JP3706558B2 - Semiconductor device and semiconductor module - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a semiconductor device and a semiconductor module, and more particularly to a structure of a semiconductor device and a semiconductor module that can release heat from a semiconductor element satisfactorily and buffer stress acting on a solder electrode.
[0002]
[Prior art]
2. Description of the Related Art In recent years, semiconductor devices have been increasingly adopted for portable devices and small / high-density mounting devices, and are required to be light, thin and small and have heat dissipation. Moreover, the semiconductor device is mounted on various substrates, and is mounted on various devices as a semiconductor module including the substrate. The substrate may be a ceramic substrate, a printed substrate, a flexible sheet, a metal substrate, a glass substrate, or the like. Here, an example of a semiconductor module mounted on the flexible sheet will be described below.
[0003]
FIG. 23 shows a semiconductor module using a flexible sheet mounted on the hard disk 100. This hard disk 100 is described in detail in, for example, Nikkei Electronics June 16, 1997 (No. 691) P92.
[0004]
The hard disk 100 is mounted on a box 101 made of metal, and a plurality of recording disks 102 are integrally attached to a spindle motor 103, and a magnetic head 104 has a small gap on the surface of each recording disk 102. Is arranged through. The magnetic head 104 is attached to the tip of a suspension 106 fixed to the end of the arm 105. The magnetic head 104, the suspension 106, and the arm 105 are integrated, and this integrated object is attached to the actuator 107.
[0005]
The recording disk 102 needs to be electrically connected to the read / write amplification IC 108 in order to perform writing and reading through the magnetic head 104. Therefore, the semiconductor module 110 in which the read / write amplification IC 108 is mounted on the flexible sheet 109 is used, and the wiring provided on the flexible sheet 110 is finally electrically connected to the magnetic head 104. The semiconductor module 110 is called a flexible circuit assembly and is generally abbreviated as FCA.
[0006]
A connector 111 attached to the semiconductor module 110 is exposed on the back surface of the box 101, and this connector (male or female) 111 and a connector (female or male) attached to the main board 112 are provided. Connected. The main board 112 is provided with wiring, and a driving IC for the spindle motor 103, a buffer memory, and other driving ICs such as an ASIC are mounted.
[0007]
For example, the recording disk 102 rotates at 4500 rpm via the spindle motor 103, and the position of the magnetic head 104 is determined by the actuator 107. Since this rotating mechanism is hermetically sealed with a lid provided on the box body 101, heat is inevitably stored, and the temperature of the read / write amplification IC 108 rises. Therefore, the read / write amplification IC 108 is attached to a portion having excellent heat conduction, such as the actuator 107 and the box 101. Further, the rotation of the spindle motor 103 tends to be as high as 5400, 7200, and 10,000 rpm, and this heat radiation becomes increasingly important.
[0008]
In order to further explain the FCA described above, its structure is shown in FIG. FIG. 24A is a plan view thereof, and FIG. 24B is a cross-sectional view of the read / write amplification IC 108 provided at the tip, taken along line AA. Since the FCA 110 is bent and attached to a part of the box body 101, the first flexible sheet 109 having a planar shape that is easy to be bent is employed.
[0009]
A connector 111 is attached to the left end of the FCA 110 and serves as a first connection portion. A first wiring 121 electrically connected to the connector 111 is bonded to the first flexible sheet 109 and extends to the right end. The first wiring 121 is electrically connected to the read / write amplification IC 108. The lead 122 of the amplification IC 108 connected to the magnetic head 104 is connected to the second wiring 123, and the second wiring 123 is connected to the second flexible sheet 124 provided on the arm 105 and the suspension 106. It is electrically connected to the upper third wiring 126. That is, the right end of the first flexible sheet 109 forms the second connection portion 127 and is connected to the second flexible sheet 124 here. Note that the first flexible sheet 109 and the second flexible sheet 124 may be provided integrally. In this case, the second wiring 123 and the third wiring 126 are provided integrally.
[0010]
A support member 128 is provided on the back surface of the first flexible sheet 109 on which the read / write amplification IC 108 is provided. The support member 128 is a ceramic substrate or an Al substrate. Through this support member 128, the metal exposed to the inside of the box body 101 is thermally coupled, and the heat of the read / write amplification IC 108 is released to the outside.
[0011]
Next, a connection structure between the read / write amplification IC 108 and the first flexible sheet 109 will be described with reference to FIG. 24B.
[0012]
The flexible sheet 109 includes a first polyimide sheet 130 (hereinafter referred to as a first PI sheet), a first adhesive layer 131, a conductive pattern 132, a second adhesive layer 133, and a second polyimide sheet 134 from the lower layer. (Hereinafter referred to as a second PI sheet) are laminated, and a conductive pattern 132 is sandwiched between the first and second PI sheets 130 and 134.
[0013]
Since the read / write amplification IC 108 is connected, the second PI sheet 134 and the second adhesive layer 133 at a desired location are removed, and an opening 135 is formed, where the conductive pattern 132 is exposed. . As shown in the figure, the read / write amplification IC 108 is electrically connected via the lead 122.
[0014]
[Problems to be solved by the invention]
In FIG. 24B, the semiconductor device packaged with the insulating resin 136 is discharged to the outside through a heat dissipation path indicated by an arrow. In particular, the insulating resin 136 becomes a thermal resistance, and when viewed from the read / write amplification IC 108 in total. It was a structure that could not release the generated heat efficiently.
[0015]
Furthermore, it demonstrates with a hard disk. The read / write transfer rate of this hard disk requires a frequency of 500 MHz to 1 GHz or higher, and the read / write speed of the read / write amplification IC 108 must be increased. For this purpose, the wiring path on the flexible sheet connected to the read / write amplification IC 108 must be shortened to prevent the temperature of the read / write amplification IC 108 from rising.
[0016]
In particular, since the recording disk 102 rotates at a high speed and becomes a space sealed by the box body 101 and the lid body, the temperature of the inside rises to about 70 to 80 degrees. On the other hand, the allowable operating temperature of a general IC is about 125 degrees, and the IC 125 for read / write amplification is allowed to increase in temperature from 80 degrees to about 45 degrees. However, as shown in the figure, if the thermal resistance of the semiconductor device itself and the thermal resistance of the FCA are large, the read / write amplification IC 108 immediately exceeds the allowable operating temperature, and cannot perform its original capability. Therefore, a semiconductor device with excellent heat dissipation, FCA, is required.
[0017]
In addition, since the operating frequency will further increase in the future, the read / write amplification IC 108 itself has a problem that the temperature rises due to heat generated by the arithmetic processing. Although the target operating frequency can be realized at room temperature, the operating frequency has to be lowered inside the hard disk due to the temperature increase.
[0018]
As described above, semiconductor devices and semiconductor modules (FCAs) have been required to have more heat dissipation with an increase in operating frequency in the future.
[0019]
On the other hand, the actuator 107 itself, the arm 105 attached thereto, the suspension 106 and the magnetic head 104 must be made as light as possible in order to reduce the moment of inertia. In particular, as shown in FIG. 17, when the read / write amplification IC 108 is mounted on the surface of the actuator 107, the weight of the IC 108 and the weight of the FCA 110 are also required.
[0020]
[Means for Solving the Problems]
The present invention has been made in view of the above-described problems. First, a semiconductor element is integrally sealed with an insulating resin face-down, and electrically connected to a bonding electrode of the semiconductor element on the back surface thereof. A semiconductor device in which a pad and an electrode for heat radiation located on the surface of the semiconductor element are exposed,
The problem is solved by providing a metal plate on the exposed portion of the heat radiation electrode so as to protrude from the back surface of the pad.
[0021]
Since the protruding metal plate is located at the surface position with the back surface of the flexible sheet, which is the first support member, the metal plate can be bonded or abutted to the inside of the housing, in particular, a portion having a flat surface, a heat radiating plate, etc. Become. Therefore, the heat of the semiconductor element can be transmitted to the heat sink.
[0022]
Second, the back surface of the pad and the back surface of the heat radiation electrode are arranged on substantially the same plane.
[0023]
Third, the semiconductor element and the heat radiation electrode are fixed by an insulating material.
[0024]
Fourth, the heat radiation electrode and the metal plate are fixed by an insulating material or a conductive material.
[0025]
Fifth, the electrode for heat radiation and the metal plate are solved by being integrally formed of the same material.
[0026]
Sixth, the problem is solved by the fact that the back surface of the insulating resin protrudes from the back surface of the pad.
[0027]
Seventh, the side surface of the pad and the back surface of the insulating resin extending from the side surface of the pad are solved by drawing the same curved surface.
