JP2002280495A - Semiconductor package - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a semiconductor package having excellent reliability and hermetic sealability without necessity of sealing by a resin and further good thermal conductivity. SOLUTION: A heat conduction sheet-like material 31 containing at least an inorganic filler of 70 to 95 pts.wt. and a thermosetting resin composition of 5 to 30 pts.wt. and having flexibility in an uncured state is manufactured. Through holes 33 are formed through the material 31, and a conductive resin composition 34 is filled in the holes 33. The material 31 and a semiconductor chip 35 are aligned at positions of the holes 33 of the material 31 and the electrodes of the chip 35 in a planar direction and superposed. The material 31 is cured by heating and pressurizing, and integrated with the chip 35. An externally extracting electrode 30 is formed on the surface of a heat conduction mixture 37 to an opposite side to the chip 35 in a state connected to the composition 34.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor package used for various electric and electronic devices and a method for manufacturing the same, and more particularly to a semiconductor package having a size substantially equal to that of a semiconductor chip and excellent heat dissipation.

[0002]

2. Description of the Related Art In recent years, semiconductor chips have been increasing in density and function, and the size and number of electrodes of semiconductor chips have been remarkable. On the other hand, with the demand for higher performance and smaller size of electronic equipment, There is a demand for miniaturization of semiconductor packages. For this reason, the semiconductor package is changed from a QFP (Quad Flat Package) type in which leads are arranged around the package to a BGA (Ball Grid) in which electrodes are arranged in an area array on the lower surface.
Array) and further downsized CSP (Chip Sca)
le Package) type. As a CSP type semiconductor package, for example, there is one having a configuration as shown in FIG. That is, as shown in FIG. 10, bumps 102 are formed on the electrodes of the semiconductor chip 101, and the semiconductor chip 101 is
05 is connected to the electrode 104 via the conductive resin 103. In addition, a sealing resin 107 is filled between the semiconductor chip 101 and the wiring board 105 to ensure airtightness. In FIG. 10, reference numeral 106 denotes an external extraction electrode.

[0003] If this CSP type semiconductor package is used, the efficiency of the substrate can be improved by reducing the size of the package, and high-speed, low-noise mounting can be performed.

[0004]

However, the conventional CSP type semiconductor package configured as described above has the following problems. That is, when reliability evaluation such as thermal shock is performed, cracks may occur in the sealing portion due to the difference in the thermal expansion coefficient between the semiconductor chip and the substrate, and the airtightness may be impaired. In addition, resin sealing or coating increases production cost and tact. Further, the thermal conductivity between the semiconductor chip and the substrate is low, and it is difficult to release heat generated in the semiconductor chip.

The present invention has been made to solve the above-mentioned problems in the prior art, and does not need to be sealed with a resin, has excellent reliability and airtightness, and can be easily manufactured at low cost. It is another object of the present invention to provide a semiconductor package which can be manufactured and has good thermal conductivity.

[0006]

In order to achieve the above object, a semiconductor package according to the present invention comprises a semiconductor chip, 70 to 95 parts by weight of an inorganic filler and 5 to 30 parts by weight of a thermosetting resin composition. A heat conductive mixture adhered and integrated at least to an electrode surface of the semiconductor chip and an end surface adjacent to the electrode surface; and an external take-out formed in the heat conductive mixture and electrically connected to the semiconductor chip. And an electrode, wherein the heat conductive mixture and the upper surface of the semiconductor chip are on the same plane. According to the configuration of the semiconductor package, it is not necessary to seal with a resin, and a semiconductor package having good thermal conductivity can be realized. Also, since the coefficient of thermal expansion in the plane direction of the heat conductive mixture as the substrate is close to that of the semiconductor chip, even after performing the reflow test,
No abnormality is particularly observed at the interface between the semiconductor chip and the package, and the change in the electric resistance including the connection between the semiconductor chip and the external extraction electrode at this time is very small. Therefore, a semiconductor package having excellent reliability can be realized.

Further, in the configuration of the semiconductor package of the present invention, it is preferable that a through hole is formed in the heat conductive mixture so as to correspond to the electrode of the semiconductor chip. Also,
In this case, the through-hole is filled with the conductive resin composition,
It is preferable that the external extraction electrode is electrically connected to the semiconductor chip via the conductive resin composition.

Further, in the configuration of the semiconductor package of the present invention, it is preferable that bumps are formed on the electrodes of the semiconductor chip. According to this preferred example, the reliability of the electrical connection between the semiconductor chip and the external extraction electrode can be improved. In this case, it is preferable that the bump penetrates the heat conductive mixture and is integrated with the external extraction electrode.

Further, in the structure of the semiconductor package of the present invention, the inorganic filler is made of Al ₂ O ₃ , Mg
The filler is preferably a filler containing at least one selected from the group consisting of O, BN and AlN. This is because these have high thermal conductivity.

In the semiconductor package of the present invention, the inorganic filler has a particle size of 0.1 to 100.
It is preferably in the range of μm.

In the semiconductor package according to the present invention, the thermosetting resin composition may include, as a main component, at least one resin selected from the group consisting of an epoxy resin, a phenol resin and a cyanate resin. It is preferred to include. This is because they have excellent electrical and mechanical characteristics.

Further, in the structure of the semiconductor package of the present invention, the thermosetting resin composition contains a brominated polyfunctional epoxy resin as a main component, and further comprises a bisphenol A type novolak resin as a curing agent, and a curing agent. It preferably contains imidazole as an accelerator.

Further, in the configuration of the semiconductor package of the present invention, at least one selected from the group consisting of a coupling agent, a dispersant, a colorant and a release agent is further added to the heat conductive mixture. Is preferred.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention relates to a thermosetting resin composition in which an inorganic filler is added at a high concentration, the thermal expansion coefficient in the plane direction is almost the same as that of a semiconductor chip, and the thermal conductivity is high. It is based on a heat conductive sheet having flexibility in a cured state. Since the heat conductive sheet has flexibility in an uncured state, the heat conductive sheet can be molded into a desired shape at a low temperature and a low pressure. Further, since the thermosetting resin composition in the heat conductive sheet material is cured by heating and pressing, the heat conductive sheet material can be used as a rigid substrate. Therefore, by using the heat conductive sheet, a heat conductive semiconductor package having a semiconductor chip mounted therein can be easily realized.

