JP3496569B2 - Semiconductor device, its manufacturing method and its mounting structure - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device having a columnar electrode, a method for manufacturing the same, and a mounting structure for the same.

[0002]

2. Description of the Related Art In a semiconductor device called, for example, a CSP (Chip Size Package), a columnar electrode connected to another circuit board is provided on an intermediate board (interposer). In the conventional method for manufacturing such a semiconductor device, as an example, as shown in FIG. 22, first, a connection pad 2 is formed on the upper surface of a silicon substrate 1 in a wafer state, and the central portion of the connection pad 2 on the upper surface is removed. The insulating film 3 is formed in a portion, and the wiring 5 extends from the upper surface of the connection pad 2 exposed through the opening 4 formed in the insulating film 3 to the upper surface of the insulating film 3.
And the connection pad portion 5a formed by the tip of the wiring 5
A columnar electrode 6 is formed on the upper surface of the.

Next, as shown in FIG. 23, a sealing film 7 made of epoxy resin is formed on the entire upper surface of the silicon substrate 1 including the columnar electrodes 6 by transfer molding or the like so that the thickness thereof is slightly higher than the height of the columnar electrodes 6. Form so that it becomes thick. Therefore, in this state, the upper surface of the columnar electrode 6 is covered with the sealing film 7. Next, by polishing the upper surface side of the sealing film 7 appropriately, as shown in FIG. 24, the columnar electrodes 6 are formed.
Expose the upper surface of. Next, after going through the dicing process,
As shown in FIG. 25, individual semiconductor chips (semiconductor devices) are obtained.

[0004]

However, in the semiconductor device thus obtained, the thickness of the sealing film 7 is the same as the height of the columnar electrode 6 as shown in FIG. 6 is less likely to sway, and as a result, after mounting on a circuit board (not shown), the columnar electrode 6 can absorb the stress generated due to the difference in thermal expansion coefficient between the silicon substrate 1 and the circuit board. However, there is a problem that cracks are likely to occur at the joint portion between the exposed surface of the columnar electrode 6 and the circuit board side, and eventually conduction failure may occur. An object of the present invention is to enable the columnar electrodes to absorb stress.

[0005]

According to another aspect of the present invention, there is provided a semiconductor device, wherein each side surface of a plurality of columnar electrodes formed on a substrate is made of a resin having a lower elastic modulus than an original sealing film. It is covered with a sealing film, and the original sealing film is provided on the substrate between these auxiliary sealing films. According to a sixth aspect of the present invention, there is provided a method of manufacturing a semiconductor device, wherein each side surface of a plurality of columnar electrodes formed on a substrate is covered with an auxiliary sealing film made of resin having a lower elastic modulus than the original sealing film. The original sealing film is formed on the substrate between these auxiliary sealing films. A method of manufacturing a semiconductor device according to an eighth aspect of the present invention is to form a sealing film having an opening at a portion corresponding to a plurality of columnar electrode forming regions and their respective vicinity on a substrate, A cylindrical auxiliary sealing film made of a resin having a lower elastic modulus than the sealing film is formed in the opening, and columnar electrodes are formed in these auxiliary sealing films. In the semiconductor device mounting structure according to the twelfth aspect of the present invention, each side surface of the plurality of columnar electrodes formed on the substrate is covered with an auxiliary sealing film made of a resin having a lower elastic modulus than the original sealing film. A semiconductor device in which an original sealing film is provided on the substrate between these auxiliary sealing films is mounted on a circuit board by a face-down method. In the semiconductor device mounting structure according to the thirteenth aspect of the present invention, each side surface of the plurality of columnar electrodes formed on the substrate is covered with an auxiliary sealing film made of a resin having a lower elastic modulus than the original sealing film. , An original sealing film is provided on the substrate between these auxiliary sealing films,
A semiconductor device in which solder balls are provided on the columnar electrodes is mounted on a circuit board by a face-down method. According to the above invention, in the semiconductor device, since the auxiliary sealing film made of resin having a lower elastic modulus than the original sealing film is interposed between the columnar electrode and the original sealing film,
The columnar electrode can be made to sway and move easily, and the stress can be absorbed by the columnar electrode.

[0006]

1 to 6 show respective manufacturing steps of a semiconductor device according to a first embodiment of the present invention. Therefore, the structure of the semiconductor device in this embodiment will be described together with the manufacturing method thereof with reference to these drawings in order.