[0028]
Eighth, a first support member provided with a conductive pattern;
A semiconductor element electrically connected to the conductive pattern is sealed face down with an insulating resin, and a pad electrically connected to a bonding electrode of the semiconductor element and a surface of the semiconductor element are formed on the back surface of the semiconductor element. A semiconductor module having a semiconductor device with exposed heat-dissipating electrodes
The conductive pattern provided on the first support member and the pad are electrically connected, and the first support member corresponding to the heat dissipation electrode is provided with an opening, and the opening The problem is solved by providing a metal plate fixed to the heat radiation electrode.
[0029]
Ninthly, the second support member to which the metal plate is fixed is adhered to the back surface of the first support member.
[0030]
Tenth, the problem is solved by forming the heat radiation electrode and the metal plate integrally with the same material.
[0031]
Eleventh, the second support member corresponding to the metal plate is provided with a fixing plate made of a conductive material, and the fixing plate and the metal plate are thermally coupled to solve the problem. .
[0032]
Twelfth, the metal plate is mainly made of Cu, the second support member is mainly made of Al, and the fixing plate is made mainly of Cu formed on the second support member. This is solved by comprising a plating film.
[0033]
Thirteenth, the problem is solved by the fact that the back surface of the insulating resin protrudes from the back surface of the pad.
[0034]
14thly, the side surface of the pad and the back surface of the insulating resin extending from the side surface of the pad are solved by drawing the same curved surface.
[0035]
Fifteenth, the semiconductor element is solved by being a hard disk read / write amplification IC.
[0036]
Sixteenth, the semiconductor element is sealed face-down integrally with the insulating resin, and the back surface thereof is extended via a pad electrically connected to the bonding electrode of the semiconductor element and a wiring integral with the pad. A semiconductor device in which the external connection electrode present and the electrode for heat dissipation arranged on the surface of the semiconductor element are exposed;
The problem is solved by providing a metal plate on the exposed portion of the heat radiation electrode so as to protrude from the back surface of the external connection electrode.
[0037]
Seventeenth, the problem is solved by arranging the back surface of the external connection electrode and the back surface of the heat radiation electrode in substantially the same plane.
[0038]
Eighteenth, the problem is solved by fixing the semiconductor element and the heat radiation electrode with an insulating material.
[0039]
Nineteenth, the problem is solved by fixing the heat radiation electrode and the metal plate with an insulating material or a conductive material.
[0040]
20th is to solve the problem by forming the heat radiation electrode and the metal plate integrally with the same material.
[0041]
Twenty-first, the problem is solved by the fact that the back surface of the insulating resin protrudes from the back surface of the external connection electrode.
[0042]
Twenty-second, the problem is solved by drawing the same curved surface on the side surface of the external connection electrode and the back surface of the insulating material extending from the side surface of the external connection electrode.
[0043]
23rd, a first support member provided with a conductive pattern;
A semiconductor element that is electrically connected to the conductive pattern is sealed face down with an insulating resin, and a back surface of the semiconductor element is electrically connected to a bonding electrode of the semiconductor element, and the pad is integrated with the pad. A semiconductor module having an external connection electrode provided via the wiring and a semiconductor device in which an electrode for heat radiation located on the surface of the semiconductor element is exposed,
The conductive pattern provided on the first support member and the external connection electrode are electrically connected, and the first support member corresponding to the heat dissipation electrode is provided with an opening, The problem is solved by providing the opening with a metal plate fixed to the heat radiation electrode.
[0044]
24thly, it solves by sticking the 2nd support member to which the said metal plate was fixed to the back surface of the said 1st support member.
[0045]
25th is to solve the problem by forming the heat radiation electrode and the metal plate integrally with the same material.
[0046]
Twenty-sixth, the second support member corresponding to the metal plate is provided with a fixing plate made of a conductive material, and the fixing plate and the metal plate are thermally coupled to solve the problem. .
[0047]
Twenty-seventh, the metal plate is mainly made of Cu, the second support member is mainly made of Al, and the fixing plate is made mainly of Cu formed on the second support member. This is solved by comprising a plating film.
[0048]
Twenty-eighth, the problem is solved by the fact that the back surface of the insulating bonding means protrudes from the back surface of the external connection electrode.
[0049]
29th is to solve the problem by drawing the same curved surface on the side surface of the external connection electrode and the back surface of the insulating bonding means bonded to the external connection electrode.
[0050]
30th, the semiconductor element is a hard disk read / write amplification IC.
[0051]
31stly, the semiconductor device of this invention is provided in the arrangement | positioning area | region of the bonding pad provided corresponding to the bonding electrode of the semiconductor element, the external connection electrode provided in the back surface of the said bonding pad, and the said semiconductor element. The pad, the external connection electrode for stress buffer provided on the back surface of the pad, the bonding means provided on the pad, and the bonding means fixed to the bonding means and electrically connected to the bonding pad. A semiconductor element and an insulating resin that seals the semiconductor element so as to expose and integrate the back surface of the pad, the back surface of the external connection electrode, and the back surface of the bonding means;
The external connection electrode for buffering stress is formed sufficiently larger than the external connection electrode, and the stress due to thermal expansion of the insulating resin is buffered and transmitted to the external connection electrode.
[0052]
Thirty-second, the problem is solved by dividing the pad and the external connection electrode for stress buffering into four.
[0053]
33rdly, the semiconductor device of this invention is provided in the bonding pad provided corresponding to the bonding electrode of the semiconductor element, the external connection electrode provided in the back surface of the said bonding pad, and the arrangement | positioning area | region of the said semiconductor element. A pad, an adhesive means provided on the pad, the semiconductor element fixed to the adhesive means and electrically connected to the bonding pad, a back surface of the pad, a back surface of the external connection electrode, and the An insulating resin that seals the semiconductor element so as to expose and integrate the back surface of the bonding means;
The external connection electrode is solved by being formed in an elongated shape.
[0054]
34thly, the semiconductor device of this invention is provided in the bonding pad provided corresponding to the bonding electrode of the semiconductor element, the external connection electrode provided in the back surface of the said bonding pad, and the arrangement | positioning area | region of the said semiconductor element. A pad, an adhesive means provided on the pad, the semiconductor element fixed to the adhesive means and electrically connected to the bonding pad, a back surface of the pad, a back surface of the external connection electrode, and the An insulating resin that seals the semiconductor element so as to expose and integrate the back surface of the bonding means;
The problem is solved by the fact that the side surfaces of the external connection electrodes have the same curved surface.
[0055]
35th is to solve the problem that the external connection electrode is a solder electrode.
[0056]
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides a semiconductor device with high heat dissipation and a light, thin and small size, and also provides a semiconductor module mounted with the semiconductor device, for example, a semiconductor module mounted on a flexible sheet (hereinafter referred to as FCA). This is to improve the characteristics of a mounted device, for example, a hard disk.
[0057]
In addition, the present invention provides a stress buffering electrode at the center of the semiconductor device, and further prevents the external connection electrode from cracking by forming the external connection electrode without a constriction.
[0058]
First, as an example of a device in which FCA is mounted, hard disk 100 is referred to in FIG. 17, and FCA is shown in FIG. A semiconductor device mounted on the FCA or a manufacturing method thereof is shown in FIGS.
1st Embodiment explaining the apparatus by which FCA is mounted
As this device, the hard disk 100 of FIG. 17 described in the section of the prior art will be described again.
[0059]
Since the hard disk 100 is mounted on a computer or the like, it is mounted on the main board 112 as necessary. The main board 112 is mounted with a female (or male) connector. The male (or female) connector 111 mounted on the FCA and exposed from the back surface of the box 101 is connected to the connector on the main board 112. In the box 101, a plurality of recording disks 102 as recording media are stacked in accordance with the capacity. Since the magnetic head 104 floats on the recording disk 102 at about 20 to 30 nm and is scanned, the interval between the recording disks 102 is set to an interval at which no problem occurs in this scanning. And it is attached to the spindle motor 103 at this interval. The spindle motor 103 is attached to the mounting board, and a connector arranged on the back surface of the mounting board has a face from the back surface of the box body 101. This connector is also connected to the connector of the main board 112. Therefore, on the main board 112, an IC for driving the read / write amplification IC 108 of the magnetic head 104, an IC for driving the spindle motor 103, an IC for driving the actuator, a buffer memory for temporarily storing data, and an ASIC for realizing a manufacturer-specific drive Etc. are implemented. Of course, other passive elements and active elements may be mounted.