According to a first aspect of the present invention, a through hole corresponding to an electrode of a semiconductor chip is formed in the heat conductive sheet,
The through-hole is filled with a conductive resin composition, and the heat conductive sheet and the semiconductor chip are overlapped with each other by aligning the through holes of the heat conductive sheet with the electrodes of the semiconductor chip in the plane direction. Then, by applying heat and pressure, the heat conductive sheet is cured and integrated with the semiconductor chip, and the semiconductor chip and the external extraction electrode are integrated. According to the first aspect of the present invention, a semiconductor package in which a semiconductor chip can be directly mounted on a substrate and which has excellent heat dissipation can be realized.

According to a second aspect of the present invention, a semiconductor chip provided with bumps is stacked face-down on the heat conductive sheet material, and then the heat conductive sheet material is cured by heating and pressing. In addition to being integrated with the semiconductor chip, the bump is penetrated through the heat conductive sheet to be integrated with the external extraction electrode.

According to a third aspect of the present invention, a through hole is formed in the heat conductive sheet and the semiconductor chip provided with the heat conductive sheet and the bump is connected to the through hole of the heat conductive sheet. Then, the semiconductor chip and the bumps of the semiconductor chip are aligned with each other in the plane direction, and then heated and pressurized, whereby the heat conductive sheet is hardened to be integrated with the semiconductor chip, and the bumps are heated. The conductive sheet-like material is integrated with an external extraction electrode by penetrating through the through hole.

According to a fourth aspect of the present invention, the heat conductive sheet is superimposed on a semiconductor chip and heated and pressurized to cure the heat conductive sheet to be integrated with the semiconductor chip. In addition, a wiring board having an electrode formed on the outermost layer prepared in advance is integrated with the heat conductive sheet to form an externally extracted electrode. The above-described first to third aspects can be used as an aspect of the integration of the heat conductive sheet and the semiconductor chip.

Hereinafter, the present invention will be described more specifically with reference to embodiments.

FIG. 1 is a sectional view showing the structure of a semiconductor package according to the present invention. As shown in FIG. 1, a heat conductive mixture 11 containing at least an inorganic filler and a thermosetting resin composition is bonded to and integrated with a semiconductor chip 12 on its electrode surface (lower surface) and an end surface adjacent thereto. I have.
The bumps 14 are formed on the electrodes of the semiconductor chip 12, and the bumps 14 are connected to the external extraction electrodes 15 via the conductive resin composition 13.

FIG. 2 is a cross-sectional view showing a heat-conducting sheet-like material which is the basis of the semiconductor package according to the present invention. As shown in FIG. 2, the heat conductive sheet 21 is formed on a release film 22. In this case, first, a mixture slurry containing at least an inorganic filler, a thermosetting resin composition, a solvent having a boiling point of 150 ° C. or higher, and a solvent having a boiling point of 100 ° C. or lower is prepared, and the mixture slurry is separated. A film is formed on the mold film 22. The method of film formation is not particularly limited, and a known doctor blade method, coater method, extrusion molding method, or the like can be used. Next, only the solvent having a boiling point of 100 ° C. or lower in the mixture slurry formed on the release film 22 is dried. Thereby, the heat conductive sheet material 21 having flexibility in an uncured state is obtained.

As a main component of the thermosetting resin composition, for example, an epoxy resin, a phenol resin or a cyanate resin can be used, and it is particularly preferable to use a brominated epoxy resin. This is because the brominated epoxy resin has flame retardancy. As a curing agent in the thermosetting resin composition, for example, a bisphenol A type novolak resin can be used, and as a curing accelerator, for example, imidazole can be used.

The filling ratio of the inorganic filler in the heat conductive sheet and the heat conductive mixture after heat curing is preferably from 70 to 95 parts by weight, more preferably from 85 to 95 parts by weight. When the filling rate of the inorganic filler is lower than 70 parts by weight,
If the thermal conductivity decreases and the filling rate of the inorganic filler is higher than 95 parts by weight, the amount of the thermosetting resin composition that imparts flexibility decreases, and the moldability deteriorates. In addition, the filling rate of the inorganic filler is calculated based on a composition not including a solvent having a boiling point of 100 ° C. or less. As the inorganic filler, for example, _{Al 2} O ₃ , MgO, BN, and AlN can be used, and these are preferable because of their high thermal conductivity. The particle size of the inorganic filler is 0.1 to 100 μm.
It is preferred that If the particle size is too small or too large, the filling rate of the inorganic filler is reduced, not only the thermal conductivity is deteriorated, but also the thermal expansion coefficient is different from that of the semiconductor chip, so that it is not suitable as a semiconductor package material .

Examples of the solvent having a boiling point of 150 ° C. or more include ethyl carbitol, butyl carbitol,
Butyl carbitol acetate can be used.
Further, as the solvent having a boiling point of 100 ° C. or lower, for example, methyl ethyl ketone, isopropanol, and toluene can be used. If necessary, a coupling agent, a dispersant, a coloring agent, and a release agent may be further added to the composition of the heat conductive sheet.

The above mixture slurry contains 150 ° C.
A solvent having a boiling point of above or a solvent having a boiling point of 100 ° C. or lower is contained, but the above-mentioned solvent is used if the thermosetting resin composition is uncured and the heat conductive sheet-like material is flexible. May not be included.

The heat conductive mixture obtained by curing the heat conductive sheet can be filled with an inorganic filler at a high concentration. Therefore, when this heat conductive mixture is used, the thermal expansion coefficient is substantially the same as that of the semiconductor chip. A semiconductor package with excellent heat dissipation can be realized.

Next, a method of manufacturing a semiconductor package having the above configuration will be described.

