JP2011054653A - Manufacturing method of semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a semiconductor device whose warpage amount is small and in which a wiring mother substrate can be enlarged, even if the difference in the thermal expansion coefficients between sealing resin and a wiring mother substrate is large, and which has inexpensive manufacturing cost and has less individual differences of warpages, in a manufacturing method of the semiconductor device for manufacturing the sealing resin in the wiring mother substrate by a mold manufacturing method. <P>SOLUTION: The manufacturing method includes a process for forming the sealing resin 21 on the wiring mother substrate 1 by the mold manufacturing method, a process for cutting the sealing resin along a dicing line arranged on the wiring mother substrate and a process for thermally-curing the sealing resin, after the resin is cut. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a semiconductor device.

  In recent years, with the miniaturization, high speed, and high functionality of digital devices, there is an increasing demand for high density mounting of semiconductor devices such as BGA (ball grid array) type semiconductor devices, and a plurality of semiconductor chips in one package. The MCP (multi-chip package) for stacking layers and the PoP (package on package) for stacking a plurality of thin packages are progressing.

  This BGA type or LGA (land grid array) type semiconductor device uses a wiring mother board in which a plurality of product forming portions are arranged and arranged, a semiconductor chip is mounted and bonded to each product forming portion, and a wiring mother is provided. After the entire substrate is molded with a sealing resin all at once, it has been manufactured by cutting into individual product units and separating them individually.

  Patent Documents 1 and 2 disclose a technique for taking measures against warping of a semiconductor wafer. Patent Document 3 discloses a technique for forming a groove in the sealing body, and Patent Document 4 discloses a technique for forming a slit in the sealing body. Patent Document 5 discloses a technique for preparing a mold for each package shape, providing a protrusion on the mold, and forming a groove in the mold part.

JP 2003-218144 A JP 2003-218275 A JP 2005-333044 A JP 2008-177440 A JP 2002-110718 A

  By the way, with the thinning of the package, the influence of the warp of the semiconductor device, which has not been a problem in the past, can no longer be ignored. In particular, the inventors of the present application have revealed that there are problems described below.

That is, the sealing resin on the upper side of the wiring mother board, for example, from an epoxy material thermal expansion coefficient of a _1, a wiring mother substrate 1 is, for example, formed from a polyimide material thermal expansion coefficient a _2. In this case, the a ₁ is greater than a _2, upon cooling to room temperature by heating and curing the sealing resin, the upper sealing resin so that shrinks larger than the wiring substrate of the lower.

  As a result, the semiconductor device itself becomes a negative warp in which the central portion is recessed downward and the peripheral portion warps upward. If this negative warpage is large, there is a disadvantage that a mounting device peels off at the peripheral portion when the semiconductor device is mounted on an external substrate or is stacked with another semiconductor device to form PoP.

In particular, considering the entire wiring mother board 1, as shown in FIGS. 10 (a) to 10 (c), the hardening shrinkage force from the center line 6 side is accumulated in the peripheral region 5 of the wiring mother board 1, so that sealing is performed. difference cure shrinkage force beta ₁ of cure shrinkage force alpha ₁ and the wiring substrate 1 of the sealing resin 2 is increased, warpage amount increases. Further, in the central region 4 of the center line 6 near the wiring mother substrate 1, but the difference in cure shrinkage force beta ₂ of hardening shrinkage force alpha ₂ and the wiring mother substrate 1 of the sealing resin 2 is small, a plus warp in the opposite There was also an inconvenience.

From the above, when the wiring mother board 1 is enlarged, there is a disadvantage that warpage of the semiconductor device 3b formed in the peripheral region 5 increases. As a result, for example, when manufacturing a product having a severe manufacturing tolerance of warp such as a PoP product, the large-sized wiring mother board 1 cannot be used, and the cost cannot be reduced. It was.
Note that none of the techniques disclosed in the cited documents 1 to 5 solves the above-described problem.