[0060]
Considering that the wiring connecting the magnetic head 104 and the read / write amplification IC 108 is as short as possible, the read / write amplification IC 108 is disposed in the actuator 107. However, since the semiconductor device of the present invention described below is very thin and lightweight, it may be mounted on the arm 105 or the suspension 106 in addition to the actuator. In this case, as shown in FIG. 1B, since the back surface of the semiconductor device 10 is exposed from the opening 12 of the first support member 11, the back surface of the semiconductor device 10 is thermally coupled to the arm 105 or the suspension 106, The heat of the semiconductor device 10 is released to the outside through the arm 105 and the box body 101.
[0061]
As shown in FIG. 17, when mounted on the actuator 107, the read / write amplification IC 108 has a read / write circuit for each channel formed on a single chip so that a plurality of magnetic sensors can read and write. However, a read / write circuit dedicated to the magnetic head 104 attached to each suspension 106 may be mounted on each suspension. In this way, the wiring distance between the magnetic head 104 and the read / write amplification IC 108 can be made much shorter than that of the structure of FIG. 18, and the impedance can be reduced correspondingly, and the read / write speed can be improved.
Second Embodiment Explaining Semiconductor Device
First, a semiconductor device of the present invention will be described with reference to FIG. 2A is a plan view of the semiconductor device, and FIG. 2B is a cross-sectional view taken along line AA.
[0062]
In FIG. 2, the following components are embedded in the insulating resin 13. That is, pads 14..., A heat radiation electrode 15 provided in a region surrounded by the pads 14, and a semiconductor element 16 provided on the heat radiation electrode 15 are embedded. The semiconductor element 16 is mounted face-down, is fixed to the heat radiation electrode 15 via an insulating adhesive means 17, and is divided into four in consideration of adhesiveness. A separation groove formed by this four division is indicated by reference numeral 18A. Further, when the gap between the semiconductor element 16 and the heat radiation electrode 15 is narrow and the insulating bonding means 17 is difficult to enter, a groove shallower than the separation groove 18A is formed on the surface thereof as in 18B. It may be formed on the surface.
[0063]
The bonding electrode 19 and the pad 14 of the semiconductor element 16 are electrically connected via a brazing material such as solder. Note that Au stud bumps may be used instead of solder.
[0064]
There are other connection methods. For example, a bump may be attached to the bonding electrode 19 of the semiconductor element, and the bump may be connected by ultrasonic waves or pressure contact. Further, solder, conductive paste, and anisotropic conductive particles may be provided around the pressed bumps. These structures will be described in detail with reference to FIG. 16 at the end of the column of the embodiment of the invention.
[0065]
Further, the back surface of the pad 14 is exposed from the insulating resin 13 and becomes the external connection electrode 21 as it is, and the side surfaces of the pads 14... And the anchoring effect is generated by this curved structure.
[0066]
This structure is composed of five materials: a semiconductor element 16, a plurality of conductive patterns 14, a heat radiation electrode 15, an insulating adhesive means 17, and an insulating resin 13 for embedding them. Further, in the region where the semiconductor element 16 is disposed, the insulating adhesive means 17 is formed on and between the heat radiation electrode 15 and the pad 14, and the insulating groove 18 is formed in the isolation groove 18 formed by etching. The adhesive bonding means 17 is provided, and the back surface of the insulating bonding means is exposed from the back surface of the semiconductor device 10A. All of these are sealed with an insulating resin 13. The pads 14, the heat radiation electrode 15, and the semiconductor element 16 are supported by the insulating resin 13 and the insulating bonding means 17.
[0067]
The insulating adhesive means 17 is preferably an adhesive made of an insulating material or an underfill material. In the case of an adhesive, it may be applied in advance to the surface of the semiconductor element 16 and fixed when the pads 14 are connected using Au bumps instead of the solder 20. The underfill material 17 may be penetrated into the gap after the solder 20 (or bump) and the pad 14 are connected.
[0068]
As the insulating resin, a thermosetting resin such as an epoxy resin, a thermoplastic resin such as a polyimide resin or polyphenylene sulfide can be used.
[0069]
Insulating resin 13 may be any resin as long as it is a resin that can be hardened using a mold, a resin that can be coated by dipping or coating. Further, as the conductive pattern 14, a conductive foil mainly made of Cu, a conductive foil mainly made of Al, or a Fe-Ni alloy, an Al-Cu laminate, an Al-Cu-Al laminate, or the like is used. Can do. Of course, other conductive materials are possible, and a conductive material that can be etched and a conductive material that evaporates with a laser are particularly preferable. In consideration of half-etching property, plating formability, and thermal stress, a conductive material mainly composed of Cu formed by rolling is preferable.
[0070]
In the present invention, since the insulating resin 13 and the insulating adhesive means 17 are also filled in the separation groove 18, the conductive pattern can be prevented from coming off. Further, by applying dry etching or wet etching as the etching and performing non-anisotropic etching, the side surfaces of the pads 14... Can be curved to generate an anchor effect. As a result, it is possible to realize a structure in which the pad 14 and the heat radiation electrode 15 do not come off from the insulating resin 13.
[0071]
Moreover, the back surface of the heat radiation electrode 15 is exposed on the back surface of the package. Therefore, the back surface of the electrode 15 for heat dissipation has a structure that can abut or adhere to the metal plate 23, the second support member 24, or the fixing plate 25 formed on the second support member 24, which will be described later. Therefore, with this structure, the heat generated from the semiconductor element 16 can be dissipated, the temperature rise of the semiconductor element 16 can be prevented, and the drive current and drive frequency of the semiconductor element 16 can be increased accordingly.
[0072]
In this semiconductor device 10A, since the pad 14 and the heat radiation electrode 15 are supported by the insulating resin 13 that is a sealing resin, a support substrate is not required. This configuration is a feature of the present invention. Since the conductive path of the conventional semiconductor device is supported by a support substrate (flexible sheet, printed circuit board, or ceramic substrate) or supported by a lead frame, a configuration that may be unnecessary is added. However, this circuit device is configured by the minimum necessary components and does not require a support substrate, so that the circuit device is thin and lightweight, and the material cost can be suppressed, so that the circuit device is inexpensive. Therefore, as described in the first embodiment, it can be mounted on an arm or suspension of a hard disk.
[0073]
Further, the pad 14 and the heat radiation electrode 15 are exposed on the back surface of the package. When this region is covered with a brazing material such as solder, the heat radiating electrode 15 has a larger area, so that the brazing material has a different thickness and gets wet. Therefore, an insulating film 26 is formed on the back surface of the semiconductor device 10A to make the film thickness of the brazing material uniform. A dotted line 27 shown in FIG. 2A indicates an exposed portion exposed from the insulating coating 26. Here, the back surface of the pad 14 is exposed in a rectangular shape, and thus the same size as this is exposed from the insulating coating 26.
[0074]
Therefore, since the parts where the brazing material gets wet are substantially the same size, the thickness of the brazing material formed here becomes substantially the same. This is the same even after solder printing and after reflow. The same applies to conductive pastes such as Ag, Au, Ag-Pd. With this structure, it is possible to accurately calculate how much the back surface of the metal plate 23 protrudes from the back surface of the pad 14.
[0075]
If the metal plate 23 and the conductive pattern 32 are set on the same surface, both the pad 14 and the heat radiation electrode 15 can be soldered at a time. The exposed portion 27 of the heat radiation electrode 15 may be formed larger than the exposed size of the pad 14 in consideration of the heat dissipation of the semiconductor element.
[0076]
Further, by providing the insulating film 26, the conductive pattern provided on the first support member 11 can be extended to the back surface of the semiconductor device 10A. In general, the wiring provided on the first support member 11 side is arranged to bypass the fixing region of the semiconductor device 10A in order to prevent a short circuit. However, the formation of the insulating film 26 bypasses the conductive pattern. Can be placed without. Moreover, since the insulating resin 13 and the insulating adhesive means 17 protrude beyond the conductive pattern, the solder SD provided on the back surface of the semiconductor device 10A does not short-circuit each other.
Third embodiment for explaining a semiconductor device 10B
FIG. 3 shows the semiconductor device 10B. 3A is a plan view thereof, and FIG. 3B is a cross-sectional view taken along the line AA. Since it is similar to the structure of FIG. 2, only different parts will be described here.
[0077]
In FIG. 2, the back surface of the pad 14 directly functions as the external connection electrode 21. However, in the present embodiment, the pad 14 has the wiring 30 formed integrally and the external connection electrode 31 formed integrally with the wiring 30. Is formed.
[0078]
In addition, the rectangle shown with a dotted line is the semiconductor element 16, and the external connection electrode 31 is arranged on the back surface of the semiconductor element 16, and the external connection electrode 31 is arranged in a ring shape as shown in the figure. This arrangement has the same or similar structure as a known BGA.