FIG. 3 is a sectional view showing the steps of a method for manufacturing a semiconductor package according to the present invention. First, as shown in FIG. 3A, the heat conductive sheet 31 is formed on the release film 32 as described above (see FIG. 2 and its description). Next, as shown in FIG. 3B, through holes 33 are formed in the release film 32 and the heat conductive sheet 31.
To form The formation of the through hole 33 is performed, for example, by laser processing using a carbon dioxide laser or an excimer laser,
This is performed by drilling, punching, or the like. In particular, the laser processing method is preferable because it is simple and has high accuracy.
Next, as shown in FIG. 3C, the through-hole 33 is filled with the conductive resin composition 34. As the conductive resin composition 34, a conductive paste formed by mixing a metal powder, a thermosetting resin, and a resin curing agent can be used. As the metal powder, for example, gold, silver, copper, palladium or nickel can be used, and these are preferable in terms of electric resistance and reliability. As the thermosetting resin, for example, an epoxy resin can be used, and as the resin curing agent, for example, imidazole can be used. Next, as shown in FIG. 3D, after the release film 32 is peeled off from the heat conductive sheet 31, the heat conductive sheet 31 and the semiconductor chip 35 are connected to the through holes of the heat conductive sheet 31. The electrodes 33 and the electrodes of the semiconductor chip 35 are overlapped so as to be aligned in the plane direction. Next, as shown in FIG. 3 (e), this is heated and pressurized, whereby the heat conductive sheet 31 is cured and integrated with the semiconductor chip 35. Heating and pressurization is performed using a mold, and the thermosetting resin composition in the heat conductive sheet material 31 is once softened and then hardened, so that the electrode surface of the semiconductor chip 35 and the end surface adjacent thereto are After the heat conductive sheet material 31 is cured, the heat conductive mixture 37 is in a bonded state. For this reason, the creeping distance from the outside to the electrode of the semiconductor chip 35 is increased, and the influence of moisture absorption and the like is reduced. Finally, an external extraction electrode 36 is formed on the surface of the heat conductive mixture 37 opposite to the semiconductor chip 35 while being connected to the conductive resin composition 34. External extraction electrode 36
For example, a screen printing method, a transfer method, or an etching method can be used as the forming method, but it is preferable to use an etching method or a transfer method because it can be integrally molded.
Through the above steps, a semiconductor package is obtained.

FIG. 4 is a sectional view showing steps of another method of manufacturing a semiconductor package according to the present invention.

FIG. 4A shows a state in which the through holes 43 are provided in the heat conductive sheet 41 by the same steps as those in FIGS. 3A and 3B. In FIG. 4A, reference numeral 42 denotes a release film.

As shown in FIG. 4B, the through-hole 43 is filled with a conductive resin composition 44. In this case, the through hole 43
The conductive resin composition 44 is filled only in the portion facing the opening 45 on one side, and the conductive resin composition 44 is not filled in the portion facing the opening 46 on the other side. Then, FIG.
As shown in (c), the surface of the heat conductive sheet 41 and the semiconductor chip 47 having the opening 46 in which the conductive resin composition 44 of the through hole 43 of the heat conductive sheet 41 is not filled is a semiconductor. The through-hole 43 and the electrode of the semiconductor chip 47 are overlapped so as to face the electrode surface of the chip 47 in the planar direction. Next, FIG.
As shown in (1), by applying heat and pressure, the heat conductive sheet 41 is cured and integrated with the semiconductor chip 47. The heating and pressurization is performed using a mold, and after the thermosetting resin composition in the heat conductive sheet-like material 41 is once softened and then cured, the electrode surface of the semiconductor chip 47 and the end surface adjacent thereto are After the heat conductive sheet 41 is cured, the heat conductive mixture 48 is in a bonded state. Finally, an external extraction electrode 49 is formed on the surface of the heat conductive mixture 48 opposite to the semiconductor chip 47 in the same manner as described above while being connected to the conductive resin composition 44. Through the above steps, a semiconductor package is obtained. At this time, the heat conductive sheet 41
Since the conductive resin composition 44 does not exist on the side of the semiconductor chip 47 facing the semiconductor chip 47, even if the heat conductive sheet 41 flows due to the embedding of the semiconductor chip 47, it is electrically connected to the semiconductor chip 47. The conductive resin composition 44 does not flow, and a short circuit or the like hardly occurs. Further, when bumps are formed on the electrodes of the semiconductor chip 47, the through holes 4
The unevenness between the bumps 3 and the bumps facilitates positioning of the heat conductive sheet 41 and the semiconductor chip 47 in the planar direction.

Next, a method for forming an external extraction electrode will be described.

FIG. 5 is a sectional view showing the steps of a method for forming an external extraction electrode by an etching method. First, FIG.
As shown in (a), a semiconductor chip 52 and a metal foil 53 are respectively stacked on the upper and lower surfaces of a heat conductive sheet material 51 in which a conductive resin composition 54 is filled in through holes. As the metal foil 53, for example, a copper foil can be used. Then, FIG.
As shown in (b), by heating and pressurizing this,
The heat conductive sheet material 51 is cured and integrated with the semiconductor chip 52 and the metal foil 53. Heating and pressurization is performed using a mold, and the thermosetting resin composition in the heat conductive sheet material 51 is softened once and then hardened, thereby forming the semiconductor chip 5.
The heat conductive mixture 55 after the heat conductive sheet material 51 has been cured is adhered to the electrode surface of the second electrode and the end surface adjacent thereto, and a metal foil is attached to the surface of the heat conductive mixture 55 opposite to the semiconductor chip 52. 53 will be in the bonded state. Then
As shown in FIG. 5C, the metal foil 53 is patterned using an etching method to form an external extraction electrode 56. Through the above steps, the external extraction electrode 56 is integrally formed with the heat conductive mixture 55. As the etching method,
Generally, for example, wet etching using ferric chloride as an etchant is used. Furthermore, nickel plating and gold plating are performed as needed. It is also possible to form solder balls.

FIG. 6 is a sectional view of each step showing a method of forming an external extraction electrode by a transfer method. First, as shown in FIG. 6A, a metal foil 61 is formed on a base film 62, and patterning is performed. As the metal foil 61, for example, a copper foil can be used. Next, as shown in FIG. 6B, the semiconductor chip 65 is stacked on the heat conductive sheet 63 in which the conductive resin composition 66 is filled in the through holes,
The electrode pattern 64 of FIG. 6A is laminated on the surface on the opposite side. Next, as shown in FIG. 6C, the heat conductive sheet 63 is cured by applying pressure and heating to be integrated with the semiconductor chip 65 and the electrode pattern 64. Heating and pressurization is performed using a mold, and after the thermosetting resin composition in the heat conductive sheet 63 is once softened and then cured, the electrode surface of the semiconductor chip 65 and the end surface adjacent thereto are formed. After the heat conductive sheet 63 is cured, the heat conductive mixture 67 is bonded, and the electrode pattern 64 is bonded to the surface of the heat conductive mixture 67 opposite to the semiconductor chip 65. Finally, base film 6
Peel 2 off. Through the above steps, the electrode pattern 64 is integrally formed with the heat conductive mixture 67 as an external extraction electrode.

