JP2006005112A - Semiconductor device and circuit board used therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable mounting without causing troubles wherein shortage between electrodes and lifting of a package during packaging, regarding a semiconductor device product in which a circuit component is mounted on a substrate and sealing is performed with resin. <P>SOLUTION: The circuit component 20 is bonded to pads 11a, 11b arranged on the circuit board 25 with solder, and mounted on the circuit board and sealed with resin 22. Accordingly, the semiconductor device product 30 is formed. On a surface of the circuit board 25, an aperture hole 13 is formed which is used for bonding the circuit component 20 on the pads 11a, 11b with solder, and whose inner peripheral side surface 13a has an overhang profile, and covering is performed with a protective film 12. The circuit component 20 forms a clearance chunk which absorbs thermal expansion amount of solder when mounting the semiconductor device product 30 on the packaging substrate near the inner peripheral side surface 13b of the aperture hole 13, and the component 20 is mounted on the circuit board 25. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a semiconductor device and a circuit board used therefor, and more particularly to a semiconductor device provided with circuit components mounted on a substrate and sealed with a resin, and a circuit board used therefor.

  Semiconductor devices such as MCM are often used in small electronic products because they have a composite function and are extremely compact. In these semiconductor devices, a circuit component such as a semiconductor device is mounted on a circuit board, and one surface of the circuit board on which the circuit component is mounted is sealed with a resin by a potting method or a resin sealing method using a resin sealing mold. In many cases, it is provided in a stopped state. A connection terminal for surface mounting such as a solder ball is provided on the other surface of the circuit board, and these semiconductor devices are mounted on the mounting board by soldering or the like.

FIG. 10 is a partially enlarged view showing a state where a circuit device 20 is mounted on a circuit board 5 and a semiconductor device in which the surface of the circuit board 5 on which the circuit component 20 is mounted is sealed with resin is mounted on a mounting board. Yes.
The circuit board 5 is formed by providing a predetermined wiring pattern on the surface of the substrate 10 and covering the surface of the substrate 10 with a protective film 12 such as a solder resist. In the wiring pattern, pads 11a and 11b are provided according to the arrangement of the electrodes 21a and 21b of the circuit component 20, and the opening hole 13 is provided in the protective film 12 according to the arrangement of the pads 11a and 11b. The electrodes 21 a and 21 b and the pads 11 a and 11 b are joined by the solder 18 in the hole 13 and mounted on the circuit board 5.

  When the above-described semiconductor device is mounted on the mounting substrate, it is mounted by reflow. During this reflow process, the semiconductor device is heated, and at that time, the solder 18 that joins the circuit component 20 to the circuit substrate 5 is added. When the solder 18 is melted and thermally expanded, the electrodes 21a and 21b are electrically short-circuited, or the circuit component 20 is pushed up from the circuit board 5 and the sealing resin 6 is peeled off from the board 10. Occurs.

In FIG. 10, when the semiconductor device is mounted, the solder 18 thermally expands and enters the gap between the circuit component 20 and the circuit board 5, electrically short-circuiting the electrodes 21 a and 21 b, and sealing resin 22 The state which made it peel from the circuit board 5 is shown.
As described above, the solder 18 that has joined the pads 11a and 11b and the electrodes 21a and 21b thermally expands to cause a problem such as an electrical short circuit. The circuit component 20 mounted on the circuit board 5 is connected to the circuit. This is because when the solder 18 is melted and thermally expanded at the time of mounting because the resin is sealed on the substrate 5, there is no place for the solder 18, and in a gap portion or the like generated between the sealing resin 6 and the circuit board 5. This is because the solder 18 enters.

  In particular, when a chip capacitor or chip resistor is mounted as the circuit component 20, these components are small and formed in a rectangular parallelepiped shape, and electrodes are provided at both ends of the component body. When mounted by solder bonding, the molten solder crawls up to the side surface of the electrode to form a meniscus shape. In order to form a meniscus in this way, a large amount of solder is required for solder joining of these components compared to the distance between the electrodes, and as a result, there is a problem that an electrical short circuit tends to occur between the electrodes.

