metal, the bump being not connected to the printed circuit board connection bump. And a semiconductor chip or other electronic device is mounted on both sides or one side, and the plurality of wiring circuit boards are stacked in the same direction, and the wiring circuit board connection bump of one wiring circuit board is connected to another wiring circuit. A method for manufacturing a semiconductor integrated circuit device, comprising: stacking a plurality of wiring circuit boards by connecting to a bump connection portion of a wiring film of a substrate. 13. At least a second metal different from at least a second metal including at least a part connected via an etching stop layer made of a second metal and a connection bump between wiring circuit boards made of a first metal and an etching stop layer made of a second metal. A bump made of a third metal, which is a metal, and having an interlayer connection and insulated and separated from each other by an insulating layer, and a bump that is not connected to the bump forming the external terminal is a bump for connecting an electronic device electrode. One or more wiring films having at least a portion connected to the interlayer connection bump are formed on the surface of the insulating layer opposite to the side on which the bumps forming the external terminals are formed, The uppermost wiring film of the wiring film should not be covered with an insulating film except for an electrode connection portion to which an electronic device electrode is connected and a bump connection portion to which a bump for connection between wiring circuit boards is connected. A plurality of printed circuit boards having a heat sink connection portion on one surface of one of the protruding portions, one of which protrudes from the other when overlapped, and an electrode of the wiring film of each of the printed circuit boards A plurality of semiconductor chips or other electronic devices in which electrodes are connected to connection portions or bumps made of the third metal but not connected to the wiring circuit board connection bumps; and the plurality of wiring circuit boards A concave heat sink that covers a wiring circuit board other than one widely formed wiring circuit board including the electronic device connected thereto, and the plurality of electronic devices connected to both sides or one side thereof. The printed circuit board is overlapped with the printed circuit board on the other printed circuit board in the same direction, and the connection circuit board connecting bumps of the printed circuit board are connected to the other printed circuit boards. A plurality of wiring circuit boards are stacked by connecting to the bump connection portion of the wiring film of the wiring circuit board, and the heat sink is connected to the heat sink connection portion of the one wiring circuit board protruding from the other wiring circuit board. A semiconductor integrated circuit device, wherein an upper edge of the printed circuit board is connected to the heat sink to cover the other printed circuit board including the electronic device connected thereto. 14. A metal different from at least the second metal, which at least partially includes a bump forming an external terminal made of the first metal and a part connected via an etching stop layer made of the second metal. Consisting of a third metal,
One or more layers of interconnects having interlayer connection bumps insulated and separated from each other by an insulating layer, and having at least a part of the insulating layer connected to the interlayer connection bump made of the third metal A printed circuit board, wherein a film is formed, and an insulating film is formed on an outermost surface of the wiring film on which a wiring film is formed, the insulating film covering a portion other than an electronic device electrode connection portion of the wiring film. 15. The electronic device electrode connection portion of the topmost wiring film is covered with gold.
4. The printed circuit board according to 4. 16. The bump according to claim 14, wherein a surface of the bump forming the external terminal is covered with solder.
The printed circuit board as described. 17. A bump-forming metal film forming an external terminal made of a first metal, an etching stop layer made of a second metal having an etching selectivity with respect to the first metal, and at least a second metal. Forming the interlayer connection bumps by patterning the interlayer connection bump formation metal film of a three-layer metal substrate in which another interlayer connection metal bump formation metal film made of a third metal is laminated. And bonding a metal foil via an insulating layer to the side of the metal substrate on which the interlayer connection bumps are formed, and forming a wiring film by patterning the metal foil. Forming a wiring film of one or more layers; and selectively etching the metal film for forming a bump forming an external terminal of the metal substrate having the three-layer structure to form a metal film for forming a bump. Forming a printed circuit board, the method comprising: 18. A method of forming a bump for connecting an electronic device electrode by selectively etching a metal film for forming a bump which forms the external terminal, wherein a solder layer selectively formed on the surface of the metal film is used as an etching mask. The method for manufacturing a printed circuit board according to claim 17, wherein 19. A metal different from at least a second metal including at least a part connected to an electronic device electrode connection bump made of a first metal and an etching stop layer made of a second metal. A wiring film made of a third metal, and a topmost wiring film of one or more wiring films laminated on the surface on which the wiring film is formed or via an insulating film on the surface. A printed circuit board characterized in that an insulating film is formed on a surface of the insulating film to cover portions other than the external terminal connection portion. 20. A gold film is formed on a surface of an outer terminal connection portion of the outermost wiring film.
The printed circuit board as described. 21. The printed circuit board according to claim 19, wherein the surface of the electronic device electrode connection bump is covered with gold. 22. A metal film for forming an electronic device electrode connection bump made of a first metal, an etching stop layer made of a second metal having an etching selectivity with respect to the first metal, and at least a second metal. Forming a wiring film by patterning a metal film for forming a wiring film on a metal substrate having a three-layer structure in which a metal film for forming a wiring film made of a third metal is stacked. A film or a single layer or a plurality of layers of wiring films formed on the wiring film via an insulating film, on the surface on which the wiring film on the outermost surface is formed, except for the external terminal connection portion of the uppermost wiring film Forming an electronic device electrode connecting bump by selectively etching the electronic device electrode connecting bump forming metal film of the three-layer metal substrate; and forming the electronic device electrode connecting bump. device A step of selectively etching the etching stop layer using the electrode connection bumps as a mask. 23. The method for manufacturing a printed circuit board according to claim 22, wherein a gold film is used as an etching mask when selectively etching the metal film for forming bumps for connecting electronic device electrodes. 24. The method of claim 1, 2, 3, 6, 7, 8, 1.
A semiconductor integrated circuit device comprising one or a plurality of semiconductor chips mounted on the printed circuit board described in 4, 15, 16, 17, 19, 20 or 21.