JP2005302835A - Semiconductor device and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor device wherein solder flashing is hard to occur between electrodes even if reflow mounting is conducted to mount the semiconductor device to another device. <P>SOLUTION: Electronic components (semiconductor device 3a, chip-type passive component 3b) are mounted to at least one main surface of a substrate 1 where a wiring pattern is formed by solder 4, and the electronic components 3a and 3b are covered with a sealing resin 6. A resin film layer 5 is provided between the sealing resin 6 and the electronic components 3a and 3b, like a shape profiling the unevenness of the surface of the substrate 1 wherein the electronic components 3a and 3b are mounted (electronic component-mounted substrate) and it is in contact with the electronic components 3a and 3b. The entry of the sealing resin 6 in between the electronic components 3a and 3b and the substrate 1 can be suppressed by the resin film layer 5. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a semiconductor device in which an electronic component and its peripheral circuit are mounted on a substrate on which a wiring pattern is formed, and a method for manufacturing the same, and more particularly to a package in which an electronic component or the like solder-mounted on a substrate is sealed with a resin. The present invention relates to a semiconductor device and a manufacturing method thereof.

  Conventionally, in a semiconductor device in which a plurality of electronic components such as semiconductor elements are mounted on a substrate on which a wiring pattern is provided, a form in which a metal cap is generally provided has been mainstream. Therefore, what is packaged by resin sealing has increased (for example, refer patent document 1). An example of a conventional semiconductor device packaged by resin sealing will be described below with reference to FIG.

  In the semiconductor device shown in FIG. 4, a plurality of electronic components such as a semiconductor element 103a and a chip-type passive component 103b are mounted on a substrate 101 on which a predetermined wiring pattern (not shown) is formed. The wiring pattern includes a land electrode 102 for mounting an electronic component, and the electronic components 103 a and 103 b are connected to the land electrode 102 using solder 104. The electronic components 103a and 103b mounted on the substrate 101 are covered with a sealing resin 105 such as an epoxy resin. When such a semiconductor device is mounted by reflow for the purpose of being incorporated into another device, for example, the solder 104 melts and flows out, thereby causing a short circuit between the electrodes (hereinafter also referred to as an interelectrode solder flash). For the purpose of suppression, it is necessary to fill the sealing resin 105 between the electronic components 103 a and 103 b and the substrate 101.

As a method of filling the sealing resin between the electronic component and the substrate, for example, a method of infiltrating the liquid resin between the electronic component and the substrate using a dispenser (injector), a method of using a transfer mold method, etc. Is mentioned. Further, as a method for efficiently injecting resin between the electronic component and the substrate, for example, a mold in which a release film is adhered to the surface of the electronic component mounted on the substrate is set in the mold, A method of pressure-injecting a sealing resin into the cavity has been proposed (see, for example, Patent Document 2).
JP 2003-188200 A JP 2001-223231 A

  However, since the distance between the electronic component and the substrate is as small as several tens of μm, and the number of electronic components mounted on the substrate is large, a sealing resin is placed between all the electronic components and the substrate. It is difficult to fill completely. For this reason, if the optimum material selection and sealing conditions and method are not used, the probability that a gap exists between the electronic component and the substrate is increased. Further, there may be a case where bubbles or gaps exist in the filled sealing resin. Solder not only melts due to heating during reflow, but also expands in volume, so if there is a closed (closed) narrow space such as a gap in the sealing resin or bubbles between the electronic component and the board, it melts. There is a problem that the expanded solder is transmitted through the narrow space, and inter-electrode solder flash is easily generated. In addition, even when the sealing resin is completely filled between the electronic component and the substrate, if there is a weak adhesive portion between the electronic component or the substrate and the filled sealing resin, The volume-expanded solder may smash the portion, and the solder may flow out into the gap formed there, causing inter-electrode solder flash.

  The semiconductor device of the present invention is a semiconductor device in which an electronic component is mounted with solder on at least one main surface of a substrate on which a wiring pattern is formed, and the electronic component is covered with a sealing resin, A resin film layer is provided between the sealing resin and the electronic component so as to conform to the surface irregularity shape of the electronic component mounting substrate on which the electronic component is mounted on the substrate and in contact with the electronic component. It is characterized by being.

