JP2007150355A - Method of manufacturing substrate with bump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a substrate with bumps in which a number of fine bumps can be formed with a high uniformity, and has high productivity. <P>SOLUTION: The method includes: a step of supplying a resin 13 comprising a solder powder and an additive 12 having a boiling point to a substrate 10 having a plurality of electrodes 11; a step of butting a plate 14 to the surface of the resin 13 supplied to the substrate 10 to maintain the distance between the substrate 10 and the plate 14 constant; a step of heating the resin 13 at a temperature more than not only a boiling point of the additive 12, but also a temperature at which the solder powder is molten to collect the solder powder on the electrode 11, thereby forming bumps; and a step of removing the plate 14. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a substrate with bumps. More particularly, the present invention relates to a method for forming bumps on electrodes formed on a substrate, and more particularly to a method for forming fine bumps with improved uniformity on electrodes arranged at a narrow pitch.

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

  However, in order to mount a next generation LSI with more than 5000 electrode terminals on a wiring board, it is necessary to form bumps corresponding to a narrow pitch of 100 μm or less on the wiring board. Technology is difficult to adapt. 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.

  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 in 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 an LSI chip or a wiring 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 the mounting of next-generation LSIs on wiring boards. ing.

  For example, solder paste made of a mixture of solder powder and flux is applied onto a substrate with electrodes on the surface, and the substrate is heated to melt the solder powder and cause a short circuit between adjacent electrodes. There is a technique for selectively forming solder bumps on electrodes with high wettability (see, for example, Patent Document 1).

  In addition, a paste-like composition (so-called chemical reaction precipitation type solder) mainly composed of an organic acid lead salt and metallic tin is solid-coated on the substrate on which the electrodes are formed, and the substrate is heated, whereby Pb and Sn are heated. There is a technique in which a substitution reaction of Pb / Sn is caused to selectively deposit on an electrode of a substrate (see, for example, Patent Document 2 and Non-Patent Document 1).

  Furthermore, after immersing the substrate with the electrode formed on the surface in the drug to form an adhesive film only on the surface of the electrode, the solder powder is brought into contact with the adhesive film to adhere the solder powder onto the electrode, and then There is a technique for selectively forming molten solder on an electrode by heating the substrate (see, for example, Patent Document 3 and Non-Patent Document 2).

  By the way, Patent Document 4 discloses a material that is used as a solder paste by kneading a flux containing resin and solder powder. In addition, a technique for mounting a semiconductor chip on a substrate using a resin containing a low-melting-point metal filler has been proposed (see, for example, Patent Document 5, Non-Patent Document 3, and Non-Patent Document 4). In this technique, a metal filler (conductive particles) in a resin is melted to form a metal bond between the substrate and the electrode of the semiconductor chip in a self-aligning manner. However, the mechanism of self-aligned formation of metal junctions is mainly explored.

Note that Non-Patent Document 3, Non-Patent Document 4 and Patent Document 5 also disclose the use of a reducing resin as the resin. The disclosed resin composition is a so-called no-flow type underfill material (see, for example, Patent Document 6). An acid anhydride curing agent is added to the resin composition, and the acid anhydride is hydrolyzed. The flux activity is caused by the carboxylic acid generated by decomposition.
JP 2000-94179 A Japanese Patent Laid-Open No. 1-157796 JP-A-7-74459 JP 2001-219294 A JP 2004-260131 A JP 2001-329048 A Electronics Packaging Technology, September 2000, pp. 38-45 EMD 96-15 10th Symposium on "Microjoining and Assembly Technology in Electronics" February 5- 6, 2004, pp.183-188 9th Symposium on "Microjoining and Assembly Technology in Electronics" February 6- 7, 2003, pp.115-120

  The techniques of Patent Document 1 and Patent Document 2 were originally developed as a technique for selectively pre-coating solder on electrodes formed on a substrate. In order to apply to bump formation necessary for flip chip mounting, There are the following problems.

  In both of the techniques of Patent Document 1 and Patent Document 2, variations in local thickness and concentration occur. Therefore, the amount of solder deposited for each electrode differs, and bumps having a uniform height cannot be obtained. Moreover, in these methods, since the paste-like composition is supplied by coating on an uneven wiring board having an electrode formed on the surface, there is a limit to the amount of solder that can be supplied with respect to electrodes that become convex portions. It is difficult to obtain a sufficient amount of solder, and it is difficult to obtain a desired bump height required in flip chip mounting.

  The technique of patent document 1 aims at making it hard to raise | generate a short circuit between adjacent terminals, having wettability with respect to a metal by controlling the surface oxidation of solder powder. However, by controlling the oxidation amount and the oxidation method, it is difficult to obtain a predetermined bump height while satisfying both the inherent wettability and the difficulty of causing a short circuit.

  Moreover, since the chemical reaction precipitation type solder material used in Patent Document 2 uses a specific chemical reaction, the degree of freedom in selecting a solder composition is low, and there is still a problem in dealing with Pb-free. It can be said that.

  On the other hand, in Patent Document 3, since the solder powder is uniformly deposited on the electrode, uniform solder bumps can be obtained, and since the degree of freedom in selecting the solder composition is large, it is easy to cope with Pb-free. It is excellent in that. However, the height of the bump is determined by the particle size of the solder powder particles to be attached. When the particle size of the solder powder particles is increased, it becomes difficult to uniformly attach the solder powder on the electrode. Therefore, if the bump height required in flip chip mounting is obtained, there is a problem that the uniformity of the bump height is lowered.

  In addition, the process of selectively forming an adhesive film on the electrode surface essential by the technique of Patent Document 3 requires a special chemical treatment using a chemical reaction, which complicates the process and reduces the cost. It also leads to improvement, and there are still problems in application to the mass production process.

  When solder bumps are to be formed by the technique disclosed in Patent Document 4, since the printing method uses a general metal mask, the problem remains that it is not suitable for narrow pitches.

  Furthermore, in the techniques disclosed in Patent Document 5, Non-Patent Document 3, and Non-Patent Document 4, since the moving distance (or simply “moving”) of the solder powder existing between the electrodes is small, the solder powder may remain. There is sex.

  The present invention has been made in view of the above points, and provides a bump forming method that can be applied to next-generation LSI flip-chip mounting, can form a large number of fine bumps more uniformly, and has high productivity. The object is to provide a method of manufacturing a substrate with a pump.