[0079]
Further, if the semiconductor element 16 is arranged as it is on the conductive patterns 14, 30, 31 and the heat radiation electrode 15, both may be short-circuited via the back surface of the semiconductor element 16. Therefore, the insulating adhesive means 17 should employ only an insulating material and cannot use a conductive material.
[0080]
The conductive pattern 32 of the first support member 11 is connected to the external connection electrode 31, and the back surface of the pad 14 and the back surface of the wiring 30 are covered with an insulating film 26. A circle indicated by a dotted line on the external connection electrode 31 and a circle indicated by a dotted line indicated on the heat radiation electrode 15 are portions exposed from the insulating coating 26.
[0081]
Furthermore, since the external connection electrode 31 extends on the back surface of the semiconductor element 16, the heat radiation electrode 15 is formed smaller than the heat radiation electrode 15 of FIG. The insulating bonding means 17 covers the heat radiation electrode 15, the external connection electrode 31, and the wiring 30. The insulating resin 13 covers the pad 14, the wiring 30, the semiconductor element 16, and the fine metal wire 20.
[0082]
In the present embodiment, when the number of pads 14 is very large and the size thereof is small, it can be rearranged as an external connection electrode via a wiring, and there is an advantage that the size of the external connection electrode 31 can be increased. Further, by providing the wiring, distortion applied to the bonding portion can be reduced. In particular, it should be formed in a wave shape. Further, since the semiconductor element 16 and the heat radiation electrode 15 are fixed by the insulating adhesive means 17 and are an insulating material, their thermal resistance becomes a problem. However, if the insulating adhesive means is made of a silicone resin mixed with a filler that contributes to heat conduction such as Si oxide or aluminum oxide, the heat of the semiconductor element 16 can be transferred well to the heat radiation electrode 15.
[0083]
Moreover, the space | interval of the electrode 15 for thermal radiation and the back surface of the semiconductor element 16 can be formed uniformly by unifying the diameter of the said filler. Therefore, when forming a minute gap in consideration of heat conduction, the gap can be formed by lightly pressing the semiconductor element 16 when the insulating bonding means is in a soft state and curing as it is.
Fourth embodiment for explaining a method of manufacturing semiconductor devices 10A and 10B
This manufacturing method only differs depending on whether the pattern is composed of the pad 14 and the heat radiation electrode 15 or the pattern in which the wiring 30 and the external connection electrode 31 are added thereto. In any case, since it is formed in a convex shape by half etching, it is substantially the same except for this pattern shape.
[0084]
Here, a manufacturing method thereof will be described using the semiconductor device 10B of FIG. 4 to 9 are cross-sectional views corresponding to the line AA in FIG. 3A.
[0085]
First, a conductive foil 40 is prepared as shown in FIG. The thickness is preferably about 10 μm to 300 μm, and here, a rolled copper foil of 70 μm is employed. Subsequently, a conductive film 41 or a photoresist is formed on the surface of the conductive foil 40 as an etching resistant mask. This pattern is the same pattern as the pads 14, wirings 30, external connection electrodes 31, and heat radiation electrodes 15 in FIG. 3A. When a photoresist is employed instead of the conductive film 41, a conductive film such as Au, Ag, Pd or Ni is formed at least in a portion corresponding to the pad in the lower layer of the photoresist. This is provided to enable bonding. (See Figure 4 above)
Subsequently, the conductive foil 40 is half-etched through the conductive film 41 or the photoresist. The etching depth may be shallower than the thickness of the conductive foil 40. Note that the shallower the etching depth, the finer the pattern can be formed.
[0086]
Then, by half-etching, the conductive patterns 14, 30 and 31 and the heat radiation electrode 15 appear in a convex shape on the surface of the conductive foil 40. Here, as described above, the conductive foil 40 is a Cu foil mainly made of Cu formed by rolling. However, a conductive foil made of Al, a conductive foil made of Fe—Ni alloy, a Cu—Al laminate, or an Al—Cu—Al laminate may be used. In particular, an Al—Cu—Al or Cu—Al—Cu laminate can prevent warping caused by a difference in thermal expansion coefficient.
[0087]
Then, an insulating adhesive means 17 is provided at a portion corresponding to the rectangular dotted line in FIG. The insulating bonding means 17 is provided on the separation groove 22 between the heat radiation electrode 15 and the external connection electrode 31, the separation groove between the heat radiation electrode 15 and the wiring 30, the separation groove between the wiring 30 and above. . Reference numeral DM denotes a flow prevention film for the solder SD1 fixed thereto. If this flow prevention film DM is not provided, the semiconductor element 16 is inclined and the insulating adhesive means 17 cannot be injected between the semiconductor element and the conductive foil, or cleaning cannot be performed. (See Figure 5 above)
Subsequently, the semiconductor element 16 is fixed to the region where the insulating bonding means 17 is provided, and the bonding electrode 19 of the semiconductor element 16 and the pad 14 are electrically connected. In the drawing, since the semiconductor element 16 is mounted in a face-down manner, the solder SD1 is employed as the connecting means.
[0088]
In this bonding, since the pads 14 are integrated with the conductive foil 40 and the back surface of the conductive foil 40 is flat, it is brought into contact with the table of the bonding machine. Therefore, when the conductive foil 40 is completely fixed to the bonding table, all the pads 14... And all the solder balls formed on the semiconductor element 16 are brought into contact with each other, and can be fixed without defective solder. The bonding table can be fixed, for example, by providing a plurality of vacuum suction holes on the entire surface of the table. There are other connection methods, and this structure will be described last with reference to FIG.
[0089]
In addition, the height of the semiconductor element 16 is reduced by that amount because the support substrate is not used and solder balls are used instead of the fine metal wires. Therefore, the thickness of the package outer shape to be described later can be reduced.
[0090]
In the case where an underfill is used as the insulating bonding means 17, the semiconductor element 16 and the pad 14 are fixed, and then the underfill is infiltrated. (See Figure 6 above)
Then, the insulating resin 13 is formed in the entire region including the semiconductor element 16. The insulating resin may be either thermoplastic or thermosetting.
[0091]
Further, it can be realized by transfer molding, injection molding, dipping or coating. As the resin material, a thermosetting resin such as an epoxy resin can be realized by transfer molding, and a thermoplastic resin such as a liquid crystal polymer and polyphenylene sulfide can be realized by injection molding.
[0092]
In the present embodiment, the thickness of the insulating resin is adjusted so that about 100 μm is covered from the back surface of the semiconductor element. This thickness can be increased or decreased in consideration of the strength of the semiconductor device. 14B, the back surface of the semiconductor element 16 may be exposed. In this case, a heat radiating fin can be attached or the heat of the semiconductor element can be directly released to the outside.
[0093]
In addition, in the resin injection, the pad 14, the wiring 30, the external connection electrode 31, and the heat radiation electrode 15 are integrated with the sheet-like conductive foil 40. Therefore, as long as the conductive foil 40 is not displaced, these copper foils are used. There is no pattern displacement. Moreover, unlike the lead frame, no resin burrs are generated between these conductive patterns.
[0094]
As described above, the insulating resin 13 is embedded with the pad 14 formed as a convex portion, the wiring 30, the external connection electrode 31, the heat radiation electrode 15, and the semiconductor element 16, and the conductive foil 40 below the convex portion is the back surface. Is exposed from. (See Figure 7 above)
Subsequently, the conductive foil 40 exposed on the back surface of the insulating resin 13 is removed, and the pad 14, the wiring 30, the external connection electrode 31, and the heat radiation electrode 15 are individually separated.
[0095]
Various methods can be considered for the separation step here, and the back surface may be removed by etching, or may be separated by grinding or grinding. Moreover, you may employ | adopt both. For example, if the insulating resin 13 is etched until the insulating resin 13 is exposed, the shaving residue of the conductive foil 40 and the burr-like metal thinned outwardly bite into the insulating resin 13 and the insulating adhesive means 17. There's a problem. Therefore, if it isolate | separates by an etching, it can form, without the metal of the electrically conductive foil 40 biting into the surface of the insulating resin 13 located between the Cu patterns, or the insulating adhesive means 17. Thereby, the short circuit of the pattern of a fine space | interval can be prevented.
[0096]
In addition, when a plurality of one unit to be the semiconductor device 10B are integrally formed, a dicing process is added after the separation process.
[0097]
Here, a dicing apparatus is employed to separate the components individually, but chocolate breaks, presses and cuts are also possible.
[0098]
Here, after the Cu pattern is separated, an insulating film 26 is formed on the separated patterns 14, 30, 31, and 15 exposed on the back surface, so that the portions indicated by the dotted circles in FIG. 3A are exposed. The coating 26 is patterned. Thereafter, dicing is performed at a portion indicated by an arrow, and the semiconductor device 10B is cut out.
