CONDUCTIVE BONDING MATERIAL, BONDING MEMBER INCLUDING THE CONDUCTIVE BONDING MATERIAL, AND BONDING METHOD

Abstract

A bonding method in which applied is a prescribed conductive bonding material, which contains a molded article of a metal powder. The metal powder is one or more selected from the group consisting of a gold powder, a silver powder, a platinum powder, and a palladium powder, and has a purity of 99.9% by mass or more, and an average particle size of 0.005 .Math.m to 1.0 .Math.m, and the conductive bonding material has a compressive deformation rate M, represented by the following expression, of 5 % or more and 30% or less when compressed with a compression pressure of 5 MPa. [Expression 1] M = {(h1 - h2)/h1} x 100, wherein h1 represents an average thickness of the conductive bonding material before compression, and h2 represents an average thickness of the conductive bonding material after the compression.

Claims

1. A conductive bonding material comprising a molded article of a metal powder, wherein the metal powder is one or more selected from the group consisting of a gold powder, a silver powder, a platinum powder, and a palladium powder, and has a purity of 99.9% by mass or more, and an average particle size of 0.005 .Math.m to 1.0 .Math.m, and the conductive bonding material has a compressive deformation rate M, represented by the following expression, of 5% or more and 30% or less when compressed with a compression pressure of 5 MPa: $\text{M=}\left\{\left(\text{h1- h2}\right)\text{/h1}\right\}\times \text{100}$ wherein h1 represents an average thickness of the conductive bonding material before compression, and h2 represents an average thickness of the conductive bonding material after the compression.

2. A bonding member comprising at least one piece of the conductive bonding material defined in claim 1, comprising: a base material, and one or more metal films formed between the base material and the conductive bonding material, the conductive bonding material being provided on the metal film.

3. The bonding member according to claim 2, comprising a plurality of pieces of the conductive bonding material on the base material, wherein an interval between the plurality of pieces of the conductive bonding material is 1 .Math.m to 10 .Math.m, and each of the pieces of the conductive bonding material has an aspect ratio R, represented by the following expression, of 1 or more and 100 or less, $\text{R=}\left\{\left(\text{X + Y}\right)\text{/2}\right\}\text{/h1}$ wherein X represents a length of a short side of each piece of the conductive bonding material in a plane direction of the base material, Y represents a length of a long side of each piece of the conductive bonding material in the plane direction of the base material, and h1 represents an average thickness of the conductive bonding material before compression.

4. A bonding method for bonding a semiconductor chip to a substrate with the bonding member defined in claim 2, comprising the steps of: mounting the conductive bonding material on the semiconductor chip by compression and heating with the semiconductor chip placed on one or more pieces of the conductive bonding material disposed on the bonding member; and bonding the semiconductor chip to the substrate by compression and heating with the semiconductor chip having the conductive bonding material mounted thereon placed on the substrate.

5. The bonding method according to claim 4, wherein in the step of mounting the conductive bonding material on the semiconductor chip, the conductive bonding material is heated at 40° C. or more and 100° C. or less while being compressed at 30 MPa or less.

6. The bonding method according to claim 5, wherein in the step of bonding the semiconductor chip to the substrate, the conductive bonding material is heated at 80° C. or more and 300° C. or less while being compressed at 30 MPa or less.

7. The bonding method according to claim 4, further comprising, after the step of bonding the semiconductor chip to the substrate, a step of sintering the conductive bonding material by heating the conductive bonding material at 100° C. or more and 300° C. or less without compression.

8. A bonding method for bonding a semiconductor chip to a substrate with the bonding member defined in claim comprising: a step of mounting the conductive bonding material on the substrate by compression and heating with the substrate placed on the conductive bonding material disposed on the bonding member; and a step of bonding the semiconductor chip to the substrate by compression and heating with the semiconductor chip placed on the metal film disposed on the conductive bonding material mounted on the substrate.