Therefore, the present invention employs the following configuration.
The method for manufacturing a semiconductor device of the present invention includes a step of forming a sealing resin on a wiring substrate by a molding method, a step of cutting the sealing resin along a dicing line provided on the wiring substrate, and after cutting Forming a sealing body by heat-curing the sealing resin.

  In the present invention, after the sealing resin is formed by the molding method, the sealing resin is cut along the dicing line and then cured by heating. As a result, when the sealing resin is heat-cured and cooled to room temperature, the curing shrinkage force is not accumulated, and even if the difference in thermal expansion coefficient between the sealing resin and the wiring board is large, the peripheral edge of the wiring board The amount of warpage of the region is reduced. As a result, it is possible to increase the size of the wiring board, and it is possible to manufacture a semiconductor device with a low manufacturing cost and a small individual difference in warpage.

FIG. 1 is a cross-sectional process diagram illustrating a method for manufacturing a semiconductor device according to a first embodiment of the present invention. FIG. 2 is a plan view showing a wiring mother board used in the first embodiment of the present invention. FIG. 3 is a plan view showing a wiring mother board used in the first embodiment of the present invention. FIG. 4 is a cross-sectional process diagram illustrating a part of the semiconductor device manufacturing method according to the first embodiment of the present invention. FIG. 5 is a diagram showing a manufacturing flow of the semiconductor device according to the first embodiment of the present invention. FIG. 6 is a cross-sectional view showing a semiconductor device manufactured by the method for manufacturing a semiconductor device according to the first embodiment of the present invention. FIG. 7A is a plan view showing a wiring mother board used in the method for manufacturing a semiconductor device of the second embodiment of the present invention, and FIG. 7B is a diagram of the second embodiment of the present invention. It is sectional process drawing which shows a part of manufacturing method of a semiconductor device. FIG. 8 is a cross-sectional process diagram illustrating a method for manufacturing a semiconductor device according to a third embodiment of the present invention. FIG. 9 is a diagram showing a manufacturing flow of the semiconductor device according to the third embodiment of the present invention. FIG. 10 is a sectional process diagram showing a part of a conventional method for manufacturing a semiconductor device.

[First Embodiment]
A method for manufacturing a semiconductor device according to a first embodiment of the present invention will be described below with reference to the drawings. In the following description, the sealing resin refers to the one before heat curing, and the sealing body refers to the one after heat curing.

First, an example of a semiconductor device manufactured by the semiconductor device manufacturing method of the present embodiment will be described.
As shown in FIG. 6, the semiconductor device 11 is a BGA (Ball Grid Array) type semiconductor device, which has a plurality of connection pads 13 on one surface 12a and is electrically connected to the connection pads 13 on the other surface 12b. A wiring board 12 having a plurality of lands 14, a semiconductor chip 15 mounted on one surface 12 a of the wiring board 12, a connection pad 13 provided on the wiring board 12, and an electrode pad 16 provided on the semiconductor chip 15 are connected. The structure includes a wire 17, a sealing body 18 made of an insulating resin that covers at least the semiconductor chip 15 and the wire 17, and an external terminal 19 such as a solder ball provided on the land 14.

  The semiconductor device 11 manufactured in the present embodiment is not limited to the above structure as long as it is manufactured using the wiring motherboard 1. For example, a multi-chip structure in which a plurality of semiconductor chips are mounted, a structure in which connection is made by bumps instead of wire bonding, or an LGA type structure having no external connection solder balls may be used.

Next, a method for manufacturing the semiconductor device of this embodiment will be described.
First, a wiring mother board 1 as shown in FIG. 2 is prepared. The wiring mother board 1 is processed by a MAP (Mold Array Process) method, and has a substantially rectangular plate shape in plan view, and a plurality of product forming portions 20 are arranged in a matrix.
The product forming portion 20 is a portion that becomes the wiring substrate 12 after being cut and separated along the dicing line 22 provided between the product forming portions 20.