[0099]
The solder 42 may be formed before dicing or after dicing.
[0100]
With the above manufacturing method, the pad, wiring, external connection electrode, heat radiation electrode, and semiconductor element are embedded in the insulating resin, and a light and thin package with excellent heat dissipation can be realized.
[0101]
In addition, as shown in FIG. 9, you may seal using the insulating adhesive means 17, without using the insulating resin 13. FIG. A pattern PTN shown in FIG. 10 shows a pad, a wiring, and an external connection electrode, and a hatched portion on the pattern PTN shows a formation pattern of a solder flow prevention film. While preventing the flow of solder, it is also applied to other regions to improve the adhesion of the insulating adhesive means. Although A to E are shown as types, other patterns may be adopted. Further, a flow preventing film may be formed over the entire conductive foil except for the solder connection portion.
Next, effects produced by the above manufacturing method will be described.
[0102]
First, since the conductive pattern is half-etched and supported integrally with the conductive foil, the substrate used for conventional support can be eliminated.
[0103]
Secondly, the conductive foil is formed with a conductive pattern that is half-etched to form a convex portion, so that the conductive pattern can be miniaturized. Accordingly, the width and interval can be reduced, and a package with a smaller planar size can be formed.
[0104]
Thirdly, since it is composed of a conductive pattern, a semiconductor element, a connecting means and a sealing material, it can be configured with the minimum necessary, can eliminate wasteful materials as much as possible, and is a light, thin and small semiconductor device with greatly reduced costs. Can be realized.
[0105]
Fourth, the pad, wiring, external connection electrode, and heat radiation electrode are formed as convex portions by half-etching, and the individual separation is performed after sealing, thus eliminating the need for tie bars and suspension leads. Therefore, the formation of tie bars (suspending leads) and the cutting of tie bars (suspending leads) are completely unnecessary in the present invention.
[0106]
Fifth, after the conductive pattern that became the convex portion is embedded in the insulating resin, the conductive foil is removed from the back surface of the insulating resin, and the conductive pattern is separated. Resin burrs generated between the leads can be eliminated.
[0107]
Sixth, the semiconductor element is fixed to the heat radiating electrode through the insulating bonding means, and the heat radiating electrode is exposed from the back surface, so that the heat generated from the semiconductor device is transferred from the surface of the semiconductor device. It can be efficiently discharged to a heat radiating electrode. Furthermore, the heat dissipation can be further improved by mixing a filler such as a Si oxide film or aluminum oxide into the insulating bonding means. If the filler size is unified, the gap between the semiconductor element 16 and the conductive pattern can be kept constant.
[0108]
Fifth Embodiment Explaining Semiconductor Devices 10A and 10B to which a Metal Plate 23 is Fixed, and a Semiconductor Module Using the Same
FIG. 1 shows this semiconductor module (FCA) 50. The mounted semiconductor device is the semiconductor device 10B shown in FIG.
[0109]
First, the first support member 11 made of a flexible sheet will be described. Here, the first PI sheet 51, the first adhesive layer 52, the conductive pattern 53, the second adhesive layer 54, and the second PI sheet 55 are laminated in that order from the lower layer. In addition, when making a conductive pattern into a multilayer, an adhesive layer is further used and the upper and lower conductive patterns may be electrically connected through a through hole. As shown in FIG. 1C, the first support member 11 is formed with a first opening 12 that can expose at least the metal plate 23.
[0110]
A second opening 56 is formed so that the conductive pattern is exposed. All of the conductive pattern 32 corresponding to the second opening 56 may be exposed, or only the connected portion may be exposed. For example, the second PI sheet 55 and the second adhesive layer 54 may all be removed, and as shown in the figure, the second PI sheet 55 is removed and only the second adhesive layer 54 is exposed. The part may be removed. In this way, the solder 27 does not flow.
[0111]
In the semiconductor device of the present invention, a metal plate 23 is bonded to the back surface of the heat radiation electrode 15. In the semiconductor module of the present invention, the back surface of the first support member and the metal plate 23 are substantially in the surface position.
[0112]
The thickness of the metal plate 23 is determined in consideration of the thickness of the first support member 11 and the fixing plate 25. When the pad 14 and the conductive pattern 32 are fixed through the solder 27, the metal plate 23 exposed from the first opening 12 is substantially flush with the back surface of the first support member 11. The thickness is determined. Therefore, it can be brought into contact with the second support member, and further, can be brought into contact with and fixed to the second support member having the fixing plate 25.
[0113]
Some specific examples of this connection structure will be described.
[0114]
In the first example, a lightweight metal plate such as Al or stainless steel or a ceramic substrate is used as the second support member 24, and the metal plate 23 fixed to the back surface of the semiconductor device 10 is brought into contact therewith. It is. That is, it is a structure in which the second support member 24 is directly contacted without using the fixing plate 25. The heat radiation electrode 15 and the metal plate 23, and the metal plate 23 and the second support member 24 are fixedly attached by selecting a soldering material such as solder or an insulating adhesive means including a filler and having excellent thermal conductivity. .
[0115]
In the second example, a lightweight metal plate such as Al or stainless steel or a ceramic substrate is used as the second support member 24, a fixing plate 25 is formed thereon, and the fixing plate 25 and the metal plate 23 are fixed. Structure.
[0116]
For example, when Al is employed as the second support member 24, the fixing plate 25 is preferably Cu. This is because Cu plating is possible on Al. The film thickness may be about 10 μm. Moreover, since it is a plating film, it can be formed in close contact with the second support member 24, and the thermal resistance between the fixing plate 25 and the second support member 24 can be made very small. Alternatively, a conductive paste may be applied as the fixing plate 25 and used instead.
[0117]
On the other hand, the Cu fixing plate 25 and the Al substrate can be fixed via an adhesive, but in this case, the thermal resistance increases.
[0118]
When a ceramic substrate is employed as the second support member 24, the fixing plate 25 is formed on an electrode formed by printing and baking a conductive paste.
[0119]
Note that the second support member 24 and the first support member 11 are fixed by the third adhesive layer 57.
[0120]
For example,
First PI sheet 51: 25 μm
Second PI sheet 55: 25 μm
First to third adhesive layers 52, 54, 57: 25 μm (after firing)
Adopt acrylic adhesive as material
Solder 27: 50 μm
The third adhesive layer 57: 25 μm
Adopt acrylic adhesive as material
Fixing plate 25: about 25 μm.
Thus, if each film thickness is adjusted and determined, after the semiconductor device 10A is fixed to the first support member 11, the second support member 24 on which the fixing plate 25 is easily provided is pasted. I can do it.
[0121]
Also, a module in which the second support member 24 is bonded to the first support member 11 is prepared, the semiconductor device 10 is disposed in the opening 56 formed in the module, and then the solder is melted. It can be melted and fixed without poor connection.
[0122]
Therefore, the heat generated from the semiconductor element 16 can be released to the second support member 24 through the heat radiation electrode 15, the metal plate 23, and the fixing plate 25. In addition, since the thermal resistance is significantly reduced as compared with the conventional structure (FIG. 17B), the drive current and drive frequency of the semiconductor element 16 can be increased. Further, the back surface of the second support member 24 can be attached to the actuator 107, the bottom surface of the box 101 or the arm 105 shown in FIG. Therefore, finally, the heat of the semiconductor element can be released to the outside through the box 101. Therefore, even if a semiconductor module is mounted on the hard disk 100, the semiconductor element itself does not reach a relatively high temperature, and the read / write speed of the hard disk 100 can be further increased. The FCA may be mounted on a device other than the hard disk. In this case, the second support member is brought into contact with a member having a small thermal resistance. When mounted on other devices, a printed board or a ceramic board may be used instead of the flexible sheet.
A sixth embodiment for explaining a semiconductor device 10C in which a heat radiation electrode 15 is projected in place of a metal plate 23 and its semiconductor module 50A
FIG. 11 shows a structure in which the heat radiation electrode 15A protrudes from the back surface of the pad 14, and the heat radiation electrode 15 and the fixing plate 25 are integrated.
[0123]
First, this manufacturing method will be described with reference to FIGS. Since FIGS. 4 to 8 show the same manufacturing method, the description up to here is omitted.
[0124]
FIG. 12 shows a state in which the insulating resin 13 is coated on the conductive foil 40, and a portion corresponding to the heat radiation electrode 15 is coated with a photoresist PR. If the conductive foil 40 is etched through the photoresist PR, the heat radiation electrode 15A can be protruded from the back surface of the pad 14, as shown in FIG. In place of the photoresist PR, a conductive film such as Ag or Au may be selectively formed and used as a mask. This coating also functions as an antioxidant film.