9. The bonding method according to claim 8, wherein in the step of mounting the conductive bonding material on the substrate, the conductive bonding material is heated at 40° C. or more and 100° C. or less while being compressed at 30 MPa or less.

10. The bonding method according to claim 9, wherein in the step of bonding the semiconductor chip to the substrate, the conductive bonding material is heated at 80° C. or more and 300° C. or less, and compressed at 30 MPa or less.

11. The bonding method according to claim 8, further comprising, after the step of bonding the semiconductor chip to the substrate, a step of sintering the conductive bonding material by heating the conductive bonding material at 100° C. or more and 300° C. or less without compression.

12. A bonding method for bonding a semiconductor chip to a substrate with the bonding member defined in claim 3, comprising the steps of: mounting the conductive bonding material on the semiconductor chip by compression and heating with the semiconductor chip placed on one or more pieces of the conductive bonding material disposed on the bonding member; and bonding the semiconductor chip to the substrate by compression and heating with the semiconductor chip having the conductive bonding material mounted thereon placed on the substrate.

13. The bonding method according to claim 5, further comprising, after the step of bonding the semiconductor chip to the substrate, a step of sintering the conductive bonding material by heating the conductive bonding material at 100° C. or more and 300° C. or less without compression.

14. The bonding method according to claim 6, further comprising, after the step of bonding the semiconductor chip to the substrate, a step of sintering the conductive bonding material by heating the conductive bonding material at 100° C. or more and 300° C. or less without compression.

15. A bonding method for bonding a semiconductor chip to a substrate with the bonding member defined in claim 3, comprising: a step of mounting the conductive bonding material on the substrate by compression and heating with the substrate placed on the conductive bonding material disposed on the bonding member; and a step of bonding the semiconductor chip to the substrate by compression and heating with the semiconductor chip placed on the metal film disposed on the conductive bonding material mounted on the substrate.

16. The bonding method according to claim 9, further comprising, after the step of bonding the semiconductor chip to the substrate, a step of sintering the conductive bonding material by heating the conductive bonding material at 100° C. or more and 300° C. or less without compression.

17. The bonding method according to claim 10, further comprising, after the step of bonding the semiconductor chip to the substrate, a step of sintering the conductive bonding material by heating the conductive bonding material at 100° C. or more and 300° C. or less without compression.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0089] FIG. 1 is a diagram illustrating an example of the appearance and cross section of a bonding member of the present invention;

[0090] FIG. 2 is a diagram illustrating another example of the appearance of the bonding member of the present invention;

[0091] FIG. 3 is a diagram illustrating examples of a use mode of a conductive bonding member disposed on the bonding member of the present invention;

[0092] FIG. 4 is a schematic diagram illustrating a first bonding method using the bonding member of the present invention;

[0093] FIG. 5 is a schematic diagram illustrating a second bonding method using the bonding member of the present invention;

[0094] FIG. 6 illustrates SEM images of a front surface (on an application surface side) and a back surface (on a base material side) in a surface layer cross section of a conductive bonding material of Example 1 of First Embodiment;

[0095] FIG. 7 is a diagram for explaining a production process (using a resist) for a bonding member of Third Embodiment;

[0096] FIG. 8 is a diagram for explaining a production process for a bonding member of Fourth Embodiment; and

[0097] FIG. 9 is a diagram illustrating the appearance of a surface of the bonding member and the appearance of a conductive bonding material produced in Fourth Embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0098] First Embodiment: An embodiment of the present invention will now be described. In the present embodiment, a conductive bonding material and a bonding member were produced by preparing a metal paste with a gold powder used as a metal powder. Then, the bonding member was used to perform a semiconductor chip bonding test.

Production and Evaluation of Conductive Bonding Material

[0099] A gold powder (average particle size: 0.3 .Math.m) produced by a wet reduction method and having a purity of 99.99% by mass was mixed with tetrachloroethylene (product name; ASAHI PERCHLOR) used as an organic solvent to prepare a metal paste (gold paste). The content of the gold powder in the gold paste was set to 90% by mass. It is noted that the purity of the gold powder was quantitatively analyzed with an ICP emission spectrometer. Besides, the particle size of the gold powder was obtained based on an average value of a major axis and a minor axis of a gold particle resulting from image analysis of an observation image (5000x) obtained with a scanning electron microscope (SEM). The particle sizes of 100 gold particles were measured to calculate the average particle size.

