JP2011187497A - Structure and method of mounting semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To downsize a mounting structure of a semiconductor device called an SOI. <P>SOLUTION: A rear face of a silicon substrate 23 of a semiconductor device 21 mounted to a printed wiring board 1 is connected to an upper layer ground line 4 of the printed wiring board 1 via a conductive adhesive layer 55, a shield cover 51, and a solder layer 11. By this, the rear face of the silicon substrate 23 of the semiconductor device 21 has ground potential. Since connection is established with the ground line 4 via the shield cover 51 in this case, a ground connection terminal connected to the rear face of the silicon substrate 23 of the semiconductor device 21 is not necessary to be arranged on the printed wiring board 1 around a mounting region of the semiconductor device 21. Since the shield cover 51 also serves as an anti-noise measure, the shield cover 51 is not necessary to be arranged outside the semiconductor device 21 and the ground connection terminal, and the structure can be downsized. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a semiconductor device mounting structure and a mounting method thereof.

  Some conventional semiconductor devices are called SOI (silicon on insulator) and have an SOI integrated circuit portion in which an insulating film is provided under a semiconductor substrate and a thin film transistor is formed under the insulating film ( For example, see Patent Document 1). In a state where this semiconductor device is mounted on a printed wiring board, the back surface of the semiconductor substrate (the surface opposite to the circuit formation surface) is ground potential in order to stabilize the potential of the semiconductor substrate due to the characteristics of the SOI integrated circuit portion. It is necessary to become.

  Next, a mounting structure of this conventional semiconductor device will be described. A semiconductor device is mounted on a printed wiring board by connecting solder balls provided on the lowermost surface thereof to connection terminals on the printed wiring board. An underfill material made of an epoxy resin or the like is provided between the semiconductor device and the printed wiring board on the upper surface of the printed wiring board and the side surface of the semiconductor device around the semiconductor device.

  The top surface of the semiconductor substrate of the semiconductor device, the outer surface of the underfill material provided on the side surface of the semiconductor device, and the upper surface of the ground connection terminal on the printed wiring board outside the underfill material are silver-coated using a dispenser. The connection member is provided by applying and curing a conductive paste such as a paste. As a result, the back surface of the semiconductor substrate of the semiconductor device is set to the ground potential. However, depending on the viscosity of the connecting member made of the conductive paste, if there is no underfill material, the conductive paste may enter the gap between the sealing film of the semiconductor device and the circuit board due to capillary action. is there. Therefore, an underfill material that is originally required when the solder ball diameter is small and the number of solder balls is small is required regardless of the diameter and number of solder balls. Furthermore, a shield case is provided outside the semiconductor device and the connection member so that the SOI integrated circuit portion of the semiconductor device is not affected from the outside or vice versa. It is necessary to suppress noise.

JP 2007-19464 A

  By the way, in the conventional semiconductor device mounting structure, since the ground connection terminals are provided on the printed wiring board outside the underfill material provided on the side surface of the semiconductor device, printing around the mounting area of the semiconductor device is possible. It is necessary to provide a ground connection terminal on the wiring board. In addition, if a shield case is provided for noise countermeasures, a shield case must be provided outside the semiconductor device and the connection member, and the plane size of the printed wiring board increases accordingly, resulting in an increase in size. There is.

  Accordingly, an object of the present invention is to provide a semiconductor device mounting structure and a mounting method thereof that can be reduced in size.