[0125]
In the structure in which the metal plate 23 is bonded as shown in FIG. 1, the workability is very poor because the metal plate 23 is as thin as about 125 μm. However, when the heat radiation electrode 15A protruding by etching is formed in this way, the above-described bonding of the metal plate 23 becomes unnecessary.
[0126]
Then, as shown in FIG. 14, after the pad 14, the wiring 30 and the external connection electrode 31 are completely separated, the insulating film 26 is covered, and the portion where the solder is disposed is exposed. Then, after the solder 42 is fixed, dicing is performed at a portion indicated by an arrow.
[0127]
The semiconductor device separated here is mounted on the first support member 11 as shown in FIG. As described above, the second support member 24 is fixed. At this time, since the heat radiation electrode 15A protrudes, it can be easily joined to the fixing plate 25 via solder or the like.
[0128]
In FIG. 14B, the back surface of the semiconductor element 16 is exposed from an insulating resin. For example, if the upper die is brought into contact with the back surface of the semiconductor element and molded, a sealing structure as shown in the figure can be realized.
Seventh embodiment for explaining a semiconductor device
15A is a plan view of a semiconductor device according to the present invention, and FIG. 15B is a cross-sectional view corresponding to the line AA in FIG. 15A.
[0129]
In the present invention, the first heat-dissipating electrode 70A and the second heat-dissipating electrode 70B are arranged on substantially the same plane, and a pad 14 is provided around this. The back surface of this pad 14 directly serves as an external connection electrode, and is located directly below the bonding electrode 19 of the semiconductor chip. Further, as shown in FIG. 3, relocation wiring may be employed. At least one bridge 71 is provided between the chips. Pads 14 are integrally formed at both ends of the bridge 71, and the pads 14 are also connected to the bonding electrode 19.
[0130]
Further, the first semiconductor chip 16A is fixed on the first heat radiation electrode 70A, and the second semiconductor chip 16B is fixed to the second heat radiation electrode 70B and connected via solder. ing.
[0131]
As is clear from the description of the manufacturing method described above, the conductive foil is half-etched and molded and supported by the insulating resin 13 before being completely separated. .
[0132]
As in this embodiment, the present invention can also make a plurality of chips into one package.
[0133]
As described above, in the embodiments so far, the structure of the IC for reading / writing amplification has been described in consideration of the heat emission. However, when various devices are assumed, it may be assumed that heat dissipation of a plurality of semiconductor elements must be considered in order to improve the characteristics. Of course, each may be packaged, but a plurality of semiconductor elements may be packaged as shown in FIG.
[0134]
Naturally, the metal plate can adopt a structure in which the heat dissipation electrode itself protrudes as shown in FIG. 11 when it is connected to the heat dissipation electrode as shown in FIG. These are mounted on a flexible sheet or mounted on a flexible sheet to which a second support member is attached.
[0135]
FIG. 16 is applicable to all the embodiments, and shows a method of connecting the bump B formed on the semiconductor element 16 and the pad 14. P denotes a plating film such as Au or Ag, and is formed as necessary.
[0136]
A is an ACP method (anisotropic conductive paste / film), in which conductive particles are interposed between the bump B and the pad 14 (or the plating film P), and electrical conduction is obtained by pressing.
[0137]
B is an SBB method (stand bump bonding) in which the bump B and the pad 14 (or plating film) are connected, and at the same time, the conductive paste CP is disposed around the bump B.
[0138]
C is an ESP method (epoxy encapsulated solder connection), and when the bump B is pressed and fixed, the solder SD is also melted and arranged around it.
[0139]
In D, an insulating adhesive means is disposed around the bumps that are press-connected in the NCP method (non-conductive paste).
[0140]
E is a GGI method (Gold / Gold Interconnection) for joining the Au bump and the Au plating film P with ultrasonic waves.
[0141]
The last F is a solder bump method, in which solder bonding is performed and insulative adhesive means and underfill are intruded therebetween. This application adopts this method.
[0142]
As described above, there are various connection methods, but the connection strength is taken into consideration and the connection method is selected. Also, such a structure can be adopted between the back surface of the external connection electrode and the first support member 11.
Eighth embodiment for explaining a semiconductor device
A semiconductor device according to the present embodiment is shown in FIG. 17A is a plan view thereof, and FIG. 17B is a cross-sectional view taken along the line AA when the semiconductor device 10E is mounted on the mounting substrate 43. FIG.
[0143]
In the above description, the electrode provided on the back surface of the region of the semiconductor element 16 is provided in order to enhance the heat dissipation action. However, these electrodes have a heat dissipation function and also have a function of buffering stress acting on the external connection electrode 21 provided in the peripheral portion of the semiconductor device.
[0144]
As shown in FIG. 17, the semiconductor device 10E is characterized in that a stress buffering electrode 21B is provided on the back surface of the heat radiation electrode 15 surrounded by the external connection electrodes 21 so as to cover the entire back surface. is there. That is, the solder electrode 21B having a size larger than that of the external connection electrode 21 is provided. This size may be equal to or larger than that of a semiconductor element. It may be slightly smaller. The effect | action by this is demonstrated below. The external connection electrode may be solder, solder bump, or conductive adhesive.
[0145]
The semiconductor device 10E according to the present invention is supported by the insulating resin 13 as a whole. Since the thermal expansion coefficients of the mounting substrate 43 and the insulating resin 13 are often different, the difference is made as small as possible. However, since it is very difficult to make them identical, the thermal expansion coefficients of the two are inevitably different. Therefore, when the temperature of both the semiconductor device 10E and the mounting substrate 43 rises, stress acts on the external connection electrode 21 that connects the two. For example, when the semiconductor device is soldered only with the external connection electrodes, the magnitude of this stress increases as the package size increases. Specifically, it is proportional to the distance from the center of the semiconductor element to the periphery of the semiconductor device.
[0146]
In the present application, the stress can be relieved by making the stress buffering electrode 21B substantially the same size as the semiconductor element 16. The region is firmly fixed to the mounting substrate by the stress buffering electrode 21B. Accordingly, the stress acting on the external connection electrode 21 is proportional to the distance from the stress buffering electrode 21 </ b> B to the center of the external connection electrode 21. As a result of the stress simulation, the maximum stress applied to the external connection electrode 21 is reduced by about 25 to 30%. Therefore, it is possible to prevent the external connection electrode 21 from being cracked. The stress buffer electrode 21B may be slightly larger or slightly smaller than the semiconductor element 16.
[0147]
FIG. 22 is a graph showing the relationship between the number of cycles (horizontal axis) and the crack generation rate (vertical axis) in the heat cycle test. Here, the method of the heat cycle test will be described. First, a semiconductor device mounted on a mounting substrate via a solder electrode is exposed to the gas phase. Next, the temperature of the gas phase is changed, and the number of semiconductor devices in which cracks have occurred in the solder electrodes due to the temperature change is measured. By performing the above operation, it is possible to evaluate the lifetime of the solder electrode with respect to temperature change. In addition, the range of the temperature change of a gaseous phase is -40 degreeC-125 degreeC, and the time of 1 cycle is about 1 hour.
[0148]
The structure of case 1 and case 2 in FIG. 22 will be described below.
[0149]
Case 1: The back surface of the pad exposed through the insulating coating and the size of the heat radiation electrode are the same. Therefore, a lot of solder is provided on the exposed portion of the heat radiation electrode, and the solder electrode is mounted on the mounting substrate as shown in FIG.
[0150]
Case 2: In Case 1, the back surface of the heat radiation electrode is exposed over substantially the entire area, and the heat radiation electrode and the electrode of the mounting substrate are fixed all over.
[0151]
In case 1, the crack generation rate increased from the time when the number of cycles exceeded 250, and the crack generation rate reached 100% when the number of cycles reached 400. In other words, when the number of cycles reaches 400, cracks have occurred in the solder electrodes of all the semiconductor devices.
[0152]
In Case 2, the crack generation rate increased from the time when the number of cycles exceeded 450, and the crack generation rate reached 100% when the number of cycles reached 600.
[0153]
From this, it can be said that the semiconductor device of case 2 has a structure in which solder cracks are less likely to occur than the semiconductor device of case 1. Therefore, it is more effective to use a large solder electrode having substantially the same size as the chip as the stress buffering electrode. This is because the distance between the solder electrodes is shortened as described above.
[0154]
Here, the solder electrode is made of a solder material, but the material here may be a generally-known brazing material, a conductive paste such as Ag or gold, or a conductive adhesive. The material for fixing the heat radiation electrode and the mounting substrate may be an insulating adhesive as long as the heat radiation electrode 15 is not electrically connected to the back surface of the chip.