[0100] Next, a gold film with a thickness of 50 nm was formed by sputtering on a base material as a metal film. Then, the gold paste was applied on the metal film disposed on the base material. As the base material, a glass wafer (diameter Φ: 100 mm, thickness: 0.5 mm) TEMPAX Float(R) manufactured by SCHOTT was used. As a method for applying the metal paste, a blade coating method in which the gold paste was dropped on the metal film disposed on the base material to be spread with a spatula in a vacuum chamber (35 kPa) was employed.

[0101] After applying the gold paste on the metal film disposed on the base material, the metal paste was dried to obtain a dried product to be contained in a conductive bonding material. This drying process was performed by heating the metal paste to a prescribed temperature in a drying furnace (air atmosphere) for drying. The drying temperature was 20° C. (Example 1), 40° C. (Example 2), 60° C. (Example 3), 65° C. (Example 4), 70° C. (Example 5), and 120° C. (Comparative Example 1). The drying time was 10 minutes. The drying conditions of each example are shown in Table 1. The dried product resulting from the drying had a thickness of 20 .Math.m to 25 .Math.m.

[0102] Then, a gold film containing the thus obtained dried product and the metal film were cut by laser processing to obtain a conductive bonding material. For the laser processing, a picosecond hybrid laser (LDH-G2510 manufactured by Spectronix, wavelength: 532 nm, pulse width: < 15 ps) was used as a laser oscillator. The processing conditions were set to an output of 1.8 W, a spot size of 18 .Math.mΦ, a frequency of 1 MHz, a moving distance per pulse of 2 .Math.m, and a cutting speed of 2000 mm/s. In the present embodiment, the gold film was cut into a grid pattern (each section: 1 mm x 1 mm). Besides, the cutting was performed with the number of repeating the irradiation of 15 times. The dimension of each conductive bonding material obtained by the cutting was 2.75 mm square. Besides, each conductive bonding material had a thickness within a range of 20 to 25 .Math.m.

Observation of Conductive Bonding Material and Measurement of Compressive Deformation Rate

[0103] Detailed appearance observation and measurement of a compressive deformation rate were performed on each conductive bonding material produced in Examples and Comparative Example. FIG. 6 illustrates SEM images (10000x) of a front surface (on an application surface side) and a back surface (on a base material side) in a surface layer cross section of the conductive bonding material of Example 1. As illustrated in FIG. 6, the metal powder was little deformed, and necking was not caused among particles in the conductive bonding material.

[0104] Next, the compressive deformation rate, against the drying temperature, of the conductive bonding material was measured. As a method for measuring the compressive deformation rate, a thickness change, in each conductive bonding material of Examples and Comparative Example, caused between before and after compression was measured. Specifically, in a conductive bonding material having a metal film formed thereon before compression, the thickness of a compression surface was measured in three points with a micrometer to calculate an average value, and thus, an average thickness (h1) before compression was measured. Thereafter, a compression pressure of 5 MPa was applied onto an area of the compression surface at room temperature of 20° C. with a flip chip bonder. After removing the pressure, the thickness was measured with a micrometer in three points the same as the measurement points for the h1 to calculate an average value, and thus, an average thickness (h2) after compression was measured. Then, based on Expression 1 described above, the compressive deformation rate was obtained. Measurement results of the compressive deformation rate are shown in Table 1.