  The wiring mother board 1 is made of, for example, a glass epoxy board having a thickness of 0.25 mm. Predetermined wiring is provided on both surfaces of the wiring mother board 1, and an unillustrated portion is provided on a part of the outer side of the wiring. An insulating film such as a solder resist is laminated.

A plurality of connection pads 13 (see FIG. 6) are arranged in the portions exposed from the solder resist of the wiring on one surface of the product forming portion 20 of the wiring motherboard 1.
In addition, a plurality of lands 14 (see FIG. 6) are arranged in a grid pattern at portions exposed from the solder resist of the wiring on the other surface of the product forming unit 20.
And the connection pad 13 and the land 14 corresponding to this are electrically connected by the internal wiring 8 (refer FIG. 6), respectively.

  Further, a frame portion 23 is provided in a region around the product forming portion 20 arranged in a matrix. Positioning holes 24 are provided in the frame portion 23 at a predetermined interval so that conveyance and positioning can be performed.

  Next, a semiconductor chip 15 (see FIG. 6) is placed at a substantially central position on one surface of each product forming part 20 of the wiring mother board 1, for example, an insulating adhesive or a fixing member such as DAF (Die Attached Film). 9 (see FIG. 6).

  After the semiconductor chip 15 is bonded and fixed to the product forming portion 20, the electrode pads 16 (see FIG. 6) formed on the one surface 15 a of the semiconductor chip 15 and the connection pads 13 of the wiring mother board 1 are connected to the conductive wires 17. (See FIG. 6).

Next, a sealing resin 21 is formed on the wiring mother board 1 by a molding method. As a mold method, any method known in the art may be used. For example, the wiring mother board 1 is sucked and held on the upper mold of the compression molding apparatus, liquid sealing resin is supplied to the lower mold of the compression molding apparatus, and the upper mold is lowered to form the wiring mother board on the lower mold. A method of forming by immersing in the liquid sealing resin thus formed and heating and compressing with an upper mold and a lower mold may be used.
As described above, as shown in FIGS. 1A and 3, the wiring mother board 1 on which the sealing resin 21 is formed by the molding method is obtained. 1, FIG. 4 (a), FIG. 7 (b) and FIG. 8 are cross-sectional views taken along the line AA 'in FIG.

Next, the sealing resin 21 is cut along all the dicing lines 22 provided on the wiring mother board 1 in a state where the sealing resin 21 is not heated and cured. At this time, as shown in FIGS. 1B, 4 </ b> A, and 4 </ b> B, a cutting groove 25 is formed in the sealing resin 21.
The depth of the cutting groove 25 is most preferably set to the same depth as the thickness l of the sealing resin 21, but a warp reduction effect is expected in consideration of the strength reduction and breakage caused by the cutting groove 25. The depth of the cutting groove 25 may be set to be shallower than the thickness l of the sealing resin 21 in the range. For example, as illustrated in FIG. 4B, the depth m may be designed to be about 50% of the thickness l of the sealing resin 21.
In this step, since the wiring mother board 1 is not individually separated, the wiring mother board 1 is not cut.

Moreover, it is preferable to use the dicing apparatus and dicing blade 26 which are utilized in the dicing process of the wiring mother board 1 later as equipment for cutting.
Thereby, an additional installation expense can be suppressed. Further, since the cutting is performed by the same dicing blade 26, it is possible to suppress the occurrence of a step on the cutting surface (side surface) of the sealing resin 21 and the wiring mother board 1 when the wiring mother board 1 is subjected to the dicing process. it can.

  Next, as illustrated in FIG. 1C, after the sealing resin 21 is cut, the sealing body 27 is formed by heating and curing the sealing resin 21. Specifically, the wiring mother board 1 is heated and held at, for example, 175 ° C. for 5 hours to completely cure the sealing resin 21, and then the heating is released to cool to room temperature (cure baking).

  After the sealing body 27 is formed on the wiring mother board 1, as shown in FIG. 1D, the process proceeds to a ball mounting process (solder ball attachment). That is, conductive solder balls are mounted on the plurality of lands 14 arranged in a grid pattern on the other surface of the product forming portion 20 of the wiring mother board 1, and bump electrodes serving as the external terminals 19 are formed.