Ninth embodiment for explaining a semiconductor device
A semiconductor device according to the present embodiment is shown in FIG. 18A is a plan view thereof, and FIG. 18B is a cross-sectional view taken along the line AA when the semiconductor device 10F is mounted on the mounting substrate 43. FIG.
[0155]
As shown in FIGS. 18A and 18B, the semiconductor device 10F is characterized in that the heat dissipation electrode 15B divided by the groove 44 is provided with an electrode 21B for stress relaxation. That is, the back surface of the semiconductor device 10F and the mounting substrate 43 are firmly coupled to each other via the stress buffering electrode 21B. Therefore, the stress acting on the external connection electrode 21 is proportional to the distance from the periphery of the stress buffering electrode 21 </ b> B to the center of the external connection electrode 21. From this, when the semiconductor device 10F is thermally expanded, the stress acting on the external connection electrode 21 can be buffered, and the external connection electrode 21 can be prevented from being cracked.
[0156]
Furthermore, by providing the groove 44, the adhesive force between the insulating adhesive means 17 and the heat radiation electrode 15 can be improved.
[0157]
In addition, although the cycle test of this structure was not implemented, it seems that the effect equivalent to the structure of FIG. 17 generate | occur | produces. As the number of divisions of the stress buffer electrode 21B increases, the structure shown in FIG. 2 is obtained. However, the number of divisions having this effect is about 2 to 8 at most. By performing this division, the amount (thickness) of the applied solder is reduced and the mountability is improved as compared with a structure in which the entire surface is solidly fixed.
Tenth Embodiment for explaining a Semiconductor Device
FIG. 19 shows a semiconductor device according to this embodiment. 19A is a plan view thereof, and FIG. 19B is a cross-sectional view taken along the line AA when the semiconductor device 10F is mounted on the mounting substrate 43. FIG.
[0158]
As shown in FIG. 19A, this semiconductor device is characterized in that the external connection electrode 21 has an elongated shape. Again, there are two causes of stress buffering.
The first is that the adhesion area of the external connection electrode 21 has increased.
Secondly, since the crack generation point CK is generated on the outer peripheral portion of the solder and on the semiconductor element side, the separation distance of the generation point CK is shortened.
[0159]
Considering prevention of solder bridge between the electrodes, the distance between the heat radiation electrode 15 and the pad 14 needs to be about 0.3 m. However, the minimum length of the fine metal wire 20 necessary for bonding is required to be about 1 mm to 0.5 mm, although it depends on the thickness of the semiconductor element 16. For example, in the semiconductor element 16 having a thickness of 0.33 mm, the shortest length of the thin metal wire is 1 mm. When the thickness of the semiconductor element is 0.1 mm, the shortest length of about 0.5 mm is required. Therefore, the pad 14 needs to enter about 0.2 to 0.4 mm from the bonding portion of the pad 14 to the inside. That is, the crack occurrence portion CK needs to be on the inside as much as possible, but it needs to be as long as possible due to wire bonding restrictions. Moreover, since the number of the pads 14 is small in the drawing, a square shape is possible. However, when a pad exceeding 200 pins is required, the width of the bonding pad needs to be narrowed. Therefore, the shape of the pad 14 is necessarily an elongated shape.
[0160]
As a result, the adhesion area increases, and at the same time, the occurrence of cracks is on the inside, and the occurrence of cracks is suppressed.
Eleventh embodiment for explaining a semiconductor device
A semiconductor device according to the present embodiment is shown in FIGS. 20A is a plan view, and FIG. 20B is a cross-sectional view taken along line AA when the semiconductor device 10G is mounted on the mounting substrate 43. FIG. 21A to 21C show the structure of the external connection electrode 21. FIG.
[0161]
As shown in FIGS. 21A and 21B, the semiconductor device 10 </ b> J is characterized by the structure of the external connection electrode 21. The problem is that, as shown in FIG. 21C, the insulating coating 26 hits the solder extension surface and the constriction NK is not formed. As long as the external connection electrode 21 does not have a constriction NK, the structure shown in FIGS. 21A and 21B may be used.
[0162]
It has been found that this constricted NK tends to concentrate stress, and therefore easily generates cracks. In addition, in a thin package having a thickness of 0.5 mm or less, the composition ratio of the insulating resin is small with respect to the constituent material of the semiconductor device because it is thin, and in an extreme case, the semiconductor element 16 is directly attached. . Since the thermal expansion coefficient of silicon, which is the material of the semiconductor element 16, and the mounting substrate are greatly different, the stress acting on the external connection electrode 21 connecting the two becomes large. Therefore, in all the embodiments of the present invention, it is important that the solder surface has a smooth curved surface without constriction.
[0163]
Next, the results of the heat cycle test will be described with reference to FIG. First, the structure of the semiconductor device used for the tests of case 3 and case 4 will be described.
[0164]
The external connection electrodes of the semiconductor devices of both the case 3 and the case 4 also have a structure having no constriction. The difference between the two lies in the structure of the stress buffer electrode. The stress buffer electrodes of the semiconductor device of case 3 are provided with a plurality of electrodes having the same size as the external connection electrodes. The stress buffering electrode of the semiconductor device of the case 4 has the same size as the semiconductor element.
[0165]
Case 3 is currently under test, but no solder cracks have occurred even if the number of cycles exceeds 750 times.
[0166]
In case 4, the crack occurrence rate is 0% even when the number of cycles reaches 1400. That is, no cracks are generated in the solder electrode even when the number of cycles is 1400.
[0167]
Next, the difference in structure between Case 1 to Case 4 will be described.
[0168]
The difference in structure between case 1 and case 2 is the shape of the electrode for stress buffering. The stress buffering electrode of the case 1 is the same size as the external connection electrode 21. On the other hand, the stress buffer electrode of the case 2 has almost the same size as the semiconductor element. That is, the stress buffering electrode of the case 2 is larger than the case 1.
[0169]
The difference in structure between case 1 and case 3 is the shape of the external connection electrode. The external connection electrode of the case 1 has a circular structure with a constriction. On the other hand, the external connection electrode of the case 2 has a long and narrow structure.
[0170]
The difference between the structures of the case 2 and the case 4 is that both have stress buffering electrodes having a size almost equal to that of the semiconductor element, but are in the shape of external connection electrodes. The external connection electrode of the case 2 has a circular structure with a constriction. On the other hand, the external connection electrode of the case 4 has a long and narrow structure.
[0171]
From this, it can be seen that solder cracks can be prevented by combining the two characteristics of the shape of the stress buffer electrode and the shape of the external connection electrode. In other words, the size of the stress buffering electrode is set to the same size as that of the semiconductor element, the shape of the external connection electrode is elongated, and the shape is not constricted.
[0172]
As described above, the feature of the present invention is that the electrode, which was originally effective as a heat radiation electrode, is firmly fixed to the mounting substrate through solder and solid, thereby preventing cracks in the external connection electrode. It turned out to be effective.
[0173]
Further, it has been found that the strength of the external connection electrode can be improved by making the external connection electrode without a constriction.
[0174]
This realizes a significant improvement in mountability of thin packages and greatly contributes to the practical use of light, thin and small packages.
[0175]
In all the embodiments described above, the insulating bonding means 17 is used as the bonding means between the semiconductor element 16 and the heat radiation electrode 15. However, this bonding means is not limited to insulating. If the back electrode of the semiconductor device is not short-circuited, conductive adhesive means may be used.
[0176]
【The invention's effect】
As is apparent from the above description, the present invention provides a semiconductor device in which a metal plate is fixed to a heat radiation electrode exposed on the back surface of a package and the metal plate protrudes from the back surface of an external connection electrode or pad. Therefore, there is a merit that the mounting on the FCA becomes easy.
[0177]
In particular, an opening is provided in the FCA, and the back surface of the FCA and the heat radiation electrode of the semiconductor device are located on the surface, so that the contact with the second support member is facilitated.
[0178]
Further, Al is used as the second support member, and a fixing plate made of Cu is formed here, and a heat radiating electrode or a metal plate is fixed to the fixing plate, so that the heat generated from the semiconductor element is second It can discharge | release outside via a support member.
[0179]
Therefore, the temperature rise of the semiconductor element can be prevented, and performance close to the original capability can be brought out. In particular, FCA mounted in a hard disk can efficiently release the heat to the outside, so that the read / write speed of the hard disk can be increased.
[0180]
Furthermore, by providing a stress buffering electrode having a size equivalent to that of the semiconductor element on the back surface of the pad at the center of the semiconductor device, the stress acting on the external connection electrode can be reduced. This can prevent the occurrence of solder cracks.