The method for manufacturing a substrate with a pump according to the present invention includes:
Supplying a resin containing solder powder and an additive having a boiling point on a substrate having a plurality of electrodes;
A step of bringing the flat plate into contact with the surface of the resin supplied on the substrate and holding the distance between the substrate and the flat plate constant;
Heating the resin above the boiling point of the additive and above the temperature at which the solder powder melts, and assembling the solder powder on the electrode to form bumps;
Removing the flat plate;
including. During heating, the molten solder powder self-assembles on the electrodes of the substrate, thereby forming bumps on the electrodes. The resin is preferably heated by heating the substrate.

  In the method of the present invention, the flat plate is brought into contact with the surface of the supplied resin, and the resin is heated in such a state that the flat plate is brought into contact with the resin surface. Incidentally, in the present invention, since the distance between the substrate and the flat plate is held constant, the distance between the electrode formed on the substrate and the flat plate is also held constant.

  The resin supplied to the substrate is a resin composition containing “solder powder” and “additive having a boiling point”, and the resin composition is applied on the substrate to form the resin composition in the form of a thin film. It is preferable to supply on a substrate.

  In the method of the present invention, when heated to such an extent that the solder powder melts, the solder powder can easily move through the resin composition, and as a result, the solder powder can easily self-assemble on the electrode. Therefore, it is preferable to perform heating at a temperature at which the viscosity of the resin decreases.

  The resin is heated at a temperature higher than the boiling point of the additive. In one embodiment of the present invention, the boiling additive is preferably convective in the resin, and in yet another embodiment, the solder powder is preferably convected in the resin by heating the resin. The features of these embodiments may be used alone, or these features may be used in any combination, or all features may be used together.

  In the above-mentioned case, since the additive boiled by heating convects in the resin and / or by convection of the solder powder in the resin, the movement of the solder powder is further promoted. Can be made uniform. As a result, the uniformly grown solder powder is self-assembled on the electrode, and it becomes possible to collectively form finer bumps with higher uniformity. Thus, since the additive convects in the resin, in the present invention, the additive can also be referred to as a “convective additive”.

  The boiling point of the additive is preferably lower than the melting point of the solder powder. However, the additive may boil at the same time or immediately after the solder powder is melted, and in this case, the above-described effects of the additive appear. In short, the phenomenon of melting of the solder and boiling of the additive may occur first, and the effects of the present invention can be used in a state where both phenomena have occurred.

In a preferred embodiment, the additive contained in the resin is at least one selected from the group consisting of a solvent, glycerin, wax (for example, wax such as electron wax), isopropyl alcohol, butyl acetate, butyl carbitol and ethylene glycol. It consists of seeds. More preferably, the additive consists of at least one selected from the group consisting of glycerin, isopropyl alcohol, butyl acetate, butyl carbitol and ethylene glycol. In the present invention, the solvent is a liquid component constituting the flux (a component that is liquid at room temperature). The flux is a so-called “flux” that is conventionally used for soldering. Examples of the solvent include alcohols such as isopropyl alcohol and organic solvents such as butyl carbitol acetate.
Moreover, even if the solvent is contained in the flux, the effect as a “convection additive” can be obtained. When a flux containing a reducing material and a solvent is used, oxygen bubbles may be generated not only from the solvent but also due to a reduction reaction of a metal oxide such as a conductor pattern or conductive particles. In this case, the bubbles are more preferable because the effect of the “convection additive” can be exhibited. The moisture contained in the substrate can also act as a “convection additive”.
In addition, when using a flux, the resin, activator, matting agent etc. which are generally contained in it may be contained in resin used for the method of this invention. Accordingly, in the present invention, the resin may contain a component other than the solvent and the solvent contained in the flux, that is, the resin may contain the flux.

  In another embodiment, the additive may be a material that liberates or produces components that can boil upon heating of the resin. That is, a compound that newly brings such a component under a thermal environment can be used as an additive. Specifically, as such a compound, a compound that decomposes by heating and results in a component having a function equivalent to that of a “convective additive”, for example, a hydrate, particularly a compound containing water of crystallization (for example, hydroxylation). Examples thereof include aluminum, dawsonite, ammonium metaborate, barium metaborate, azodicarbonamide, sodium bicarbonate).

  In a preferred embodiment, the resin supplied to the substrate, that is, the resin constituting the bump-forming resin composition is a thermosetting resin (for example, epoxy resin), a thermoplastic resin (for example, polycarbonate resin), or a photocurable resin. Any one of (for example, UV curable) resin (for example, photo-curable epoxy resin), and unless it adversely affects the present invention, any one type is used as a main component, and other resin (for example, phenol resin) is used. It may be included. As can be easily understood from the contents of the present specification, in the case of a curable resin, the curing reaction must not be completed upon heating, and preferably does not proceed so much even if the curing reaction starts, and is substantially cured. It is preferred that the reaction does not start. After the bump is formed, the curing reaction may proceed or may be completed. For this purpose, the resin may be further heated.

  In a preferred embodiment, when the resin is heated, the supplied resin may be pressed by applying a certain pressure to the flat plate. As described above, the heating may be performed so that the distance between the electrode and the flat plate does not fluctuate. As a result, the resin may be pressed over at least a part of the heating period. The flat plate is preferably made of a material having low wettability (for example, glass) with respect to the material constituting the solder powder or having a layer of such material on the contact surface with the resin.

  The solder powder preferably has a sharp particle size distribution, and particularly preferably has substantially the same particle size (that is, the solder powders have substantially the same particle size. ). In a preferred embodiment, the width (or thickness) of the constant gap provided between the electrode formed on the substrate and the flat plate is preferably wider than the particle size of the solder powder, and is considerably wide. Is preferred. For example, the maximum particle size of the solder powder is preferably 100% or less of the gap, and more preferably 90% or less.

  As described above, since the distance between the flat plate and the substrate is held constant, a constant gap is provided between the flat plate and the substrate. In a preferred embodiment, bubbles generated by boiling of the additive due to heating are discharged to the outside from a peripheral portion of a gap existing between the substrate and the flat plate.

  In a preferred embodiment, a metal pattern having substantially the same shape as the electrode is formed on a flat surface of the flat plate facing the substrate at a position facing the plurality of electrodes formed on the substrate. In this case, the flat plate may be an LSI chip. The substrate may also be an LSI chip.

  In a preferred embodiment, the flat plate is removed away from the resin surface while the bump is melted. When the flat plate is separated from the resin surface, bumps higher than the gap between the electrode and the flat plate are formed on the electrode. After such bumps are formed, the substrate is cooled.

