Laminated film

Abstract

To provide a laminate film which can impart sufficient heat dissipation to a fine structure.SOLUTION: A laminate film 11 comprises: a substrate film 12; and a self-adhesive film 13 and an adhesive film 14 which are provided on one surface side of the substrate film 12. The adhesive film 14 includes: a thermosetting resin layer 15 which includes heat transfer particles S made of metal or a metal oxide; and a metal layer 16.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a laminated film.

Background Art

[0002] In recent years, for example, in the field of semiconductor devices, the requirements for high integration and miniaturization have been increasing. As one aspect of semiconductor devices, there is a structure in which a semiconductor chip is laminated on a controller chip disposed on a substrate. The semiconductor assembly described in Patent Document 1 has a structure called a so-called dorman structure. This conventional semiconductor assembly includes a package substrate, a controller die disposed on the package substrate, and a memory die disposed above the controller die, and the memory die is supported by a support member such as a pillar.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the semiconductor device as described above, since there are heat-generating components such as a controller chip, ensuring heat dissipation is important. In the current situation where the high integration and miniaturization of semiconductor devices are progressing, a technology that can add sufficient heat dissipation to the fine structure of the device is required.

[0005] The present disclosure has been made to solve the above problems, and an object thereof is to provide a laminated film capable of forming a bonding piece that can add sufficient heat dissipation to a fine structure.

Means for Solving the Problems

[0006] A laminated film relating to one aspect of this disclosure comprises a base film, an adhesive film and a bonding film provided on one side of the base film, wherein the bonding film comprises a thermosetting resin layer containing heat transfer particles made of metal or metal oxide, and a metal layer.

[0007] In this laminated film, the adhesive film provided on one side of the base film together with the adhesive film comprises a thermosetting resin layer containing heat transfer particles made of metal or metal oxide, and a metal layer. In this laminated film, heat dissipation paths can be formed by the thermosetting resin layer and the metal layer in the fine bonded pieces obtained by dicing the adhesive film. Therefore, by applying these bonded pieces to various devices such as semiconductor devices, it is possible to add sufficient heat dissipation to fine structures.

[0008] The thermal conductivity of the heat transfer particles may be 10 W / m·K or higher. This allows for more efficient formation of heat dissipation paths through the thermosetting resin layer and the metal layer.

[0009] The heat transfer particles may be metal particles having silver on their surface. In this case, good thermal and electrical conductivity can be added to the thermosetting resin layer.

[0010] A laminated film relating to one aspect of this disclosure comprises a base film, an adhesive film and a bonding film provided on one side of the base film, wherein the bonding film is composed of a thermosetting resin layer having a thermal conductivity of 2.0 W / m·K or more after curing, and a metal layer.

[0011] In this laminated film, the adhesive film provided on one side of the base film along with the adhesive film comprises a thermosetting resin layer having a thermal conductivity of 2.0 W / m·K or higher after curing, and a metal layer. In this laminated film, heat dissipation paths can be formed by the thermosetting resin layer and the metal layer in the fine bonded pieces obtained by dicing the adhesive film. Therefore, by applying these bonded pieces to various devices such as semiconductor devices, it is possible to add sufficient heat dissipation to fine structures.

[0012] The adhesive film may have a structure in which a thermosetting resin layer and a metal layer are laminated in that order from the adhesive film side. In this case, the optical contrast between the resin material and the metal material can improve the visibility of the joined piece during pickup. In addition, sufficient rigidity is added to the adhesive film, which reduces its ability to follow the lifting jig, but improves its ability to follow the pickup tool such as a suction collet.

[0013] The adhesive film may have a structure in which a thermosetting resin layer is laminated with a metal layer in between. In this case, the pickability of the bonded pieces can be further ensured even without performing a thermosetting treatment on the thermosetting resin layer.