First, as shown in FIG. 1, connection pads 12 are formed on the upper surface of a silicon substrate (semiconductor substrate) 11 in a wafer state.
Is formed, and an insulating film 13 made of silicon oxide or the like is formed on a portion of the upper surface of the connection pad 12 excluding the central portion,
A wiring 15 is formed from the upper surface of the connection pad 12 exposed through the opening 14 formed in the insulating film 13 to the upper surface of the insulating film 13, and the columnar electrode is formed on the upper surface of the connection pad portion 15a formed by the tip of the wiring 15. The thing in which 16 was formed is prepared. In this case, the columnar electrode 16 is formed by electrolytic plating of gold, copper, nickel or the like.

Next, as shown in FIG. 2, a resin (eg, polyimide) having a lower elastic modulus than the epoxy resin, which is the material of the original sealing film described later, is formed on the entire upper surface of the silicon substrate 11 including the columnar electrodes 16. Resin, an epoxy resin containing an elastomer) to form an auxiliary sealing film 17 by a screen printing method,
It is formed by a dispensing method, a dipping method, or the like so that the thickness thereof is slightly larger than the height of the columnar electrodes 16. Therefore, in this state, the upper surface of the columnar electrode 16 is covered with the auxiliary sealing film 17.

Next, a photoresist film 18 is formed on the columnar electrode 16 at a predetermined position on the upper surface of the auxiliary sealing film 17. In this case, the plane size of the photoresist film 18 is larger than the plane size of the columnar electrode 16 to some extent. Next, when the auxiliary sealing film 17 is etched by using the photoresist film 18 as a mask, the auxiliary sealing film 17 remains on the side surface and the upper surface of the columnar electrode 16 as shown in FIG. That is, only the side surface and the upper surface of the columnar electrode 16 are covered with the auxiliary sealing film 17. Then, the photoresist film 18 is peeled off.

Next, as shown in FIG. 4, the auxiliary sealing film 17 is formed.
A sealing film 19 made of an epoxy resin is formed on the entire upper surface of the silicon substrate 11 including the film by a transfer molding method, a dispensing method, a dipping method, a screen printing method, etc. Form. Next, the upper surfaces of the sealing film 19 and the auxiliary sealing film 17 are appropriately polished to expose the upper surfaces of the columnar electrodes 16 as shown in FIG. In this state, the columnar electrode 1
6, the upper surfaces of the auxiliary sealing film 17 and the sealing film 19 are flush with each other. Next, through a dicing step, individual semiconductor chips (semiconductor devices) 20 are obtained as shown in FIG.

Next, FIG. 7 is a sectional view showing an example of a state in which the semiconductor device 20 shown in FIG. 6 is mounted on the circuit board 21. In this case, the semiconductor device 20 has the circuit board 21.
It is mounted by a face-down method with an anisotropic conductive adhesive 23 on top. That is, the connection terminal 22 is provided at a predetermined location on the upper surface of the circuit board 21. The anisotropic conductive adhesive 23 is made of an insulating adhesive 24 in which conductive particles 25 are mixed almost uniformly. The lower end surface of the columnar electrode 16 of the semiconductor device 20 is conductively connected to the connection terminal 22 of the circuit board 21 via the conductive particles 25 of the anisotropic conductive adhesive 23. Further, the lower surface of the semiconductor device 20 is provided on the upper surface of the circuit board 21 by the anisotropic conductive adhesive 2
3 is adhered via the insulating adhesive 24.

By the way, in the semiconductor device 20, the original sealing film 1 is provided between the columnar electrode 16 and the original sealing film 19.
Since the auxiliary sealing film 17 made of a resin having a lower elastic modulus than 9 is interposed, the columnar electrode 16 can be easily rocked. As a result, the semiconductor device 20 is connected to the circuit board 21.
After mounting on top, the columnar electrode 16 can absorb the stress generated due to the difference in thermal expansion coefficient between the silicon substrate 11 and the circuit substrate 21. Therefore, it is possible to prevent cracks from easily occurring at the joint between the lower end surface of the columnar electrode 16 and the connection terminal 22, and thus to prevent poor conduction from occurring.

As shown in FIG. 8, the semiconductor device 20
May be mounted on the circuit board 21 via the conductive paste 26 by a face-down method. In this case, the conductive paste 26 is used for the connection terminals 2 of the circuit board 21.
It is previously provided on the upper surface of 2 by a screen printing method, a transfer method, a dispenser method, or the like.

