JP2007095763A - Flip chip mounting method and method of connection between substrates - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flip chip mounting method which is applicable to flip chip mounting of next generation LSIs and which is superior in productivity and reliability. <P>SOLUTION: While the connection terminal 11 of a circuit substrate 21 and the electrode terminal 12 of a semiconductor chip 20 are kept in contact with each other; the semiconductor chip 20 is arranged opposite to the substrate, and a resin 30 containing conductive particles is applied into a gap between the semiconductor chip 20 and the circuit substrate 21. The gap therebetween is made larger until it becomes a specified gap, thereby self-gathering the resin 30 between the facing terminals by boundary tension, and then the self-gathered resin 30 therein is cured. At this time, the assembly of the conductive particles included in the self-gathered resin 30 forms a connection body for electrically connecting the facing terminals. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a flip chip mounting method for mounting a semiconductor chip on a circuit board, and an inter-substrate connection method for connecting substrates on which a plurality of electrodes are formed.

  In recent years, with the increase in the density and integration of semiconductor integrated circuits (LSIs) used in electronic devices, the number of electrode terminals of an LSI semiconductor chip and the narrowing of the pitch are rapidly increasing. For mounting these semiconductor chips on a circuit board, flip chip mounting is widely used in order to reduce wiring delay. In this flip-chip mounting, solder bumps are generally formed on electrode terminals of a semiconductor chip, and are generally joined together to connection terminals formed on a circuit board via the solder bumps.

  However, in order to mount a next-generation LSI with more than 5,000 electrode terminals on a circuit board, it is necessary to form bumps corresponding to a narrow pitch of 100 μm or less. Difficult to adapt to it.

  Further, since it is necessary to form a large number of bumps corresponding to the number of electrode terminals, high productivity is also required by shortening the mounting tact per chip in order to reduce the cost.

  Similarly, the semiconductor integrated circuit changes from the peripheral electrode terminal to the area-arranged electrode terminal due to an increase in the electrode terminals. Furthermore, it is expected that the semiconductor process will progress from 90 nm to 65 nm and 45 nm due to demands for higher density and higher integration.

  As a result, the miniaturization of the wiring further progresses, and the capacitance between the wirings increases, so the problems of high speed and power consumption loss become serious, and the dielectric constant (Low-K) of the insulating film between the wiring layers is reduced. There is a growing demand. Realization of such a low-K insulating film is obtained by making the insulating layer material porous (porous), so that the mechanical strength is weak, which is an obstacle to thinning the semiconductor.

  In addition, as described above, when an area-arranged electrode terminal is configured, there is a problem with the strength on the porous film due to the low-K conversion, so that bumps are formed on the area-arranged electrode, and flip-chip mounting It has become difficult. Therefore, there is a demand for a low-load flip-chip mounting method suitable for thin and high-density semiconductors corresponding to future progress of semiconductor processes.

  Conventionally, as a bump forming technique, a plating method, a screen printing method, or the like has been developed. Although the plating method is suitable for narrow pitches, the process is complicated and there are problems with productivity. The screen printing method is excellent in productivity, but the mask is used to reduce the pitch. Is not suitable.

  Under these circumstances, recently, several techniques for selectively forming solder bumps on electrodes of a semiconductor chip or a circuit board have been developed. These technologies are not only suitable for the formation of fine bumps, but also allow for the formation of bumps at a time, so they are excellent in productivity and attract attention as technologies that can be applied to circuit boards for next-generation LSIs. ing.

  For example, in the technique described in Patent Document 1, a solder paste made of a mixture of conductive particles and flux is solidly applied on a substrate on which electrodes are formed, and the conductive particles are melted by heating the substrate. And solder bumps are selectively formed on electrodes with high wettability.

  Moreover, the technique described in Patent Document 2 is a method in which a paste-like composition (chemical reaction deposition solder) mainly composed of an organic acid lead salt and metallic tin is applied onto a substrate on which an electrode is formed. Is heated to cause a substitution reaction between Pb and Sn, and a Pb / Sn alloy is selectively deposited on the electrode of the substrate.

  By the way, the flip chip mounting using the conventional bump forming technique is such that after mounting the semiconductor chip on the circuit board on which the bump is formed, a resin called underfill is used to fix the semiconductor chip to the circuit board. And a step of injecting between the circuit board and the circuit board.