  In a preferred embodiment, a step of cooling the substrate is included after the step of forming the bumps, and after the substrate is cooled, the flat plate in contact with the resin surface is removed away from the resin surface.

  In a preferred embodiment, a step of cooling the substrate is further included after the step of removing the flat plate, and a step of removing the resin is included after the cooling of the substrate. For example, since a resin is usually present around the formed bump so as to surround the bump, it is preferable to remove the resin by, for example, ultrasonic cleaning with a solvent.

  In a preferred embodiment, in the resin supplying step on the substrate, the resin is supplied so as to cover at least the plurality of electrodes formed on the substrate, and the solder powder melted upon heating is self-assembled on the electrodes. Bumps can be formed substantially only on the electrodes. The resin may be supplied by any appropriate method, for example, by a method such as dispenser application.

  In a preferred embodiment, a metal film having high wettability with respect to solder powder is preferably formed on the surface of the plurality of electrodes of the substrate. Such a metal film is preferably a thin film of a metal such as Cu, Au, or an alloy containing such a metal. Such a metal film can be formed by sputtering, for example.

  On the surface of the substrate on which the plurality of electrodes are not formed, a film having low wettability with respect to the solder powder may be formed. For example, a solder resist film may be formed.

  The solder constituting the solder powder may be any suitable solder material, but in certain preferred embodiments, the solder powder comprises a so-called lead-free solder material.

  In a preferred embodiment, the resin (that is, the resin composition) supplied to the substrate is preferably 0.5 to 30% by volume of solder powder, more preferably 0.5 to 20% by volume, based on the total basis. Contains in proportion. In addition, in one embodiment, the resin to be supplied (that is, the resin composition) contains an additive in a proportion of, for example, 0.1 to 20% by volume, preferably 1 to 10% by volume, based on the entire standard. ing. The volume% is based on the volume at room temperature (25 ° C.). The resin may contain a necessary amount of other components, for example, components contained in the above-described flux, if necessary.

  In connection with the present invention, there is provided a resin composition comprising a resin, that is, a solder powder and an additive (convective additive) used in the method of manufacturing a substrate with bumps of various embodiments as described above. The This resin composition for bump formation is a resin composition that can be used for bump formation on electrodes of a substrate or a semiconductor chip when a semiconductor chip is flip-chip mounted on a substrate.

  In the method for manufacturing a substrate with bumps according to the present invention, the solder powder melted during heating moves in the resin, the additive present in the resin boils by heating, and the boiling additive convects in the resin. Thus, the movement of the solder powder in the resin is promoted, and the bonding between the molten solder powders proceeds uniformly in the resin. As a result, a uniformly grown molten solder powder combination is formed on the highly wettable electrode, and bumps can be formed on a large number of electrodes with good uniformity.

  Further, since the flat plate is brought into contact with the surface of the resin supplied on the substrate, the boiling additive is prevented from being discharged to the outside from the exposed surface (that is, the upper surface) of the resin. Since the convection of the additive is effectively maintained, bumps with higher uniformity can be formed.

  Furthermore, in the method of the present invention, since the kinetic energy of the additive that convects by boiling is given to the solder powder dispersed in the resin, the solder powder can be efficiently self-assembled on the electrode. The amount of solder powder contained in the resin can be reduced.

BEST MODE FOR CARRYING OUT THE INVENTION

  The inventor of the present application pays attention to the excellent mass productivity of the solder leveler method, which has a proven track record as a technology for pre-coating solder on a printed circuit board, and causes bump height variations when trying to apply this to solder bump formation. As a result of various studies on the reason why a bump having a desired height cannot be obtained, the following idea has been reached. Note that this idea is only an estimation of the inventors, and the present invention is not limited by this idea.

  Consider a process in which bumps are selectively formed on an electrode by molten solder in a process of forming bumps using a solder paste made of solder powder and flux. First, when the solder paste applied on the substrate is heated, the solder powder melts and floats in the flux. When the molten solder powder comes into contact with other molten solder in the vicinity, the molten solder powder is bonded to each other and solder balls grow. When the grown solder ball settles and adheres to the electrode, it spreads on the electrode surface due to the wettability of the solder, and a solder bump is formed on the electrode surface.

  Since the bump forming process is completed in a very short time (several seconds to several tens of seconds), it can be assumed that the bump forming process proceeds in a very local region. Solder paste is a mixture of solder powder and flux, and even if the molten solder powder floats in the flux, the space in which the molten solder powder can move is originally small. Therefore, it can be considered that most of the solder balls adhering to the electrode are formed by melting and bonding the solder powder existing in the vicinity of the electrode.

  Further, in the solder paste, the distribution of the particle size of the solder powder is not necessarily uniform, and further, the thickness of the oxide film inevitably formed on the surface of the solder powder is not necessarily uniform. Since it is thought that it is not limited, the size of the solder ball formed in the local region tends to vary. In addition, since the solder paste itself supplied by coating on the substrate can also vary in local thickness and solder powder concentration, the variation in the size of the solder balls forming the bumps may be further promoted. is there.

  On the other hand, in order to increase the solder bumps, it is sufficient to apply a thick solder paste, but as described above, the bonding process of the molten solder powder in the solder paste is considered as a cause of the variation in the size of the solder bumps. As described above, even if a bump having a desired height is obtained, the problem of height variation remains unresolved.

  Therefore, the inventor of the present application has studied the method of allowing the bump forming process to proceed in a wider area than the above-described local bump forming process, and has come up with the present invention.

  First, it was considered that if the solder powder is contained in the resin, a sufficient space for the solder powder to move can be secured. Here, if a resin whose viscosity is reduced at a temperature at which the solder powder melts, preferably a resin, is used as the resin, it is easy to float and move the molten solder powder in the resin.

  However, as described above, the bump formation process is completed in a very short time, and it is considered that it is not always sufficient to simply provide a spatial space in which the solder powder can move. In addition, when the molten solder powder self-assembles on the electrode only by its wettability, the phenomenon that the locally bonded solder powder self-assembles on the electrode with high wettability varies, resulting in uniform It is conceivable that a large bump cannot be obtained. Therefore, the inventors have come to the idea that the bump forming process can be more reliably advanced in a wider area by adding means for forcibly moving the molten solder powder.

