JP5298768B2 - Electronic component and manufacturing method thereof - Google Patents

Description

  The present invention relates to an electronic component in which a semiconductor element is mounted on a circuit board and a manufacturing method thereof.

  Currently, the demand for high-density mounting of electronic components is increasing year by year, and the bare chip mounting method is attracting attention. Further, the connection structure in the bare chip mounting has been changed from the face-up mounting by the wire bonding method to the face-down mounting in which the protruding terminals formed on the electrodes of the semiconductor element are directly connected to the circuit board. Since face-down mounting enables the distance between connection terminals to be shorter than wire bonding, it has electrical characteristics such as multi-terminal connection and high-capacity signal transmission at high speed. It is an excellent connection method.

In face-down mounting, after connecting to a circuit board using a protruding terminal formed on a semiconductor element, an underfill adhesive is filled between the semiconductor element and the circuit board to disperse the stress applied to the protruding electrode. Is generally adopted.
JP 2002-141633 A JP 2006-147801 A JP 2006-290736 A JP 2007-311700 A Special table 2007-520073 gazette JP 2008-218949 A

  As described above, the semiconductor element is mounted on the circuit board via the underfill adhesive, and the thermal expansion difference between the semiconductor element and the circuit board causes distortion, warpage, and the like. Particularly in recent years, the density of copper wiring in circuit boards has increased in the trend of higher functionality, higher density, and lower costs. Since the thermal expansion coefficient of copper is as high as 17 ppm / ° C., the thermal expansion coefficient of the circuit board also tends to be larger than that of the semiconductor element of 4 ppm / ° C.

  Such a situation not only makes it difficult to maintain contact connection, but also causes great stress in the actual operating environment, which may lead to degradation such as cracking of the semiconductor element and destruction of the joint. It was difficult to fully satisfy the characteristics.

  An object of the present invention is to provide an electronic component that can effectively relieve stress applied from a circuit board to a semiconductor element while maintaining contact connection between the circuit board and the semiconductor element, and a method for manufacturing the same. .

According to one aspect of the embodiment, via a circuit board on which connection electrodes are formed, and a protruding terminal formed on the circuit board and formed by a bundle of carbon element linear structures. A semiconductor element electrically connected to the connection electrode ; a resin layer formed between the circuit board and the semiconductor element in a region excluding a region where at least the protruding terminal is formed; and the semiconductor element And the semiconductor element is sandwiched between the projecting terminal and the structure by the elastic force of the projecting terminal. Electronic components are provided.

According to another aspect of the embodiment , a step of forming a projecting terminal having elasticity formed by a bundle of linear structures of carbon elements on one surface of the semiconductor element ; and the semiconductor element A step of forming a first adhesive layer whose adhesive strength is reduced by heating on the one surface of the substrate, and a region where a connection electrode to which at least the protruding terminal is connected is formed on the circuit board. Forming the second adhesive layer having an opening, and connecting the one surface of the semiconductor element and the circuit board so that the protruding terminal is connected to the connection electrode through the opening. A step of adhering the semiconductor element to the circuit board by the first adhesive layer and the second adhesive layer, and fixing to the circuit board so as to cover the other surface side of the semiconductor element. Forming a structure and heat treatment And reducing the adhesive force of the first adhesive layer and peeling the semiconductor element from the circuit board by the elastic force of the protruding terminal, and the semiconductor element is disposed between the protruding terminal and the structure. There is provided a method of manufacturing an electronic component having a step of fixing to a substrate.

  According to the disclosed electronic component and the manufacturing method thereof, the semiconductor element can be mounted on the circuit board without impairing the elasticity of the projecting terminal having elasticity, so that the semiconductor element is added between the semiconductor element and the circuit board. Mechanical stress and thermal stress can be effectively absorbed by the protrusion terminal. Thereby, the contact connection between the semiconductor element and the circuit board can be maintained, and the operation of the semiconductor element can be ensured over a long period of time.

[First Embodiment]
The electronic component and the manufacturing method thereof according to the first embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a schematic cross-sectional view showing the structure of the electronic component according to the present embodiment, and FIGS. 2 and 3 are process cross-sectional views showing the method for manufacturing the electronic component according to the present embodiment.

  First, the structure of the electronic component according to the present embodiment will be described with reference to FIG.

  On the circuit board 30, connection electrodes 32 are formed for electrical connection between a predetermined wiring pattern (not shown) and a semiconductor element. On the circuit board 30 on which the connection electrode 32 is formed, the semiconductor element 10 is mounted. The semiconductor element 10 is electrically connected to the connection electrode 32 of the circuit board 30 by a protruding terminal 22 formed by a bundle of carbon nanotubes oriented in a direction perpendicular to the surface of the semiconductor element 10. A resin layer 34 is formed in a region between the circuit board 30 and the semiconductor element 10 except at least a region where the protruding terminals 22 are formed. The circuit board 30 and the semiconductor element 10 are bonded by this resin layer 34. In the present specification, the resin layer 34 may be referred to as an adhesive layer.