Therefore, flip chip mounting technology using an anisotropic conductive material (for example, patent document) as a method of simultaneously performing electrical connection between opposing electrode terminals of a semiconductor chip and a circuit board and fixing the semiconductor chip to the circuit board. 3) has been developed. This is because a thermosetting resin containing conductive particles is supplied between a circuit board and a semiconductor chip, and the semiconductor chip and the circuit board are heated by simultaneously pressing the semiconductor chip and heating the thermosetting resin. This is a method of simultaneously realizing electrical connection between the electrode terminals and fixing of the semiconductor chip to the circuit board.
JP 2000-94179 A Japanese Patent Laid-Open No. 1-157796 JP 2000-332055 A

  However, in the flip-chip mounting using the anisotropic conductive material described above, conduction between the opposing electrode terminals is obtained by mechanical contact of the conductive particles uniformly dispersed in the resin. The conductive particles contributing to the conduction between them are limited to some conductive particles contained in the resin. In addition, a certain load is required for reliable electrical connection between the electrode terminals facing the conductive material, which is not suitable for mounting an area-arranged semiconductor integrated circuit using a porous film (Low-K).

  Furthermore, the conductive particles that do not contribute to the conduction between the opposing electrode terminals also become a factor that hinders the insulation between the adjacent electrode terminals.

  In other words, flip chip mounting using anisotropic conductive material is a solution in terms of productivity and reliability in order to be applied to semiconductor chips for next-generation LSIs with more than 5,000 connection terminals. There are many issues to be solved.

  The present invention has been made in view of the above points, and can be applied to flip chip mounting of next-generation LSIs, and can be applied to flip chip mounting with high productivity and reliability. An object is to provide a connection method.

  In the flip chip mounting method of the present invention, a semiconductor chip having a plurality of electrode terminals is arranged facing a substrate having a plurality of connection terminals, and the connection terminals of the substrate and the electrode terminals of the semiconductor chip are connected via a connection body. A flip chip mounting method for electrical connection, wherein a semiconductor chip is disposed opposite to a substrate in a state where a connection terminal of the substrate and an electrode terminal of the semiconductor chip are in contact with each other, and the gap is formed between the semiconductor chip and the substrate. A first step of supplying a resin containing conductive particles, and expanding the gap between the semiconductor chip and the substrate until a predetermined interval is reached, whereby the resin is placed between the connection terminal of the substrate and the electrode terminal of the semiconductor chip. A second step of self-assembling by interfacial tension and a third step of curing the self-assembled resin between the terminals, and collecting conductive particles contained in the self-assembled resin But it characterized in that it constitutes a connection member for electrically connecting the electrode terminals of the connection terminal and the semiconductor chip of the substrate.

  In a preferred embodiment, the aggregate of conductive particles constitutes a connection body by contacting the conductive particles with each other.

  In a preferred embodiment, in the second step, after the resin is self-assembled between the connection terminal of the substrate and the electrode terminal of the semiconductor chip, the resin is heated, and the conductive particles contained in the resin are contained. The method further includes a step of melting.

  In a preferred embodiment, after the resin is supplied onto the substrate, the first step is such that the semiconductor chip is opposed to the substrate such that the connection terminal of the substrate and the electrode terminal of the semiconductor chip are in contact with each other. It consists of the process of arranging.

  In a preferred embodiment, after the third step, the method further includes a step of supplying an underfill material to a gap between the substrate and the semiconductor chip and then curing the underfill material.

  In a preferred embodiment, in the first step, the substrate surface other than the connection terminals is preferably subjected to a water repellent treatment in advance.

  In a preferred embodiment, the resin is preferably made of a material that contracts when the resin is cured in the third step, whereby the contact of the conductive particles is preferably strengthened.

  In a preferred embodiment, the connection terminals are arranged in an array on the substrate surface.

  In a preferred embodiment, it is preferable to repeat the second step.

  In a preferred embodiment, the substrate is a circuit board, and a plurality of semiconductor chips are flip-chip mounted on the substrate.

  According to the inter-substrate connection method of the present invention, a second substrate having a plurality of electrodes is disposed so as to face a first substrate having a plurality of electrodes, and an electrode of the first substrate, an electrode of the second substrate, The inter-substrate connection method for electrically connecting the first substrate and the second substrate with the electrode of the first substrate and the electrode of the second substrate in contact with each other. A first step of supplying a resin containing conductive particles into a gap between the first substrate and the second substrate, and a gap between the first substrate and the second substrate. The second step of self-assembling the resin by interfacial tension between the electrode of the first substrate and the electrode of the second substrate, and curing the self-assembled resin between the electrodes An aggregate of conductive particles contained in the self-assembled resin is a first group. It is inter-board connection method comprising the electrode and has an electrode of the second substrate to constitute a connection member for electrically connecting.