  However, the inventors have come up with the idea that a resin containing solder powder further contains a component in a boiling state at a temperature at which the solder powder is in a molten state as an additive. That is, the boiling additive convects in the resin, thereby promoting the movement of the solder powder in the resin, and the bonding of the molten solder powder proceeds over a wide area in the resin. I thought. Such a component may be a component boiling at a temperature at which the solder powder melts or lower (preferably a little lower temperature), or a temperature higher than the temperature at which the solder powder melts (preferably a little higher). The component boiling at the temperature) may be used, but the former is preferred.

  Therefore, the inventor of the present application uses a resin containing only solder powder and a resin further containing an additive (for example, a component boiling at a temperature at which the solder powder melts or lower). A comparative experiment of bump formation was performed. A resin containing only solder powder and a resin containing solder powder and an additive were applied on a printed circuit board on which circular electrodes were arranged in an array, and then heated while bringing a flat plate into contact therewith.

  As a result, when a resin containing only solder powder is used, the solder layer is not satisfactorily formed as shown in FIG. 16, and the solder powder remains dispersed in the region between the electrodes. On the other hand, when a resin containing solder powder and an additive is used, solder bumps are satisfactorily formed on all the electrodes as shown in FIG. Solder powder does not remain in the region between the electrode and the electrode), and clearly the difference from the case where no additive is contained can be confirmed.

  The following materials and conditions were used in the comparative experiments described above:

In the case of FIG. 16 Resin: Epoxy resin Solder powder: SnAgCu (melting point: 220 ° C.)
Ratio of resin and solder powder: 50% by weight: 50% by weight
Printed circuit board: ALIVH manufactured by Matsushita Electronic Components Co., Ltd.
(Electrode diameter and pitch: diameter 300 μm, pitch 500 μm)
Substrate heating temperature: 250 ° C

In the case of FIG. 17 Additive (convective additive): added as flux (boiling point: 170 ° C.)
Ratio of resin, solder powder and flux: 45% by weight: 50% by weight: 5% by weight
Other conditions are the same as in FIG.

  In the case of FIG. 17, the additive contained in the resin is boiling at the temperature at which the solder powder is melted, and as the boiling additive convects in the resin, the bumps are favorably formed on the electrodes. It has been observed that the convection of the additive contained in the resin has the effect of promoting the movement of the molten solder powder, which promotes the uniform bonding of the molten solder powder. Guessed. In the case of FIG. 16, since there is no additive that convects as such, the effect cannot be expected, and it is considered that the solder powder remains.

  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. In addition, this invention is not limited to the following embodiment.

(Embodiment 1)
FIGS. 1A to 1E are diagrams showing basic steps of a method for manufacturing a substrate with bumps in Embodiment 1 of the present invention.

  First, a substrate 10 on which a plurality of electrodes 11 are formed is prepared (FIG. 1A). Next, as shown in FIG. 1B, a resin 13 containing solder powder (not shown) and the additive 12 is supplied onto the substrate 10. Such a resin may be produced by mixing these components by any appropriate method, and the resin may be supplied by any suitable method. For example, the resin may be supplied by forming a thin layer of such a resin on the substrate 10. Then, as shown in FIG. 1C, the flat plate 14 is brought into contact with the surface of the resin 13 supplied onto the substrate 10, and the solder powder is melted by heating the substrate 10 while maintaining the contact state. Resin 13 is heated to a temperature. In another embodiment, the thing of the state of FIG.1 (c) may be put into a heating atmosphere (for example, oven), and may be heated.

  During this heating, the melted solder powder self-assembles, and the solder balls 15 grown by the self-assembly are collectively formed on the plurality of electrodes 11 in a self-aligned manner (FIG. 1D). Thereafter, as shown in FIG. 1 (e), the flat plate 14 is removed away from the surface of the resin 13, and then the resin 13 is removed to obtain the substrate 10 on which the bumps 16 are formed on the plurality of electrodes. It is done. In the embodiment shown in FIG. 1 (e), the resin around the bumps 16 is removed by washing with a solvent.

  2A to 2C are views showing a process of flip-chip mounting the semiconductor chip 20 on the substrate 10 using the substrate 10 on which the bumps 16 are formed (that is, a substrate with bumps).

  After preparing the substrate 10 (that is, the substrate with bumps) on which the bumps 16 obtained in the steps of FIGS. 1A to 1E are formed (FIG. 2A), as shown in FIG. In addition, the semiconductor chip 20 is mounted on the substrate 10 such that the electrode 11 of the substrate 10 and the electrode 21 of the semiconductor chip 20 are in contact via the bumps 16. When these are heated in this state, the bumps 16 are melted and the electrodes 11 and 21 are joined. Then, as shown in FIG. 2C, after the underfill material 22 is injected between the substrate and the semiconductor chip, the substrate 10 is heated to thermally cure the underfill material 22 and perform flip lip mounting. Finalize.

  Here, with reference to FIGS. 3A to 3C, a mechanism for satisfactorily forming uniform bumps in the present invention will be described.

  In FIG. 3A, after supplying the resin 13 containing solder powder and additives onto the substrate 10, the flat plate 14 is brought into contact with the surface of the resin 13, and the substrate 10 is heated to a temperature at which the solder powder melts. Shows the state. In the drawings, the solder powder and additives contained in the resin are omitted.

  When the heating temperature of the substrate is set higher than the boiling point of the additive, by heating the substrate, the solder powder melts and the additive also boils, and the arrow shown in FIG. Thus, the boiling additive becomes a gas and convects in the resin 13. The convection of the boiling additive promotes the movement of the molten solder powder through the resin, and the bonding between the solder powders proceeds uniformly.

  As shown in FIG. 3B, the melted solder powders are combined to grow into solder balls 32 having a uniform size. Since the melted solder powder has high wettability with respect to the electrode 11 and low wettability with respect to the portion of the substrate 10 where no electrode exists, the grown solder balls 32 are selectively self-adhered on the electrode 11. Will gather. As a result, when the self-assembly progresses, the solder balls 32 formed on the electrode 11 grow to a size up to contact with the flat plate 14 as shown in FIG. A (bump) 15 is formed on the electrode 11.

  In addition, the direction of the convection of the additive indicated by the arrows in FIGS. 3A and 3B is schematically shown for easy understanding, and indicates the actual moving direction of the additive. It is not a thing. As shown in FIGS. 3A and 3B, bubbles (gas) generated by boiling the additive convect, that is, move through a gap provided between the substrate 10 and the flat plate 14. From the periphery of the gap, it was observed that the exhaust steam 31 exits to the outside. Therefore, it is considered that the convection movement of the additive occurs in a wider area, and the molten solder powder is promoted to move over a certain distance due to the convection of the additive.