  Thus, the electronic component of the present embodiment in which the semiconductor element 10 is mounted face-down on the circuit board 30 is formed.

  Since the carbon nanotubes forming the protruding terminals 22 have a low resistance, a large current can flow. Further, since the carbon nanotube has high elasticity (spring property), the connection can be maintained by contact connection such as a connector. Furthermore, this contact connection also has an effect that the stress caused by the difference in thermal expansion coefficient between the circuit board 30 and the semiconductor element 10 can be absorbed by the deformation of the carbon nanotubes.

  In general face-down mounting, the circuit board and the semiconductor element are connected to each other with a protruding terminal, and then a sealant called underfill is filled in the gap between the circuit board and the semiconductor element to apply stress to the protruding terminal. Is distributed. However, when a similar method is used even when a carbon nanotube bundle is used as the protruding terminal, the effect of the carbon nanotubes may be hindered by the underfill sealant.

  In other words, when a bundle of carbon nanotubes is used as the projecting terminal, if the underfill is filled / cured, the carbon nanotubes get wet with the underfill sealant and are fixed by curing, so that the spring property expected for the carbon nanotubes Will be damaged. Moreover, when the space | interval between carbon nanotubes is large, an underfill will penetrate | invade between carbon nanotubes, and spring property will fall further.

  In this regard, in the electronic component according to the present embodiment, the connection electrode 32 of the circuit board 30 and the semiconductor element 10 are electrically connected by the protruding terminal 22 formed by a bundle of carbon nanotubes. A resin layer 34 for bonding the circuit board 30 and the semiconductor element 10 is formed between the circuit board 30 and the semiconductor element 10 except for at least the region where the protruding terminals 22 are formed. As in the electronic component according to the present embodiment, the resin layer 34 is formed between the circuit board 30 and the semiconductor element 10 excluding at least the region where the protruding terminals 22 are formed, so that the protruding terminals 22 become the resin layer 34. The resin material will not get wet. Therefore, even when a bundle of carbon nanotubes is used as the protruding terminals 22, the resin layer 34 does not impair the spring properties of the carbon nanotubes.

  Therefore, by forming such an electronic component, mechanical stress and thermal stress applied between the semiconductor element 10 and the circuit board 30 are more effective by the protruding terminals 22 of the carbon nanotube bundle in which the spring property is maintained. Can be absorbed. Thereby, the contact connection between the semiconductor element 10 and the circuit board 30 can be maintained, and the operation of the semiconductor element 10 can be guaranteed over a long period of time.

  The formation region of the resin layer 34 is not particularly limited as long as the semiconductor element 10 can be stably bonded onto the circuit board 30. For example, as shown in FIG. 1, a plurality of openings may be provided in the resin layer 34 corresponding to the formation regions of the plurality of protruding terminals 22. Two or more protruding terminals 22 may be arranged in one opening. Alternatively, the resin layer 34 may be formed only in the peripheral portion of the semiconductor element 10. Alternatively, the resin layers 34 may be formed only at the four corners of the semiconductor element 10. The resin layer 34 can also be used as a wiring protective layer of the circuit board 30. In consideration of this viewpoint, the formation region of the resin layer 34 can also be set.

  Although the resin material of the resin layer 34 is not specifically limited, For example, an epoxy resin, an acrylic resin, an epoxy acrylate resin, or the like can be applied.

  From the viewpoint of reducing the stress applied between the circuit board 30 and the semiconductor element 10, as a constituent material of the resin layer 34, heat in a range between the thermal expansion coefficient of the semiconductor element 10 and the thermal expansion coefficient of the circuit board 30 is used. It is desirable to select a material having an expansion coefficient. From this viewpoint, it is desirable to select a material having a thermal expansion coefficient of about 5 to 50 ppm / ° C. as the resin layer 34.

  Further, when the semiconductor element 10 is firmly bonded on the circuit board 30, the stress absorption effect by the protruding terminals 22 of the carbon nanotube bundle cannot be sufficiently exhibited. From the viewpoint of bonding the circuit board 30 and the semiconductor element 10 while exhibiting the effect of the spring property of the protruding terminals 22 of the carbon nanotube bundle, it is desirable to apply a highly elastic material as the constituent material of the resin layer 34. . From this viewpoint, it is desirable to select a material having an elastic modulus of about 5 to 15 GPa as the resin layer 34.