  In a preferred embodiment, in the second step, after the resin is self-assembled between the electrode of the first substrate and the electrode of the second substrate, the resin is heated and the conductive material contained in the resin is contained. A step of melting the conductive particles.

  In the flip chip mounting body of the present invention, a semiconductor chip having a plurality of electrode terminals is arranged facing a substrate having a plurality of connection terminals, and the connection terminals of the substrate and the electrode terminals of the semiconductor chip are interposed via the connection body. In the electrically connected flip chip mounting body, the connection body includes a resin containing conductive particles supplied to a gap between the substrate and the semiconductor chip arranged in a state where the connection terminal and the electrode terminal are in contact with each other. Further, it is characterized in that it is composed of an aggregate of conductive particles which are self-assembled between the connection terminal and the electrode terminal by enlarging the gap between the substrate and the semiconductor chip and contained in the self-assembled resin.

  In a preferred embodiment, the flip chip mounting body is fixed with an underfill material supplied to a gap between the substrate and the semiconductor chip.

  In the flip chip mounting method according to the present invention, the resin containing the conductive particles supplied to the gap between the semiconductor chip and the substrate is self-assembled by the interfacial tension between the opposing terminals, and contained in the self-assembled resin. The aggregate | assembly of the electroconductive particle which comprises comprises the connection body which electrically connects between terminals. Therefore, the conductive particles contained in the resin can be used effectively. Further, since there is no resin containing conductive particles between adjacent terminals, the insulation between adjacent terminals can be improved, and a highly reliable flip chip mounting body can be realized.

  Furthermore, since the connection body (resin containing conductive particles) that electrically connects the terminals can be formed in a self-assembled manner, it can also be applied to the narrow-pitch flip chip mounting of the next generation LSI.

  In addition, by self-assembling the resin containing conductive particles between the terminals and curing the self-assembled resin, the electrical connection between the semiconductor chip and the terminal of the substrate and the fixing of the semiconductor chip to the substrate can be achieved. At the same time, a flip-chip mounting body with high productivity can be realized.

  Similarly, also in the inter-substrate connection method according to the present invention, the resin containing conductive particles supplied to the gap between the substrates is self-assembled by the interfacial tension between the opposing electrodes, and the self-assembled resin The aggregate of conductive particles contained therein constitutes a connection body that electrically connects the electrodes. Therefore, the conductive particles contained in the resin can be used effectively. In addition, since there is no resin containing conductive particles between the adjacent electrodes, the insulation between the adjacent electrodes can be improved, and a highly reliable inter-substrate connection can be realized.

  The applicant of the present application has studied flip-chip mounting applicable to semiconductor chips for next-generation LSIs and has proposed a novel flip-chip mounting method capable of forming fine bumps with high uniformity (Japanese Patent Application No. 2004-267919). ).

  FIGS. 1A to 1C are process cross-sectional views showing the basic process of the flip chip mounting method disclosed by the present applicant in the above-mentioned patent application specification.

  First, as shown in FIG. 1A, a resin 13 containing solder powder (not shown) and a convection additive 15 is supplied onto a circuit board 21 on which a plurality of connection terminals 11 are formed.

  Next, as shown in FIG. 1B, the surface of the resin 13 supplied on the circuit board 21 is brought into contact with the semiconductor chip 20. At this time, the semiconductor chip 20 having the plurality of electrode terminals 12 is arranged to face the circuit board 21 having the plurality of connection terminals 11. In this state, the resin 13 is heated to melt the solder powder dispersed in the resin 13.

  As shown in FIG. 1C, the melted solder powder is bonded to each other in the resin 13 and self-assembles between the connection terminal 11 and the electrode terminal 12 having high wettability, thereby forming a connection body 18. Finally, the resin 13 is cured, and the semiconductor chip 20 is fixed to the circuit board 21 to complete the flip chip mounting body.

  This method is characterized in that the resin 13 containing solder powder further contains a convection additive 15 that boils at a temperature at which the solder powder melts. That is, at the temperature at which the solder powder is melted, the convection additive 15 contained in the resin 13 boils, and the boiled convection additive 15 convects in the resin 13, thereby melting the resin 13. The movement of the solder powder is promoted, and uniform bonding of the molten solder powder proceeds. As a result, the molten solder powder that has grown uniformly self-assembles between the connection terminal 11 of the circuit board 21 having high wettability and the electrode terminal 12 of the semiconductor chip 20, whereby the connection terminal 11 and the electrode terminal 12 In the meantime, the connection body 18 with high uniformity can be formed.