TABLE-US-00001 No. Drying Temperature (°C) Drying Time (min) Compressive Deformation Rate (%) Example 1 20 10 25 Example 2 40 10 24 Example 3 60 10 20 Example 4 65 10 13 Example 5 70 10 10 Comparative Example 1 120 10 3

[0105] It is understood from Table 1 that the compressive deformation rate is basically liable to reduce as the drying temperature increases. In the sample dried at 120° C. (Comparative Example 1), however, the compressive deformation rate was definitely low. On the contrary, in the conductive bonding materials of Examples, definite compressive deformation was caused even with a compression pressure of 5 MPa.

Bonding Test for Bonding Member by First Bonding Method

[0106] Next, the bonding member of each of Examples and Comparative Example was used to perform a bonding test for bonding a semiconductor chip (GaN) to a substrate (Si). In the present embodiment, the conductive bonding material had a dimension of a thickness of 50 .Math.m × 2.75 mm square, the semiconductor chip had a dimension of a thickness of 0.525 mm × 2 mm square, and the Si substrate had a dimension of a thickness of 0.75 mm × 10 mm square. It is noted that bonding surfaces of the semiconductor chip and the Si substrate were precedently plated, as an intermediate layer, with Ti (thickness: 50 nm), Pt (thickness: 50 nm) and Au (thickness: 300 nm).

[0107] A method for bonding the semiconductor chip was performed through similar procedures to those of the first bonding method illustrated in FIG. 4. First, the semiconductor chip was placed on the conductive bonding material, and compressed and heated to mount the conductive bonding material on the semiconductor chip. As conditions for this mounting, the mounting was performed at a compression pressure of 2.5 MPa and a temperature of 100° C.

[0108] Next, the semiconductor chip having the conductive bonding material mounted thereon was picked up from the base material, and was placed on the substrate, and the semiconductor chip was bonded to the substrate by applying a pressure for 5 seconds under heating. Heating conditions in the bonding process were 200° C. on a Si substrate side and 100° C. on a semiconductor chip side. Compressing conditions were set to two types, 5 MPa and 10 MPa, and either pressure was applied for 5 seconds.

[0109] After the bonding process, a heat treatment was performed for post sintering of the bonded conductive bonding material. The post sintering was performed with a drying furnace under conditions of heating to 200° C. for 60 minutes in the air without compression.

[0110] After the semiconductor chip was bonded through these processes, bonding strength of the conductive bonding material was measured. This evaluation was performed by using shearing strength. The shearing strength was set as a value obtained by dividing, by the area of the semiconductor chip (2 mm square), a shear load measured with a die shear measuring apparatus at a shear rate of 100 .Math.m/s and a step back interval of 100 .Math.m. Results are shown in Table 2.

TABLE-US-00002 No. Drying Temperature (°C) Compressive Deformation Rate (%) Shear Strength (MPa) Test Pressure: 5 MPa Test Pressure: 10 MPa Example 1 20 25 36 42 Example 2 40 24 35 41 Example 3 60 20 30 35 Example 4 65 13 28 33 Example 5 70 10 27 32 Comparative Example 1 120 3 15 25

[0111] It is understood from Table 2 that when the compression pressure was set to as low as 5 MPa in using the conductive bonding material having a low compressive deformation rate less than 5% as in Comparative Example 1, the shear strength did not reach even 20 MPa. In Comparative Example 1, when the compression pressure was increased to 10 MPa, shear strength more than 20 MPa could be obtained. On the contrary, when the compressive deformation rate was increased by drying at a low temperature as in the conductive bonding materials of Examples, effective bonding strength could be obtained through compression with a low pressure. In this manner, the conductive bonding material of the present invention can obtain sufficient bonding strength simultaneously with reducing both the temperature and the pressure employed in bonding.

Bonding Test for Bonding Member by Second Bonding Method

[0112] Next, the bonding member of each of Examples and Comparative Example was used to perform a bonding test for bonding a semiconductor chip (GaN) to a substrate (Si) by the second bonding method. The same substrate and semiconductor chip as those used in the first bonding method were used.

[0113] A method for bonding the semiconductor chip was performed through similar procedures to those of the second bonding method illustrated in FIG. 5. First, the substrate was placed on the conductive bonding material, and was compressed and heated to mount the conductive bonding material on the substrate. As conditions for this mounting, the mounting was performed at a compression pressure of 2.5 MPa and a temperature of 100° C.