  Therefore, the present invention has been made to solve these problems. For a semiconductor device in which circuit components are mounted on a substrate and sealed with a resin, a solder that joins the circuit components to the circuit substrate at the time of mounting is provided. To provide a semiconductor device capable of reliable mounting without causing problems such as an electrical short circuit between electrodes or peeling of a sealing resin even when melted and thermally expanded, and a circuit board suitably used for the semiconductor device With the goal.

The present invention has the following configuration in order to achieve the above object.
That is, the circuit component is a semiconductor device that is solder-bonded to a pad provided on the circuit board and mounted on the circuit board, and the circuit component is sealed with resin, and is formed on the surface of the circuit board. An opening hole having an inner peripheral side surface overhanged for solder bonding the circuit component to the pad is formed on the pad and covered with a protective film, and the circuit component attaches the semiconductor device to the mounting substrate. A gap portion that absorbs the thermal expansion amount of the solder at the time of mounting is formed in the vicinity of the inner peripheral side surface of the opening hole, and is mounted on the circuit board.
In addition, the circuit board used in the semiconductor device, characterized in that an opening hole whose inner peripheral side surface is an overhang shape is formed on the pad on the surface of the circuit board, and is covered with a protective film. To do.

The circuit component is a semiconductor device that is solder-bonded to a pad provided on the circuit board and mounted on the circuit board, and the circuit component is sealed with a resin, and is formed on the surface of the circuit board. An opening hole for soldering the circuit component to the pad is formed on the pad to cover the protective film, and a groove is formed in the area of the opening hole on the pad. The groove portion is mounted on the circuit board as a gap portion that absorbs the amount of thermal expansion of solder when the semiconductor device is mounted on a mounting board.
The opening hole has an inner peripheral side surface formed in an overhang shape.
Further, a circuit board used in the semiconductor device, wherein an opening hole is formed on the surface of the circuit board and covered with a protective film, and a groove portion is formed in the area of the opening hole on the pad. Is formed.
The opening hole has an inner peripheral side surface formed in an overhang shape.

The circuit component is a semiconductor device that is solder-bonded to a pad provided on the circuit board and mounted on the circuit board, and the circuit component is sealed with a resin, and is formed on the surface of the circuit board. An opening hole for soldering the circuit component to the pad is formed on the pad to cover the protective film, and the pad is formed to protrude from the surface of the protective film, and between at least a pair of pads. The circuit component to be mounted is separated from the circuit board, and the resin is filled between the circuit component and the circuit board so that the circuit component is mounted on the circuit board.
The protective film in a region where the circuit component and the circuit board face each other is provided with a recess for forming the protective film in a thin thickness.
Also, a circuit board used in the semiconductor device, wherein an opening hole is formed on the surface of the circuit board to cover the protective film, and the pad is formed so as to protrude from the surface of the protective film. It is characterized by being.

  According to the semiconductor device and the circuit board used therefor according to the present invention, when the semiconductor device is mounted on the mounting board, even if the solder used when mounting the circuit components on the circuit board is thermally expanded, the heat of the solder By providing a gap portion that absorbs the amount of expansion, it is possible to avoid problems such as electrical short-circuiting between electrodes of circuit components and separation of the sealing resin from the circuit board. It can be provided as a high semiconductor device.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings.
(First embodiment)
FIG. 1 is a cross-sectional view showing a configuration of a circuit board 25 used in a semiconductor device. The circuit board 25 of the present embodiment is similar to the circuit board 5 used in the conventional semiconductor device shown in FIG. 10, the electrodes 21 a of the circuit components 20 such as chip capacitors and chip resistors mounted on the circuit board 25, The pads 11a and 11b are provided on the surface of the substrate 10 in accordance with the arrangement of the electrodes 21b, and the protective film 12 is provided with the opening holes 13 on the pads 11a and 11b in accordance with the arrangement of the electrodes 21a and 21b. is there.