  As can be easily understood from the description of the additive described above, the term “convection” used in relation to the additive in the present specification does not mean only strict convection but the additive as a form of motion. Of various movements. Since one form of such movement may include convection, the term “convection” is used for convenience. Therefore, in the present invention, as long as the additive that boiled in the resin 13 moves, the kinetic energy is given to the solder powder dispersed in the resin 13 and the movement of the solder powder is promoted. Such movement is included in “convection” used in this specification for convenience.

  Note that when the term “convection” is used with respect to the solder powder, as in the previous case, not only strictly convection is maintained but also various movements as movement forms are meant. Since one form of such movement may include convection, the term “convection” is used for convenience.

  Since the solder powder contained in the resin is not necessarily uniformly dispersed, if the movement of the solder powder is not promoted as in the present invention, only the solder powder existing in the vicinity contributes to the bonding. As a result, the size of the grown solder ball varies. When such a phenomenon occurs, when bumps are formed on a large number of electrodes formed on the substrate, it is difficult to form bumps having a uniform height and cannot be applied to a mass production process.

  In the present invention, the movement of the molten solder powder is sufficiently promoted by the convection of the boiling additive, so that local growth of the molten solder powder is suppressed. As a result, the molten solder powder grows in a wider area in the resin, and bumps having a uniform height can be formed on the electrodes over the entire substrate.

  In addition, the additive contained in the resin has the effect of forcibly moving the solder powder dispersed in the resin, so it is compared to using only wettability to self-assemble on the electrode. Thus, the solder powder can be self-assembled on the electrode more efficiently. Therefore, it is possible to form a necessary bump on the electrode with an appropriate amount of solder powder without containing excessive solder powder in the resin.

  Again, the embodiment of the present invention will be described in more detail with reference to FIGS. First, as shown in FIG. 1A, a substrate 10 having an electrode 11 formed on the surface is prepared. Here, as the substrate 10, a resin substrate or a semiconductor chip used as a circuit substrate can be used, but other substrates may be used as long as electrodes are formed on the surface. Moreover, although there is no restriction | limiting in the pitch of the electrode 11, the method of this invention is preferable in the case of a pitch of 500 micrometers or less, and a pitch of 250 micrometers or less is more preferable. The material of the electrode 11 is Cu, Au, or the like.

  Next, as shown in FIG. 1B, the surface of the substrate 10 on which the electrode 11 is formed is sufficiently washed with a solvent or the like, and then solder powder (not shown) and an additive 12 are formed on the surface of the substrate 10. And a resin 13 containing. Here, as the solder powder, for example, Sn—Ag solder powder (including those added with Cu or the like) can be used, but other solder powder may be used. For example, as another solder powder, Pb-free solder, Pb-Sn solder that becomes Sn-Zn-based or Sn-Bi-based alloy after melting, or low melting point solder material powder that becomes Cu-Ag-based alloy after melting Can be used. The solder powder preferably has a melting point in the range of 100 to 300 ° C, more preferably in the range of 130 to 280 ° C.

  The additive 12 is preferably a material that boils at a temperature at which the substrate 10 is heated to dissolve the solder powder, for example, at a temperature of 100 to 300 ° C. or lower. For example, a solvent used for a resin flux containing an organic acid as an active ingredient can be used as an additive. Other than this, for example, wax (more specifically, electron wax or the like), glycerin, isopropyl alcohol, butyl acetate, butyl carbitol, ethylene glycol, or the like may be used. The additive is a temperature slightly lower than the melting point of the solder powder, preferably 10 to 100 ° C., more preferably 10 to 60 ° C., or the boiling point of the additive and the melting point of the solder powder are substantially the same. Alternatively, it may boil at a temperature slightly higher than the melting point of the solder powder, preferably 10 to 100 ° C higher, more preferably 10 to 20 ° C higher and higher.

  When the boiling point of the additive is lower than the melting point of the solder powder, the additive is boiled first, and the movement of the solder that melts thereafter is promoted. On the other hand, when the boiling point of the additive is higher than the melting point of the solder powder, the solder is first melted and then the additive is boiled, and the movement of the melted solder is promoted. In this case, the heating temperature in the heating step is higher than the melting point of the solder, but even in this case, the heating must be performed to a temperature at which the solder melts.

  In the present invention, as the resin, for example, an epoxy resin can be used. However, for example, other thermosetting resins, thermoplastic resins, or ultraviolet curable photocuring resins may be used. In order to facilitate the movement of the solid or molten solder powder during the heating performed in the present invention, those having a low viscosity at the heating temperature are preferred. In the case of a curable resin, curing may begin upon heating, but curing must not proceed to such an extent that the above-described effects resulting from the additive are hindered. It is preferable that curing does not proceed substantially in the heating step.

  Next, as shown in FIG. 1 (c), the flat plate 14 is brought into contact with the surface of the resin 13 applied to the surface of the substrate 10, and the contact state is kept constant (that is, the substrate 10 and the flat plate 14). The resin 13 is heated to a temperature at which the substrate 10 is heated to melt the solder powder (for example, a temperature higher than about 220 ° C. in the case of Sn-Ag solder powder). Heat. At this time, since the viscosity of the resin can be reduced to ½ or less at room temperature, the molten solder powder is in a floating state in the resin.

  During this heating, the additive 12 contained in the resin boils and moves in the resin as bubbles. The movement of the molten solder powder is promoted by the convective additive 12, and the bonding between the molten solder powders proceeds uniformly. As shown in FIG. , Formed on the electrode 11 in a self-aligning manner.

  Here, the reason why the flat plate 14 is brought into contact with the resin surface is to prevent the boiling additive 12 from going out from the upper surface of the resin. By doing so, the boiling additive moves in the resin composition in a direction parallel to the substrate and exits from the peripheral portion of the substrate, so that a wider range of movement of the molten solder powder is promoted. The

  Further, as the flat plate 14, it is preferable to use a material made of a material having low wettability with respect to solder powder, such as a glass plate. This is because if the wettability is low, the selectivity of the solder ball growth on the electrode 11 of the substrate 10 becomes relatively large. The same effect can be obtained even if a film of a material having low wettability with respect to solder powder (for example, a solder resist) is formed on the surface of the flat plate 14.