A mounting structure of a semiconductor device according to claim 1 includes an insulating substrate provided with wiring and ground wiring on one surface, a semiconductor substrate, an insulating film, and an SOI integrated circuit portion, and the insulating substrate. A semiconductor device connected to the wiring via a first connection material, a shield cover connected to the ground wiring and provided on the insulating substrate so as to cover the semiconductor device, and the semiconductor substrate And a second connecting material connected between the shield cover.
A mounting structure of a semiconductor device according to a second aspect of the present invention is the mounting structure of the semiconductor device according to the first aspect, wherein the first connecting material is solder, and the second connecting material is a conductive adhesive, solder. It is either of these.
A mounting structure of a semiconductor device according to a third aspect of the present invention is the semiconductor device mounting structure according to the first aspect, wherein the insulating substrate is a film substrate.
A mounting structure of a semiconductor device according to a fourth aspect of the present invention is the mounting structure of the first aspect, wherein the lower end portion of the shield cover is connected to the outermost part of the ground wiring via a solder layer. It is a feature.
A mounting structure of a semiconductor device according to a fifth aspect of the present invention is the mounting structure according to the first aspect, wherein the wiring is an upper layer wiring, the ground wiring is an upper layer ground wiring, and on the other surface of the insulating substrate, A lower layer wiring and a lower layer ground wiring are provided connected to the upper layer wiring and the upper layer ground wiring.
According to a sixth aspect of the present invention, in the semiconductor device mounting structure according to the first aspect, the electronic component is provided on the insulating substrate in the shield cover so as to be connected to the land of the wiring. It is characterized by this.
A mounting structure of a semiconductor device according to a seventh aspect of the present invention is the mounting structure of the semiconductor device according to the sixth aspect, wherein the electronic component is connected to a land of the wiring via a solder layer. is there.
A mounting structure of a semiconductor device according to an invention of claim 8 is the invention according to claim 6, wherein the height of the electronic component is higher than the height of the semiconductor device, and the second connection material A protrusion is provided on the lower surface of the shield cover above, and the protrusion is embedded in the upper surface of the second connection material.
According to a ninth aspect of the present invention, there is provided a semiconductor device mounting method comprising: a semiconductor device having a semiconductor substrate, an insulating film, and an SOI integrated circuit portion on an insulating substrate provided with wiring and ground wiring on one surface; A step of connecting to the wiring via a first connection material; a step of forming a second connection material on the back surface of the semiconductor substrate; and covering the semiconductor device on the insulating substrate to provide the second connection. Arranging a shield cover so as to be connected to the material, and connecting a lower end portion of the shield cover to the ground wiring.
According to a tenth aspect of the present invention, there is provided a semiconductor device mounting method according to the ninth aspect, wherein an electronic component is provided in a shield cover on the insulating substrate, and an electrode of the electronic component is connected to the wiring. The method includes a step of connecting to a land via a solder layer.
According to an eleventh aspect of the present invention, there is provided a semiconductor device mounting method according to the ninth aspect, wherein the first connection material is solder, and the second connection material is a conductive adhesive, solder. It is either of these.

  According to the present invention, the upper surface of the semiconductor substrate of the semiconductor device mounted on the insulating substrate is connected to the ground wiring on the insulating substrate via the second connection material and the shield cover provided thereon. Therefore, there is no need to provide a ground connection terminal connected to the upper surface of the semiconductor substrate of the semiconductor device on the insulating substrate around the mounting region of the semiconductor device. The mounting area can be reduced.

Sectional drawing of the mounting structure of the semiconductor device as 1st Embodiment of this invention. Sectional drawing of the mounting structure of the semiconductor device as 2nd Embodiment of this invention. Sectional drawing of the mounting structure of the semiconductor device as 3rd Embodiment of this invention.

(First embodiment)
FIG. 1 shows a sectional view of a semiconductor device mounting structure as a first embodiment of the present invention. In this semiconductor device mounting structure, the semiconductor device 21 and the chip component (electronic component) 41 are provided on the upper surface of the printed wiring board 1, and the shield cover 51 covers the semiconductor device 21 and the chip component 41 on the printed wiring board 1. Is provided.

  First, the printed wiring board 1 will be described. The printed wiring board 1 includes a planar rectangular film substrate (insulating substrate) 2 made of polyimide resin or the like. On the upper surface of the film substrate 2, first and second upper layer wirings 3a and 3b and an upper layer ground wiring 4 made of copper foil or the like are provided. The outermost portion of the upper ground wiring 4 may be provided in a rectangular frame shape around the upper surface of the film substrate 2 or may be provided at the four corners of the upper periphery of the film substrate 2. .