FIG. 7 is a sectional view showing steps of another method of manufacturing a semiconductor package according to the present invention. First, FIG.
As shown in FIG. 2A, a heat conductive sheet 71 is formed on the release film 72 as described above (FIG. 2, FIG.
And its description). Next, as shown in FIG. 7B, a semiconductor chip 73 having bumps 74 on electrodes is prepared. As the bump, for example, a bump formed by bonding gold or aluminum by a known method or a bump formed with a solder ball can be used. Next, as shown in FIG. 7C, after the release film 72 is peeled from the heat conductive sheet 71, the semiconductor chip 73 having the bumps 74 on the electrodes is placed on the heat conductive sheet 71. Lay face down. Next, as shown in FIG. 7D, this is heated and pressurized, whereby the heat conductive sheet 71 is cured and integrated with the semiconductor chip 73. Heating and pressurization is performed using a mold, and after the thermosetting resin composition in the heat conductive sheet 71 is once softened and cured, the thermosetting resin composition is cured on the electrode surface of the semiconductor chip 73 and the end surface adjacent thereto. After the heat conductive sheet 71 is cured, the heat conductive mixture 76 adheres. At this time, the bumps 74 of the semiconductor chip 73 penetrate the heat conductive sheet 71 and are exposed on the back side of the heat conductive sheet 71 (that is, the heat conductive mixture 76). Finally, an external extraction electrode 75 is formed on the back surface of the heat conductive mixture 76 while being connected to the bump 74 of the semiconductor chip 73. Through the above steps, a semiconductor package is obtained. The external extraction electrode 75
Is the same as described above. When a semiconductor package is manufactured by the above method, a step of processing a through hole and a step of filling a conductive resin composition can be omitted, so that productivity is improved. In addition, since the conductive resin composition is not interposed, the electric resistance between the external extraction electrode 75 and the semiconductor chip 73 is reduced.

FIG. 8 is a cross-sectional view showing the steps of another method for manufacturing a semiconductor package according to the present invention. First, as shown in FIG. 8A, the heat conductive sheet 81 is formed on the release film 83 as described above (FIG. 2, FIG.
And a description thereof), a through hole 82 is formed in the release film 83 and the heat conductive sheet 81. Then, FIG.
As shown in (b), a semiconductor chip 84 having bumps 85 on electrodes is prepared. Next, as shown in FIG. 8C, after the release film 83 is peeled from the heat conductive sheet 81, the planar direction of the through hole 82 of the heat conductive sheet 81 and the bump 85 of the semiconductor chip 84 is changed. Align the position of and overlap. Next, as shown in FIG. 8D, the resultant is heated and pressurized, whereby the heat conductive sheet 81 is cured and integrated with the semiconductor chip 84. Heating and pressurization is performed using a mold, and the thermosetting resin composition of the heat conductive sheet 81 is once softened and then hardened, so that heat is applied to the electrode surface of the semiconductor chip 84 and the end surface adjacent thereto. After the conductive sheet material 81 is cured, the heat conductive mixture 87 is in a bonded state. At this time, the bumps 85 of the semiconductor chip 84 penetrate through the through holes 82 of the heat conductive sheet 81,
Heat conductive sheet 81 (that is, heat conductive mixture 87)
Is exposed on the back side of. Finally, the heat transfer mixture 8
An external extraction electrode 86 is formed on the back surface of the semiconductor chip 7 while being connected to the bump 85 of the semiconductor chip 84. Through the above steps, a semiconductor package is obtained. When a semiconductor package is manufactured by the above method, the step of filling the conductive resin composition can be omitted, so that productivity is improved. Further, since the through hole 82 is formed in the heat conductive sheet 81 and the bump 85 is formed in the semiconductor chip 84, the heat conductive sheet 81 and the semiconductor chip 84 are formed.
Can be easily aligned in the plane direction. The through hole 82
After the conductive resin composition is filled in the substrate, the heat conductive sheet material 81 and the semiconductor chip 84 may be aligned and stacked, and may be integrally molded.

FIG. 9 is a cross-sectional view showing the steps of another method for manufacturing a semiconductor package according to the present invention.

First, as shown in FIG.
A heat conductive sheet material 91 in which the conductive resin composition 94 is filled in the through holes 93, prepared by the same steps as (a) to (c), is prepared, and as shown in FIG. 9B. A wiring board 9 having an electrode pattern 95 formed on the outermost layer.
6 is prepared. In FIG. 9A, reference numeral 92 denotes a release film. As the wiring substrate 96, for example, a glass-epoxy substrate, a ceramic substrate such as alumina or AlN,
A glass-ceramic low-temperature firing substrate or the like can be used, but a substrate whose main component is a heat conductive mixture is particularly preferable. This is because the coefficient of thermal expansion with the heat conductive mixture after the heat conductive sheet material 91 is cured becomes substantially equal, and the reliability is improved. Also, because the materials are the same, the adhesive strength is increased. Next, as shown in FIG. 9C, the heat conductive sheet material 91 and the semiconductor chip 97 are overlapped with each other so that the through holes 93 of the heat conductive sheet material 91 and the electrodes of the semiconductor chip 97 are aligned in the plane direction. The heat conductive sheet material 91 and the wiring board 96 are
The through-hole 93 and the electrode pattern 95 on the wiring board 96 are aligned in the planar direction and overlapped. Next, as shown in FIG. 9D, the resultant is heated and pressurized, whereby the heat conductive sheet material 91 is cured and integrated with the semiconductor chip 97 and the wiring board 96. Heating and pressurization is performed using a mold,
After the thermosetting resin composition of the heat conductive sheet material 91 is once softened and then hardened, the heat conduction after the heat conductive sheet material 91 is hardened is applied to the electrode surface of the semiconductor chip 97 and the end surface adjacent thereto. The mixture 98 adheres and the wiring substrate 96 adheres. At this time, the electrodes of the semiconductor chip 97 and the electrode patterns 95 on the wiring board 96 are formed.
Are electrically connected via the conductive resin composition 94.
Through the above steps, a semiconductor package is obtained. When a semiconductor package is manufactured by the above method, the interval between electrodes connected to the outside can be wider than the electrode interval of the semiconductor chip 97 by using the wiring board 96, so that the semiconductor package can be easily mounted. . Further, since the electrodes can be rearranged by the wiring board 96, the wiring design of the board for connecting the semiconductor package is facilitated, and the versatility is increased.