  In order for the molten solder powders to bond and grow into solder balls 15 having a uniform size, it is preferable that the solder powders dispersed in the resin have substantially the same particle size. Further, the boiling additive 12 is formed on the substrate 10 so that the additive 12 moves in the resin over a wide range to some extent, or the molten solder powder can move freely in the resin to some extent. A gap formed between the electrode 11 and the flat plate 14 is maintained at a constant distance during heating. At this time, it is preferable that the certain gap be wider than the particle size of the solder powder. For example, it is preferable to fix the flat plate 14 so that the flat plate 14 is not displaced in order to prevent shape distortion in the solder ball 15 formed on the electrode 11 during heating.

  In another embodiment, for example, by applying a certain pressure to the flat plate 14 and heating the substrate 10 while pressing the resin 13, uniform solder balls 15 without shape distortion can be formed.

  Finally, as shown in FIG. 1E, if the flat plate 14 is removed and then the resin 13 is removed, the substrate 10 having the bumps 16 of uniform size formed on the plurality of electrodes 11 is obtained. . Here, after removing the flat plate 14, the resin 13 may be left. However, there is a possibility that minute solder powder may remain as a residue in the resin 13 after the bump formation. In view of the property, it is preferable to remove the resin 13 together with the solder powder residue.

  As described above, the boiled additive has a function of forcibly moving the solder powder dispersed in the resin 13, so that the additive is self-assembled on the electrode 11 using only wettability. Therefore, the solder powder can be self-assembled on the electrode 11 more efficiently. Therefore, the necessary bump on the electrode 11 can be obtained with an appropriate amount of solder powder without containing excessive solder powder in the resin 13. 16 can be formed. The optimum content of the solder powder can be set as described below, for example.

All of the solder powder contained in the volume (V _B ) of the resin composition 13 (including the solder powder and additives) supplied onto the substrate 10 forms the bumps 16 on the electrodes 11 of the substrate 10. It is considered that the following relational expression (1) is established between the total volume (V _A ) of the bumps 16 and the volume (V _B ) of the resin 13:
V _A : V _B ≈S _A : S _B (1)
In the formula (1), S _A represents the total area of the electrode 11 on the substrate 10, and S _B represents the area of the substrate 10.

Thereby, content of the solder powder contained in the resin composition 13 is represented by the following formula (2):
(The content of the solder powder, _{vol%) = V A / V B} = S A / S B × 100 ··· (2)

Therefore, the content of the solder powder contained in the resin composition 13 can be generally set based on the following equation (3).
(Solder powder content, volume%) = (S _A / S _B × 100) + α (3)
In the formula (3), α is a parameter for adjusting the excess and deficiency when the solder powder self-assembles on the electrode 11 of the substrate 10 and can be determined according to various conditions. Zero.

  For example, when the fluidity of the resin 13 used is low (viscosity is high) during heating, the free movement of the solder powder in the resin 13 is suppressed. The rate of self-assembly on the electrode) decreases. Therefore, in this case, it is preferable that solder powder including an amount (α is a positive value) to compensate for the shortage is contained in the resin 13. As other factors that affect the self-assembly rate of the solder powder, the effect of promoting the movement by the additive, the wettability of the electrode, and the like can be considered. As can be easily understood, after determining the bump formation conditions, the value of α can be experimentally determined by, for example, trial and error. As described above, the parameter (α) for adjusting the excess and deficiency when the solder powder self-assembles between the terminals is determined by various conditions, but in order to meet the purpose of preventing the deterioration of the dielectric strength of the bump, etc. , Α is preferably set in the range of ± 10% by volume, more preferably in the range of ± 5% by volume.

  The arrangement of the electrodes 11 on the substrate 10 can take various forms. For example, for the typical arrangement of the electrodes 11 as shown in FIG. 4 and FIG. When the amount is obtained, the following values are obtained.

Arrangement shown in FIG. 4 (peripheral arrangement): 0.5 to 5% by volume
Arrangement shown in FIG. 5 (area array arrangement) 15 to 30% by volume

From this, in order to form the necessary bumps on the electrode 11, the solder powder dispersed in the resin 13 is usually composed of 0.5 to 30% by volume, preferably 0.5 to 20% by volume. If it is contained in the resin 13 (that is, a resin composition containing solder powder and additives) as a product, it is sufficient.
In this way, the content of the solder powder can be suppressed to a small amount due to the operational effect produced by the convection in the resin 13 of the additive dispersed in the resin 13. In general, the weight ratio between the solder powder and the resin or additive is about 7, so the ratio of 0.5 to 30% by volume corresponds to the ratio of approximately 3 to 75% by weight.

  In an embodiment of the present invention, the resin may include a flux. In this case, the additive 12 contained in the resin is a flux solvent. When flux is used, convection of the boiling flux solvent promotes the movement of the molten solder powder, and the flux resin and / or the active component is unavoidably removed on the surface of the solder powder. The effect to be performed can be exhibited at the same time. Before the solder powder is contained in the resin 13, it is preferable to remove the oxide film on the surface of the solder powder in advance. However, even if such control is not possible, a more uniform effect can be obtained by the synergistic effect of the flux. High bumps can be formed.

  As described above, the bump forming method of the present invention not only can form bumps on a plurality of electrodes with good uniformity, but also has an excellent effect that a plurality of bumps can be collectively formed in a very short time. Have The reason for this is thought to be that the convection velocity of the boiling additive is fast, but when applied to mass production, the cost advantage is great.

  The resin containing the above-described solder powder and additive is used as a bump-forming resin composition for forming bumps on the substrate or the electrodes of the semiconductor chip when the semiconductor chip is flip-chip mounted on the substrate. Can be used. At this time, the boiling point of the additive is preferably lower than the melting point of the solder powder, and as the resin, a thermosetting resin, a thermoplastic resin, or a photocurable resin such as ultraviolet curing is used as a main component. It is preferable to do.

(Embodiment 2)
Hereinafter, Embodiment 2 according to various modifications to Embodiment 1 described above will be described with reference to the drawings.

  FIGS. 6A to 6D are views showing a bump forming method in the case where a flat plate in contact with a resin having a metal pattern formed on the flat plate surface is used.

  First, as shown in FIG. 6A, a resin 13 containing solder powder (not shown) and an additive 12 is applied to the surface of the substrate 10 on which a plurality of electrodes 11 are formed.

  Next, as shown in FIG. 6B, the flat plate 14 is brought into contact with the surface of the resin 13 applied to the surface of the substrate 10 and the contact state is kept constant (that is, the substrate 10 and the flat plate). The resin 13 is heated to a temperature at which the solder powder is melted by heating the substrate 10, while maintaining the distance between them to be constant. At this time, a metal pattern 30 having substantially the same shape as the electrode 11 is formed on the flat surface of the flat plate 14 at a position facing the plurality of electrodes 11 formed on the substrate 10.