[0114] Next, the substrate having the conductive bonding material mounted thereon was picked up from the base material and reversed, the semiconductor chip was placed on the metal film disposed on the conductive bonding material, and the semiconductor chip was bonded to the substrate by applying a pressure for 5 seconds under heating. Heating conditions in the bonding process were 200° C. on a Si substrate side and 100° C. on a semiconductor chip side. Compressing conditions were set to two types, 5 MPa and 10 MPa, and either pressure was applied for 5 seconds.

[0115] After the bonding process, a heat treatment was performed for post sintering of the bonded conductive bonding material. The post sintering was performed with a drying furnace under conditions of heating to 200° C. for 60 minutes in the air without compression.

[0116] After the semiconductor chip was bonded through these processes, bonding strength of the conductive bonding material was measured. This evaluation was performed by using shearing strength. The shearing strength was set as a value obtained by dividing, by the area of the semiconductor chip (2 mm square), a shear load measured with a die shear measuring apparatus at a shear rate of 100 .Math.m/s and a step back interval of 100 .Math.m. As a result, in employing the second bonding method, shear strength equivalent to the results shown in Table 2 obtained by the first bonding method described above was obtained. It was confirmed based on these results that also in employing the second bonding method, the conductive bonding material of the present invention can obtain sufficient bonding strength simultaneously with reducing both the temperature and the pressure employed in bonding.

[0117] Second Embodiment: In the present embodiment, metal pastes were prepared from a plurality of types of metal powders having different compositions and particle sizes to produce conductive bonding materials. Specifically, metal powders of not only gold but also platinum, silver and palladium were used. All of these metal powders were commercially available high purity metal powders produced by a wet reduction method. It is noted that a low purity gold powder (98%) was applied in a part of this examination. As for this gold powder, gold bullion containing a slight amount of an impurity metal was used as a raw material in the wet reduction method.

[0118] The contents of a solvent and a metal powder in each metal paste were the same as those of First Embodiment. The drying temperature after applying the metal paste on the base material was 60° C. (or 65° C. in some samples), and the drying time was 10 minutes. After drying the metal paste, laser processing was performed under the same conditions as those employed in First Embodiment to produce the conductive bonding material in the same size.

[0119] Then, the various conductive bonding materials thus produced were used to perform a bonding test for a semiconductor chip. The semiconductor chip and a substrate used here were the same as those used in First Embodiment. Besides, the bonding conditions were the same as those employed in the first bonding method in First Embodiment. Table 3 shows the constitutions and compressive deformation rates of the various conductive bonding materials produced in the present embodiment as well as shearing strength obtained in the bonding test.

TABLE-US-00003 No. Metal Powder Drying Temperature Compressive Deformation Rate Shear Strength (Test Pressure: 5 MPa) Metal Purity Particle Size 1 Au 99.99% 0.3 .Math. m 60° C. 20% 30 MPa 2 0.5 .Math. m 16% 28 MPa 3 1 \. 2 .Math. m 18% 18 MPa 4 98% 0 \. 3 .Math. m 17% 15 MPa 5 Ag 99. 90% 0 \. 5 .Math. m 21% 25 MPa 6 Pt 0 \. 3 .Math. m 18% 28 MPa 7 Pd 0 \. 3 .Math. m 18% 27 MPa

[0120] It was confirmed from Table 3 that the conductive bonding material could be produced from a metal powder other than gold, and that bonding at a low pressure could be performed with such a material (Nos. 5 to 7). Besides, as for an average particle size of the metal powder, when the particle size was 1.0 .Math.m or less, an effective conductive bonding material could be obtained, but when a coarse gold powder having a particle size larger than 1.0 .Math.m was used, the bonding strength varied even when the other conditions were favorable (No. 3). The same should apply when the purity of the gold powder was low (No. 4). The particle size and the purity of the gold powder little affects the compressive deformation rate of the conductive bonding material if the drying temperature is low. When the particle size and the purity of the metal powder are inappropriate, however, the plastic deformation and the densification of the metal powder in the bonding process are harmfully affected, which probably reduces the bonding strength. When the bonding conditions alone were changed to those of the bonding test by the second bonding method of First Embodiment to measure shear strength in the same manner as in the present embodiment, results similar to the results shown in Table 3 obtained by the first bonding method were obtained.