  On the lower surface of the film substrate 2, first and second lower layer wirings 5a and 5b and a lower layer ground wiring 6 made of copper foil or the like are provided. The first and second upper-layer wirings 3a and 3b and the upper-layer ground wiring 4, and the first and second lower-layer wirings 5a and 5b and the lower-layer ground wiring 6 are provided in a through hole 7 provided in the film substrate 2. They are connected to each other through a vertical conduction part 8 made of a metal paste or the like.

  An upper overcoat film 9 made of a solder resist or the like is provided on the upper surface of the film substrate 2 including the first and second upper layer wirings 3 a and 3 b and the upper layer ground wiring 4. First and second openings 10a and 10b and an opening 11 are provided in the upper overcoat film 9 in the portions corresponding to the lands of the first and second upper-layer wirings 3a and 3b and the outermost portion of the upper-layer ground wiring 4. It has been.

  A lower overcoat film 12 made of a solder resist or the like is provided on the lower surface of the film substrate 2 including the first and second lower layer wirings 5a and 5b and the lower layer ground wiring 6. First and second openings 13a and 13b and an opening 14 are provided in the lower overcoat film 11 at portions corresponding to the lands of the first and second lower layer wirings 5a and 5b and the outermost part of the lower layer ground wiring 6. It has been.

Next, the semiconductor device 21 will be described. The semiconductor device 21 is generally called a CSP (chip size package) and includes an SOI substrate 22. The SOI substrate 22 is provided with an insulating film 24 made of silicon oxide or the like on the lower surface of a planar rectangular silicon substrate (semiconductor substrate) 23, and an SOI integrated circuit portion 25 formed by forming a thin film transistor on the lower surface of the insulating film 24. It has a structured. In this case, the source / drain region of the thin film transistor of the SOI integrated circuit portion 25 is connected to the silicon substrate 23 through a vertical conduction portion (not shown) provided in the insulating film 24.

A plurality of connection pads 26 made of an aluminum-based metal or the like are provided on the periphery of the lower surface of the SOI integrated circuit portion 25 so as to be connected to the SOI integrated circuit portion 25. A passivation film (insulating film) 27 made of silicon oxide or the like is provided on the lower surface of the SOI integrated circuit portion 25 excluding the peripheral portion of the SOI integrated circuit portion 25 and the central portion of the connection pad 26. It is exposed through an opening 28 provided in the passivation film 27. A protective film (insulating film) 29 made of polyimide resin or the like is provided on the lower surface of the passivation film 27. An opening 30 is provided in the protective film 29 in a portion corresponding to the opening 28 of the passivation film 27.

A wiring 31 is provided on the lower surface of the protective film 29. The wiring 31 has a two-layer structure of a base metal layer 32 made of copper or the like provided on the lower surface of the protective film 29 and an upper metal layer 33 made of copper provided on the lower surface of the base metal layer 32. One end of the wiring 31 is connected to the connection pad 26 via the openings 28 and 30 of the passivation film 27 and the protective film 29.

A columnar electrode 34 made of copper is provided on the lower surface of the land of the wiring 31. A sealing film 35 made of an epoxy resin containing silica filler or the like is provided around the columnar electrode 34 on the lower surface of the protective film 29 including the wiring 31. Here, the columnar electrode 34 is provided such that the lower surface thereof is flush with the lower surface of the sealing film 35 by one to several μm. A solder ball (first connecting material) 36 is provided on the lower surface of the columnar electrode 34.

The semiconductor device 21 is connected to the land of the first upper layer wiring 3a through the first opening 10a of the upper layer overcoat film 9 so that the upper layer overlayer of the printed wiring board 1 is achieved. It is mounted on the coat film 9 by the face-down method.

Next, the chip component 41 will be described. The chip component 41 includes a capacitor, a resistor, and the like. The chip component 41 has both electrodes (not shown) connected to the land of the second upper layer wiring 3b via the solder layer 42 provided in the second opening 10b of the upper layer overcoat film 9. Therefore, it is provided on the upper overcoat film 9 of the printed wiring board 1.