After the manufacturing process shown in FIG. 5, solder balls 27 may be formed on the columnar electrodes 16 as shown in FIG. The mounting structure in this case is as shown in FIG. That is, the columnar electrode 1 of the semiconductor chip 20
6 through the solder balls 27 to the connection terminals 2 of the circuit board 21.
It will be connected to 2. In this case, the columnar electrode 16 absorbs the stress so that cracks are less likely to occur at the joint between the lower end surface of the columnar electrode 16 and the solder ball 27. Solder ball 2
Before forming 7, the columnar electrodes 16 may be surface-treated with nickel / gold, nickel / solder, nickel / tin, or the like.

Next, FIGS. 11 to 16 show respective manufacturing steps of the semiconductor device according to the second embodiment of the present invention. Therefore, the structure of the semiconductor device in this embodiment will be described together with the manufacturing method thereof with reference to these drawings in order.

First, as shown in FIG. 11, connection pads 12 are formed on the upper surface of a silicon substrate 11 in a wafer state,
An insulating film 13 made of silicon oxide or the like is formed on a portion of the upper surface of the connecting pad 12 excluding the central portion, and the connecting pad 1 exposed through an opening 14 formed in the insulating film 13.
The wiring 15 is prepared from the upper surface of 2 to the upper surface of the insulating film 13. In this case, the tip portion of the wiring 15 is the connection pad portion 15a.

Next, as shown in FIG. 12, a sealing film 19 made of epoxy resin is formed on the upper surface of the silicon substrate 11. In this case, the opening 19a is formed in the portion of the sealing film 19 corresponding to the connection pad portion 15a (that is, the portion corresponding to the plurality of columnar electrode formation regions and their respective vicinity).
As a method of forming the opening 19a, when the sealing film 19 is formed by a dispensing method or a dipping method, there is a method of forming the opening 19a by irradiating a laser such as an excimer laser or a YAG laser. When the sealing film 19 is formed by a transfer molding method or a screen printing method, the opening 19 is formed by laser irradiation.
a may be formed, or the opening 19a may be formed at the same time when the sealing film 19 is formed.

Next, as shown in FIG. 13, in each opening 19a of the sealing film 19, a resin having a lower elastic modulus than the epoxy resin which is the original material of the sealing film 19 (for example, silicone-modified epoxy) is used. The auxiliary sealing film 17 made of resin or polyimide resin is formed by screen printing. In this case, the auxiliary sealing film 17 is formed so that the upper part thereof is slightly raised on the sealing film 19. Next, as shown in FIG.
Central part of the auxiliary sealing film 17 (that is, a columnar electrode formation region)
Then, the opening 17a is formed by irradiating a laser such as an excimer laser or a YAG laser. In this state, the auxiliary sealing film 17 has a tubular shape, and the connection pad portion 15a is formed.
Is exposed.

Next, as shown in FIG. 15, the auxiliary sealing film 1
The columnar electrode 16 is formed on the upper surface of the connection pad portion 15a in the opening 17a of FIG. As a method of forming the columnar electrodes 16, there is a method of forming by a screen printing method using a conductive adhesive or a conductive paste, and a method of forming by electroless plating of gold, copper, nickel or the like. Next, through a dicing step, as shown in FIG. 16, individual semiconductor chips (semiconductor devices) 20 are obtained.

Next, FIG. 17 shows the semiconductor device 2 shown in FIG.
2 is a sectional view showing an example of a state in which 0 is mounted on the circuit board 21. FIG. In this case, the semiconductor device 20 is mounted on the circuit board 21 via the anisotropic conductive adhesive 23 by a face-down method. That is, the connection terminal 22 is provided at a predetermined location on the upper surface of the circuit board 21.
The anisotropic conductive adhesive 23 is made of an insulating adhesive 24 in which conductive particles 25 are mixed almost uniformly. The lower end surface of the columnar electrode 16 of the semiconductor device 20 is conductively connected to the connection terminal 22 of the circuit board 21 via the conductive particles 25 of the anisotropic conductive adhesive 23. In addition, the lower surface of the semiconductor device 20 is adhered to the upper surface of the circuit board 21 via the insulating adhesive 24 of the anisotropic conductive adhesive 23.

