JP2013069999A - Semiconductor device and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor device that prevents an excess spread of an underfill material filled with spaces between semiconductor chips in the horizontal direction even if the number of stacks of the semiconductor chips is increased, and to provide a method of manufacturing the same.SOLUTION: A semiconductor device 10 includes a supporting substrate 5 in which a recess 5a is formed on one primary surface, a stack 4 that includes a plurality of semiconductor elements 1a to 1d housed in the recess 5a, and an underfill material 6 that is filled in the recess 5a and seals the stack 4. The stack 4 includes the semiconductor element 1a that is disposed on the bottom surface side of the recess 5a and does not have a through electrode, and the semiconductor elements 1b to 1d that are subjected to flip-chip connection onto the semiconductor element 1a in one stage or multiple stages and have through electrodes 2b to 2d.

Description

  Embodiments described herein relate generally to a semiconductor device and a manufacturing method thereof.

  Recently, as a stacked semiconductor device, a semiconductor chip having through electrodes (TSV) stacked in the vertical direction to improve the integration density and the operation speed is known. In such a semiconductor device, the semiconductor chips are connected to each other by flip-chip connection, and an underfill material (liquid curable resin) is filled in a minute gap of about 10 μm or more between the semiconductor chips and sealed. The The underfill material is filled by utilizing the underfill material supplied to the side surfaces of the stacked semiconductor chips permeating into the gaps between the chips by capillary action.

  However, in this case, when the number of semiconductor chips to be stacked increases and the height increases, the underfill material must be supplied to a high position, and the underfill material inevitably spreads in the horizontal direction, and the peripheral bonding pads. There is a risk of causing contamination and the enlargement of the semiconductor device.

JP 2010-278334 A

  The problem to be solved by the present invention is that even when the number of stacked semiconductor chips is increased, it is possible to supply the underfill material between the semiconductor chips at high positions without excessively spreading in the horizontal direction. An object of the present invention is to provide a semiconductor device capable of preventing contamination of pads and the like and an increase in size of the device, and a manufacturing method thereof.

  The semiconductor device according to the embodiment includes a support substrate having a recess formed on one main surface, a stacked body including a plurality of semiconductor elements housed in the recess, and the recess is filled to seal the stacked body. And an underfill material. The laminated body includes a semiconductor element that does not have a through electrode disposed on the bottom surface side of the recess, and a semiconductor element that has a through electrode that is flip-chip connected to the semiconductor element in one or more stages.

It is sectional drawing which shows the structure of the semiconductor device by one Embodiment. FIG. 3 is a cross-sectional view showing a manufacturing process of the semiconductor device shown in FIG. 1. FIG. 3 is a cross-sectional view showing a manufacturing step of the semiconductor device after the step shown in FIG. It is sectional drawing which shows the structure of the semiconductor device by one Embodiment. FIG. 5 is a cross-sectional view showing a manufacturing step of the semiconductor device shown in FIG. 4. FIG. 5 is a cross-sectional view showing a manufacturing step of the semiconductor device after the step shown in FIG. 4.

  Hereinafter, embodiments will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a cross-sectional view showing the structure of the semiconductor device according to the first embodiment.

  A semiconductor device (semiconductor package) 10 shown in FIG. 1 is a so-called stacked semiconductor device, in which a plurality of semiconductor elements (semiconductor chips) 1a to 1d are stacked. In this embodiment, the case where the number of stacked semiconductor elements (semiconductor chips) is four will be mainly described. However, the number of stacked semiconductor elements (semiconductor chips) is not particularly limited. It may be a layer, 8 layers, 16 layers, 32 layers, or the like.

  Each of the plurality of semiconductor elements 1a to 1d is made of a semiconductor substrate such as a silicon substrate. One of them, that is, the semiconductor element 1a does not have a through electrode, and an electrode pad 2a is formed on one surface thereof. On the other hand, the remaining semiconductor elements 1b to 1d have through electrodes 2b to 2d, and connection pads (not shown) provided integrally with the respective through electrodes 2b to 2d are provided on both surfaces thereof. Yes.