  For example, as the epoxy resin, solid type or liquid type bisphenol A type epoxy, bisphenol F type epoxy, naphthalene type epoxy, or the like can be used. As the curing agent, 2-phenyl-4-methylimidazole, 2-undecylimidazole, 2,4-diamino-6- [2-methylimidazole- (1)]-ethyl-S-triazine, 1-cyanoethyl-2 -Ethyl-4-methylimidazole, 1-cyanoethyl-2-undecylimidazole or the like is used, and acetone, xylene or the like is preferably used as the solvent. For adjusting the thermal expansion coefficient and the elastic modulus, silica filler is used, and the addition amount is 30 to 70 wt%. Moreover, you may give photosensitivity to this. Examples of a method for imparting photosensitivity include a method of adding a monofunctional monomer such as isobutyl acrylate, t-butyl acrylate, or lauryl acrylate.

  When an acrylic resin is used, for example, tetraethylene glycol diacrylate, tripropylene glycol diacrylate, bisphenol A, EO adduct diacrylate, or the like can be used.

  Further, the film shape is desirable in terms of controlling the thickness as compared with the liquid state and omitting the pre-baking step after applying the liquid resist. In the case of a film, in addition to the liquid epoxy resin described above, bisphenol A type, bisphenol F type, naphthalene type solid epoxy resin, and 2,4-diamino-6- [2-methylimidazole- (1)]- A solid curing agent such as ethyl-S-triazine can be used.

  When the semiconductor element 10 generates heat during operation, a heat spreader may be formed on the semiconductor element 10.

  Next, the method for manufacturing the electronic component according to the present embodiment will be described with reference to FIGS.

  For example, as shown in FIG. 2A, the semiconductor element 10 includes a substrate 12 having a number of transistors and other elements and a multilayer wiring layer (not shown) formed on the surface, and a pad electrode formed on the uppermost layer. 14 and a passivation film 16 formed on the substrate 12 and the pad electrode 14. In the passivation film 16, an opening that exposes a part of the pad electrode 14 is formed.

  For example, an Al (aluminum) film 18 having a thickness of 5 nm and an Fe (iron) film 20 having a thickness of 2 nm, for example, are selectively formed on the pad electrode 14 of the semiconductor element 10 by, for example, a lift-off method (FIG. 2). (B)). The Al film 18 and the Fe film 20 can be deposited by sputtering, for example.

  Next, using the Fe film 20 as a catalyst, carbon nanotubes are grown on the Fe film 20 by, for example, a CVD method to form protruding terminals 22 of a bundle of carbon nanotubes (FIG. 2C). The growth of the carbon nanotubes is performed using, for example, a hydrocarbon gas such as acetylene and methane as a source gas, and an alcohol source such as ethanol and methanol at a growth temperature of 300 to 700 ° C., for example, 600 ° C. at a pressure of 100 Pa, for example. Can grow. The length of the carbon nanotube can be controlled by the growth time, and is, for example, 100 μm here.

  Alternatively, the protruding terminals 22 of the carbon nanotube bundle may be formed by transferring the carbon nanotube bundle onto the pad electrode 14 of the semiconductor element 10. For example, first, an adhesive containing solder or conductive fine particles is formed on the pad electrode 14 of the semiconductor element 10 in advance. Next, carbon nanotubes grown on another substrate (for example, a silicon substrate) are pressed onto the pad electrode 14 of the semiconductor element 10 and fixed onto the pad electrode 14 with the solder or adhesive. Thereafter, the bundle of carbon nanotubes can be transferred onto the pad electrode 14 by removing the substrate.

  In the above example, the Fe film 20 is used as the catalyst metal used for the growth of the carbon nanotubes, but other materials may be used as the catalyst. For example, a film made of a catalyst containing a transition metal such as Ni (nickel) or Co (cobalt) may be used. These catalysts may be in the form of a thin film or fine particles. Further, a catalyst may be contained in a support material such as zeolite, or a self-organized arrangement of proteins such as ferritin containing a metal element serving as a catalyst may be utilized.

  Thus, the protruding terminals 22 of the bundle of carbon nanotubes are formed on the pad electrode 14 of the semiconductor element 10.

  On the other hand, a connection electrode 32 for connecting the protruding terminals 22 of the semiconductor element 10 is formed on the circuit board 30 on which the semiconductor element 10 is mounted.

  A resin layer 34 of a photosensitive adhesive resin material is formed on the circuit board 30 (FIG. 3A). Although the formation method of the resin layer 34 is not specifically limited, For example, the method of coating-forming a photosensitive resin sheet, the method of apply | coating and forming by a spin coat method, etc. are mentioned.

  Next, an opening 36 exposing at least a region where the connection electrode 32 is formed is formed in the resin layer 34 by photolithography (FIG. 3B).

  Instead of forming the resin layer 34 and the opening 36, the resin layer 34 having the opening 36 may be formed directly on the circuit board 30 by, for example, screen printing.