  Specifically, using the ball mount tool 28 in which a plurality of suction holes are formed in accordance with the arrangement of the lands 14 on the wiring mother board 1, the solder balls are sucked and held in the suction holes, and the held solder balls are The flux is transferred and mounted on the land 14 of the wiring motherboard 1 at a time. Then, after mounting the solder balls on all the product forming portions 20, the wiring mother board 1 is reflowed to fix the solder balls and form the bump electrodes to be the external terminals 19.

Thereafter, as shown in FIGS. 1E and 1F, the wiring mother board 1 on which the solder balls are mounted is transferred to a dicing process (individual piece cutting), and the wiring mother board 1 is cut by a dicing line 22. The product forming unit 20 is separated.
Specifically, the sealing body 27 side of the wiring mother board 1 is bonded to a dicing tape 29, and the wiring mother board 1 is supported by the dicing tape 29. Thereafter, the wiring mother board 1 is cut along the dicing lines 22 vertically and horizontally by a dicing blade 26 of a dicing apparatus (not shown), and is cut and separated for each product forming portion 20. After cutting and separating, the semiconductor device 11 is obtained by picking up from the dicing tape 29.

In the manufacturing method of the semiconductor device according to the present embodiment, after the sealing resin 21 is formed on the wiring mother board 1 by the molding method, the sealing resin 21 is cut along the dicing line 22 and then cured by heat curing. A body 27 is formed.
That is, as shown in FIG. 5, immediately after the conventional sealing resin 21 is formed by a molding method, the sealing resin 21 is heated and cured and cooled to room temperature (curing bake), and then a ball mounting step (solder ball attachment). And a dicing process (cutting pieces). On the other hand, in this embodiment, after the sealing resin 21 is formed by the molding method, the uncured sealing resin 21 is cut along the dicing line 22, and then the sealing resin 21 is heated and cured. Then, it is cooled to room temperature, and a ball mounting process and a dicing process are performed.

As a result, when the resin is heat-cured and cooled to room temperature, the sealing resin 21 is individualized, and as shown in FIG. Is not accumulated in the peripheral area. As a result, even if the difference in thermal expansion coefficient between the sealing resin 21 and the wiring mother board 1 is large, the amount of warpage of the peripheral region of the wiring mother board 1 is reduced. As a result, the wiring mother board 1 can be enlarged, and the semiconductor device 11 can be manufactured with a low manufacturing cost and a small solid difference in warpage.
When the sealing resin 21 is cured by heating and cooled to room temperature, since the sealing resin 21 is individualized, it is possible to prevent the central region of the wiring mother board 1 from being positively warped.

  Moreover, since the manufacturing method of the semiconductor device of this embodiment can be manufactured with a standard member and a manufacturing apparatus without using a new raw material and a manufacturing jig, manufacturing cost can be reduced.

[Second Embodiment]
Next, a method for manufacturing a semiconductor device according to the second embodiment of the present invention will be described. The manufacturing method of the semiconductor device according to the present embodiment is a modification of the first embodiment, and description of similar parts will be omitted as appropriate.

  First, also in the present embodiment, the wiring mother board 1 is prepared as in the first embodiment, the semiconductor chip 15 is mounted on the product forming unit 20, and the electrode pads 16 formed on the semiconductor chip 15 and the wiring mother board 1 are formed. The connection pad 13 is connected by a conductive wire 17. Thereafter, a sealing resin 31 (see FIG. 7) is formed on the wiring mother board 1 by a molding method.