A feature of the circuit board 25 according to the present embodiment is that the shape of the opening hole 13 is a shape in which the diameter gradually increases from the opening side toward the inner bottom surface (the surface of the pad) (in other words, the opening region expands). The inner peripheral side surface 13a of the hole 13 is formed in an overhang shape.
Thus, in order to form the inner peripheral side surface 13a of the protective film 12 in an overhang shape, when the protective film material such as a solder resist is exposed and developed to form the opening hole 13, the opening time 13 is longer than the normal exposure time. The exposure can be performed for a long time, and a method can be used in which light is diffused laterally from the opening of the mask during exposure.
In the conventional circuit board 5 shown in FIG. 10, the inner peripheral side surface of the opening hole has an upright shape (straight shape) with respect to the pad surface. Thus, in the circuit board generally used conventionally, the inner peripheral side surface of the opening hole has an upright shape.

FIG. 2 shows a semiconductor device 30 in which the circuit component 20 is mounted on the circuit board 25 shown in FIG. 1 and one surface side of the circuit board 25 on which the circuit component 20 is mounted is sealed with a resin 22. 2A is a cross-sectional view, and FIG. 2B is a plan view.
When soldering the circuit component 20 to the circuit board 25, a solder paste is printed in accordance with the arrangement of the opening holes 13 provided in the circuit board 25, and the circuit component 20 is set on the circuit board 25 and reflowed. The circuit component 20 is a portion of the opening hole 13 exposed on the pads 11a and 11b, and the electrodes 21a and 21b and the pads 11a and 11b are joined by the solder 18 and are electrically connected to the circuit board 25 and mounted.
In the circuit board 25 used in the semiconductor device 30 of the present embodiment, the inner peripheral side surface 13a of the opening hole 13 has an overhang shape. Therefore, when the circuit component 20 is soldered to the circuit board 25, The solder 18 is not filled in the entire inside of the opening hole 13, and a gap is generated in the vicinity of the inner peripheral side surface 13 a of the opening hole 13.

  FIG. 2B shows a planar arrangement of each part in a state where the circuit component 20 is joined by the solder 18 at the part of the opening hole 13 formed on the pads 11a and 11b. A broken line A indicates an outline of the opening hole 13 on the pads 11a and 11b. Since the inner peripheral side surface 13a has an overhang shape in the opening hole 13, the opening region gradually widens on the inner bottom surface side, and the region where the solder 18 is joined on the pads 11a and 11b (the hatched portion in the broken line in the figure) ) And the inner peripheral side surface 13a of the opening hole 13, a gap portion 13b is formed, and the circuit component 20 is soldered.

FIG. 3 shows a state in which the semiconductor device 30 shown in FIG. 2 is mounted on a mounting board. FIG. 3 is an enlarged view of the semiconductor device 30 in the mounted state, and does not show the mounting substrate.
As described above, when the semiconductor device 30 is mounted, the solder 18 joining the circuit component 20 to the circuit board 25 is melted by reflow, and the solder 18 is thermally expanded at that time. In the case of the semiconductor device 30 of the present embodiment, the solder 18 is melted and thermally expanded at the time of mounting because the gap portion 13b is formed in the region near the inner peripheral side surface 13a of the opening hole 13. At this time, the solder 18 enters the gap portion 13b and is mounted. FIG. 3 shows a state in which the solder 18 is filled in the opening hole 13 and mounted.

  In the case of the semiconductor device 30 of the present embodiment, as described above, the inner peripheral side surface 13a of the opening hole 13 provided in the pads 11a and 11b of the circuit board 25 has an overhang shape, so that the solder 18 is heated during mounting. Even if expanded, the gap portion 13b in the opening hole 13 becomes a region that absorbs the expansion of the solder 18, and the solder 18 enters the gap portion between the circuit board 25 and the circuit component 20 to cause an electrical short circuit. It is possible to prevent the circuit component 20 from being pushed up from the circuit board 25, and the semiconductor device 30 can be reliably mounted.