  Next, the semiconductor element 10 on which the protruding terminals 22 are formed is aligned so that the protruding terminals 22 of the semiconductor element 10 and the connection electrodes 32 of the circuit board 30 face each other, and is mounted on the circuit board 30 and pressed. Then, heating is performed (FIG. 3C).

  As a result, the circuit board 30 and the semiconductor element 10 are bonded together by the resin layer 34, and the protruding terminals 22 and the connection electrodes 32 are electrically connected in the openings 36 of the resin layer 34 (FIG. 3 ( d)).

  At this time, the protruding terminals 22 of the bundle of carbon nanotubes are bent by the pressure when the semiconductor element 10 is joined. Thereby, an elastic force (biasing force) due to the carbon nanotubes acts from the protruding terminals 22 in the direction of the semiconductor element 10 and in the direction of the connection electrode 32, and the electrical connection between the semiconductor element 10 and the circuit board 30 is ensured. Can do. Further, since the circuit board 30 and the semiconductor element 10 are fixed by the resin layer 34, it is possible to prevent the semiconductor element 10 from being displaced after being placed on the circuit board 30.

  In this way, the electronic component of this embodiment in which the semiconductor element 10 is mounted face-down on the circuit board 30 can be formed.

  As described above, according to the present embodiment, the semiconductor element can be mounted on the circuit board without impairing the spring property of the carbon nanotubes forming the protruding terminals. Therefore, the semiconductor element is added between the semiconductor element and the circuit board. Mechanical stress and thermal stress can be effectively absorbed by the protruding terminals. Thereby, the contact connection between the semiconductor element and the circuit board can be maintained, and the operation of the semiconductor element can be ensured over a long period of time.

[Second Embodiment]
An electronic component and a manufacturing method thereof according to a second embodiment of the present invention will be described with reference to FIGS. The same components as those in the electronic component and the manufacturing method thereof according to the first embodiment shown in FIGS.

  FIG. 4 is a schematic sectional view showing the structure of the electronic component according to the present embodiment, and FIGS. 5 to 7 are process sectional views showing the method for manufacturing the electronic component according to the present embodiment.

  First, the structure of the electronic component according to the present embodiment will be described with reference to FIG.

  A connection electrode 32 is formed on the circuit board 30. On the circuit board 30 on which the connection electrode 32 is formed, the semiconductor element 10 is mounted. The semiconductor element 10 is electrically connected to the connection electrode 32 by a protruding terminal 22 of a bundle of carbon nanotubes oriented in a direction perpendicular to the surface of the semiconductor element 10. A resin layer 34 is formed on the circuit board 30 between the circuit board 30 and the semiconductor element 10 except at least the region where the protruding terminals 22 are formed. On the circuit board 30 on which the semiconductor element 10 is formed, a structure 42 having a spacer 38 and a lid 40 is formed so as to cover the semiconductor element 10. The semiconductor element 10 is not bonded to the resin layer 34, and is sandwiched between the protruding terminal 22 and the lid body 40 by the urging force of the carbon nanotube as an elastic body that forms the protruding terminal 22. .

  As described above, in the electronic component according to the present embodiment, like the electronic component according to the first embodiment, the connection electrode 32 of the circuit board 30 and the semiconductor element 10 are electrically connected by the protruding terminals 22 of the bundle of carbon nanotubes. Has been. The resin layer 34 is formed at least in a region excluding the region where the protruding terminals 22 are formed, and the protruding terminals 22 do not get wet with the resin material of the resin layer 34. Therefore, even when a carbon nanotube bundle is used as the protruding terminal 22, the resin layer 34 does not impair the spring property of the carbon nanotube.

  Furthermore, in the electronic component according to the present embodiment, the semiconductor element 10 is not bonded to the resin layer 34, and the connection between the circuit board 30 and the semiconductor element 10 is only the protruding terminal 22 except for the structure 42. . In other words, the circuit board 30 and the semiconductor element 10 are not restrained by the resin layer 34, and the effect of absorbing the stress applied between the circuit board 30 and the semiconductor element 10 is the same as that of the electronic component according to the first embodiment. Greater than the case.

  Further, the semiconductor element 10 and the structure 42 are not fixed with an adhesive or the like, and the semiconductor element 10 is only held by the urging force of the protruding terminals 22. Therefore, the stress caused by the difference in thermal expansion between the semiconductor element 10 and the structure 42 is easily relaxed.

  Therefore, by forming such an electronic component, mechanical stress or thermal stress applied between the semiconductor element 10 and the circuit board 30 is further increased by the protruding terminals 22 of the carbon nanotube bundle in which the spring property is maintained. It can be absorbed effectively. Thereby, the contact connection between the semiconductor element 10 and the circuit board 30 can be maintained, and the operation of the semiconductor element 10 can be guaranteed over a long period of time.