  The plurality of semiconductor elements 1a to 1d have a structure in which the semiconductor elements 1b to 1d having the through electrodes 2b to 2d are flip-chip connected to the semiconductor element 1a having no through electrode. That is, the electrode pad 2a of the semiconductor element 1a having no through electrode and the connection pad on the semiconductor element 1a side of the semiconductor element 1b having the adjacent through electrode 2b are connected by the metal bump 3a such as a solder bump, A connection pad on the other side of the semiconductor element 1b having the through electrode 2b is connected to a connection pad on the semiconductor element 1b side of the semiconductor element 1c having the adjacent through electrode 2c by a metal bump 3b such as a solder bump. Similarly, the connection pad on the other side of the semiconductor element 1c having the through electrode 2c is connected to the connection pad on the semiconductor element 1c side of the semiconductor element 1d having the adjacent through electrode 2d by the metal bump 3c such as a solder bump. ing.

  The plurality of semiconductor elements 1a to 1d flip-chip connected to form the stacked body 4 are accommodated in the recess 5a formed on one main surface of the support substrate 5 and underfilled in the recess 5a. Material 6 is filled. By providing the support substrate 5, it is possible to fill the gaps between the semiconductor elements 1 a to 1 d without spreading the underfill material 6 in the horizontal direction.

  That is, the support substrate 5 has a function of preventing the underfill material 6 from spreading in the horizontal direction. Therefore, the material constituting the support substrate 5 may be any material that can have such a function, in other words, any material that does not deform when filled with the underfill material 6, such as metal, resin, ceramic, and the like. The material can be used. From the viewpoint of ease of processing and the like, metal or resin is preferable. Further, if a metal material having shielding properties such as aluminum is used, a shielding effect against noise can be provided. In addition, if a material having high thermal conductivity such as copper is used, it can have a function as a heat radiating material that releases the heat of the semiconductor elements 1a to 1d to the outside. Further, 42 alloy is preferable when a silicon (Si) substrate is used as a semiconductor substrate constituting the semiconductor elements 1a to 1d because the linear expansion coefficient approximates that of silicon.

  In addition, since the support substrate 5 becomes a constituent member of the semiconductor device 10 as it is, it can have a function of suppressing warpage of the semiconductor elements 1a to 1d and the wiring substrate 7 described later during the manufacturing process of the semiconductor device. The support substrate 5 can also have a function as a transport member for the semiconductor elements 1a to 1d.

  The support substrate 5 may have a composite structure in which, for example, the bottom is formed of a metal material, the side is formed of a plastic material, the main body is formed of a plastic material, and the metal material is attached to the bottom surface of the bottom. In such an example, as described later, the cutting operation of the support substrate 5 in the manufacturing process of the semiconductor device 10 can be facilitated.

  In order to reduce the size and thickness of the semiconductor device 10, the height h of the support substrate 5 is, for example, 0.4 to 0.7 mm when the number of stacked semiconductor elements as shown in FIG. When the number of laminations is 8, it is preferably 0.6 to 0.9 mm, and when the number of laminations is 16, it is preferably 0.8 to 1.1 mm. Further, the distance w from the outer edge of the support substrate 5 to the ends of the semiconductor elements 1a to 1d is 320 μm or less, preferably 320 to 200 μm. Furthermore, the thickness d of the bottom portion of the support substrate 5 is 300 μm or less, preferably 100 to 150 μm.

  Moreover, as the underfill material 6 filled in the recess 5a of the support substrate 5, for example, an epoxy resin is used. As the resin used for the underfill material 6, it is preferable to select a material that is sufficiently filled between the semiconductor elements 1a to 1d and that does not generate voids.