Next, the sealing resin 31 is cut along the dicing line 22 provided on the wiring motherboard 1 in a state where the sealing resin 31 is not cured by heating. At this time, in the first embodiment, cutting is performed along all of the dicing lines 22 provided on the wiring motherboard 1, but in this embodiment, cutting is performed along a part of the dicing lines 22.
For example, as shown in FIG. 7A, the dicing line 22 is cut by being thinned at intervals of one line or two lines. That is, the dicing line 22 includes a cutting line 33 that cuts the sealing resin 31 without being heated and cured, and a cutting line 34 that is cut after being heated and cured. In addition, what is necessary is just to set suitably the space | interval which thins out the dicing line 22 to cut | disconnect from the relationship of the thermal expansion coefficient of the sealing resin 31 to be used, the wiring motherboard 1, etc.

  Thereafter, as in the first embodiment, after cutting the sealing resin 31, the sealing resin 31 is heated and cured to form the sealing body 32, and the ball mounting process and the dicing process are performed. Thus, the semiconductor device 11 is obtained.

As in the first embodiment, the method for manufacturing the semiconductor device according to the present embodiment is such that when the sealing resin 31 is heated and cured and cooled to room temperature, the sealing resin 31 is individualized and cured and contracted. Power is no longer accumulated. As a result, even if the difference in thermal expansion coefficient between the sealing resin 31 and the wiring mother board 1 is large, the amount of warpage of the peripheral region of the wiring mother board 1 is reduced. As a result, the wiring mother board 1 can be enlarged, and the semiconductor device 11 can be manufactured with a low manufacturing cost and a small solid difference in warpage.
Moreover, since it can manufacture with a standard member and a manufacturing apparatus, without using a new raw material and a manufacturing jig, manufacturing cost can be reduced.

  Moreover, compared with 1st Embodiment, the working time at the time of cut | disconnecting the sealing resin 31 which is not heat-hardened can be reduced. In addition, since the use time of the dicing blade 26 is reduced as compared with the first embodiment, the maintenance interval of the dicing blade 26 can be lengthened.

[Third Embodiment]
Next, a method for manufacturing a semiconductor device according to the third embodiment of the present invention will be described. The manufacturing method of the semiconductor device of this embodiment is different from that of the first embodiment in that the sealing resin is heat-cured after passing through the dicing process, and the same parts as those of the first embodiment are appropriately selected. Description is omitted.

First, also in the present embodiment, the wiring mother board 1 is prepared as in the first embodiment, the semiconductor chip 15 is mounted on the product forming unit 20, and the electrode pads 16 formed on the semiconductor chip 15 and the wiring mother board 1 are formed. The connection pad 13 is connected by a conductive wire 17.
Next, as shown in FIG. 8A, a sealing resin 41 is formed on the wiring motherboard 1 by a molding method.

  Thereafter, as shown in FIG. 8B, the process proceeds to the ball mounting step in a state where the sealing resin 41 is not cured by heating. That is, conductive solder balls are mounted on the plurality of lands 14 arranged on the other surface of the product forming portion 20 of the wiring mother board 1, and bump electrodes serving as the external terminals 19 are formed.

After mounting the solder balls on the wiring mother board 1, as shown in FIGS. 8C and 8D, the process proceeds to a dicing process, and the wiring mother board 1 is cut by the dicing line 22, thereby forming the product forming portion. Separate every 20th.
Specifically, the sealing resin 41 side of the wiring mother board 1 is bonded to the dicing tape 29, and the wiring mother board 1 is supported by the dicing tape 29. Thereafter, the wiring mother board 1 is cut along the dicing lines 22 vertically and horizontally by a dicing blade 26 of a dicing device (not shown), and is cut and separated for each product forming portion 20. After cutting and separating, the pickup is picked up from the dicing tape 28.

Thereafter, as shown in FIG. 8E, after the individual separation through the dicing process, the sealing resin 41 is heat-cured and cooled to room temperature. Specifically, the semiconductor device 11 before the individualized sealing resin 41 is heat-cured is mounted on a mounting jig (not shown). After that, for example, heating and holding at 175 ° C. for 5 hours is performed, heating is released, and cooling is performed to room temperature. Thereby, the sealing resin 41 is completely cured and shrunk, and the sealing body 42 is formed.
The semiconductor device 11 is obtained as described above.