  In addition, the applicant of the present application separately proposed a method for forming a uniform connection body by using a resin containing a bubble generating agent instead of the convection additive and self-assembling molten solder powder between terminals. (Japanese Patent Application No. 2005-094233).

  2A to 2D are process cross-sectional views showing the basic process of the flip chip mounting method disclosed by the applicant of the present application in the above patent application specification.

  FIG. 2A corresponds to the process shown in FIG. 1B, and a state where the resin 14 containing the solder powder 16 and the bubble generating agent is supplied to the gap between the circuit board 21 and the semiconductor chip 20. Indicates. The resin 14 is different in that a bubble generating agent (not shown) is contained instead of the convective additive 15.

  When the resin 14 is heated in this state, bubbles 19 are generated from the bubble generating agent contained in the resin 14. Then, as shown in FIG. 2B, the resin 14 is pushed out of the bubbles 19 as the generated bubbles 19 grow. At the same time, the solder powder 16 is pushed out of the bubble 19 together with the resin 14. This is because the resin 14 containing the solder powder 16 is excellent in wettability with the solder powder 16 and therefore cannot exist in the bubbles and moves together with the resin 14.

  The resin 14 pushed out by the growth of the bubbles 19 is self-assembled between the connection terminals 11 of the circuit board 21 and the electrode terminals 12 of the semiconductor chip 20 as shown in FIG. A columnar resin with the 12 ends as a boundary is formed.

  When the resin 14 is further heated, as shown in FIG. 2D, the solder powder 16 contained in the resin 14 self-assembled between the terminals is melted, and the solder powders 16 are melt-bonded. At this time, since the connection terminal 11 and the electrode terminal 12 have high wettability with respect to the melted and bonded solder powder 16, the connection body 18 made of the melted solder powder 16 is formed between the terminals. Thereby, the flip chip mounting body in which the semiconductor chip is mounted on the circuit board is obtained.

  In addition, after forming the connection body 18 between the terminals, the resin 14 remaining between the terminals is cured, or an underfill material is injected into the gap between the semiconductor chip 20 and the circuit board 21 and cured, thereby making the semiconductor The chip 20 may be fixed to the circuit board 21.

  The feature of this method is that the resin 14 containing solder powder is foamed with a bubble generating agent contained in the resin 14 so that the self-adhesion between the connection terminal 11 of the circuit board 21 and the electrode terminal 12 of the semiconductor chip 20 occurs. It is in the point to gather. That is, the connection body 18 can be formed between the connection terminal 11 and the electrode terminal 12 by further heating the resin 14 self-assembled between the terminals and melting the solder powder 16 contained in the resin 14. .

  In the above two methods proposed by the applicant of the present application, the first method is that the convection additive that convects in the resin directly acts on the molten solder powder contained in the resin, so that the molten solder powder is removed. In contrast to the self-assembly between the terminals, the second method allows the bubbles generated from the bubble generating agent contained in the resin to act on the resin during its growth process, causing the resin to self-assemble between the terminals. The solder powder contained in the resin is melted.

  However, in both methods, there is a step of heating the resin containing the convection additive or the bubble generating agent in order to boil the convective additive contained in the resin or to generate bubbles from the bubble generating agent. Necessary.

  The inventor of the present application has come up with the present invention by studying a method of forming a connection body between terminals in a self-assembled manner at room temperature without heating the resin to obtain a flip chip mounting body.

  Embodiments of the present invention will be described below with reference to the drawings. In the following drawings, components having substantially the same function are denoted by the same reference numerals for the sake of simplicity. The present invention is not limited to the following embodiments.

  FIGS. 3A to 3C and FIGS. 4A to 4C are process cross-sectional views illustrating basic processes of the flip chip mounting method according to the embodiment of the present invention.

  First, as shown in FIG. 3A, a resin 30 containing conductive particles (not shown) is supplied onto a circuit board 21 having a plurality of connection terminals 11. Here, it is preferable that the conductive particles are uniformly dispersed in the resin 30 and the resin 30 has a viscosity that can flow at room temperature.

  Next, as shown in FIG. 3B, the semiconductor chip 20 having the plurality of electrode terminals 12 is mounted on the circuit board so that the connection terminals 11 of the circuit board 21 and the electrode terminals 12 of the semiconductor chip 20 are in contact with each other. 21 is arranged opposite to 21. At this time, the resin 30 on the connection terminal 11 of the circuit board 21 is pushed out, and as a result, the gap between the semiconductor chip 20 and the circuit board 21 is filled with the resin 30.