  The plurality of semiconductor elements 1 a to 1 d are accommodated so that the semiconductor element 1 a having no through electrode is positioned on the bottom surface side of the support substrate 5. The semiconductor element 1a is bonded and fixed to the bottom surface of the support substrate 5 with an adhesive 8 such as a die attach film (DAF).

  The semiconductor device 10 shown in FIG. 1 further includes a wiring substrate 7 for connecting the semiconductor elements 1a to 1d accommodated in the recesses 5a of the support substrate 5 to the outside.

  As the wiring substrate 7, a multilayer wiring substrate using an insulating substrate such as a resin substrate, a ceramic substrate, or a glass substrate as a base material is used. Examples of the wiring board 7 to which the resin board is applied include a general multilayer copper-clad laminate (multilayer printed wiring board). An electrode pad 7a is provided on one surface of the wiring board 7, and an external electrode 11 such as a solder bump is fixed thereon. Further, the other surface of the wiring board 7 is provided with a surface wiring layer 7b and an electrode pad (not shown), and the electrode pad of the wiring board 7 and the uppermost layer in the recess 5a (in FIG. The electrode pads on the wiring substrate 7 side of the semiconductor element 1d (located below) are connected by metal bumps 12 such as solder bumps. Inside the wiring substrate 7, an inner wiring layer 7c connected to the surface wiring layer 7b and the electrode pad 7a on the external electrode 11 side is further provided. The external electrode 11 and the semiconductor element 1d are electrically connected through the electrode pad 7a on the external electrode 11 side, the inner wiring layer 7c, the surface wiring layer 7b, the electrode pad on the semiconductor element 1d side, and the metal bump 12. Yes.

  An underfill material 13 is filled and solidified in a gap between the support substrate 5, the module including the semiconductor elements 1 a to 1 d and the underfill material 6, and the wiring substrate 3. Hereinafter, the underfill material 6 filled in the recess 5a of the support substrate 5 is referred to as a first underfill material 6, and a module including the support substrate 5, the semiconductor elements 1a to 1d and the underfill material 6, and the wiring substrate 7 The underfill material 13 filled in the gap between them is referred to as a second underfill material 13. For the second underfill material 13, the same resin as that used for the first underfill material 6 can be used. From the viewpoint of reducing the amount of protrusion, use of a film-like sealing material, NCF (Non Conductive Film), or the like is also preferable.

  Next, the manufacturing process of the semiconductor device 10 according to this embodiment will be described with reference to FIGS.

  First, as shown in FIG. 2A, a support substrate 5A having a plurality of recesses 5a (only two are shown in the example of the drawing) formed on one main surface is prepared, and the recess 5a is provided in the recess 5a. The semiconductor elements 1a to 1d are arranged while being stacked in order. Of the semiconductor elements 1a to 1d to be arranged, first, the semiconductor element 1a having no through electrode is fixed to the bottom surface of the recess 5a with the electrode pad 2a formation surface facing upward. For fixing, an adhesive 8 such as a die attach film is used. Next, the remaining semiconductor elements 1b to 1d are sequentially stacked on the semiconductor element 1a. At this time, the electrode pads facing each other of the semiconductor elements 1a to 1d are stacked while being connected by metal bumps 3a to 3c such as solder bumps.

  The recess 5a of the support substrate 5A has such a depth that the upper surface of the uppermost semiconductor element 1d is not exposed from at least the upper surface of the support substrate 5A when the semiconductor elements 1a to 1d to be accommodated are stacked and connected. Further, the recess 5a is provided with a thickness that does not impair its function on the side surface of the recess when it is cut in a subsequent process, for example, a width that leaves a side wall with a thickness of 0.1 to 0.3 mm. .

  In this way, when the stack 4 of the plurality of semiconductor elements 1a to 1d is accommodated in the respective recesses 5a provided on the support substrate 5A, the recesses 5a are under-treated as shown in FIG. Filling material 6 is filled and cured. The underfill material 6 is supplied between the side wall of the recess 5a and the side surface of the stacked body 4 of the semiconductor elements 1a to 1d and filled in the gaps between the stacked semiconductor elements 1a to 1d. When the filling is completed, the underfill material 6 is cured.