The manufacturing method of the semiconductor device according to the present embodiment cuts and separates the wiring mother board 1 for each product forming unit 20 in a state where the sealing resin 41 is not cured by heating after the sealing resin 41 is formed on the wiring mother board 1 by a molding method. Then, the sealing body 41 is formed by heating and curing the sealing resin 41 and cooling to room temperature.
That is, as shown in FIG. 9, immediately after forming the conventional sealing resin 41 by a molding method, the sealing resin 41 is heated and cured and cooled to room temperature, and then a ball mounting process and a dicing process are performed. On the other hand, in this embodiment, after the sealing resin 41 is formed by the molding method, the ball mounting process and the dicing process are performed in a state where the sealing resin 41 is not heated and cured, and then the sealing resin 41 is heated and cured. Then, the sealing body 42 is formed by cooling to room temperature.

  As a result, when the resin is heat-cured and cooled, the sealing resin 41 is individualized so that the curing shrinkage force is not accumulated. As a result, even if the difference in thermal expansion coefficient between the sealing resin 41 and the wiring mother board 1 is large, the amount of warpage of the peripheral region of the wiring mother board 1 is small. As a result, the wiring mother board 1 can be enlarged, and the semiconductor device 11 can be manufactured with a low manufacturing cost and a small solid difference in warpage.

  In addition, unlike the first embodiment, the method for manufacturing a semiconductor device according to the present embodiment has no work of forming a cutting groove in the sealing resin 41, and only the manufacturing process of the standard semiconductor device 11 is replaced. An increase in total manufacturing time can be prevented. Further, since the cutting operation is performed only once, no step is generated on the cut surface (side surface) of the semiconductor device 11.

  Moreover, since it can manufacture with a standard member and a manufacturing apparatus, without using a new raw material and a manufacturing jig, manufacturing cost can be reduced.

  In the present embodiment, since the work is performed over a plurality of steps in a state where the sealing resin 41 is not heat-cured, monitoring is performed so as not to increase external defects such as damage to the flexible sealing resin 41 and adhesion of foreign substances.・ It is necessary to respond.

  As mentioned above, although this invention was demonstrated based on embodiment, it cannot be overemphasized that this invention can be variously changed in the range which is not limited to the said embodiment and does not deviate from the summary.

  Since the present invention relates to the manufacture of semiconductor devices, it can be widely used in the manufacturing industry for manufacturing semiconductor devices.

DESCRIPTION OF SYMBOLS 1 ... Wiring mother board, 12 ... Wiring board, 12a ... One side of a wiring board, 12b ... Other side of a wiring board, 13 ... Connection pad, 14 ... Land, 15 ... Semiconductor chip, 21, 31, 41 ... sealing resin, 22 ... dicing line,

Claims (5)

Forming a sealing resin on the wiring board by a molding method;
Cutting the sealing resin along a dicing line provided on the wiring board;
And a step of heat-curing the sealing resin after cutting. Preparing a wiring board having a connection pad on one side and a plurality of lands electrically connected to the connection pad on the other side;
Mounting a semiconductor chip on one surface of the wiring board;
Electrically connecting the connection pads and electrode pads provided on the semiconductor chip;
Forming a sealing resin on the wiring board by a molding method;
Cutting the sealing resin along a dicing line provided on the wiring board;
And a step of heat-curing the sealing resin after cutting.   3. When cutting the sealing resin along a dicing line provided on the wiring board, only a part of the sealing resin in the thickness direction is cut. The manufacturing method of the semiconductor device as described in any one of Claims 1-3.   2. The sealing resin is cut along only a part of the dicing line when the sealing resin is cut along a dicing line provided on the wiring board. 4. A method for manufacturing a semiconductor device according to any one of 3 above. Forming a sealing resin on the wiring board by a molding method;
Cutting and separating the wiring board and the sealing resin along a dicing line provided on the wiring board;
And a step of heat-curing the sealing resin after being separated.

Images