[0014] The metal layer may be formed from a silver layer, a gold layer, an aluminum layer, or a copper layer. In this case, sufficient heat transfer properties of the metal layer can be ensured, and the heat dissipation efficiency of the heat dissipation path formed by the thermosetting resin layer and the metal layer can be sufficiently increased in the fine bonding piece. [Effects of the Invention]

[0015] According to this disclosure, it is possible to form a bonding piece that can provide sufficient heat dissipation to a fine structure. [Brief explanation of the drawing]

[0016] [Figure 1] This is a schematic cross-sectional view showing an example of a semiconductor device having a dolmen structure. [Figure 2]It is a schematic plan view showing a laminated film according to an embodiment of the present disclosure. [Figure 3] It is a schematic cross-sectional view showing a laminated film according to an embodiment of the present disclosure. [Figure 4] It is a schematic cross-sectional view showing a joined piece obtained from the laminated film shown in FIGS. 2 and 3. [Figure 5] It is a schematic cross-sectional view showing a laminated film according to a modified example of the present disclosure. [Figure 6] It is a schematic cross-sectional view showing a joined piece obtained from the laminated film shown in FIG. 5.

Mode for Carrying Out the Invention

[0017] Hereinafter, a preferred embodiment of a laminated film according to one aspect of the present disclosure will be described in detail with reference to the drawings.

[0018] In the following description, the same reference numerals are used for the same elements, and overlapping descriptions are omitted. The dimensions and dimensional ratios in the drawings are for convenience and do not necessarily reflect the actual dimensions. In this specification, a numerical range indicated by "~" includes the numerical values described before and after "~" as the minimum value and the maximum value, respectively. The upper limit value or the lower limit value of the numerical range described step by step in this specification may be replaced with the upper limit value or the lower limit value of the numerical range of other steps. Also, the "layer" in this specification includes both an aspect formed on the entire surface of the object to be formed and an aspect formed on a part of the object to be formed when observed as a plan view.

[0019] First, as a semiconductor device configured using a laminated film 11 (described later) according to an embodiment of the present disclosure, a semiconductor device having a dorn structure will be exemplified. FIG. 1 is a schematic cross-sectional view showing an example of a semiconductor device having a dorn structure. The semiconductor device 1 shown in the figure includes a substrate 2, a controller chip 3 disposed on one surface of the substrate 2, a plurality of memory chips 4, 5, 6, and a plurality of wires W that electrically connect each of these chips to electrodes (not shown) on the substrate 2. The controller chip 3, the memory chips 4, 5, 6, and the wires W are encapsulated by an encapsulant 7.

[0020] The substrate 2 is, for example, an organic substrate. The substrate 2 may be a metal substrate such as a lead frame. A plurality of support pieces Da are disposed around the controller chip 3. An adhesive layer 8 is provided on one surface of each of the controller chip 3 and the memory chips 4, 5, 6. The controller chip 3 is fixed to the surface of the substrate 2 via the adhesive layer 8. The memory chips 4, 5, 6 are laminated stepwise via the adhesive layer 8 so that a connection space for the wires W is formed. The laminate of the memory chips 4, 5, 6 is supported above the controller chip 3 (on the side opposite to the substrate 2) by a plurality of support pieces Da via the adhesive layer 8 on one surface of the lowermost memory chip 4.

[0021] The support piece Da is a fine bonding piece D obtained from the laminated film 11 of the present embodiment. In the bonding piece D, a heat dissipation path by a thermosetting resin layer 15 and a metal layer 16, which will be described later, is formed. When the bonding piece D is applied as the support piece Da of the semiconductor device 1 having a dorn structure, a heat dissipation path between the memory chips 4, 5, 6 and the substrate 2 and an indirect heat dissipation path between the controller chip 3 and the substrate can be established, and sufficient heat dissipation can be added to these fine structures. In the example of FIG. 1, wires W are used for connecting the substrate 2 and the controller chip 3, but the substrate 2 and the controller chip 3 may be configured to be bump-connected (for example, connected using Cu bumps and solder).