  Before filling the underfill material 6, electrode pads are formed on the upper surface of the uppermost semiconductor element 1d. However, when filling the underfill material 6, these electrode pads are exposed. In some cases, the electrode pad may be exposed in a subsequent planarization process or a subsequent metal bump formation process.

  Next, as shown in FIG. 2C, the upper surface of the underfill material 6 and, if necessary, the upper surface of the supporting substrate 5A are further planarized, and then soldered onto the exposed electrode pads on the upper surface of the semiconductor element 1d. A metal pump 12 is formed by mounting balls or the like.

  Next, as shown in FIG. 3 (d), the support substrate 5 is fixed to a dicing tape or the like (not shown), and then cut using a blade such as a diamond blade, so that one recess 5a is formed. The substrate 5 is divided into modules comprising the semiconductor elements 1 a to 1 d and the underfill material 6 accommodated in the recess 5 a. In FIG. 3D, the code | symbol 31 has shown the cutting part by a braid | blade. As described above, the support substrate 5 is entirely made of a plastic material, the bottom is made of a metal material, the side is made of a plastic material, or a metal material is pasted on the lower surface of the support substrate made of a plastic material. When the attached one is used, the cutting work becomes easy.

  Next, as shown in FIG. 3E, the above modules are turned upside down, and the inner wiring layer 7c, the surface wiring layer 7b, the electrode pads of the wiring board 7 on which the electrode pads are formed, and the semiconductor element 1d. The electrode pads formed on the upper surface of the semiconductor device are connected by the metal bumps 12, and the gap between the semiconductor element 1 d and the wiring substrate 7 is filled with an underfill material 13 and cured.

  Next, as shown in FIG. 3 (f), electrode pads 7 a are formed on the lower surface of the wiring substrate 7, and solder balls are mounted to form the external electrodes 11. Thereafter, the wiring substrate 7 is cut using a blade at the position of the cutting portion 31 of the support substrate 5 to manufacture the semiconductor device 10 shown in FIG.

  In the manufacturing method described above, a module is manufactured by cutting the support substrate 5 and then mounted on the wiring substrate 7. In this method, the degree of freedom in alignment between the electrode pads on the wiring board 7 and the metal bumps 12 provided on the electrode pads on the semiconductor element 1d is increased. That is, even if there is a slight misalignment between the position of the electrode pad on the wiring board 7 and the position of the metal bump 12 on the semiconductor element 1d, the position of the mounted module can be controlled. Connection reliability with the metal bumps 12 on the semiconductor element 1d can be improved.

  In this method, the semiconductor elements 1a to 1d are stacked in the recess 5a of the support substrate 5A in the step of FIG. 2A. However, the stacking of the semiconductor elements 1a to 1d is performed in another stage. They may be stacked on top of each other and accommodated in the recess 5 a as the stacked body 4.

(Second Embodiment)
FIG. 4 is a cross-sectional view showing the structure of the semiconductor device (semiconductor package) 20 according to the second embodiment. In the present embodiment, in order to avoid overlapping description, description of points common to the first embodiment will be omitted or simplified, and differences will be mainly described.

  A semiconductor device (semiconductor package) 20 shown in FIG. 4 replaces the wiring substrate 7 in order to connect the semiconductor elements 1a to 1d housed in the recesses 5a of the support substrate 5 to the outside in the semiconductor device 10 shown in FIG. The rewiring layer 41 is provided.

  The rewiring layer 41 is provided on the recess 5 a formation surface of the support substrate 5 via the first insulating film 42. One end of the rewiring layer 41 is connected to an electrode pad formed on the surface of the semiconductor element 1 d on the rewiring layer 41 side, and the other end is formed with an external electrode such as a solder bump via a post 43. In FIG. 4, reference numerals 44 and 45 denote a second insulating film formed between the rewiring layer 41 and the external electrode 11 formation surface, and a resin layer made of epoxy resin or the like. In the drawing, the second insulating film 44 is shown as an integral part of the first insulating film 42.