In this example, the semiconductor chip 97 and the electrode pattern 95 are electrically connected using the method described with reference to FIG. 3, but the semiconductor chip 97 and the electrode pattern on the wiring board 96 are connected. The method of causing the same is not limited to this. For example, the same effect can be obtained even when the method described with reference to FIGS. 4, 7, and 8 is used.

In each of the above-described manufacturing methods, the case where a semiconductor package is manufactured using one semiconductor chip has been described as an example. However, the semiconductor package may be manufactured as follows. . That is, first,
A plurality of semiconductor chips are prepared, and a plurality of semiconductor chips are processed as needed, and then the plurality of semiconductor chips are superimposed on the heat conductive sheet. Next, by applying heat and pressure, the heat conductive sheet is cured and integrated with the plurality of semiconductor chips. Next, an external extraction electrode is formed. Finally,
A plurality of integrated semiconductor packages are individually divided. If a semiconductor package is manufactured by the above method, a large number of semiconductor packages can be obtained at one time.

In each of the above-mentioned production methods, the temperature during heating and pressurization is preferably in the range of 170 to 260 ° C. If the temperature is too low, the curing of the thermosetting resin composition becomes insufficient, and if the temperature is too high, the thermosetting resin composition starts to decompose. The pressure at the time of heating and pressurizing is preferably in the range of 1 to 20 MPa.

[0042]

The present invention will be described below in more detail with reference to specific examples.

(Example 1) In preparing a heat conductive sheet material as a basis of the present invention, an inorganic filler, a thermosetting resin composition, and a solvent were mixed, and a mixing action was performed so that a sufficient dispersion state was obtained. A slurry was made by mixing the promoting alumina balls. The composition of the heat conductive sheet material is shown in the following (Table 1).

[0044]

[Table 1]

Here, AL-33 (average particle size: 12 μm) manufactured by Sumitomo Chemical Co., Ltd. was used as Al ₂ O ₃ , and NVR-1010 manufactured by Nippon Rec Co., Ltd. was used as epoxy resin.
(Including a curing agent), and butyl carbitol acetate (Kanto Chemical Co., Ltd., boiling point 240 ° C.) was used as a solvent having a boiling point of 150 ° C. or higher.

First, the composition shown in Table 1 was weighed, and methyl ethyl ketone (MEK, boiling point: 79.6 ° C., manufactured by Kanto Chemical Co., Ltd.) solvent was added until the slurry viscosity became about 20 Pa · s. Was added and the mixture was rotationally mixed at a speed of 500 rpm for 48 hours in a pot. MEK at this time is for viscosity adjustment and is an important component in adding a high concentration of inorganic filler.
Since it volatilizes in the subsequent drying step and does not remain in the resin composition, it is not described in the above (Table 1). Then
A polyethylene terephthalate (PET) film having a thickness of 75 μm is prepared as a release film, and the slurry is applied thereon with a doctor blade method using a blade gap (gap between the blade and the release film) of about 1.4 mm.
Was formed. Next, the MEK solvent in the slurry was
It was left to dry at a temperature of 00 ° C. for 1 hour. Thereby, a flexible heat conductive sheet (thickness of about 750 μm)
m) was obtained.

Experiment No. 1d produced as described above
Of a heat conductive sheet with a release film (inorganic filler: 90% by weight) is cut into a predetermined size, and a carbon dioxide laser is used to cut the same 250 μm pitch from the surface of the release film using a carbon dioxide laser. Were formed at equal intervals at a through hole having a diameter of 150 μm.

In this through hole, as a conductive resin composition,
Spherical copper powder: 85 parts by weight, bisphenol A type epoxy resin as resin composition (Epicoat 828, manufactured by Yuka Shell Epoxy): 3 parts by weight, glycidyl ester-based epoxy resin (YD-171, manufactured by Toto Kasei): 9 parts by weight and an amine adduct curing agent (MY-2) as a curing agent
4, manufactured by Ajinomoto Co.): A paste obtained by kneading 3 parts by weight with three rolls was filled by a screen printing method. Then, after peeling off the PET film from the heat conductive sheet material filled with the paste in the through hole, a 10 mm square semiconductor chip is aligned with the electrode and the through hole on one surface of the heat conductive sheet material. A copper foil having a thickness of 35 μm and having one surface roughened was bonded to the surface on the opposite side with the roughened surface facing the heat conductive sheet. Next, this is placed in a mold so as to have a constant thickness, and heated and pressed at a pressing temperature of 175 ° C. and a pressure of 3 MPa for 1 hour using a hot press, whereby the heat conductive sheet material is cured, and the semiconductor chip and the copper are cured. Integrated with foil. In this case, since the thermosetting resin composition in the heat conductive sheet material is once softened and then hardened, the heat conduction after the heat conductive sheet material is hardened is applied to the electrode surface of the semiconductor chip and the end surface adjacent thereto. The mixture is in a bonded state, and the heat conductive mixture (heat conductive sheet)
And the semiconductor chip are firmly integrated. In addition, the thermally conductive mixture after the thermal conductive sheet is cured is firmly adhered to the roughened surface of the copper foil. Further, the epoxy resin in the conductive resin composition (paste) is also cured, and the semiconductor chip and the copper foil are mechanically and electrically connected. Finally,
An external extraction electrode was formed by patterning the copper foil using an etching technique. Through the above steps, the semiconductor package shown in FIG. 1 was obtained.