[0121] Third Embodiment: In this embodiment, resist application and pattern etching were performed on a base material having a metal film formed thereon, and the metal paste of First Embodiment was applied on the resultant to produce a bonding member. Thereafter, a bonding test for a semiconductor chip was performed. FIG. 7 illustrates a production process for producing a bonding member of the present embodiment. Now, the production process for producing the bonding member of the present embodiment will be described with reference to FIG. 7.

1 Preparation of Base Material

[0122] A base material similar to that used in First Embodiment was prepared, and a metal film was formed on the base material. As the metal film, a gold film having a thickness of 50 nm was formed by sputtering. Then, a resist was applied on the base material (on the metal film) (FIG. 7(i)). In the present embodiment, a commercially available photoresist (AZP4903, manufactured by Kayaku Microchem Corp.) was dropped on the base material to be spin coated, and the resultant was prebaked. Then, the resist film was etched by masking and exposure to form a resist film having a hole pattern for forming a conductive bonding material (FIG. 7(ii)). In the present embodiment, the resist film was treated by patterning under conditions of irradiating g-line (wavelength: 436 nm) at an illuminance of 2100 mj/cm.sup.2 for an exposure time of 150 seconds, and etching the resultant.

2 Application of Metal Paste

[0123] Next, the metal paste was applied on the base material (on the metal film) to fill the metal paste in gaps in the resist film. The metal paste was the same as that used in First Embodiment. The metal paste was applied in a vacuum chamber (35 kPa) at room temperature by dropping the metal paste on the base material (on the metal film) to be spread with a spatula, so as to fill the metal paste in the gaps in the resist film. Thereafter, preliminary drying was performed in the vacuum chamber evacuated (5 kPa) at room temperature. Then, an excessive portion of the metal paste after the preliminary drying was removed with a blade (FIG. 7(iii)).

3 Drying of Metal Paste

[0124] Then, the metal paste resulting from the preliminary drying was dried to form a conductive bonding material containing a dried product (FIG. 7(iv)). In the same manner as in First Embodiment, the base material was placed in a drying furnace (air atmosphere) to be dried at a drying temperature of 65° C. for 10 minutes.

4 Post-process Removal of Resist Film

[0125] After the drying process, the resist film was removed with a stripping solution. In the present embodiment, the base material was immersed in acetone to remove the resist film. Through this resist removal, a bonding member on which a plurality of pieces of the conductive bonding material having a prescribed aspect ratio were disposed at a prescribed interval was produced (FIG. 7(v)). In the bonding member produced in the present embodiment, all the pieces of the conductive bonding material had an aspect ratio of 5, and the interval between the pieces of the conductive bonding material was 2 to 5 .Math.m.

[0126] Besides, the height (thickness) of the conductive bonding material was 10 ± 1 .Math.m, which was substantially the same as the thickness of the resist. As a result, it was confirmed that the conductive bonding material disposed on the bonding member of the present embodiment was excellent in flatness as a whole. In this manner, it was confirmed that when the resist was appropriately applied, the heights of the respective pieces of the conductive bonding material could be made equal, and that a conductive bonding material in the shape of a film in a pseudo manner could be formed.

Bonding Test

[0127] The bonding member production method of the present embodiment produced through the above-described processes was used to perform a bonding test for bonding a GaN semiconductor chip (thickness of 0.6 mm x 5 mm square) to a Si substrate (thickness of 0.75 mm x 10 mm square; Ti/Pt/Au plated). The bonding test here was performed basically through the same procedures as those of the first bonding method and the second bonding method of First Embodiment.