  The formation region of the resin layer 34 is not particularly limited as long as it is a region excluding at least the region where the protruding terminals 22 are formed. The point that the resin layer 34 is formed in a region excluding at least the region where the protruding terminals 22 are formed from the viewpoint of maintaining the spring property of the protruding terminals 22 is the same as in the case of the first embodiment.

  In the present embodiment, the resin layer 34 is used for temporarily fixing the semiconductor element 10 on the circuit board 30 in the manufacturing process (see the manufacturing method described later), and the above-described electronic component according to the present embodiment is described above. It is not an indispensable component for producing the effect of. However, the resin layer 34 can also be used as a wiring protective layer of the circuit board 30, and it is also useful to set the formation region of the resin layer 34 in consideration of such a viewpoint.

  Although the resin material of the resin layer 34 is not specifically limited, For example, an epoxy resin, an acrylic resin, an epoxy acrylate resin, or the like can be applied.

  The structure 42 having the spacer 38 and the lid 40 can be used not only as a member for supporting the semiconductor element 10 but also as a heat spreader for dispersing heat from the semiconductor element 10. When used as a heat spreader, the structure 42 is desirably formed of a material having high thermal conductivity, such as Cu (copper) or Al (aluminum).

  Between the semiconductor element 10 and the lid 40, as necessary from the viewpoint of improving thermal conductivity, a thermal conductive sheet such as an indium sheet or a carbon nanotube sheet, a resin having thermal conductivity, for example, a silica filler, You may make it provide the epoxy-type adhesive agent containing a metal filler, metal films, such as SnPb and InAg.

  Alternatively, a stress relaxation layer that relaxes the stress applied between the semiconductor element 10 and the lid 40 may be formed between the semiconductor element 10 and the lid 40. As the elastic composition for forming the stress relaxation layer, for example, a gel-like material such as a silicone-based resin or a urethane rubber-based resin can be used.

  Next, the method for manufacturing the electronic component according to the present embodiment will be explained with reference to FIGS.

  First, in the same manner as in the electronic component manufacturing method according to the first embodiment, a protruding terminal 22 of a bundle of carbon nanotubes is formed on the pad electrode 14 of the semiconductor element 10 (FIG. 5A).

  Next, a resin layer 24 of a resin material that loses adhesive force by heating is formed on the semiconductor element 10 on which the protruding terminals 22 are formed (FIG. 5B). The method for forming the resin layer 24 is not particularly limited, and examples thereof include a method for coating a photosensitive resin sheet, a method for coating by spin coating, and a method for forming by screen printing.

  As the resin material that loses its adhesive strength by heating, a thermally decomposable resin material, for example, a resin material that vaporizes by heating can be applied. Such a resin material is not particularly limited, and for example, polybutene (vaporization temperature: about 200 ° C.) can be applied.

  The temperature at which the resin material that forms the resin layer 24 loses its adhesive force is preferably higher than the curing temperature of the resin material that forms the resin layer 34 formed on the circuit board 30. This is because the circuit board 30 and the semiconductor element 10 are temporarily bonded by the resin layers 24 and 34 in a later process.

  On the other hand, on the circuit board 30 on which the semiconductor element 10 is mounted, for example, in the same manner as the electronic component manufacturing method according to the first embodiment shown in FIGS. A layer 34 is formed (FIG. 6A).

  Next, a spacer 38 is formed on the circuit board 30 on which the resin layer 34 having the opening 36 is formed by an adhesive or screwing (FIG. 6B). The spacer 38 is fixed to the circuit board 30 together with the lid body 40 to support the semiconductor element 10, and the constituent material of the spacer 38 is not particularly limited. When the spacer 38 is used as a heat spreader together with the lid 40, it is desirable to apply a material having high thermal conductivity, such as Cu (copper) or Al (aluminum), as a constituent material of the spacer 38.

  Next, the semiconductor element 10 on which the protruding terminals 22 are formed is aligned so that the protruding terminals 22 of the semiconductor element 10 and the connection electrodes 32 of the circuit board 30 face each other, and is mounted on the circuit board 30 and pressed. And heating is performed (FIG. 6C).

  As a result, the circuit board 30 and the semiconductor element 10 are bonded together by the resin layer 34 and the resin layer 24, and the protruding terminals 22 and the connection electrodes 32 are electrically connected in the openings 36 of the resin layer 34. (FIG. 7A).

  At this time, the protruding terminals 22 of the carbon nanotube bundle are bent by the pressure when the semiconductor element 10 is joined. Thereby, an elastic force (biasing force) due to the carbon nanotubes acts from the protruding terminals 22 in the direction of the semiconductor element 10 and in the direction of the connection electrode 32, and the electrical connection between the semiconductor element 10 and the circuit board 30 is ensured. Can do. Further, since the circuit board 30 and the semiconductor element 10 are fixed by the resin layer 34 and the resin layer 24, it is possible to prevent the semiconductor element 10 from being displaced after being placed on the circuit board 30.