As a reliability evaluation, the maximum temperature is 260 ° C.
, A reflow test for 10 seconds was performed 20 times. At this time, no abnormality was particularly observed at the interface between the semiconductor chip and the package, and it was confirmed that strong adhesion was obtained. Also, when the change in the electric resistance including the connection between the semiconductor chip and the external extraction electrode at this time was measured, the initial connection resistance before the reflow test was 35 mΩ / via, whereas the initial connection resistance after the reflow test was 35 mΩ / via. The connection resistance was 40 mΩ / via, and the amount of change was very small.

As a comparative example, a semiconductor package in which a semiconductor chip was mounted on a conventional glass epoxy substrate via a solder bump and a sealing resin was manufactured. In this semiconductor package, since the thermal expansion coefficients of the semiconductor chip and the substrate were different, the resistance value was increased at the junction between the semiconductor chip and the substrate, and the wire was broken in ten reflow tests. In contrast,
In the semiconductor package of this example, since the thermal expansion coefficient of the heat conductive mixture as a substrate in the planar direction was close to that of the semiconductor chip, the change in the resistance value due to the reflow test was slight.

Also, when a constant current is applied to the semiconductor chip to generate 1 W of heat continuously, no change is observed in the appearance of the semiconductor package, and the connection between the semiconductor chip and the external extraction electrode is included. However, the change in electric resistance was also very small.

Next, in order to evaluate the basic characteristics of the heat conductive mixture, the heat conductive sheet produced with the composition shown in the above (Table 1) was peeled off from the release film, and the heat resistant release property was again measured. The film was sandwiched between films (polyphenylene sulfide: PPS, thickness 75 μm) and cured at a temperature of 200 ° C. and a pressure of 5 MPa. Thereafter, the PPS release film is peeled off,
After processing into predetermined dimensions, the thermal conductivity, coefficient of thermal expansion, and dielectric strength were measured. The results are shown below (Table 2).

[0053]

[Table 2]

Here, the thermal conductivity was determined by heating the sample surface cut into a 10 mm square by contacting the surface with a heater and measuring the temperature rise on the opposite surface. Also,
The withstand voltage in the above (Table 2) is obtained by converting the AC withstand voltage in the thickness direction of the heat conductive mixture into the AC withstand voltage per unit thickness. The dielectric strength is affected by the adhesion between the thermosetting resin composition and the inorganic filler in the heat conductive mixture.
That is, if the wettability between the inorganic filler and the thermosetting resin composition is poor, micro gaps are formed therebetween, and as a result, the strength and the dielectric strength of the heat conductive mixture are reduced. Generally, the withstand voltage of the resin alone is about 15 kV / mm, and if it is 10 kV / mm or more, it is determined that good adhesion is obtained.

From the results shown in Table 2 above, the heat conductive mixture obtained from the heat conductive sheet produced by the above-described method is about 20 times more heat conductive than the conventional glass epoxy substrate. Having. Further, the thermal expansion coefficient of the heat conductive mixture obtained by adding 90 parts by weight or more of Al ₂ O ₃ was close to that of silicon. From the above, it can be seen that the heat conductive mixture obtained from the heat conductive sheet produced by the above method is suitable for a package for directly mounting a semiconductor chip.

(Example 2) Another example of a semiconductor package in which a heat conductive sheet produced in the same manner as in Example 1 above was used and integrated with a semiconductor chip without using a conductive resin composition. Is shown. The composition of the heat conductive sheet used in this example is shown below. (1) Inorganic filler: Al ₂ O ₃ (“AS-40” (trade name) manufactured by Showa Denko KK, spherical, average particle diameter 12 μm)
m) 90 parts by weight (2) Thermosetting resin: 9 parts by weight of cyanate ester resin (“AroCyM30” (trade name) manufactured by Asahi Ciba Co., Ltd.) (3) Solvent: butyl carbitol (manufactured by Kanto Chemical Co., Ltd.)
0.5 parts by weight of boiling point 228 ° C.) (4) Other additives: 0.3 parts by weight of carbon black (manufactured by Toyo Carbon Co., Ltd.), dispersant (“Plysurf A208F” manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) Product name)) 0.
2 parts by weight First, on a semiconductor chip electrode of 10 mm square,
Au bumps were formed using a known wire bonding method. Next, this semiconductor chip was superimposed on a heat conductive sheet (550 μm thick) produced with the above composition, and on the opposite surface, a release PPS film was produced by etching. An external electrode pattern made of a copper foil having a thickness of 35 μm and roughened on one side was aligned with the electrode of the semiconductor chip and overlapped. Next, this is placed in a mold so as to have a constant thickness, and is heated and pressed at a pressing temperature of 180 ° C. and a pressure of 5 MPa for 1 hour using a hot press, whereby the heat conductive sheet material is cured, and the semiconductor chip and the outside are hardened. It was integrated with the electrode pattern (external extraction electrode). Finally, the release film was peeled off to complete the semiconductor package.

When the conductivity of the semiconductor chip and the external extraction electrode was confirmed, almost all the electrodes were conductive.
It was confirmed that the connection between the semiconductor chip and the external extraction electrode was good.

As the reliability evaluation, the maximum temperature was 2
A reflow test at 60 ° C. for 10 seconds was performed 20 times. At this time, no particular abnormality was observed at the interface between the semiconductor chip and the semiconductor package, and it was confirmed that strong adhesion was obtained. Also, there was no change in the electrical connection, and it was confirmed that there was no disconnection between the semiconductor chip and the external extraction electrode.