[0181]
Furthermore, by forming the external connection electrode of the semiconductor device into an elongated shape and having no constriction, it is possible to buffer the stress acting on the solder electrode and improve the strength of the solder electrode itself. Therefore, solder cracks can be prevented.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a semiconductor module of the present invention.
FIG. 2 illustrates a semiconductor device of the present invention.
FIG. 3 is a diagram illustrating a semiconductor device of the present invention.
FIG. 4 is a diagram illustrating a method for manufacturing a semiconductor device of the present invention.
FIG. 5 is a diagram illustrating a method for manufacturing a semiconductor device of the present invention.
FIG. 6 is a diagram illustrating a method for manufacturing a semiconductor device of the present invention.
FIG. 7 is a diagram illustrating a method for manufacturing a semiconductor device of the present invention.
FIG. 8 is a diagram illustrating a method for manufacturing a semiconductor device of the present invention.
FIG. 9 illustrates a semiconductor device of the present invention.
FIG. 10 is a diagram illustrating a flow prevention film formed on a conductive pattern.
FIG. 11 is a diagram illustrating a semiconductor module of the present invention.
FIG. 12 is a diagram illustrating a method for manufacturing a semiconductor device of the present invention.
FIG. 13 is a diagram illustrating a method for manufacturing a semiconductor device of the present invention.
FIG. 14 is a diagram illustrating a method for manufacturing a semiconductor device of the present invention.
FIG. 15 is a diagram illustrating a semiconductor device of the present invention.
FIG. 16 illustrates a connection structure between a semiconductor element and a pad.
FIG 17 illustrates a semiconductor device of the invention.
18 is a diagram illustrating a semiconductor device of the present invention. FIG.
FIG 19 is a diagram illustrating a semiconductor device of the invention.
FIG. 20 is a diagram illustrating a semiconductor device of the present invention.
FIG. 21 is a diagram illustrating a semiconductor device of the present invention.
FIG. 22 is a diagram for explaining an experimental result of a heat cycle using the semiconductor device of the present invention.
FIG. 23 is a diagram illustrating a hard disk.
FIG. 24 is a diagram for explaining a conventional semiconductor module employed in FIG.
[Explanation of symbols]
10 Semiconductor devices
11 First support member
12 First opening
14 Pad
16 Semiconductor elements
23 Metal plate
24 Second support member
56 Second opening

Claims (30)

The semiconductor element is sealed with the insulating resin in a face-down manner, and a pad electrically connected to the bonding electrode of the semiconductor element and a heat radiation electrode located on the surface of the semiconductor element are exposed on the back surface thereof. A semiconductor device,
Under the semiconductor element, an insulating adhesive means different from the insulating resin is provided,
The semiconductor device according to claim 1 , wherein the insulating bonding means protrudes more outward than the pad . The semiconductor element is sealed with the insulating resin in a face-down manner, and a pad electrically connected to the bonding electrode of the semiconductor element and a heat radiation electrode located on the surface of the semiconductor element are exposed on the back surface thereof. A semiconductor device,
A metal plate is provided on the exposed portion of the heat radiation electrode so as to protrude from the back surface of the pad,
A semiconductor device, wherein a back surface of the insulating resin protrudes from a back surface of the pad.   3. The semiconductor device according to claim 1, wherein the back surface of the pad and the back surface of the heat radiation electrode are arranged on substantially the same plane. 4. The semiconductor device according to claim 1, wherein the semiconductor element and the heat radiation electrode are fixed by the insulating adhesive means .   The semiconductor device according to claim 1, wherein the heat radiation electrode and the metal plate are fixed by an insulating material or a conductive material.   3. The semiconductor device according to claim 1, wherein the heat radiation electrode and the metal plate are integrally formed of the same material.   The semiconductor device according to claim 1, wherein a side surface of the pad and a back surface of the insulating resin extending from the side surface of the pad draw the same curved surface. A first support member provided with a conductive pattern, and a semiconductor element electrically connected to the conductive pattern are integrally sealed with an insulating resin facedown, and a bonding electrode of the semiconductor element is formed on the back surface thereof. A semiconductor module having an electrically connected pad and a semiconductor device in which an electrode for heat dissipation located on the surface of the semiconductor element is exposed;
The conductive pattern provided on the first support member and the pad are electrically connected, and the first support member corresponding to the heat dissipation electrode is provided with an opening, and the opening Includes a metal plate fixed to the heat radiation electrode.   The semiconductor module according to claim 8, wherein a second support member to which the metal plate is fixed is attached to a back surface of the first support member.   10. The semiconductor module according to claim 8, wherein the heat radiation electrode and the metal plate are integrally formed of the same material.   The second support member corresponding to the metal plate is provided with a fixing plate made of a conductive material, and the fixing plate and the metal plate are thermally coupled to each other. The semiconductor module according to 10.   The metal plate is made of Cu as a main material, the second support member is made of Al as a main material, and the fixing plate is made of a plating film mainly made of Cu formed on the second support member. The semiconductor module according to claim 11.   The semiconductor module according to claim 8, wherein a back surface of the insulating resin protrudes from a back surface of the pad.   The semiconductor module according to claim 8, wherein a side surface of the pad and a back surface of the insulating resin extending from the side surface of the pad draw the same curved surface.   15. The semiconductor module according to claim 8, wherein the semiconductor element is a hard disk read / write amplification IC. A semiconductor element is sealed face down with an insulating resin, and a pad electrically connected to a bonding electrode of the semiconductor element is provided on the back surface of the semiconductor element, and an external portion is extended through wiring integrated with the pad. A semiconductor device in which a connection electrode and an electrode for heat dissipation arranged on the surface of the semiconductor element are exposed,
Under the semiconductor element, an insulating adhesive means different from the insulating resin is provided,
The semiconductor device according to claim 1 , wherein the insulating bonding means protrudes more outward than the pad . A semiconductor element is sealed face down with an insulating resin, and a pad electrically connected to a bonding electrode of the semiconductor element is provided on the back surface of the semiconductor element, and an external portion is extended through wiring integrated with the pad. A semiconductor device in which a connection electrode and a heat dissipation electrode arranged on the surface of the semiconductor element are exposed, and a metal plate is protruded from the back surface of the external connection electrode to the exposed portion of the heat dissipation electrode. Provided,
A semiconductor device, wherein a back surface of the insulating resin protrudes from a back surface of the external connection electrode.   18. The semiconductor device according to claim 16, wherein a back surface of the external connection electrode and a back surface of the heat radiation electrode are arranged on substantially the same plane. 18. The semiconductor device according to claim 16, wherein the semiconductor element and the heat radiation electrode are fixed by the insulating adhesive means .   18. The semiconductor device according to claim 16, wherein the heat radiation electrode and the metal plate are fixed with an insulating material or a conductive material.   18. The semiconductor device according to claim 16, wherein the heat radiation electrode and the metal plate are integrally formed of the same material.   18. The semiconductor device according to claim 16, wherein a side surface of the external connection electrode and a back surface of the insulating material extending from the side surface of the external connection electrode draw the same curved surface. A first support member provided with a conductive pattern, and a semiconductor element electrically connected to the conductive pattern are integrally sealed with an insulating resin facedown, and a bonding electrode of the semiconductor element is formed on the back surface thereof. A semiconductor module having an electrically connected pad, an external connection electrode provided via a wiring integral with the pad, and a semiconductor device in which a heat dissipation electrode located on the surface of the semiconductor element is exposed. ,
The conductive pattern provided on the first support member and the external connection electrode are electrically connected, and the first support member corresponding to the heat dissipation electrode is provided with an opening, A semiconductor module, wherein an opening is provided with a metal plate fixed to the heat radiation electrode.   24. The semiconductor module according to claim 23, wherein a second support member to which the metal plate is fixed is attached to a back surface of the first support member.   25. The semiconductor module according to claim 23, wherein the heat radiation electrode and the metal plate are integrally formed of the same material.   The said 2nd supporting member corresponding to the said metal plate is provided with the adhering board which consists of electrically-conductive materials, The said adhering board and the said metal plate are thermally couple | bonded, The Claim 24 or Claim characterized by the above-mentioned. 25. The semiconductor module according to 25.   The metal plate is made of Cu as a main material, the second support member is made of Al as a main material, and the fixing plate is made of a plating film mainly made of Cu formed on the second support member. 27. The semiconductor module according to claim 26.   28. The semiconductor module according to claim 23, wherein a back surface of the insulating adhesive means protrudes from a back surface of the external connection electrode.   24. The semiconductor module according to claim 23, wherein a side surface of the external connection electrode and a back surface of the insulating adhesive means bonded to the external connection electrode draw the same curved surface.   30. The semiconductor module according to claim 23, wherein the semiconductor element is a read / write amplification IC for a hard disk.

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