  Next, the lid body 40 is joined to the frame body 38 with an adhesive or a screw to form the structure body 40 (FIG. 7B). The lid 40 is fixed to the circuit board 30 together with the spacers 38 to support the semiconductor element 10 later, and the constituent material of the lid 40 is not particularly limited. When the lid 40 is used as a heat spreader, it is desirable to apply a material having high thermal conductivity, such as Cu (copper) or Al (aluminum), as the constituent material of the lid 40.

  When the lid 40 is formed, a member for improving the thermal conductivity between them or relaxing the stress between them is interposed between the back surface of the semiconductor element 10 and the lid 40. Also good. As such a member, for example, a heat conductive sheet such as an indium sheet or a carbon nanotube sheet, or a stress relaxation layer that relaxes stress applied between the semiconductor element 10 and the lid 40 can be applied. As the elastic composition for forming the stress relaxation layer, for example, a gel-like material such as a silicone-based resin or a urethane rubber-based resin can be used.

  When the lid body 40 is joined to the spacer 38 to form the structure 42, the semiconductor element 10 is fixed to the circuit board 30 by the resin layer 34 and the resin layer 24, and thus misalignment of the semiconductor element 10 occurs. There is no.

  Next, heat treatment is performed at a predetermined temperature according to the constituent material of the resin layer 24 to reduce the adhesive force of the resin layer 24. For example, when polybutene which is a thermally decomposable resin material is used as the resin layer 24, the resin layer 24 is vaporized and extinguished by heating at 200 ° C.

  As a result, the semiconductor element 10 is lifted by the urging force of the carbon nanotubes as the elastic body forming the protruding terminals 22, and is peeled from the resin layer 34 and pressed against the lid 40. Thus, the semiconductor element 10 is sandwiched between the protruding terminal 22 and the lid body 40. At this time, by providing a certain gap between the semiconductor element 10 and the lid 40, the gap between the peeled semiconductor element 10 and the circuit board 30 can be kept constant.

  In this way, the electronic component of this embodiment in which the semiconductor element 10 is mounted face-down on the circuit board 30 can be formed.

  As described above, according to the present embodiment, the semiconductor element can be mounted on the circuit board without impairing the spring property of the carbon nanotubes forming the protruding terminals. Therefore, the semiconductor element is added between the semiconductor element and the circuit board. Mechanical stress and thermal stress can be effectively absorbed by the protruding terminals. Thereby, the contact connection between the semiconductor element and the circuit board can be maintained, and the operation of the semiconductor element can be ensured over a long period of time.

[Modified Embodiment]
The present invention is not limited to the above embodiment, and various modifications can be made.

  For example, in the embodiment described above, an example in which a bundle of carbon nanotubes is used as the projecting terminal 22 having elasticity has been described, but the projecting terminal 22 is not limited to this. For example, a linear structure of another carbon element can be used instead of the carbon nanotube. Examples of such a linear structure include carbon nanowires, carbon rods, and carbon fibers. These linear structures are the same as the carbon nanotubes except that their sizes are different. In addition to the linear structure of carbon element, other structures having elasticity may be used.

  In the second embodiment, a thermally decomposable resin material is used as the resin material for forming the resin layer 24. However, the resin material is not limited to this as long as the resin material loses the adhesive force by heating. . In addition to the thermally decomposable resin material, for example, a thermoplastic resin material, a thermally peelable resin material, a release agent, and the like can be applied.

  As the thermoplastic resin material, a resin material that softens at a temperature of about 180 to 300 ° C. can be used. Such a resin material is not particularly limited, and examples thereof include polycarbonate, polypropylene, polyethersulfone, and polyamide.

  As the heat-peelable resin material, a resin material whose adhesive strength is reduced by heating can be applied. Such a resin material is not particularly limited. For example, a resin material containing a foaming agent that expands by heating, for example, a heat release sheet “Riva Alpha” manufactured by Nitto Denko Corporation can be applied. it can.

  Examples of the release agent include “Mold Release” manufactured by Fine Chemical Co., Ltd., which is a silicone release agent. Even when the release agent is used, the semiconductor element can be temporarily bonded to the circuit board with a certain holding force, as in the case of other resin materials. When the heating (or the element generates heat) after the temporary bonding, a physical force is applied due to a difference in thermal expansion coefficient between the circuit board and the semiconductor element, and the adhesive force is reduced. By this mechanism, the semiconductor element can be detached from the circuit board.

  Moreover, the resin layer 24 does not need to be a material that loses the adhesive force completely by heating. If the adhesive force between the resin layer 34 and the resin layer 24 can be reduced to such an extent that it can be peeled off from the resin layer 34 by the biasing force obtained from the projecting terminal 22 having a spring property, the adhesive force is completely There is no need to lose.