[0128] During this bonding test, the semiconductor chip mounted on the conductive bonding material was not shifted, and could be accurately bonded to the Si substrate. In addition, as a result of the bonding test, shear strength (test pressure: 5 MPa) of a bonding portion between the semiconductor chip and the Si substrate exhibited a sufficient bonding force of 30 MPa or more.

[0129] Fourth Embodiment: In this embodiment, a bonding member was produced in the same manner as in Third Embodiment except that, on a base material provided with a metal film and a resist film having a hole pattern, a metal film was further formed to form the metal film in two layers on a bottom of a conductive bonding material. FIG. 8 illustrates a production process for producing the bonding member of the present embodiment. The production process for producing the bonding member of the present embodiment will now be described with reference to FIG. 8.

1 Preparation of Base Material

[0130] In the same manner as in Third Embodiment, a metal film having a thickness of 50 nm was formed on a base material, and a resist was further applied thereon (FIG. 8(i)). Then, in the same manner as in Third Embodiment, a resist film having a hole pattern was formed (FIG. 8(ii)). On the base material having the pattern of the resist film, a gold film having a thickness of 5 nm was formed by sputtering (FIG. 8(iii)).

2 Application of Metal Paste

[0131] In the same manner as in Third Embodiment, a metal paste was filled in gaps in the resist film (metal film), the resultant was subjected to preliminary drying in a vacuum chamber at room temperature, and then, an excessive portion of the metal paste after the preliminary drying was removed with a blade (FIG. 8(iv)).

3 Drying of Metal Paste

[0132] Then, the metal paste after the preliminary drying was dried to form a conductive bonding material containing a dried product (FIG. 8(v)). In the same manner as in Third Embodiment, the base material was placed in a drying furnace (air atmosphere) to be dried at 65° C. for 10 minutes.

4 Post Process Removal of Resist Film

[0133] After the drying process, the metal film disposed on the resist film was removed by etching with aqua regia (FIG. 8(vi)). Thereafter, in the same manner as in Third Embodiment, the resist film was removed with a stripping solution, and thus, a bonding member on which a plurality of pieces of the conductive bonding material having a prescribed aspect ratio were disposed at a prescribed interval was produced (FIG. 8(vii)). In the bonding member produced in the present embodiment, all the pieces of the conductive bonding material had an aspect ratio of 5, and the interval between the pieces of the conductive bonding material was 2 to 5 .Math.m. FIG. 9 illustrates the appearance of a surface of the bonding member produced in this Fourth Embodiment, and the appearance of the conductive bonding material partially enlargedly observed.

Bonding Test

[0134] The bonding member of the present embodiment produced through the above-described processes was used to perform a bonding test under the same conditions as those employed in Third Embodiment. As a result, also during the bonding test of the present embodiment, the semiconductor chip was not shifted, and could be accurately bonded. In addition, as a result of the bonding test, shear strength of a bonding portion between the semiconductor chip and the Si substrate exhibited a sufficient bonding force (30 MPa or more).

Industrial Applicability

[0135] As described so far, the present invention is useful as a conductive bonding material applied to die bonding or flip-chip bonding of a semiconductor device to a substrate. According to a conductive bonding material of the present invention and a bonding member including the same, sufficient bonding strength can be obtained simultaneously with reducing both a temperature and a pressure employed in bonding. Accordingly, it is particularly suitable as a bonding member in an organic substrate requiring temperature reduction in bonding, and a compound semiconductor requiring pressure reduction in bonding.

REFERENCE SIGNS LIST

[0136] 1 bonding member [0137] 2 conductive bonding material [0138] 3 base material [0139] 4 semiconductor chip [0140] 5 substrate [0141] 6 photoresist film [0142] 7 resist film [0143] 8 metal paste [0144] 9 blade [0145] 11, 13 metal film [0146] 12 excessive portion of metal paste [0147] d interval between pieces of conductive bonding material [0148] W width of bonding surface