Next, the shield cover 51 will be described. The shield cover 51 is made of a metal such as aluminum, and has a flanged portion 53 provided at the lower end portion of a headed rectangular tube-shaped cover main body 52. The shield cover 51 is connected to the outermost surface of the upper-layer ground wiring 4 via the solder layer 54 provided in the opening 11 of the upper-layer overcoat film 9 by the lower surface of the flange portion 53 being printed. It is provided on the upper overcoat film 9 of the wiring board 1. In this state, the semiconductor device 21 and the chip component 41 are covered with the shield cover 51 and are electromagnetically cut off from the outside.

A certain amount of space is formed between the upper surface of the silicon substrate 23 of the semiconductor device 21 and the shield cover 51 disposed thereon. A conductive adhesive layer (second connection material) 55 is provided between the central portion of the upper surface of the silicon substrate 23 of the semiconductor device 21 and the shield cover 51 disposed thereon. The conductive adhesive layer 55 is made of a conductive filler such as silver, copper, or carbon dispersed in a binder made of a thermosetting resin such as an epoxy resin. Alternatively, a connection material such as solder may be used. In this state, the upper surface of the silicon substrate 23 of the semiconductor device 21 is connected to the upper ground wiring 4 via the conductive adhesive layer 55, the shield cover 51, and the solder layer 54. It is like that.

As described above, in this semiconductor device mounting structure, the conductive adhesive layer 55 provided between the central portion of the upper surface of the silicon substrate 23 of the semiconductor device 21 and the shield cover 51 disposed thereon is used as the shield cover. Since the upper surface of the silicon substrate 23 of the semiconductor device 21 is set to the ground potential by being connected to the upper-layer ground wiring 4 via the 51 and the solder layer 54, the printed wiring board around the mounting region of the semiconductor device 21 There is no need to provide a ground connection terminal on 1, and accordingly, the plane size of the printed wiring board 1 can be reduced, and the size can be reduced.

Next, an example of a method for mounting the semiconductor device 21 and the like will be described. First, the printed wiring board 1, the semiconductor device 21, the chip component 41, and the shield cover 51 are prepared. Next, a solder paste is applied to the first and second openings 10a and 10b and the opening 11 of the upper overcoat film 9 of the printed wiring board 1 by screen printing or the like. Next, the semiconductor device 21 and the chip component 41 are simply arranged at each predetermined location on the printed wiring board 1. Next, the shield cover 51 is simply disposed at a predetermined location on the printed wiring board 1.

Next, a conductive adhesive is applied to the center of the upper surface of the silicon substrate 23 of the semiconductor device 21 by screen printing or the like. Next, when reflow is performed at a temperature at which the solder melts, the solder balls 36 of the semiconductor device 21 are connected to the lands of the first upper wiring 3a through the first openings 10a of the upper overcoat film 9, Further, both electrodes of the chip component 41 are connected to the land of the second upper wiring 3b through the solder layer 42 provided in the second opening 10b of the upper overcoat film 9, and the flange portion of the shield cover 51. The lower surface of 53 is connected to the outermost part of the upper layer ground wiring 4 through a solder layer 54 provided in the opening 11 of the upper layer overcoat film 9, and the thermosetting resin in the conductive adhesive is cured. A conductive adhesive layer 55 is formed. In this case, a dedicated process for curing the thermosetting resin in the conductive adhesive is not required. Thus, the semiconductor device mounting structure shown in FIG. 1 is obtained.

(Second Embodiment)
FIG. 2 shows a sectional view of a semiconductor device mounting structure as a second embodiment of the present invention. This semiconductor device differs from the semiconductor device mounting structure shown in FIG. 1 in that the chip component 41 is lower than the semiconductor device 21 in the semiconductor device mounting structure shown in FIG. On the other hand, the height of the chip component 41 is higher than the height of the semiconductor device 21. For this reason, the columnar protrusion 61 is formed on the lower surface of the shield cover 51 in the portion corresponding to the center of the upper surface of the silicon substrate 23 of the semiconductor device 21. The protrusion 61 is embedded in the central portion of the upper surface of the conductive adhesive layer 55 provided in the central portion of the upper surface of the silicon substrate 23 of the semiconductor device 21.