A method for manufacturing a semiconductor device of the present invention includes:
(A) forming at least one electronic component on at least one main surface of the substrate on which the wiring pattern is formed by soldering to form an electronic component mounting substrate;
(B) A resin film is placed on the electronic component mounting substrate, and using a fluid having a predetermined pressure, pressure is applied to the resin film from the side opposite to the electronic component mounting substrate to thereby remove the resin film. Along the uneven surface shape of the electronic component mounting substrate, the resin film is cured to form a resin film layer,
(C) forming a sealing resin for sealing the electronic component on the resin film layer;
It is characterized by including.

  According to the semiconductor device and the method for manufacturing the semiconductor device of the present invention, it is possible to provide a semiconductor device in which inter-electrode solder flash is unlikely to occur even when reflow mounting is performed for mounting on another device, for example.

  When the electronic component mounted substrate is a substrate mounted with an electronic component, the semiconductor device of the present invention has a resin film layer in contact with the electronic component so as to follow the surface uneven shape of the electronic component mounted substrate. The sealing resin layer is provided thereon. Accordingly, when the sealing resin layer is formed, the resin film layer prevents the sealing resin from entering between the electronic component and the substrate, so that the sealing resin does not enter between the electronic component and the substrate. Can do. As a result, the solder whose volume is expanded by remelting during reflow mounting flows into the gaps or voids remaining in the sealing resin filled between the electronic component and the substrate, or the sealing resin and the electronic component or It is possible to suppress a portion of the adhesive force with the substrate being weak and flowing. Therefore, it is possible to suppress the occurrence of inter-electrode solder flash. In addition, according to such a configuration, for example, a component (for example, a SAW (Surface Acoustic Wave) filter, etc.) whose characteristics do not appear when a resin is filled between the substrates is mounted as an electronic component. However, since the sealing resin can be prevented from entering between the electronic component and the substrate, the occurrence of defective products can be prevented.

  The resin film layer can be formed of a thermosetting resin or an ultraviolet curable resin. The thermosetting resin can be suitably used because it has high adhesive strength with the adherend and has good tensile strength and heat resistance. On the other hand, an ultraviolet curable resin can be suitably used because it can be cured in a short time, has good workability, and can be cured at a low temperature.

  When the resin film layer is formed using a thermosetting resin, the resin film layer can be formed of a material containing at least one resin selected from an epoxy resin and a polyimide resin.

  The thickness of the resin film layer is preferably 10 μm or more and 100 μm or less, and more preferably 15 μm or more and 50 μm or less. This is because a predetermined pressure is applied when aligning the resin film layer with the concavo-convex shape of the surface of the electronic component mounting substrate.

  Moreover, when the electronic component is mounted on both main surfaces of the substrate by soldering, it is preferable that the resin film layer is provided on both main surfaces of the substrate.

  In the method for manufacturing a semiconductor device of the present invention, the resin film layer is made to conform to the uneven surface shape of the electronic component mounting substrate using a fluid having a predetermined pressure. Thereby, the above-described semiconductor device of the present invention can be easily manufactured. The predetermined pressure of the fluid used here is not particularly limited because it depends on the strength of the resin film to be used, etc., but in order to efficiently make the shape along the surface uneven shape of the electronic component mounting substrate, 0.5 MPa or more It is preferably 10 MPa or less, and more preferably 1.0 MPa or more and 3.0 MPa or less. The fluid to be used may be liquid or gas. For example, water, silicon oil, fluorine-based inert liquid, or the like can be used.

  Moreover, when the resin film is formed with the material containing a thermosetting resin, it is preferable that the fluid used in the process of bonding a resin film to a board | substrate and an electronic component is a heat medium. This is because the resin film can be cured while being pressed to form a shape along the uneven surface of the electronic component mounting substrate, so that it is not necessary to perform a separate heat treatment and the number of steps can be reduced. As the heat medium, for example, at least one selected from water, silicone oil, and fluorine-based inert liquid can be used. Moreover, since it depends on the thermosetting temperature of the resin film to be used, it is not particularly limited, but the temperature of the heat medium is preferably 60 ° C to 200 ° C, more preferably 100 ° C to 150 ° C. The thermosetting resin is preferably cured at a temperature of 100 ° C. or higher because curing properties are improved when cured at a temperature of the glass transition point (about 100 ° C.) or higher. Further, when the solder material is exposed to a high temperature for a long time, embrittlement progresses, resulting in an increase in connection resistance value and a decrease in connection strength. Therefore, the temperature of the heat medium is preferably 150 ° C. or lower in order to prevent the solder material from being altered.