[0022] Next, the laminated film used in the manufacture of the aforementioned bonding piece D will be described. Figure 2 is a schematic plan view showing a laminated film according to one embodiment of the present disclosure. Figure 3 is a schematic cross-sectional view thereof. As shown in Figures 2 and 3, the laminated film 11 comprises a base film 12 and an adhesive film 13 and an adhesive film 14 provided on one side of the base film 12.

[0023] In this embodiment, the base film 12 is a long film that extends in one direction with a predetermined width. The laminate L of the adhesive film 13 and the bonding film 14 is arranged at predetermined intervals in the direction of extension of the base film 12. The base film 12 is the film that forms the base of the laminate film 11. For example, it is formed from a material such as polyethylene terephthalate (PET) or polyolefin. The base film 12 may be heat-shrinkable.

[0024] The adhesive film 13 is a film for fixing the adhesive film 14 to the ring frame 18 (see Figure 5, etc.), which will be described later. The adhesive film 13 may also be a dicing film. The adhesive film 13 is formed into a circular shape with a diameter smaller than the width of the base film 12 by processing means such as punching. The adhesive film 13 is made of, for example, an ultraviolet-curing adhesive and has the property of decreasing in adhesiveness when exposed to ultraviolet light. The adhesive layer of the adhesive film 13 may be a pressure-sensitive (non-ultraviolet-curing) adhesive in addition to an ultraviolet-curing adhesive.

[0025] In the example shown in Figure 2, in addition to the circular adhesive film 13 in the center of the base film 12 in the width direction, adhesive films 13, 13 are further arranged at both ends of the base film 12 in the width direction, surrounding the central adhesive film 13. These adhesive films 13, 13 at both ends serve to eliminate the difference in unevenness between the center and both ends of the laminated film 11 when the laminated film 11 is in roll form. As a result, even when the number of turns increases, the occurrence of defects such as winding misalignment and voids due to the difference in unevenness can be avoided.

[0026] The adhesive film 14 is a film for forming the support piece Da (see Figure 1) in the semiconductor device 1 described above. The adhesive film 14 may also be a die attach film. The adhesive film 14 is formed into a circular shape with a diameter slightly smaller than that of the adhesive film 13 by processing means such as punching. As shown in Figure 3, the adhesive film 14 is composed of a thermosetting resin layer 15 and a metal layer 16. The thermosetting resin layer 15 and the metal layer 16 are laminated in the order of thermosetting resin layer 15 and metal layer 16 from the adhesive film 13 side.

[0027] The thermosetting resin composition constituting the thermosetting resin layer 15 can reach a fully cured state (stage C) after a partial curing (stage B) treatment. The thermosetting resin composition includes an epoxy resin, a curing agent, and an elastomer (e.g., an acrylic resin). The thermosetting resin composition may further include inorganic fillers and curing accelerators as needed.

[0028] The thermal conductivity (at 25°C) of the cured thermosetting resin layer 15 is, for example, 2.0 W / m·K or higher. When the thermal conductivity of the cured thermosetting resin layer 15 is 2.0 W / m·K or higher, sufficient heat transfer of the resulting bonded piece D can be ensured. The thermal conductivity of the cured thermosetting resin layer 15 may be 5.0 W / m·K or higher. There is no particular upper limit to the thermal conductivity of the cured thermosetting resin layer 15, but it may be, for example, 30 W / m·K or lower.

[0029] The thermosetting resin layer 15 contains heat transfer particles S made of metal or metal oxide. The heat transfer particles S are particles used to enhance the heat transfer properties of the thermosetting resin layer 15. The thermal conductivity of the heat transfer particles S is, for example, 10 W / m·K or higher. The thermal conductivity of the heat transfer particles S may be 30 W / m·K or higher.

[0030] Examples of heat transfer particles S include metal particles such as nickel particles, copper particles, silver particles, aluminum particles, and alumina particles. The heat transfer particles S may also be particles in which the surface of a core particle such as a metal particle or resin particle is coated with a layer made of a conductive material such as metal. These particles may be used individually or in combination of two or more types.