  In the second embodiment, the resin material whose adhesive strength is reduced by heating is formed on the semiconductor element 10 side. However, the resin material whose adhesive strength is reduced by heating may be formed on the circuit board 30 side. That is, the resin layer 24 may be formed on the circuit board 30 side, and the resin layer 34 may be formed on the semiconductor element 10 side.

  In addition, the constituent materials, the manufacturing method, and the manufacturing conditions described in the above embodiment are not limited to the description, and can be appropriately changed according to the purpose and the like.

[Example 1]
On the silicon substrate, an aluminum (Al) film having a thickness of 5 nm and an iron (Fe) film having a thickness of 2 nm were deposited by sputtering to form a catalytic metal layer.

  Next, carbon nanotubes having a length of 100 μm were grown on the silicon substrate on which the catalytic metal layer was formed by the CVD method. The film formation conditions were as follows: acetylene gas was used as the source gas, argon gas was used as the carrier gas, the pressure in the film formation chamber was 100 Pa, and the temperature was 600 ° C. The length of the carbon nanotube was controlled by the film formation time.

  Next, an adhesive containing conductive fine particles was formed on the electrode portion of the semiconductor element mounted on the circuit board.

  Next, the silicon substrate on which the carbon nanotubes are formed is pressed against the electrode surface of the semiconductor element, the carbon nanotubes are fixed on the electrode on which the adhesive is formed, and the silicon substrate is removed to thereby attach the carbon nanotubes on the electrodes of the semiconductor element. Transcribed. Thus, a protruding terminal of a bundle of carbon nanotubes was formed on the electrode of the semiconductor element.

  Next, a photosensitive resin sheet having a thickness of 50 μm was laminated at 120 ° C. on the circuit board on which the semiconductor elements were mounted, and left for 1 hour, and then a glass mask was placed on the circuit board and subjected to an exposure process.

  Next, the photosensitive resin sheet was developed, and the photosensitive resin sheet on the connection electrode of the circuit board was removed by etching. In this way, a resin layer was formed in which openings for exposing the connection electrodes of the circuit board were formed.

  Next, the semiconductor device was positioned so that the protruding terminals of the semiconductor element were accommodated in the openings of the resin layer of the circuit board, and heated to 150 ° C. while applying a pressure of 3 MPa. Thereafter, heat treatment was performed at 170 ° C. for 1 hour to cure the resin layer. Thus, the semiconductor element was bonded on the circuit board by the resin layer.

  After confirming that there was no electrical problem with respect to the semiconductor element assembled in this way, the following connection reliability evaluation was performed.

  As a result of performing 2000 cycles of a repeated temperature cycle test at −55 to 125 ° C., the resistance increase was as good as 10% or less. In addition, as a result of leaving for 1000 hours in an environment of 121 ° C./85% RH, the resistance increase was as good as 10% or less as in the cycle test.

[Example 2]
Carbon nanotubes having a length of 100 μm were grown on a silicon substrate by the same method as in Example 1.

  Next, the carbon nanotubes were transferred onto the silicon substrate on the electrodes of the 300 μm-thick semiconductor element by the same method as in Example 1 to form protruding terminals of a bundle of carbon nanotubes.

  Next, the surface of the semiconductor element on which the protruding terminals were formed was coated with polybutene having a thickness of about 100 nm.

  Next, a resin layer having an opening for exposing the connection electrode was formed on the circuit board by the same method as in Example 1.

  Next, a spacer having a height of 380 μm was set on the circuit board in accordance with the mounting position of the lid (heat spreader) connected to the back surface of the semiconductor element, and fixed with an adhesive.

  Next, the semiconductor device was positioned so that the protruding terminals of the semiconductor element were accommodated in the openings of the resin layer of the circuit board, and heated to 150 ° C. while applying a pressure of 3 MPa. Thus, the semiconductor element was bonded on the circuit board by the resin layer.

  Next, a copper plate having a size of 42 × 42 × 1 mm was placed in the vicinity of the back surface of the semiconductor element as a lid, and fixed to the spacer with an adhesive.

  Next, heat treatment at 200 ° C. was performed to thermally decompose the polybutene. As a result, the semiconductor element was peeled off from the circuit board by the elastic force (biasing force) of the carbon nanotubes, the back surface was in contact with the lid, and the semiconductor element was sandwiched between the protruding terminal and the lid.

  After confirming that there was no electrical problem with respect to the semiconductor element assembled in this way, the following connection reliability evaluation was performed.

  As a result of performing 2000 cycles of a repeated temperature cycle test at −55 to 125 ° C., the resistance increase was as good as 10% or less. In addition, as a result of leaving for 1000 hours in an environment of 121 ° C./85% RH, the resistance increase was as good as 10% or less as in the cycle test.