(Embodiment 3) Still another embodiment of a semiconductor package integrated with a semiconductor chip using a heat conductive sheet produced in the same manner as in Embodiment 1 will be described.
The composition of the heat conductive sheet used in this example is shown below. (1) Inorganic filler: Al ₂ O ₃ (“AM-28” (trade name) manufactured by Sumitomo Chemical Co., Ltd., spherical, average particle diameter 12 μm)
m) 87 parts by weight (2) Thermosetting resin: phenol resin (“Phenolite, VH4150” (trade name) manufactured by Dainippon Ink and Chemicals, Inc.)
11 parts by weight (3) Solvent: ethyl carbitol (manufactured by Kanto Chemical Co., Ltd.
Boiling point: 202 ° C.) 1.5 parts by weight (4) Other additives: 0.3 parts by weight of carbon black (manufactured by Toyo Carbon Co., Ltd.), coupling agent (“Plenact KR-55” manufactured by Ajinomoto Co., Inc. (product) Name)) 0.
2 parts by weight First, the heat conductive sheet material (600 μm in thickness) produced with the above composition was cut into a predetermined size, and
A through hole was formed in the same manner as described above. Next, a semiconductor chip on which a pump was formed in the same manner as in Example 2 was stacked on the heat conductive sheet while aligning the position of the pump and the through-hole. Glass-alumina low-temperature firing substrate with corresponding electrodes (wiring layer =
4 layers, thickness 0.4 mm) were overlapped while adjusting the position. Next, this is put into a mold so as to have a constant thickness, and a press temperature of 180 ° C. and a pressure of 5MP are applied using a hot press.
By heating and pressing at a for 1 hour, the heat conductive sheet was cured and integrated with the semiconductor chip and the glass-alumina low temperature fired substrate. Through the above steps, a semiconductor package was manufactured.

When the conductivity of the semiconductor and the external extraction electrode was confirmed, it was confirmed that almost all the electrodes had conductivity and the connection between the semiconductor chip and the external extraction electrode was good.

As the reliability evaluation, the maximum temperature was 2
A reflow test at 60 ° C. for 10 seconds was performed 20 times. At this time, no abnormality was particularly observed at the interface between the semiconductor chip and the heat conductive mixture and at the interface between the wiring board and the heat conductive mixture, and it was confirmed that strong adhesion was obtained. Also, there was no change in the electrical connection, and it was confirmed that there was no disconnection between the semiconductor chip and the external extraction electrode.

(Embodiment 4) Still another embodiment of a semiconductor package integrated with a semiconductor chip using a heat conductive sheet produced in the same manner as in Embodiment 1 will be described.
The composition of the heat conductive sheet used in this example is shown below. (1) Inorganic matter Filler: Al ₂ O ₃ (manufactured by Showa Denko KK "AS-40" (trade name), spherical, average particle size 12μ
m) 89 parts by weight (2) Thermosetting resin: 10 parts by weight of brominated epoxy resin (“EF-134” manufactured by Nippon Lec Co., Ltd.) (3) Other additives: carbon black (Toyo Carbon Co., Ltd.) )) 0.4 parts by weight, coupling agent (“Plenact KR-46B” (trade name) manufactured by Ajinomoto Co., Inc.)
0.6 parts by weight First, a thermally conductive sheet (thickness: 700 μm) prepared with the above composition was cut into a predetermined size on a PET film, and grids were formed in the plane direction in the same manner as in Example 1 above. Through holes corresponding to the electrodes of 3 × 3 semiconductor chips were formed in a shape, and the through holes were filled with the same conductive resin composition (paste) as in Example 1 by the same method. . Next, after peeling off the PET film from the heat conductive sheet material filled with paste in the through-holes, three 10 mm square semiconductor chips are stacked vertically and horizontally in a grid shape while aligning the positions of the electrodes and the through-holes, A copper foil having a thickness of 35 μm and having one surface roughened was bonded to the opposite surface with the roughened surface facing the heat-conductive sheet. Next, this is placed in a mold so as to have a constant thickness, and heated and pressed at a pressing temperature of 175 ° C. and a pressure of 3 MPa for 1 hour using a hot press, whereby the heat conductive sheet material is cured, and the semiconductor chip and the copper are cured. Integrated with foil. Next, the copper foil was patterned using an etching technique to form an external extraction electrode. Finally, the plurality of integrated semiconductor packages were individually divided by a diamond rotary cutter.

The appearance of these semiconductor packages was the same as that of the package manufactured in Example 1 above, and the reliability was evaluated by performing a reflow test 20 times at a maximum temperature of 260 ° C. for 10 seconds to evaluate the reliability. No abnormalities were observed. Further, the change in the electric resistance value before and after the reflow at this time was very small.

In Examples 1 and 4, copper powder was used as the conductive filler of the conductive resin composition. However, the conductive filler is not necessarily limited to copper powder. Other metal powders such as palladium and nickel can also be used. In particular, when silver or nickel is used, the electrical conductivity of the conductive portion can be maintained high.

[0065]

As described above, according to the present invention,
A semiconductor package in which a semiconductor chip, a substrate, and an external extraction electrode are integrated with each other can be obtained by using a heat conductive sheet having flexibility in an uncured state. The heat conductive mixture obtained by curing this heat conductive sheet material can be filled with an inorganic filler at a high concentration, and therefore has excellent heat conductivity, so if this heat conductive mixture is used as a semiconductor package, In addition, the heat dissipation of the semiconductor chip is improved. Further, the heat conductive mixture obtained by curing the heat conductive sheet material has a thermal expansion coefficient close to that of a semiconductor chip, and thus has excellent reliability as a semiconductor package.

Further, since the heat conductive sheet has flexibility, the semiconductor chip can be easily integrated. Therefore, a sealing resin is not required, and a semiconductor package having excellent airtightness and thermal conductivity can be obtained. Further, if this heat conductive sheet is used, the external extraction electrode can be integrated simultaneously with the molding and curing by the metal foil bonding or pattern transfer method, so that the external extraction electrode can be easily formed. Further, since a wiring board having electrodes formed on the outermost layer can be used as external extraction electrodes, a semiconductor package having excellent mountability can be obtained.

Further, according to the present invention, it is possible to obtain a semiconductor package which is highly reliable, has a small resistance change, and is capable of good electrical connection.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a semiconductor package according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a configuration of a heat conductive sheet according to one embodiment of the present invention.

FIG. 3 is a process chart showing a method of manufacturing a semiconductor package according to an embodiment of the present invention.

FIG. 4 is a cross-sectional view illustrating another method of manufacturing the semiconductor package according to the embodiment of the present invention;

FIG. 5 is a cross-sectional view illustrating a method of forming an external extraction electrode of a semiconductor package according to an embodiment of the present invention.