By the way, also in this case, in the semiconductor device 20, the auxiliary sealing film 17 made of resin having a lower elastic modulus than the original sealing film 19 is provided between the columnar electrode 16 and the original sealing film 19. Since the interposition is provided, the columnar electrode 16 can be made to sway and move easily. As a result, after mounting the semiconductor device 20 on the circuit board 21, the silicon substrate 1
The columnar electrode 16 can absorb the stress generated due to the difference in thermal expansion coefficient between the wiring board 1 and the circuit board 21. Therefore, it is possible to prevent cracks from easily occurring at the joint between the lower end surface of the columnar electrode 16 and the connection terminal 22,
As a result, it is possible to prevent poor conduction.

As shown in FIG. 18, the semiconductor device 2
0 may be mounted on the circuit board 21 via the conductive paste 26 by a face-down method. Also in this case, the conductive paste 26 is previously provided on the upper surface of the connection terminal 22 of the circuit board 21 by a screen printing method, a transfer method, a dispenser method, or the like.

Further, after the manufacturing process shown in FIG.
As shown in, the solder balls 27 may be formed on the columnar electrodes 16. The mounting structure in this case is as shown in FIG. That is, the columnar electrodes 16 of the semiconductor chip 20 are connected to the connection terminals 22 of the circuit board 21 via the solder balls 27. And in this case,
By absorbing the stress in the columnar electrode 16, the columnar electrode 1
It is possible to prevent cracks from easily occurring at the joint between the lower end surface of 6 and the solder ball 27. Before the solder balls 27 are formed, the columnar electrodes 16 may be surface-treated with nickel / gold, nickel / solder, nickel / tin, or the like.

By the way, in the case of the manufacturing process shown in FIG. 15, the columnar electrode 16 is provided on the upper surface of the connection pad portion 15a in the opening 17a of the auxiliary sealing film 17, and the upper part thereof is to some extent from the upper surface of the auxiliary sealing film 17. Although it is formed so as to project, it is not limited to this. For example, as shown in FIG. 21, the columnar electrode 16 is formed on the upper surface of the connection pad portion 15a in the opening 17a of the auxiliary sealing film 17 so that the upper surface thereof is lower than the upper surface of the auxiliary sealing film 17 to some extent. The solder balls 27 may be formed on the columnar electrodes 16. Also in this case, before forming the solder balls 27, nickel / gold, nickel / solder,
You may make it surface-treat with nickel / tin etc.

In the above embodiment, the present invention is applied to CS.
Although the case where it is applied to a semiconductor device called P has been described, the present invention is not limited to this, and, for example, although not shown in FIG.
The present invention can also be applied to a semiconductor device including a semiconductor chip in which a columnar electrode 16 is formed on a wiring (underlying metal layer) 15 on a connection pad 12.

[0026]

As described above, according to the present invention, in a semiconductor device, between the columnar electrodes and the original sealing film, auxiliary sealing made of a resin having a lower elastic modulus than the original sealing film is formed. Since the film is interposed, the columnar electrode can be easily oscillated, and the columnar electrode can absorb the stress, and the conduction failure can be made less likely to occur.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of what was initially prepared when manufacturing a semiconductor device according to a first embodiment of the present invention.

FIG. 2 is a sectional view of a manufacturing process subsequent to FIG.

FIG. 3 is a cross-sectional view of the manufacturing process following FIG.

FIG. 4 is a cross-sectional view of the manufacturing process following FIG.

FIG. 5 is a cross-sectional view of the manufacturing process following FIG.

FIG. 6 is a cross-sectional view of the manufacturing process following FIG.

7 is a sectional view of an example of a state in which the semiconductor device shown in FIG. 6 is mounted on a circuit board.

8 is a cross-sectional view of another example of a state in which the semiconductor device shown in FIG. 6 is mounted on a circuit board.

9 is a cross-sectional view when solder balls are formed after the manufacturing process shown in FIG.

FIG. 10 is a cross-sectional view showing a state in which the semiconductor device shown in FIG. 9 is mounted on a circuit board.

FIG. 11 is a cross-sectional view of what was initially prepared in manufacturing the semiconductor device according to the second embodiment of the present invention.

FIG. 12 is a cross-sectional view of the manufacturing process following FIG.

FIG. 13 is a cross-sectional view of the manufacturing process following FIG.

FIG. 14 is a cross-sectional view of the manufacturing process following FIG.

FIG. 15 is a cross-sectional view of the manufacturing process following FIG.

16 is a cross-sectional view of the manufacturing process following FIG.

17 is a sectional view of an example of a state in which the semiconductor device shown in FIG. 16 is mounted on a circuit board.

FIG. 18 is a sectional view of another example of a state in which the semiconductor device shown in FIG. 16 is mounted on a circuit board.