  Embodiments of the present invention will be specifically described below with reference to the drawings.

  FIG. 1 is a cross-sectional view showing an embodiment of a semiconductor device of the present invention. As shown in FIG. 1, in the semiconductor device of the present embodiment, a semiconductor element 3a and a chip-type passive component 3b are mounted as electronic components on a substrate 1 on which a predetermined wiring pattern (not shown) is formed. ing. The wiring pattern includes a land electrode 2 for mounting an electronic component arranged at a predetermined position, and the electronic components 3 a and 3 b are electrically connected to the land electrode 2 using solder 4. Furthermore, the resin film layer 5 is provided so as to follow the surface unevenness shape of the substrate 1 (electronic component mounting substrate) on which the electronic components 3a and 3b are mounted in this manner. The resin film layer 5 is provided in contact with the electronic components 3a and 3b and covers the surfaces of the electronic components 3a and 3b. The electronic parts 3 a and 3 b whose surfaces are covered with the resin film layer 5 are further covered with a sealing resin 6.

  The resin film layer 5 is formed using a film. For this reason, it is provided so as to cover the surfaces of the electronic components 3 a and 3 b, but hardly enters between the electronic components 3 a and 3 b and the substrate 1. Further, the resin film layer 5 prevents the sealing resin 6 from entering between the electronic components 3a, 3b and the substrate 1 when forming the sealing resin 6, so that the electronic components 3a, 3b and the substrate Between 1 and not filled with resin, there is a void. As described above, since the resin is not filled between the electronic components 3a and 3b and the substrate 1, even if the solder is remelted and the volume expansion occurs in the heat treatment process at the time of reflow mounting, the gap of the filled resin, etc. The solder 4 is not transmitted through the closed narrow space. Thus, by adopting a configuration in which the resin is not filled between the electronic components 3a and 3b and the substrate 1, even when the solder 4 is remelted, inter-electrode solder flash is less likely to occur.

  In order for the resin film layer 5 to conform to the surface irregularity shape of the electronic component mounting substrate, the resin film layer 5 preferably has elasticity. Therefore, the resin film layer 5 preferably has a tensile elongation at break [%] of 120% or more at room temperature according to the test method defined in JIS K7127. By using a stretchable resin film in this way, it is possible to easily conform to the surface irregularity shape of the electronic component mounting substrate and to adhere to the surfaces of the electronic components 3a and 3b.

  Moreover, it is preferable that the resin film layer 5 has a high adhesive force. If the adhesive force between the electronic components 3a, 3b and the resin film layer 5 is weak, solder melted during reflow mounting may flow between the electronic components 3a, 3b and the resin film layer 5 to cause inter-electrode solder flash. Therefore, it is preferable that the adhesive force between the surface of the electronic component 3a, 3b and the resin film layer 5 is high in order to reliably prevent this. Therefore, it is preferable that the resin film layer 5 has a width of 20 N / 20 mm or more by a peeling adhesive force that peels in a 90 ° direction with respect to the bonding surface.

  Moreover, although mentioned later, since a pressure is applied in order to make the resin film layer 5 follow the surface uneven | corrugated shape of the board | substrate 1, it is preferable that the resin film layer 5 has the intensity | strength which is not damaged even if it pressurizes. Therefore, the resin film layer 5 preferably has a tensile strength at break [MPa] of 200 MPa or more according to a test method defined in JIS K7127.

  In the present embodiment, a thermosetting resin or an ultraviolet curable resin having the above characteristics is used for the resin film layer 5. The substrate 1 is made of an insulating material such as ceramic or resin, and a wiring pattern is formed on at least one main surface. The substrate 1 may have a multilayer wiring structure in which a wiring pattern is also provided inside the substrate 1. The chip-type passive component 3b includes a chip resistor, a chip capacitor, a chip inductor, and the like. For the sealing resin 6, for example, a thermosetting resin such as an epoxy resin can be used.

  Next, a method for manufacturing the semiconductor device of the present embodiment shown in FIG. 1 will be described with reference to FIGS. 2A to 2F and FIGS. 3A to 3D.

  First, the process of bonding the resin film layer 5 to the electronic component mounting substrate will be described with reference to FIGS. 2A to 2F. Here, an example of a bonding process when the resin film layer 5 is formed of an ultraviolet curable resin will be described.