(Second Embodiment)
FIG. 4A is a cross-sectional view showing the configuration of the second embodiment of the circuit board used in the semiconductor device, and FIG. 4B shows the pads 11 a and 11 b formed on the substrate 10 of the circuit board 26. A plan view is shown.
Similarly to the circuit board 25 described in the first embodiment, the circuit board 26 of the present embodiment is also provided with pads 11a and 11b on the board 10 in accordance with the arrangement of the electrodes 21a and 21b of the circuit component 20, Opening holes 13 are opened on the pads 11a and 11b, and the surface of the substrate 10 is covered with a protective film 12 such as a solder resist. The substrate 10 is provided with a through hole, a conductor layer 14 is provided on the inner surface of the through hole, and the pads 11a and 11b provided on one surface of the substrate 10 via the conductor layer 14 and the other of the substrate 10 are provided. A land (not shown) provided on the surface is electrically connected. Reference numeral 15 denotes an electrical insulating layer.

  Also in the circuit board 26 of the present embodiment, the inner peripheral side surface 13a of the opening hole 13 is formed in an overhang shape, but the characteristic configuration of the circuit board 26 of the present embodiment is that the pads 11a and 11b This is because the groove 16 is formed. As shown in FIG. 4B, the groove 16 is formed in an elongated shape over substantially the entire width of the opening hole 13 with the width direction of the pads 11a and 11b as the longitudinal direction. In addition, if the groove part 16 is provided in the opening hole 13, the shape, the arrangement position, and the number of arrangement will not be specifically limited.

The width of the groove 16 is set so that the solder does not enter the groove 16 when the circuit component 20 is soldered to the circuit board 26. Generally, if the width of the groove is about 200 μm or less, the solder will not enter the groove during solder joining. Therefore, the width of the groove 16 formed in the pads 11a and 11b may be set to about 100 to 200 μm or less. In the present embodiment, the groove 16 has a width of 50 μm, a length of 500 μm, and a depth of about 30 μm.
In addition, as a method of forming the groove portion 16 in the pads 11a and 11b, a method of forming a via hole by a build-up method used when forming a multilayer wiring board, a laser beam is irradiated to the pads 11a and 11b, and the groove is formed. A forming method can be used.

  FIG. 5 shows a state in which the circuit component 20 is mounted on the circuit board 26 by solder bonding, and one surface of the circuit board 26 is sealed with the resin 22 to form the semiconductor device 31. The electrodes 21a and 21b of the circuit component 20 and the pads 11a and 11b are joined by solder 18 through the opening holes 13 of the pads 11a and 11b, and the circuit component 20 is soldered to the circuit board 26. Since the inner peripheral side surface 13a of the opening hole 13 is formed in an overhang shape, a gap portion is formed between the solder 18 and the inner peripheral side surface 13a of the opening hole 13, and at the same time, the solder 18 is formed in the groove portion 16. Since it does not enter, the groove part 16 remains as a gap part.

FIG. 6 shows a state where the semiconductor device 31 shown in FIG. 5 is mounted on a mounting board. The solder 18 that has melted and expanded at the time of mounting fills the gap formed on the inner peripheral side surface of the opening hole 13 and enters the groove 16 to be mounted.
In the semiconductor device 31 of this embodiment, the inner peripheral side surface 13a of the opening hole 13 is formed in an overhang shape, and is formed in the vicinity of the inner peripheral side surface of the opening hole 13 by forming the groove 16 in the pads 11a and 11b. The formed gap portion and the groove portion 16 act as a margin space for absorbing the expansion of the solder 18 when the solder 18 is thermally expanded.

Also in the case of the semiconductor device 31 of the present embodiment, by absorbing the expansion of the solder 18 in the marginal space portion, even if the solder 18 is thermally expanded during reflow, the circuit component 20 is peeled off from the circuit board 26, The problem that the solder 18 enters the gap between the electrodes 21a and 21b of the circuit component 20 and the electrodes 21a and 21b are electrically short-circuited can be avoided.
In the semiconductor device 31 of the present embodiment, the inner peripheral side surface 13a of the opening hole 13 has an overhang shape. However, the opening hole 13 is a straight hole like a normal opening hole, and groove portions are formed in the pads 11a and 11b. It is possible to form only 16 to absorb the expansion of the solder 18.