  Note that the contact between the connection terminal 11 of the circuit board 21 and the electrode terminal 12 of the semiconductor chip 20 does not necessarily have to be a state where the resin 30 is completely extruded, and the resin 30 remains between the opposing terminals. It doesn't matter.

  Further, the resin 30 is supplied by arranging the circuit board 21 and the semiconductor chip 20 so that the connection terminals 11 and the electrode terminals 12 facing each other face each other, and then the gap between the semiconductor chip 20 and the circuit board 21 is set. It may be done later to fill.

  From this state, as shown in FIG. 3C, the gap 30 between the semiconductor chip 20 and the circuit board 21 is increased to a predetermined distance, whereby the resin 30 is replaced with the connection terminal 11 of the circuit board 21 and the semiconductor. The electrode 20 is self-assembled between the electrode terminals 12 of the chip 20 by interfacial tension.

  Hereinafter, with reference to FIGS. 4A to 4C and FIGS. 5A to 5D, the resin 30 has an interfacial tension between the connection terminal 11 of the circuit board 21 and the electrode terminal 12 of the semiconductor chip 20. Explains the mechanism of self-assembly.

4A to 4C show process cross-sectional views (partially enlarged) when the gap between the semiconductor chip 20 and the circuit board 21 is expanded from D ₁ to D ₃ , and FIG. -(D) shows the top view of the semiconductor chip 20 corresponding to the process.

  FIG. 5A shows a state where the electrode terminals 12 of the semiconductor chip 20 are in contact with the connection terminals 11 of the circuit board 21, and a resin is formed in the gap between the semiconductor chip 20 other than the electrode terminals 12 and the circuit board 21. 30 is filled.

From this state, the gap between the semiconductor chip 20 and the circuit board 21 is gradually enlarged. FIG. 4A shows the state at the gap D ₁ , and as the gap expands, the resin 30 enters between the terminals facing each other, while the resin 30 in the gap between the semiconductor chip 20 and the circuit board 21. A part of the cavity 40 is generated.

  This is because when a small gap occurs between the terminals, the resin 30 begins to enter the gap due to capillary phenomenon, and even if the gap further expands, due to the interfacial tension between the resin 30 and the connection terminals 11 and electrode terminals 12, This is because the resin 30 that has entered between the terminals is maintained as it is between the terminals.

  In addition, the volume of the gap between the semiconductor chip 20 and the circuit board 21 increases as the gap increases, and at the same time, a part of the resin 30 in the gap between the semiconductor chip 20 and the circuit board 21 moves between the terminals. As a result, a cavity 40 is generated in the resin 30 remaining in the gap between the semiconductor chip 20 and the circuit board 21.

  FIG. 5B is a plan view of the semiconductor chip 20 in the state of FIG. As shown in FIG. 5B, the resin 30 that has reached the periphery of the semiconductor chip 20 is reduced to the vicinity of the outermost row of the electrode terminals 12 arranged in an array, and the resin 30 is interposed between the adjacent electrode terminals 12. The cavity 40 is generated.

  Further, as the gap between the semiconductor chip 20 and the circuit board 21 is increased, the cavity 40 of the resin 30 becomes larger as shown in FIG. 4B, and as shown in FIG. The electrode terminals 12 are assembled so as to surround the periphery.

Then, when the gap between the semiconductor chip 20 and the circuit board 21 is increased to a predetermined distance (D ₃ ), the resin 30 is formed on the circuit board 21 as shown in FIGS. 4 (c) and 5 (d). Self-assembly occurs between the connection terminal 11 and the electrode terminal 12 of the semiconductor chip 20.

  Note that the mechanism of self-assembly between the terminals of the resin 30 described above is based on a process using the interfacial tension between the resin 30 and the terminals, so that the gap between the semiconductor chip 20 and the circuit board 21 is slowly expanded at a predetermined speed. Preferably it is done. In some cases, a step of narrowing or widening the gap once in the middle to make self-assembly more surely may be included.

  In addition, since the resin 30 that has entered between the terminals is maintained as it is between the terminals, the magnitude of the interfacial tension between the connection terminal 11 and the electrode terminal 12 of the resin 30 is as follows: the resin 30, the semiconductor chip 20, and the circuit board 21. It is preferable that the interfacial tension is larger than that.

  FIG. 6 is an enlarged cross-sectional view showing a state where the resin 30 self-assembles between the electrode terminal 12 of the semiconductor chip 20 and the connection terminal 11 of the circuit board 21.

  By curing the resin 30 self-assembled between the terminals, the semiconductor chip 20 is fixed to the circuit board 21, and the aggregate of the conductive particles 16 contained in the self-assembled resin 30 becomes an electrode terminal of the semiconductor chip 20. 12 and the connection body which electrically connects the connection terminal 11 of the circuit board 21 are comprised.