  The electronic component 3a, 3b in a state where the electronic components 3a, 3b are solder mounted is formed on the substrate 1 provided with the wiring pattern (see FIG. 2A).

  Next, a resin film to be the resin film layer 5 is placed on the electronic component mounting substrate 20, and this state is placed between the lower mold 11 for attaching the resin film and the upper mold 12 for attaching the resin film. (See FIG. 2B.) A drain valve 13 is provided on the lower mold 11 for attaching the resin film. The upper mold 12 for attaching the resin film includes an ultraviolet lamp 15 for irradiating the resin film layer 5 with ultraviolet rays, a tempered glass 14 provided to face the resin film layer 5, and a resin in a later step. A fluid injection part 16 for injecting a fluid for applying pressure to the film layer 5 is provided. That is, the ultraviolet rays emitted from the ultraviolet lamp 15 are applied to the resin film layer 5 through the tempered glass 14.

  Next, the lower mold 11 for adhering the resin film and the upper mold 12 for adhering the resin film are joined, and the air inside the cavity 18 of these molds is decompressed by the vacuum pump 17 (see FIG. 2C). By reducing the pressure inside the cavity 18 in this manner, air bubbles are less likely to be mixed between the resin film layer 5, the electronic components 3a, 3b, and the substrate 1, and therefore the resin film layer 5, the electronic components 3a, 3b, and the substrate 1 are not mixed. Adhesiveness with is improved.

  Next, water having a predetermined pressure (here, 1.0 MPa to 3.0 MPa) is injected from the fluid injection portion 16, and pressure is applied to the resin film layer 5 from a surface opposite to the surface facing the substrate 1. (See FIG. 2D.) By applying fluid pressure to the resin film layer 5 in this manner, the resin film layer 5 having a shape along the surface irregularity shape of the electronic component mounting substrate 20 is formed. Here, water is used as the fluid used for pressurization, but other fluids can naturally be used.

  Next, the ultraviolet ray lamp 15 irradiates the resin film layer 5 with ultraviolet rays to cure the resin film layer 5 in this shape (see FIG. 2E). Thereafter, the water inside the cavity 18 is discharged from the drain valve 13.

  After the above steps, the resin film layer-attached electronic component mounting board 19 to which the resin film layer is bonded is taken out of the mold (see FIG. 2F).

  The resin film layer 5 can be bonded to the electronic component mounting substrate 20 by the above method. Here, an example in which the resin film layer 5 is formed of an ultraviolet curable resin has been described. However, in the case where the resin film layer 5 is formed of a thermosetting resin, a process of applying pressure using a heat medium as a fluid and the resin It is preferable to perform in parallel with the process of applying heat to the film.

  Next, an example in which the sealing resin 6 is formed using the transfer molding method will be described with reference to FIGS. 3A to 3D.

  The electronic component mounting substrate 19 with the resin film layer is disposed between the lower mold 21 for resin sealing and the upper mold 22 for resin sealing (see FIG. 3A). The lower mold 21 for resin sealing is provided with a sealing resin injector 23 and a sealing resin container 24 that stores the sealing resin. The upper mold 22 for resin sealing is provided with a sealing resin injection path forming portion 25 for forming an injection path for the sealing resin 26 when bonded to the lower mold 21 for resin sealing.

  Next, the lower mold 21 for resin sealing and the upper mold 22 for resin sealing are joined, and the sealing resin 26 accommodated in the sealing resin container 24 is sealed with the sealing resin injector 23 using the sealing resin injector 23. It inject | pours in the cavity formed by the lower mold | type 21 for a stop, and the upper mold | type 22 for resin sealing (refer FIG. 3B). Here, a thermosetting resin is used as the sealing resin 26, and the sealing resin 26 is cured by performing a heat treatment after the injection.

  Next, the one in which the sealing resin 6 is formed on the electronic component mounting substrate 19 with the resin film layer is released (see FIG. 3C) and divided into individual pieces by dicing or the like (see FIG. 3D).

  Through the above steps, the sealing resin 16 is formed, and the semiconductor device in the present embodiment is obtained.

  Note that a similar semiconductor device can be obtained by sealing the resin film layer-equipped electronic component mounting substrate 19 by a liquid epoxy printing method.