(Third embodiment)
FIG. 7A is a cross-sectional view showing the configuration of the third embodiment of the circuit board used in the semiconductor device.
Similarly to the circuit boards 25 and 26 in each of the above-described embodiments, the circuit board 27 of the present embodiment is provided with pads 11a and 11b on the board 10 in accordance with the arrangement of the electrodes 21a and 21b of the circuit component 20. The surface is covered with a protective film 12.
The circuit board 27 according to the present embodiment is characterized by providing the pads 11a and 11b so that the pads 11a and 11b protrude from the surface position of the protective film 12 such as a solder resist that covers the surface of the substrate 10, and the pads 11a and 11b. This is because the recess 12a is formed in the protective film 12 in the intermediate region sandwiched.

As shown in FIG. 7A, in the circuit board 27 of the present embodiment, the wiring pattern 17 is formed on the substrate 10, and the pads 11 a and 11 b are provided so as to cover the wiring pattern 17.
FIG. 7B shows a planar arrangement of the wiring pattern 17 and the pads 11a and 11b. The pads 11a and 11b are formed wider than the line width of the wiring pattern 17, and are arranged facing each other with a predetermined interval. In order to provide the pads 11 a and 11 b so as to protrude from the surface of the protective film 12, the wiring pattern 17 is formed on the surface of the substrate 10, the opening hole 13 is formed, and the surface of the substrate 10 is covered with the protective film 12. The plating may be performed so that the plating is raised to a predetermined thickness in the opening hole 13. The pads 11 a and 11 b are provided so as to protrude from the surface of the protective film 12 by about 5 to 10 μm.

In the present embodiment, the recess 12a formed in the protective film 12 is formed in an elongated groove shape as the direction in which the longitudinal direction intersects the opposing direction of the pads 11a and 11b, as shown in FIG. Is formed. The recess 12a is an intermediate region between the pads 11a and 11b and is provided to reduce the thickness of the protective film 12.
As a method of forming the recess 12a, when patterning the protective film 12 such as a solder resist, a method of forming an opening hole in accordance with the position where the recess 12a is formed to form the recess 12a, the protective film 12 having a predetermined thickness After the formation, the method of forming the recess 12a by laser processing can be used.

FIG. 8 shows a semiconductor device 32 in which the circuit component 20 is soldered to the circuit board 27 and sealed with resin 22. The electrodes 21a and 21b of the circuit component 20 and the pads 11a and 11b are joined by the solder 18, and the circuit component 20 is mounted so as to pass between the pads 11a and 11b.
Since the pads 11a and 11b are formed so as to protrude from the surface of the protective film 12, the circuit component 20 is supported away from the surface of the circuit board 27, and a recess 12a is formed in the middle of the pads 11a and 11b. As a result, it becomes possible to ensure a large separation distance between the circuit component 20 and the protective film 12 at an intermediate position between the pads 11a and 11b, so that the circuit component 20 is mounted on the circuit board 27 by the resin 22 When sealed, the portion sandwiched between the circuit component 20 and the circuit board 27 can be reliably filled with the resin 22.

  FIG. 9 shows an example in which a circuit component 20 is mounted on a conventional circuit board 7 as a comparative example. In the conventional circuit board 7, the protective film 12 is opened at the pads 11 a and 11 b formed on the wiring pattern 17, and when the circuit component 20 is solder-bonded to the circuit board 7, the intermediate is sandwiched between the pads 11 a and 11 b. In the region, a slight gap 19 is generated between the circuit board 7 and the circuit component 20. Therefore, when the circuit component 20 is mounted on the circuit board 7 and sealed with the resin 22, the gap 19 is hardly filled with the resin 22, and the gap 19 remains as it is between the circuit board 7 and the circuit component 20. It becomes a state. As a result, there is a problem that when the semiconductor device is mounted on the mounting substrate, the thermally expanded solder 18 enters the gap 19 and the electrodes 21a and 21b are electrically short-circuited by the solder 18.

  On the other hand, in the case of the semiconductor device 32 of the present embodiment, the resin 22 is surely provided also in the region portion sandwiched between the pads 11a and 11b by ensuring a wide space between the circuit component 20 and the circuit board 27. It is possible to prevent the communication space from being generated between the pads 11a and 11b. In addition, by extending the concave portion 12a long in the longitudinal direction, the resin 22 can be easily filled into the gap portion between the circuit component 20 and the circuit board 27 from the side surface direction of the circuit component 20, and the pad 11a can be more reliably secured. , 11b can be prevented from being electrically short-circuited.