  Second, the same effects as those of the first embodiment can be obtained in the second embodiment. In this embodiment, since the redistribution layer technology is used to connect to the outside, the semiconductor device can be further reduced in size and thickness.

  Next, the manufacturing process of the semiconductor device 20 according to this embodiment will be described with reference to FIGS.

  As described above, the semiconductor device 20 includes the rewiring layer 41 in order to connect the semiconductor elements 1a to 1d to the outside. Therefore, in the manufacture, as shown in FIG. 5C, after the upper surface of the underfill material 6 and, if necessary, the upper surface of the support substrate 5A are further flattened, Thus, a layer including the rewiring layer 41 connected to the electrode pad provided on the upper surface of the semiconductor element 1d as shown in FIG. 4 is formed (FIG. 6D).

  Next, a solder ball or the like is mounted on the post 43 to form the external electrode 11, and the support substrate 5A is fixed to a dicing tape or the like (not shown), and a support substrate is used using a blade such as a diamond blade. 5A, the first and second insulating films 42 and 44 on the upper surface, and the resin layer 45 are cut (FIG. 6E). Thereby, the semiconductor device 20 shown in FIG. 4 is manufactured.

  In this manufacturing method, the steps up to FIG. 6C are the same as the steps of FIG. 2A and FIG.

  According to at least one of the embodiments described above, since the underfill material can be prevented from spreading in the horizontal direction by the support substrate in which the recesses are formed, even if the number of stacked semiconductor elements is large, the gap is formed between the upper semiconductor elements. The underfill material can be supplied in a small amount of use up to the height required for filling. In addition, since the thickness of the side wall and the bottom of the recess can be reduced, the semiconductor device does not increase in size or thickness.

  In addition, since the support substrate becomes a constituent member of the semiconductor device as it is, it is possible to suppress warping of the semiconductor element during the manufacturing process of the semiconductor device. In addition, since the support substrate can function as a transport member for the semiconductor element, the semiconductor devices can be collectively assembled, and productivity can be increased. Furthermore, it becomes possible to provide a shielding effect against noise.

  As mentioned above, although several embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 1a-1d ... Semiconductor element (semiconductor chip), 2b-2d ... Through electrode, 4 ... Laminated body, 5 ... Support substrate, 5a ... Recessed part, 6 ... (1st) underfill material, 7 ... Wiring board, 10, DESCRIPTION OF SYMBOLS 20 ... Semiconductor device (semiconductor package), 11 ... External electrode, 13 ... (2nd) underfill material, 31 ... Cutting part, 41 ... Rewiring layer.

Claims (5)

A support substrate having a recess formed on one main surface; a laminate composed of a plurality of semiconductor elements housed in the recess; and an underfill material that fills the recess and seals the laminate. ,
The laminated body is composed of a semiconductor element having no through electrode disposed on the bottom surface side of the recess and a semiconductor element having a through electrode flip-chip connected to the semiconductor element in one or more stages. Semiconductor device.   The semiconductor device according to claim 1, further comprising: a wiring board for electrically connecting a semiconductor element in the recess to the outside on the recess forming surface of the support substrate.   3. The semiconductor device according to claim 2, wherein the uppermost semiconductor element in the recess is flip-chip connected to the wiring board.   2. The semiconductor device according to claim 1, further comprising: a rewiring layer for electrically connecting a semiconductor element in the recess to the outside on the recess forming surface of the support plate. Preparing a support substrate having a recess formed on one main surface;
Placing a semiconductor element having no through electrode on the bottom surface of the recess of the support substrate;
A step of stacking a plurality of semiconductor elements having through electrodes on a semiconductor element not having the through electrodes by flip chip connection in order;
A step of filling the recess with an underfill material and sealing the stacked body.

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