  The semiconductor device and the manufacturing method thereof according to the present invention are mounted on a substrate with solder, and can be applied to a semiconductor device in which heat treatment is performed at a high temperature when mounted on another device, for example.

It is sectional drawing which shows one Embodiment of the semiconductor device of this invention. It is sectional drawing which shows 1 process of the method of bonding a resin film in an example of the manufacturing method of the semiconductor device of this invention. It is sectional drawing which shows 1 process of the method of bonding a resin film in an example of the manufacturing method of the semiconductor device of this invention. It is sectional drawing which shows 1 process of the method of bonding a resin film in an example of the manufacturing method of the semiconductor device of this invention. It is sectional drawing which shows 1 process of the method of bonding a resin film in an example of the manufacturing method of the semiconductor device of this invention. It is sectional drawing which shows 1 process of the method of bonding a resin film in an example of the manufacturing method of the semiconductor device of this invention. It is sectional drawing which shows 1 process of the method of bonding a resin film in an example of the manufacturing method of the semiconductor device of this invention. It is sectional drawing which shows 1 process of the method of forming sealing resin in an example of the manufacturing method of the semiconductor device of this invention. It is sectional drawing which shows 1 process of the method of forming sealing resin in an example of the manufacturing method of the semiconductor device of this invention. It is sectional drawing which shows 1 process of the method of forming sealing resin in an example of the manufacturing method of the semiconductor device of this invention. It is sectional drawing which shows 1 process of the method of forming sealing resin in an example of the manufacturing method of the semiconductor device of this invention. It is sectional drawing which shows an example of the conventional semiconductor device.

Explanation of symbols

1 Substrate 2 Land electrode 3a Semiconductor element (electronic component)
3b Chip-type passive components (electronic components)
4 Solder 5 Resin film layer 6 Sealing resin 11 Lower mold for pasting resin film 12 Upper mold for pasting resin film 13 Drain valve 14 Tempered glass 15 Ultraviolet lamp 16 Fluid injection part 17 Vacuum pump 18 Cavity 19 Electron with resin film layer Component mounting board 20 Electronic component mounting board 21 Lower mold for resin sealing 22 Upper mold for resin sealing 23 Sealing resin injection machine 24 Sealing resin container 25 Sealing resin injection path forming section 26 Sealing resin

Claims (10)

An electronic component is mounted by solder on at least one main surface of a substrate on which a wiring pattern is formed, and the electronic component is covered with a sealing resin,
A resin film layer is provided between the sealing resin and the electronic component so as to conform to the surface irregularity shape of the electronic component mounting substrate on which the electronic component is mounted on the substrate and in contact with the electronic component. A semiconductor device characterized in that the semiconductor device is provided.   The semiconductor device according to claim 1, wherein the resin film layer is formed of a material containing a thermosetting resin or an ultraviolet curable resin.   The semiconductor device according to claim 2, wherein the resin film layer is formed of a material containing at least one resin selected from an epoxy resin and a polyimide resin.   The semiconductor device according to claim 1, wherein a thickness of the resin film layer is 10 μm or more and 100 μm or less.   The semiconductor device according to claim 1, wherein electronic parts are mounted on both main surfaces of the substrate by soldering, and the resin film layer is provided on both main surfaces of the substrate. (A) forming at least one electronic component on at least one main surface of the substrate on which the wiring pattern is formed by soldering to form an electronic component mounting substrate;
(B) A resin film is placed on the electronic component mounting substrate, and using a fluid having a predetermined pressure, pressure is applied to the resin film from the side opposite to the electronic component mounting substrate to thereby remove the resin film. Along the uneven surface shape of the electronic component mounting substrate, the resin film is cured to form a resin film layer,
(C) forming a sealing resin for sealing the electronic component on the resin film layer;
A method for manufacturing a semiconductor device, comprising:   The method for manufacturing a semiconductor device according to claim 6, wherein the pressure of the fluid used in the step (b) is 0.5 MPa or more and 10 MPa or less.   The method for manufacturing a semiconductor device according to claim 6, wherein the resin film layer is formed of a material containing a thermosetting resin, and the fluid used in the step (b) is a heat medium.   The method for manufacturing a semiconductor device according to claim 8, wherein the heat medium is at least one selected from water, silicon oil, and a fluorine-based inert liquid.   The method of manufacturing a semiconductor device according to claim 8, wherein the temperature of the heat medium is 60 ° C. or higher and 200 ° C. or lower.

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