FIG. 19 is a cross-sectional view when solder balls are formed after the manufacturing process shown in FIG.

FIG. 20 is a cross-sectional view showing a state in which the semiconductor device shown in FIG. 19 is mounted on a circuit board.

21 is a cross-sectional view of a modification example shown in FIG.

FIG. 22 is a sectional view of an initially prepared semiconductor device when manufacturing an example of a conventional semiconductor device.

FIG. 23 is a cross-sectional view of the manufacturing process following FIG. 22.

24 is a cross-sectional view of the manufacturing process subsequent to FIG. 23.

FIG. 25 is a cross-sectional view of the manufacturing process following FIG. 24.

[Explanation of symbols]

11 Silicon substrate 12 connection pads 13 Insulating film 15 wiring 16 columnar electrodes 17 Auxiliary sealing film 19 Sealing film 20 Semiconductor device 21 circuit board 22 Connection terminal 23 Anisotropic conductive adhesive 26 Conductive paste 27 Solder Ball

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01L 21/60 311 H01L 21/92

Claims (16)

(57) [Claims] 1. A side surface of each of a plurality of columnar electrodes formed on a substrate is covered with an auxiliary sealing film made of a resin having a modulus of elasticity lower than that of the original sealing film. A semiconductor device comprising an original sealing film provided on a substrate. 2. The semiconductor device according to claim 1, wherein upper surfaces of the columnar electrode, the auxiliary sealing film, and the sealing film are flush with each other. 3. The semiconductor device according to claim 1, wherein an upper portion of the columnar electrode is projected from an upper surface of the auxiliary sealing film. 4. The semiconductor device according to claim 1, wherein an upper surface of the columnar electrode is lower than an upper surface of the auxiliary sealing film. 5. The semiconductor device according to claim 1, wherein solder balls are provided on the columnar electrodes. 6. The side surfaces of a plurality of columnar electrodes formed on a substrate are covered with an auxiliary sealing film made of a resin having a lower elastic modulus than the original sealing film, and the substrate is provided between these auxiliary sealing films. A method for manufacturing a semiconductor device, comprising forming an original sealing film on the semiconductor device. 7. The method of manufacturing a semiconductor device according to claim 6, wherein the upper surfaces of the columnar electrode, the auxiliary sealing film, and the sealing film are flush with each other. 8. A sealing film having openings in openings corresponding to a plurality of columnar electrode formation regions and their respective vicinity is formed on a substrate, and the sealing film is more elastic than the sealing film in each opening. A method of manufacturing a semiconductor device, comprising forming a cylindrical auxiliary sealing film made of a resin having a low rate, and forming a columnar electrode in the auxiliary sealing film. 9. The method of manufacturing a semiconductor device according to claim 8, wherein the columnar electrode is formed so that its upper surface projects from the upper surface of the auxiliary sealing film. 10. The method of manufacturing a semiconductor device according to claim 8, wherein the columnar electrode is formed so that its upper surface is lower than the upper surface of the auxiliary sealing film. 11. The method of manufacturing a semiconductor device according to claim 6, wherein a solder ball is formed on the columnar electrode. 12. A side surface of a plurality of columnar electrodes formed on a substrate is covered with an auxiliary sealing film made of a resin having a lower elastic modulus than the original sealing film, and the space between the auxiliary sealing films is increased. A semiconductor device mounting structure, wherein a semiconductor device having an original sealing film provided on a substrate is mounted on a circuit board by a face-down method. 13. A side surface of a plurality of columnar electrodes formed on a substrate is covered with an auxiliary sealing film made of a resin having an elastic modulus lower than that of the original sealing film, and the auxiliary sealing film between the auxiliary sealing films is formed. A mounting structure of a semiconductor device, wherein a semiconductor device having an original sealing film provided on a substrate and solder balls provided on the columnar electrodes is mounted on a circuit board by a face-down method. 14. The semiconductor device mounting structure according to claim 12 or 13, wherein the upper surfaces of the columnar electrode, the auxiliary sealing film and the sealing film of the semiconductor device are flush with each other. . 15. The mounting structure of a semiconductor device according to claim 12, wherein an upper portion of the columnar electrode of the semiconductor device is projected from an upper surface of the auxiliary sealing film. 16. The semiconductor device mounting structure according to claim 13, wherein an upper surface of the columnar electrode of the semiconductor device is lower than an upper surface of the auxiliary sealing film.