(Third embodiment)
FIG. 3 shows a cross-sectional view of a semiconductor device mounting structure as a third embodiment of the present invention. This semiconductor device differs from the semiconductor device mounting structure shown in FIG. 1 in that the columnar electrode 34 is omitted from the semiconductor device 21. In this case, an opening 37 for connecting the solder ball 36 to the land of the wiring 31 is formed in the sealing film 35 in a portion corresponding to the land of the wiring 31. Further, the sealing film 35 may be formed of a solder resist.

DESCRIPTION OF SYMBOLS 1 Printed wiring board 2 Film substrate 3a, 3b 1st, 2nd upper layer wiring 4 Upper layer ground wiring 5a, 5b 1st, 2nd lower layer wiring 6 Lower layer ground wiring 8 Vertical conduction part 9 Upper layer overcoat film 12 Lower layer overcoat Film 21 Semiconductor device 22 SOI substrate 23 Silicon substrate 24 Insulating film 25 SOI integrated circuit part 26 Connection pad 27 Passivation film 29 Protective film 31 Wiring 34 Columnar electrode 35 Sealing film 36 Solder ball (first connection material)
41 Chip component 42 Solder layer 51 Shield cover 54 Solder layer 55 Conductive adhesive layer (second connecting material)

Claims (11)

An insulating substrate provided with wiring and ground wiring on one side;
A semiconductor device having a semiconductor substrate, an insulating film, and an SOI integrated circuit portion, and connected to the wiring of the insulating substrate via a first connection material;
A shield cover connected to the ground wiring and provided on the insulating substrate so as to cover the semiconductor device;
A second connecting material connected between the semiconductor substrate and the shield cover;
A mounting structure of a semiconductor device, comprising: 2. The semiconductor device mounting structure according to claim 1, wherein the first connection material is solder, and the second connection material is one of a conductive adhesive and solder. 2. The semiconductor device mounting structure according to claim 1, wherein the insulating substrate is a film substrate. 2. The semiconductor device mounting structure according to claim 1, wherein a lower end portion of the shield cover is connected to an outermost portion of the ground wiring through a solder layer. The wiring according to claim 1, wherein the wiring is an upper layer wiring, the ground wiring is an upper layer ground wiring, and a lower layer wiring and a lower layer ground wiring are connected to the upper layer wiring and the upper layer ground wiring on the other surface of the insulating substrate. A mounting structure of a semiconductor device, wherein the semiconductor device mounting structure is connected. 2. The semiconductor device mounting structure according to claim 1, wherein an electronic component is provided on the insulating substrate in the shield cover so as to be connected to the land of the wiring. 7. The semiconductor device mounting structure according to claim 6, wherein the electronic component is connected to a land of the wiring via a solder layer. In the invention according to claim 6, the height of the electronic component is higher than the height of the semiconductor device, a protrusion is provided on the lower surface of the shield cover on the second connection material, A mounting structure for a semiconductor device, wherein the mounting structure is embedded in an upper surface of the second connection material. Connecting a semiconductor device having a semiconductor substrate, an insulating film, and an SOI integrated circuit portion to the wiring via a first connection material on an insulating substrate provided with wiring and ground wiring on one surface;
Forming a second connection material on the back surface of the semiconductor substrate;
On the insulating substrate, covering the semiconductor device, arranging a shield cover so as to be connected to the second connection material, and connecting a lower end portion of the shield cover to the ground wiring;
A method for mounting a semiconductor device, comprising: The invention according to claim 9, further comprising a step of providing an electronic component in the shield cover on the insulating substrate and connecting an electrode of the electronic component to a land of the wiring via a solder layer. Mounting method of semiconductor device. 10. The method of mounting a semiconductor device according to claim 9, wherein the first connection material is solder, and the second connection material is one of a conductive adhesive and solder.

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