  As shown in FIG. 6, the conductive particles 16 are in contact with each other and are in contact with the connection terminal 11 and the electrode terminal 12, thereby achieving electrical connection between the opposing terminals. Thereby, a flip chip mounting body is obtained.

  According to the present invention, the resin 30 containing the conductive particles 16 supplied to the gap between the semiconductor chip 20 and the circuit board 21 self-assembles with the interfacial tension between the opposing terminals, and the self-assembled resin The aggregate | assembly of the electroconductive particle 16 to contain comprises the connection body which electrically connects between terminals. Therefore, the conductive particles 16 contained in the resin 30 can be used effectively. Further, since the resin 30 containing the conductive particles 16 does not exist between adjacent terminals, the insulation between the adjacent terminals can be improved, and a highly reliable flip chip mounting body can be realized.

  Furthermore, since the connection body (resin 30 containing the conductive particles 16) that electrically connects the terminals can be formed in a self-assembled manner, it can also be applied to narrow-pitch flip chip mounting of next-generation LSIs. is there.

  In addition, the resin 30 containing the conductive particles 16 is self-assembled between the terminals, and the self-assembled resin 30 is cured, so that the electrical connection between the terminals of the semiconductor chip 20 and the circuit board 21, and the semiconductor chip 20 can be fixed to the circuit board 21 at the same time, and a highly productive flip chip mounting body can be realized.

  Further, unlike the above-described flip chip mounting method proposed by the applicant of the present invention, the method of the present invention does not need to contain a convection additive or a bubble generating agent in the resin 30, so that the resin 30 is not heated. At room temperature, the connection body can be formed in a self-assembled manner between the terminals to obtain a flip chip mounting body.

  In the above method, the aggregate of conductive particles 16 contained in the resin 30 self-assembled between the terminals electrically connects the electrode terminals 12 of the semiconductor chip 20 and the connection terminals 11 of the circuit board 21. Constructs a connection body. In this method, the conductive particles 16 are brought into contact with each other to make an electrical connection. In order to further improve the reliability of the connection, the resin 30 that is self-assembled between the terminals is cured to form a semiconductor chip. In the step of fixing 20 to the circuit board 21, a material that the resin 30 contracts may be used. As the resin 30 contracts, the contact of the conductive particles 16 is strengthened, thereby improving the connection reliability.

  Alternatively, after the resin 30 is self-assembled between the terminals, the resin 30 is heated and the conductive particles 16 contained in the resin 30 are melted, so that the molten conductive particles 16 are formed as shown in FIG. A coupled connection 18 may be formed. Thereby, the resistance value of the connection body 18 falls and the connection reliability is also improved. In this case, even if not all of the conductive particles 16 are melted, only the surface of the conductive particles 16 may be melted and the interface between the conductive particles 16 may be in a metal-bonded state.

  According to the above-described method, the semiconductor chip 20 is fixed to the circuit board 21 by curing the resin 30 that is self-assembled between the terminals. However, as shown in FIGS. By supplying the underfill material to the gap between the substrate 21 and the semiconductor chip 20, it is possible to fix with higher reliability.

  FIG. 8A shows a state in which a resin containing conductive particles is self-assembled between the electrode terminal 12 of the semiconductor chip 20 and the connection terminal 11 of the circuit board 21 to form the connection body 18 between the terminals. It is sectional drawing.

  Thereafter, as shown in FIG. 8B, the underfill material 50 is supplied to the gap between the circuit board 21 and the semiconductor chip 20, and then the underfill material 50 is cured, so that the circuit board 21 of the semiconductor chip 20 is cured. Can be more firmly fixed.

  According to the method of the present invention, the resin 30 containing the conductive particles 16 is self-assembled between the terminals by the action of the interfacial tension between the resin 30 and the terminals, but a circuit board other than the connection terminals 11 and the electrode terminals 12. By subjecting the surface of 21 (or semiconductor chip 20) to a water repellent treatment in advance, self-assembly of the resin 30 between the terminals is performed more smoothly.

  That is, the ease with which the resin 30 self-assembles between the terminals depends on the magnitude of the interfacial tension between the resin 30 and the circuit board 21 (or the semiconductor chip 20). Therefore, the interface between the resin 30 and the circuit board 21 (or the semiconductor chip 20) is obtained by preliminarily treating the surface of the circuit board 21 other than the connection terminals 11 (or the semiconductor chip 20 other than the electrode terminals 12). The tension can be reduced, which makes the self-assembly of the resin 30 between the terminals smoother.