It is sectional drawing which shows the structure of 1st Embodiment of a circuit board. 1A is a cross-sectional view illustrating a configuration of a first embodiment of a semiconductor device, and FIG. It is sectional drawing which shows the state which mounted the semiconductor device of 1st Embodiment. It is sectional drawing (a) which shows the structure of 2nd Embodiment of a circuit board, and a top view (b). It is sectional drawing which shows the structure of 2nd Embodiment of a semiconductor device. It is sectional drawing which shows the state which mounted the semiconductor device of 2nd Embodiment. It is sectional drawing (a) which shows the structure of 3rd Embodiment of a circuit board, and a plane part (b). It is sectional drawing which shows the structure of 3rd Embodiment of a semiconductor device. It is sectional drawing which shows the conventional structure of a semiconductor device. It is sectional drawing which shows the state which mounted the conventional semiconductor device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Board | substrate 11a, 11b Pad 12 Protective film 12a Recessed part 13 Port hole 13a Inner peripheral side surface 13b Gap part 16 Groove part 17 Wiring pattern 18 Solder 19 Gap 20 Circuit component 21a, 21b Electrode 22 Resin 25, 26, 27 Circuit board 30, 31, 32 Semiconductor device

Claims (9)

The circuit component is solder-bonded to a pad provided on the circuit board and mounted on the circuit board, and the circuit component is a semiconductor device formed by sealing with resin,
On the surface of the circuit board, a protective film is formed by forming an opening hole on the pad, the inner peripheral side surface of which is an overhang shape for soldering the circuit component to the pad,
The circuit component is mounted on the circuit board by forming a gap portion that absorbs the thermal expansion amount of solder when mounting the semiconductor device on the mounting board in the vicinity of the inner peripheral side surface of the opening hole. A semiconductor device characterized by the above.   The circuit board used for the semiconductor device according to claim 1, wherein an opening hole whose inner peripheral side surface has an overhang shape is formed on the surface of the circuit board and is covered with a protective film. Feature circuit board. The circuit component is solder-bonded to a pad provided on the circuit board and mounted on the circuit board, and the circuit component is formed by sealing with resin,
On the surface of the circuit board, an opening hole for soldering the circuit component to the pad is formed on the pad to cover the protective film, and a groove is formed in the area of the opening hole on the pad. And
The semiconductor device, wherein the circuit component is mounted on the circuit board as a gap portion that absorbs the thermal expansion amount of solder when the semiconductor device is mounted on a mounting board.   The semiconductor device according to claim 3, wherein an inner peripheral side surface of the opening hole is formed in an overhang shape.   4. The circuit board used in the semiconductor device according to claim 3, wherein an opening hole is formed on the pad and covered with a protective film on a surface of the circuit board, and in the region of the opening hole on the pad. A circuit board characterized in that a groove is formed in the circuit board.   6. The circuit board according to claim 5, wherein the opening hole has an inner peripheral side surface formed in an overhang shape. The circuit component is solder-bonded to a pad provided on the circuit board and mounted on the circuit board, and the circuit component is formed by sealing with resin,
On the surface of the circuit board, an opening hole for soldering the circuit component to the pad is formed on the pad to cover the protective film, and the pad is formed to protrude from the surface of the protective film. ,
The circuit component mounted between at least a pair of pads and the circuit board are spaced apart, and the resin is filled between the circuit component and the circuit board so that the circuit component is mounted on the circuit board. Semiconductor device.   8. The semiconductor device according to claim 7, wherein a recess for forming the protective film in a thin thickness is provided in the protective film in a region where the circuit component and the circuit board face each other.   8. A circuit board for use in a semiconductor device according to claim 7, wherein an opening hole is formed on the pad and covered with a protective film on the surface of the circuit board, and the pad protrudes from the surface of the protective film. A circuit board characterized by being formed.

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