  In this heating process, the melted solder powder is self-assembled by the convection of the boiling additive 12, and the grown solder balls 15 are self-aligned on the plurality of electrodes 11 as shown in FIG. Are collectively formed. At this time, since the wettability of the molten solder powder is greater on the surface of the electrode 11 than on the surface of the substrate 10, the grown solder balls 15 are formed on the electrode 11 in a self-aligned manner. Since the metal pattern 30 formed on the flat plate 14 is also present at a position facing the electrode 11, the grown solder ball 15 is formed in a self-aligned manner with respect to the metal pattern 30 having high wettability. The selectivity of bump formation on the top can be further increased.

  Finally, as shown in FIG. 6D, if the flat plate 14 is removed and the resin 13 is removed, the substrate 10 in which the bumps 16 are reliably formed on the plurality of electrodes 11 is obtained.

  Next, a method for controlling the height of the bump formed on the electrode will be described with reference to FIGS.

  The method for manufacturing a substrate with bumps according to the present invention is characterized in that bump heights can be more uniformly formed on a plurality of electrodes, but another substrate (for example, a semiconductor chip) is attached to the substrate on which the bumps are formed. When mounting, a certain bump height is required to ensure the bonding between the electrodes. However, when the area of the electrode is reduced, it becomes difficult to form a sufficient amount of bumps on the electrode.

The method as shown in FIGS. 7A and 7B is effective as a method for dealing with such a problem. By heating the substrate 10, when forming the solder balls 15 on the electrode 11, as shown in FIG. 7 (a), the solder balls 15 is adapted to distortion-like height d _1. Next, when the flat plate 14 is removed while the solder ball 15 is melted, the distorted solder ball 15 has a height d ₂ (d) due to its surface tension, as shown in FIG. ₂ > d ₁ ) to form a spherical bump 16. Thus, a sufficiently high bump can be formed. Since the volume of the distortion-shaped solder balls 15 are uniformly formed, the height d ₂ of the bump 16 is also formed uniformly.

On the other hand, as a method for making the bump height more uniform, a method as shown in FIGS. 8A and 8B is effective. That is, as shown in FIG. 8A, the substrate 10 is heated to form the solder balls 15 on the electrodes 11, the substrate 10 is cooled, and then the flat plate 14 is removed. At this time, the solder balls 15, but becomes the height d ₁ of the distortion-like, since already in a cooled state, even remove the flat plate 14, the shape is not changed, the distortion of the height d ₁ A bump 16 is formed on the electrode 11. According to this method, since the bump height can be controlled by the distance between the substrate and the flat plate, bumps having a more uniform height can be formed.

  Next, a method for supplying the resin onto the substrate will be described with reference to FIGS.

  First, FIG. 9A and FIG. 9B are a plan view and a cross-sectional view showing a state where the resin 13 is supplied onto the substrate 10 on which the electrode 11 is formed. In FIG. 9A, the electrode 11 is not originally visible, but is shown by a solid line for understanding. The electrodes 11 are formed in an array on the substrate 10. In this state, when the substrate 10 is heated by the method of the present invention, uniform and good bumps are formed on the electrode 11.

  However, as shown in FIGS. 10A and 10B, when the electrodes 11 are arranged along the periphery of the substrate 10 (that is, in the case of a peripheral arrangement), the electrodes 11 are formed on the substrate 10. When the resin 13 is supplied, the substrate 10 is heated, and bumps are formed on the electrodes 11, the solder balls 40 may remain as residues in the vicinity of the center of the substrate 10 as shown in FIG. 11.

  This is because the electrodes 11 are formed only around the substrate 10, so when the solder powder dispersed in the resin 13 melts and grows into solder balls, the solder balls grown near the center of the substrate 10 are This is considered to be because it cannot move to the electrode 11 around the substrate 10.

  This residue can be removed at the same time by removing the resin 13 from the substrate after the bump is formed. However, there are cases where the resin 13 is left as it is, and the substrate mounting process may be entered. In this case, it is preferable not to generate a residue.

  Therefore, as shown in FIG. 12, the resin 13 is supplied so as to cover the plurality of electrodes 11 formed on the substrate 10, and the resin 13 is not supplied to the region 50 in the center of the substrate where the electrodes 11 are not formed. By doing so, the above-mentioned residue can be prevented from being generated.

  Next, a method for improving the selectivity of bump formation on the electrode will be described with reference to FIGS.

  The method of selectively forming the molten solder powder contained in the resin 13 on the electrode utilizes the difference in wettability of the solder powder. That is, solder bumps are selectively formed on the electrodes when the wettability is large with respect to the electrodes and the wettability is small with respect to the substrate.

  Therefore, if the relative difference in wettability can be increased, the selectivity of bump formation on the electrode can be further improved, and as a result, the uniformity of the bump can be further improved.

  FIG. 13 shows an example in which a metal film 60 having high wettability with respect to solder powder is formed on the surface of the electrode 11 formed on the substrate 10. Usually, Cu or Au is used as an electrode material. By forming a metal film 60 having high wettability (for example, Sn-based alloy) with respect to other solder powder, the selectivity of bump formation on the electrode can be increased. Can be improved.

  FIG. 14 shows an example in which a film 61 having low wettability with respect to solder powder is formed on the surface of the substrate 10. For example, since a solder resist used in a printed circuit board or the like has low wettability with respect to solder powder, the selectivity of bump formation on the electrode can be improved by forming such a film.

  Next, an example in which the method of the present invention is applied to flip chip mounting in which a semiconductor chip is placed on a wiring board will be described with reference to FIGS.

  First, as shown in FIG. 15A, a resin 13 containing solder powder (not shown) and an additive 12 is applied onto a wiring board 10 having an electrode 11 formed on the surface thereof. Here, for example, the additive 12 is included using a flux, and the resin 13 is, for example, an ultraviolet curable resin.

  Next, as shown in FIG. 15B, the semiconductor chip 70 having the electrode terminals 71 formed on the surface is placed on the resin 13 formed on the wiring substrate 10. The electrode terminal 71 of the semiconductor chip 70 is disposed at a position facing the electrode 11 of the wiring substrate 10. It should be noted that the semiconductor chip 70 plays the same role as the flat plate 14 described in FIG.