  The water repellency treatment on the surface of the circuit board 21 other than the connection terminals 11 (or the semiconductor chip 20 other than the electrode terminals 12) can be performed, for example, by a method as shown in FIGS.

  As shown in FIG. 9A, after forming a metal film to be the connection terminal 11 on the surface of the circuit board 21, a resist 60 is applied.

  Next, as shown in FIG. 9B, the resist 60 is patterned leaving a region to be a connection terminal, and then the metal film to be the connection terminal 11 is removed by etching using the resist 60 as a mask. In this state, after applying a paint for water repellent coating (for example, EGC-1700 electronic coating agent; manufactured by Sumitomo 3M) to the surface of the circuit board 21, the resist 60 is lifted off.

  As a result, as shown in FIG. 9C, the water-repellent coating film 70 remains on the surface of the circuit board 21 other than the connection terminals 11, and the interfacial tension between the surface and the resin 30 can be made extremely low.

  Here, the resin 30 and the conductive particles 16 used in the flip chip mounting method of the present invention are not particularly limited, but the following materials can be used.

  Examples of the resin 30 include a thermosetting resin such as an epoxy resin, a phenol resin, and a silicone resin, a thermoplastic resin such as a fluorine resin, a polyimide resin, and a polyamide resin, or a light (ultraviolet) curable resin, or a combination thereof. However, it is preferable to have a viscosity that allows fluidization at room temperature.

  Further, as the conductive particles 16, a solder alloy such as Sn—Bi, Sn—Pb, or Sn—Ag, or a metal such as Cu, Ag, or AgCu can be used. In the present invention, since the electrical connection between the conductive particles is achieved by the contact between the conductive particles, it is preferable that the oxide film grow as little as possible on the surface of the conductive particles. Moreover, the state which melt | dissolves only the surface of the electroconductive particles which mutually contact, and makes a metal bond in a mutual interface may be sufficient.

  In the flip chip mounting method described above, the circuit board 21 may be formed of a circuit board, and a plurality of semiconductor chips 20 may be flip chip mounted on the circuit board 21. Further, the semiconductor chip 20 may have a configuration in which the semiconductor chip is mounted on an interposer having a plurality of electrode terminals (lands) (for example, CSP, BGA, etc.).

  The present invention can be applied not only to flip-chip mounting but also to inter-substrate connection for electrically connecting electrodes of substrates each having a plurality of electrodes. Inter-board connection can be made by the following method.

  First, in a state where the electrode of the first substrate and the electrode of the second substrate are in contact with each other, the second substrate is arranged to face the first substrate, and the first substrate and the second substrate are arranged. A resin containing conductive particles is supplied into the gap.

  Next, by gradually widening the gap between the first substrate and the second substrate until a predetermined distance is reached, the resin is caused to have an interfacial tension between the electrodes of the first substrate and the second substrate. Self-assemble. Thereafter, the resin self-assembled between the electrodes is cured.

  Here, the aggregate of conductive particles contained in the self-assembled resin constitutes a connection body that electrically connects the electrode of the first substrate and the electrode of the second substrate.

  Note that as the first substrate or the second substrate, a circuit board, a semiconductor wafer, a semiconductor chip (including a bare chip and a mounting chip), or the like can be used.

  As mentioned above, although this invention was demonstrated by suitable embodiment, such description is not a limitation matter and of course various modifications are possible. For example, the resin 30 preferably has a flowable viscosity at room temperature, but may be reduced to a flowable viscosity by heating.

  According to the present invention, it is possible to provide a flip-chip mounting method and a substrate-to-substrate connection method that are applicable to flip-chip mounting of next-generation LSIs and have high productivity and reliability.

(A)-(c) is process sectional drawing which shows the flip-chip mounting method using resin containing a convection additive (A)-(d) is process sectional drawing which shows the flip chip mounting method using resin containing a bubble generating agent. (A)-(c) is process sectional drawing which shows the flip chip mounting method in embodiment of this invention. (A)-(c) Process sectional drawing explaining the mechanism of the self-assembly between the terminals of resin in this invention (A)-(d) is a process top view explaining the mechanism of the self-assembly between the terminals of resin in the present invention. The expanded sectional view which showed the state which the resin in this invention self-assembled between terminals The expanded sectional view which showed the formation method of the connection object in the present invention (A)-(b) is process sectional drawing which shows the other flip-chip mounting method in this invention. (A)-(c) is process sectional drawing which shows the method of the water-repellent treatment of the substrate surface in this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Connection terminal 12 Electrode terminal 13, 14, 30 Resin 15 Convection additive 16 Conductive particle (solder powder)
18 connection body 19 bubble 20 semiconductor chip 21 circuit board 40 cavity 50 underfill material 60 resist 70 water repellent coating film