[0031] The heat transfer particle S has an electrical conductivity (at 0°C) of 40 × 10⁻⁶. 6 The metal particles may be composed of metals with a conductivity of S / m or higher. In this case, the metal particles may be composed of one type of metal, or they may be metal-coated metal particles composed of two or more types of metals. By using such metal particles, the heat transfer properties of the thermosetting resin layer 15 can be further improved. The electrical conductivity (0°C) is 40 × 10⁻⁶. 6 Examples of metals with a conductivity of S / m or higher include gold, silver, and copper. The electrical conductivity of the heat transfer particle S (at 0°C) is 45 × 10⁻⁶. 6 It may be S / m or more, 50×10 6 S / m or higher is also acceptable.

[0032] The heat transfer particles S may be metal particles having at least silver on their surface, from the viewpoint of having good thermal and electrical conductivity, and also from the viewpoint of being resistant to oxidation. Specifically, the heat transfer particles S may be silver particles or silver-coated copper particles (silver-coated copper powder) in which the surface of copper particles is coated with silver. In this case, the thermal conductivity (20°C) of the heat transfer particles S can be 350 W / m·K or higher, and the electrical conductivity (0°C) can be 50 × 10⁻⁶. 6 It can be set to S / m or higher.

[0033] There are no particular restrictions on the shape of the heat transfer particles S. The shape of the heat transfer particles S can be, for example, flake-shaped or spherical. When the shape of the heat transfer particles S is spherical, it tends to be easier to obtain a thermosetting resin layer 15 with a predetermined surface roughness without performing a physical smoothing treatment.

[0034] The average particle size of the heat transfer particles S is, for example, 0.01 to 10 μm. When the average particle size of the heat transfer particles S is 0.01 μm or larger, it prevents an increase in viscosity when preparing the adhesive varnish, and allows the desired amount of heat transfer particles S to be included in the thermosetting resin layer 15. Furthermore, it ensures the wettability of the thermosetting resin layer 15 to the adherend, resulting in better adhesion.

[0035] When the average particle size of the heat transfer particles S is 10 μm or less, the film moldability is improved, and the heat transfer properties of the thermosetting resin layer 15 are enhanced by the addition of the heat transfer particles S. In addition, the thickness of the thermosetting resin layer 15 can be made thinner, enabling higher stacking of semiconductor devices to which the bonding piece D is applied, and suppressing the occurrence of chips / cracks caused by the heat transfer particles S protruding from the thermosetting resin layer 15.

[0036] The average particle size of the heat transfer particles S may be, for example, 0.1 μm or more, 0.5 μm or more, 1.0 μm or more, or 1.5 μm or more. The average particle size of the heat transfer particles S may also be, for example, 8.0 μm or less, 7.0 μm or less, 6.0 μm or less, 5.0 μm or less, 4.0 μm or less, or 3.0 μm or less. When the average particle size of the heat transfer particles S is 5.0 μm or less, it tends to be easier to obtain a thermosetting resin layer 15 having a predetermined surface roughness without performing a physical smoothing treatment.

[0037] The average particle size of heat transfer particles S refers to the particle size (D50) when the ratio (volume fraction) of heat transfer particles S to the total volume of all components is 50%. The average particle size (D50) of heat transfer particles S can be determined, for example, by using a laser scattering particle size analyzer such as Microtrac to measure a suspension of heat transfer particles S suspended in water using the laser scattering method.

[0038] The metal layer 16, along with the highly heat-conductive thermosetting resin layer 15, is a layer that enhances the heat transfer properties of the adhesive film 14. The metal layer 16 is formed from silver, gold, aluminum, or copper. The thermal conductivity of the metal layer 16 (at 25°C) is, for example, 400 W / m·K or higher. If the thermal conductivity of the metal layer 16 is 200 W / m·K or higher, sufficient heat transfer properties can be ensured for the resulting bonded piece D. The thermal conductivity of the metal layer 16 may also be 10 W / m·K or higher. There is no particular upper limit to the thermal conductivity of the metal layer 16, but it may be, for example, 10 W / m·K or lower.