  Next, by heating the wiring board 10 and heating the resin 13, the solder powder is melted and the solder balls 72 are self-assembled between the electrode 11 and the electrode terminal 71 as shown in FIG. It is formed. As a result, the electrode terminals 71 of the semiconductor chip 70 are connected to the electrodes 11 of the wiring board 10 via the solder balls 72. In this state, the ultraviolet curable resin 13 is irradiated with ultraviolet rays 73 to cure the resin 13, thereby completing the flip chip mounting of the semiconductor chip 70. In this case, since the resin 13 functions as an underfill, supplying the underfill can be omitted.

In flip chip mounting using normal metal bonding,
1) forming solder bumps on the electrodes of the wiring board;
2) A process of placing a semiconductor chip on a wiring board and joining the electrodes through bumps by solder reflow;
3) A step of injecting an underfill material between the wiring board and the semiconductor chip to fix the semiconductor chip,
3 different steps are required.

  On the other hand, in the flip chip mounting shown in FIGS. 15A to 15C, the electrodes are connected simultaneously with the formation of the solder bumps, and the resin 13 can function as an underfill. Since the process can be executed only by the solder bump formation process, the number of processes can be greatly shortened, which is very effective for reducing the mass production cost.

  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.

  The present invention provides a “method of manufacturing a substrate with bumps” that can form a large number of fine bumps with high uniformity and has high productivity.

1A to 1E are process cross-sectional views illustrating a method for manufacturing a substrate with bumps according to an embodiment of the present invention. 2A to 2C are process sectional views showing a flip chip mounting method using a substrate with bumps obtained by the manufacturing method of the present invention. FIGS. 3A to 3C are diagrams for explaining the mechanism of bump formation. FIG. 4 is a plan view showing a peripheral arrangement of electrodes in the present invention. FIG. 5 is a plan view showing the arrangement of an area array of electrodes in the present invention. 6A to 6D are process cross-sectional views showing a method for carrying out a method for manufacturing a substrate with bumps using a flat plate on which a conductive pattern is formed. FIG. 7A and FIG. 7B are diagrams showing a method for controlling the bump height. FIG. 8A and FIG. 8B are diagrams showing another method for controlling the bump height. FIG. 9A is a plan view of the substrate showing a state where the resin is supplied to the substrate having the electrode arrangement of the area array, and FIG. 9B is a cross-sectional view thereof. FIG. 10A is a plan view of a substrate showing a state in which resin is supplied to a substrate having an electrode array in the periphery, and FIG. 10B is a cross-sectional view thereof. 11 is a plan view of the substrate showing a state where a residue is generated on the surface after bump formation. FIG. 12 is a view showing a mode of “application of resin on a substrate” performed in the manufacturing method of the present invention. FIG. 13 is a view showing a state in which a metal film is formed on the electrode surface. FIG. 14 is a diagram showing a state in which a film is formed on the substrate surface. 15A to 15C are process cross-sectional views showing a flip chip mounting method related to the present invention. FIG. 16 is a photograph showing a state after a resin containing solder powder is applied on a circular electrode and heated. FIG. 17 is a photograph showing a state after a resin containing solder powder and an additive is applied on a circular electrode and heated.

Explanation of symbols

10 Substrate 11, 21 Electrode 12 Additive (or Convection Additive)
13 Resin 14 Flat Plate 15, 32, 71 Solder Ball 16 Bump 20, 70 Semiconductor Chip 21 Electrode 22 Underfill Material 30 Metal Pattern 31 Vapor 35 Convection 60 Metal Film 61 Film 71 Electrode Terminal

Claims (15)

Supplying a resin containing solder powder and an additive having a boiling point on a substrate having a plurality of electrodes;
A step of bringing a flat plate into contact with the surface of the resin supplied on the substrate and holding the distance between the substrate and the flat plate constant;
Heating the resin at a temperature equal to or higher than the boiling point of the additive and a temperature at which the solder powder melts, and collecting the solder powder on the electrode to form bumps;
Removing the flat plate;
A method for manufacturing a substrate with bumps including:   The method for manufacturing a substrate with bumps according to claim 1, wherein the solder powder convects in the resin in a molten state.   The said additive consists of 1 type, or 2 or more types chosen from the group which consists of glycerin, isopropyl alcohol, butyl acetate, butyl carbitol, and ethylene glycol, With bumps of Claim 1 or 2 characterized by the above-mentioned. A method for manufacturing a substrate.   The method for manufacturing a substrate with bumps according to claim 1, wherein the solder powder has substantially the same particle size.   The constant gap provided between the electrode formed on the substrate and the flat plate is wider than the particle size of the solder powder, according to any one of claims 1 to 4. Of manufacturing a substrate with bumps.   The method for manufacturing a substrate with bumps according to claim 1, wherein the resin is heated while pressing the resin by applying a certain pressure to the flat plate.   The bubble generated by boiling the additive evaporates to the outside from a peripheral portion of a gap provided between the substrate and the flat plate. The manufacturing method of the board | substrate with a bump as described in 2.   The metal pattern having substantially the same shape as that of the electrode is formed on the flat surface of the flat plate facing the substrate at a position facing the plurality of electrodes formed on the substrate. Item 8. A method for manufacturing a substrate with bumps according to any one of Items 1 to 7.   2. The bump is formed in a state where the bump is melted, and the bump is formed on the electrode so as to be higher than an interval of a gap provided between the electrode and the flat plate. The manufacturing method of the board | substrate with a bump as described in any one of -8.   9. The substrate is cooled after the step of forming the bumps, and after the substrate is cooled, a flat plate in contact with the resin surface is separated from the resin surface. The manufacturing method of the board | substrate with a bump as described in any one of these.   The method according to claim 1, further comprising a step of cooling the substrate after the step of removing the flat plate, and a step of removing the resin after the cooling of the substrate. The manufacturing method of the board | substrate with a description bump.   The method for manufacturing a substrate with bumps according to claim 1, wherein the solder powder is made of a lead-free solder material.   The method for manufacturing a substrate with bumps according to any one of claims 1 to 12, wherein the solder powder is contained in the resin at a ratio of 0.5 to 30% by volume.   The method for manufacturing a substrate with bumps according to any one of claims 1 to 13, wherein the substrate is a wiring substrate or a semiconductor chip.   The substrate with bumps according to any one of claims 1 to 14, wherein the resin is mainly composed of any one of a thermosetting resin, a thermoplastic resin, and a photo-curable resin. Manufacturing method.