Claims (14)

A flip chip in which a semiconductor chip having a plurality of electrode terminals is arranged facing a substrate having a plurality of connection terminals, and the connection terminals of the substrate and the electrode terminals of the semiconductor chip are electrically connected via a connecting body. An implementation method,
In a state where the connection terminal of the substrate and the electrode terminal of the semiconductor chip are in contact with each other, the semiconductor chip is disposed to face the substrate, and conductive particles are contained in the gap between the semiconductor chip and the substrate. A first step of supplying a resin;
A second step of self-assembling the resin between the connection terminal of the substrate and the electrode terminal of the semiconductor chip by expanding the gap between the semiconductor chip and the substrate until a predetermined distance is reached; ,
A third step of curing the resin self-assembled between the terminals,
A flip characterized in that an aggregate of conductive particles contained in the self-assembled resin constitutes the connection body that electrically connects the connection terminal of the substrate and the electrode terminal of the semiconductor chip. Chip mounting method. 2. The flip chip mounting method according to claim 1, wherein the conductive particle aggregate forms the connection body by contacting the conductive particles with each other. 3. In the second step, the resin is self-assembled between the connection terminal of the substrate and the electrode terminal of the semiconductor chip, and then the resin is heated to melt the conductive particles contained in the resin. The flip chip mounting method according to claim 1, further comprising: In the first step, after the resin is supplied onto the substrate, the semiconductor chip is disposed so as to face the substrate so that the connection terminal of the substrate and the electrode terminal of the semiconductor chip are in contact with each other. The flip-chip mounting method according to claim 1, comprising the steps of: 2. The flip according to claim 1, further comprising a step of supplying an underfill material to a gap between the substrate and the semiconductor chip after the third step and then curing the underfill material. Chip mounting method. 2. The flip chip mounting method according to claim 1, wherein in the first step, the surface of the substrate other than the connection terminals is subjected to a water repellent treatment in advance. 2. The flip chip according to claim 1, wherein the resin is made of a material that shrinks when the resin is cured in the third step, whereby contact of conductive particles is reinforced. 3. Implementation method. 2. The flip chip mounting method according to claim 1, wherein the connection terminals are arranged in an array on the substrate surface. 2. The flip chip mounting method according to claim 1, wherein the second step is repeated. The board is composed of a circuit board,
2. The flip chip mounting method according to claim 1, wherein a plurality of semiconductor chips are flip chip mounted on the substrate. A second substrate having a plurality of electrodes is arranged to face a first substrate having a plurality of electrodes, and the electrodes of the first substrate and the electrodes of the second substrate are electrically connected via a connecting body. Board-to-board connection method,
The second substrate is disposed to face the first substrate in a state where the electrode of the first substrate and the electrode of the second substrate are in contact with each other, and the first substrate and the first substrate A first step of supplying a resin containing conductive particles to a gap between the two substrates;
By gradually widening the gap between the first substrate and the second substrate until a predetermined distance is reached, the resin can be interfaced between the electrode of the first substrate and the electrode of the second substrate. A second step of self-assembling with tension;
A third step of curing the resin self-assembled between the electrodes,
The aggregate of conductive particles contained in the self-assembled resin constitutes the connection body that electrically connects the electrode of the first substrate and the electrode of the second substrate. The inter-board connection method. In the second step, after the resin is self-assembled between the electrode of the first substrate and the electrode of the second substrate, the resin is heated and conductive particles contained in the resin are contained. The inter-substrate connection method according to claim 11, further comprising a melting step. A flip in which a semiconductor chip having a plurality of electrode terminals is arranged facing a substrate having a plurality of connection terminals, and the connection terminals of the substrate and the electrode terminals of the semiconductor chip are electrically connected via a connection body In the chip mounting body,
In the connection body, a resin containing conductive particles supplied to a gap between the substrate and the semiconductor chip arranged in a state where the connection terminal and the electrode terminal are in contact with each other is formed of the substrate and the semiconductor chip. A flip-chip mounting body comprising an aggregate of conductive particles that are self-assembled between the connection terminal and the electrode terminal by enlarging the gap and contained in the self-assembled resin. The flip chip mounting body according to claim 13, wherein the flip chip mounting body is fixed by an underfill material supplied to a gap between the substrate and the semiconductor chip.

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