FIG. 6 is a cross-sectional view illustrating another method of forming the external lead-out electrode of the semiconductor package according to the embodiment of the present invention;

FIG. 7 is a cross-sectional view illustrating another step in the method for manufacturing a semiconductor package according to the embodiment of the present invention;

FIG. 8 is a cross-sectional view illustrating another method of manufacturing the semiconductor package according to one embodiment of the present invention;

FIG. 9 is a cross-sectional view illustrating a step in another method for manufacturing a semiconductor package according to an embodiment of the present invention.

FIG. 10 is a cross-sectional view showing a semiconductor package according to the related art.

[Explanation of symbols]

11, 37, 48, 55, 67, 76, 87, 98 Heat conduction mixture 12, 35, 47, 52, 65, 73, 84, 97, 1
01 Semiconductor chip 13, 34, 44, 54, 66, 94, 103 Conductive resin composition 14, 74, 85, 102 Bump 15, 36, 49, 56, 75, 86, 95, 106
External extraction electrode 21, 31, 41, 51, 63, 71, 81, 91 Thermal conductive sheet 22, 22, 42, 72, 83, 92 Release film 33, 43, 82 Through hole 53, 61 Metal foil 62 Base film 64 External extraction electrode pattern 95, 104 Electrode 96, 105 Wiring board 107 Sealing resin

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[Procedure amendment]

[Submission Date] April 26, 2002 (2002.4.2
6)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction contents]

[0006]

To achieve the above object, according to an aspect of the first structure of a semiconductor package according to the present invention includes a semiconductor chip, an inorganic filler 70 to 95 parts by weight of the thermosetting resin composition 5-30 A heat conductive mixture including at least a weight part and bonded and integrated to an electrode surface of the semiconductor chip and an end surface adjacent to the electrode surface; a through hole formed in the heat conductive mixture; and filling the through hole. Conducted conductivity
A resin composition, and an external extraction electrode formed on the heat conductive mixture , wherein the electrode of the semiconductor chip is
The part taking-out electrode is electrically connected with the conductive resin composition.
And said that you have been continued. According to the first configuration of the semiconductor package, it is not necessary to seal with a resin, and a semiconductor package having good thermal conductivity can be realized. In addition, since the thermal expansion coefficient in the plane direction of the heat conductive mixture as the substrate is close to that of the semiconductor chip, even after performing the reflow test, no particular abnormality is recognized at the interface between the semiconductor chip and the package. The change in the electrical resistance including the connection between the semiconductor chip and the external extraction electrode is also very small. Therefore, a semiconductor package having excellent reliability can be realized.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction contents]

Further, the semiconductor package according to the present invention
The second configuration, a semiconductor chip, an inorganic filler 70-9
Less 5 parts by weight and 5 to 30 parts by weight of thermosetting resin composition
And adjacent to the electrode surface of the semiconductor chip and the electrode surface.
The heat-conductive mixture integrated by bonding to the end faces
A bump formed on an electrode of the semiconductor chip;
An external extraction electrode formed on the conductive mixture,
The bump penetrates through the heat conducting mixture and the external
It is characterized by being connected to an output electrode .

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Deleted

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction contents]

Further, the semiconductor package of the present invention
In the first or second configuration, the inorganic filler is Al
_The filler is preferably a filler containing at least one selected from the group consisting of ₂ O ₃ , MgO, BN and AlN. This is because these have high thermal conductivity.

[Procedure amendment 6]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction contents]

Further, the semiconductor package of the present invention
In the first or second configuration, the particle diameter of the inorganic filler is preferably in the range of 0.1 to 100 μm.

[Procedure amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction contents]

Further, the semiconductor package of the present invention
In the first or second configuration, the thermosetting resin composition comprises:
It is preferable that at least one resin selected from the group consisting of an epoxy resin, a phenol resin and a cyanate resin is contained as a main component thereof. This is because they have excellent electrical and mechanical characteristics.

[Procedure amendment 8]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction contents]

Further, the semiconductor package of the present invention
In the first or second configuration, the thermosetting resin composition contains a brominated polyfunctional epoxy resin as a main component, and further contains a bisphenol A type novolak resin as a curing agent and imidazole as a curing accelerator. It is preferred to include.

[Procedure amendment 9]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction contents]

Further, the semiconductor package of the present invention
In the first or second configuration, it is preferable that at least one selected from the group consisting of a coupling agent, a dispersant, a colorant, and a release agent is further added to the heat conductive mixture.

Claims (10)

[Claims] 1. A semiconductor chip comprising: an inorganic filler;
At least 95 parts by weight and at least 5 to 30 parts by weight of a thermosetting resin composition, and a heat conductive mixture bonded and integrated to an electrode surface of the semiconductor chip and an end surface adjacent to the electrode surface;
A semiconductor package, comprising: an external extraction electrode formed on the heat conductive mixture and electrically connected to the semiconductor chip, wherein the heat conductive mixture and an upper surface of the semiconductor chip are on the same plane. 2. The semiconductor package according to claim 1, wherein a through hole is formed in the heat conductive mixture so as to correspond to an electrode of the semiconductor chip. 3. The conductive resin composition is filled in the through hole,
3. The semiconductor package according to claim 2, wherein an external extraction electrode is electrically connected to the semiconductor chip via the conductive resin composition. 4. The semiconductor package according to claim 1, wherein bumps are formed on electrodes of the semiconductor chip. 5. The semiconductor package according to claim 4, wherein the bump penetrates the heat conductive mixture and is integrated with the external extraction electrode. 6. An inorganic filler comprising Al ₂ O ₃ , Mg
The semiconductor package according to claim 1, wherein the filler is a filler containing at least one selected from the group consisting of O, BN, and AlN. 7. The inorganic filler has a particle size of 0.1 to 100.
The semiconductor package according to claim 1, which is in a range of μm. 8. The semiconductor package according to claim 1, wherein the thermosetting resin composition contains, as a main component, at least one resin selected from the group consisting of an epoxy resin, a phenol resin, and a cyanate resin. 9. A thermosetting resin composition comprising a brominated polyfunctional epoxy resin as a main component, a bisphenol A type novolak resin as a curing agent, and imidazole as a curing accelerator. A semiconductor package according to claim 1. 10. The semiconductor package according to claim 1, wherein at least one selected from the group consisting of a coupling agent, a dispersant, a colorant, and a release agent is further added to the heat conductive mixture.