[Example 3]
An electronic component was manufactured in the same manner as in Example 2 except that a thermoplastic resin was used instead of the thermally decomposable resin (polybutene). Polyether sulfone was used as the thermoplastic resin.

  After confirming that there was no electrical problem with respect to the semiconductor element assembled in this way, the following connection reliability evaluation was performed.

  As a result of performing 2000 cycles of a repeated temperature cycle test at −55 to 125 ° C., the resistance increase was as good as 10% or less. In addition, as a result of leaving for 1000 hours in an environment of 121 ° C./85% RH, the resistance increase was as good as 10% or less as in the cycle test.

[Example 4]
An electronic component was manufactured in the same manner as in Example 2 except that a heat release sheet was used instead of the thermally decomposable resin (polybutene). As the thermal release sheet, “Riva Alpha” manufactured by Nitto Denko Corporation was used. This sheet is a resin whose adhesive strength is reduced by heating.

  After confirming that there was no electrical problem with respect to the semiconductor element assembled in this way, the following connection reliability evaluation was performed.

  As a result of performing 2000 cycles of a repeated temperature cycle test at −55 to 125 ° C., the resistance increase was as good as 10% or less. In addition, as a result of leaving for 1000 hours in an environment of 121 ° C./85% RH, the resistance increase was as good as 10% or less as in the cycle test.

[Example 5]
An electronic component was manufactured in the same manner as in Example 2 except that a silicone-based release agent was used instead of the thermally decomposable resin (polybutene). As a mold release agent of silicone type, “Mold Release” manufactured by Fine Chemical Co., Ltd. was used.

  After confirming that there was no electrical problem with respect to the semiconductor element assembled in this way, the following connection reliability evaluation was performed.

  As a result of performing 2000 cycles of a repeated temperature cycle test at −55 to 125 ° C., the resistance increase was as good as 10% or less. In addition, as a result of leaving for 1000 hours in an environment of 121 ° C./85% RH, the resistance increase was as good as 10% or less as in the cycle test.

It is a schematic sectional drawing which shows the structure of the electronic component by 1st Embodiment of this invention. It is process sectional drawing (the 1) which shows the manufacturing method of the electronic component by 1st Embodiment of this invention. It is process sectional drawing (the 2) which shows the manufacturing method of the electronic component by 1st Embodiment of this invention. It is a schematic sectional drawing which shows the structure of the electronic component by 2nd Embodiment of this invention. It is process sectional drawing (the 1) which shows the manufacturing method of the electronic component by 2nd Embodiment of this invention. It is process sectional drawing (the 2) which shows the manufacturing method of the electronic component by 2nd Embodiment of this invention. It is process sectional drawing (the 3) which shows the manufacturing method of the electronic component by 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Semiconductor element 12 ... Substrate 14 ... Pad electrode 16 ... Passivation film 18 ... Al film 20 ... Fe film 22 ... Projection terminal 24 ... Resin layer 30 ... Circuit board 32 ... Connection electrode 34 ... Resin layer 36 ... Opening 38 ... Spacer 40 ... Lid 42 ... Structure

Claims (3)

A circuit board on which connection electrodes are formed;
A semiconductor element formed on the circuit board and electrically connected to the connection electrode via a protruding terminal having elasticity formed by a bundle of linear structures of carbon elements ;
A resin layer formed between the circuit board and the semiconductor element in a region excluding a region where at least the protruding terminals are formed;
A structure formed so as to cover the semiconductor element and fixed to the circuit board;
The electronic component is characterized in that the semiconductor element is sandwiched between the projecting terminal and the structure by the elastic force of the projecting terminal. Forming a projecting terminal having elasticity formed by a bundle of linear structures of carbon elements on one surface of the semiconductor element;
Forming on the one surface of the semiconductor element a first adhesive layer whose adhesive strength is reduced by heating;
Forming a second adhesive layer having an opening in a region where at least a connection electrode to which the protruding terminal is connected is formed on a circuit board;
The one surface of the semiconductor element is opposed to the circuit board so that the protruding terminal is connected to the connection electrode through the opening, and the semiconductor element is attached to the first adhesive layer and the circuit board. Adhering to the circuit board by a second adhesive layer;
Forming a structure fixed to the circuit board so as to cover the other surface side of the semiconductor element;
Heat treatment is performed to reduce the adhesive force of the first adhesive layer, and the semiconductor element is peeled from the circuit board by the elastic force of the protruding terminal, and the semiconductor element is separated from the protruding terminal, the structure, and A method of manufacturing an electronic component, comprising: In the manufacturing method of the electronic component of Claim 2 ,
The temperature at which the adhesive force of the first adhesive layer is lowered is higher than the temperature at which the second adhesive layer is cured.

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