[0039] There are no particular restrictions on the ratio of the thickness of the metal layer 16 to the thickness of the thermosetting resin layer 15, but for example, the thickness of the metal layer 16 may be greater than the thickness of the thermosetting resin layer 15. In this case, the overall heat transfer properties of the adhesive film 14 can be further improved. In addition, the adhesive film 14 has improved suction to pickup tools such as suction collets, making it possible to pick up the bonded piece D with a smaller push-up height. From the viewpoint of ensuring the heat transfer properties of the adhesive film 14, it is preferable that there is no gap at the interface between the thermosetting resin layer 15 and the metal layer 16.

[0040] The metal layer 16 also functions as a layer that increases the rigidity of the adhesive film 14. By including the metal layer 16 in the adhesive film 14, the rigidity of the adhesive film 14 is increased, which reduces its ability to follow lifting jigs and the like, but improves its ability to follow pickup tools such as suction collets.

[0041] When forming a bonded piece D using the laminated film 11 described above, for example, a fixing step, a piece formation step, and a pick-up step are performed. In the fixing step, the laminated body L of the adhesive film 13 and the bonding film 14 is fixed to a ring frame (not shown). For the fixing step, a general laminating apparatus used for laminating adhesive films onto semiconductor wafers can be used, for example.

[0042] In the individualization process, the adhesive film 14 is divided into multiple bonding pieces D by dicing it with a blade. Here, the adhesive film 14 is diced using a grid-like cutting pattern in a plan view. As a result, multiple bonding pieces D, which form a rectangular shape in a plan view, are arranged in a matrix on the adhesive film 13 (see Figure 2).

[0043] In the pickup process, the bonding pieces D are picked up sequentially from the adhesive film 13. If the adhesive layer of the adhesive film 13 is an ultraviolet-curing adhesive, ultraviolet light is irradiated onto the adhesive film 13 in the pickup process to reduce the adhesive strength between the adhesive film 13 and the bonding film 14. If the adhesive layer of the adhesive film 13 is a pressure-sensitive (non-ultraviolet-curing) adhesive, the pickup process can be carried out without irradiating with ultraviolet light.

[0044] Subsequently, the joining piece D is picked up by suction using a suction collet. This allows the joining piece D, formed by the thermosetting resin layer 15 and the metal layer 16, to be obtained. When suctioning the joining piece D with the suction collet, the joining piece D to be picked up may be pushed up from the adhesive film 13 side using a push-up jig.

[0045] As described above, in the laminated film 11, the adhesive film 14 provided on one side of the base film 12 together with the adhesive film 13 is composed of a thermosetting resin layer 15 containing heat transfer particles S made of metal or metal oxide, and a metal layer 16.

[0046] In such a laminated film 11, a heat dissipation path P can be formed in the fine bonded pieces D obtained by dicing the adhesive film 14, using a thermosetting resin layer 15 and a metal layer 16, as shown in Figure 4. Therefore, by applying this bonded piece to various devices such as semiconductor devices, it becomes possible to add sufficient heat dissipation to the fine structure.

[0047] In the laminated film 11, the thermal conductivity of the heat transfer particles S is 10 W / m·K or higher. This allows for more efficient formation of the heat dissipation path P by the thermosetting resin layer 15 and the metal layer 16. When the heat transfer particles S are metal particles having silver on their surface, good thermal and electrical conductivity can be added to the thermosetting resin layer 15.

[0048] In the laminated film 11, the adhesive film 14 has a structure in which a thermosetting resin layer 15 and a metal layer 16 are laminated in order from the adhesive film 13 side. This improves the visibility of the bonded piece D during pickup due to the optical contrast between the resin material and the metal material. In addition, sufficient rigidity is added to the adhesive film 14, which reduces its ability to follow the lifting jig, but improves its ability to follow the pickup tool such as a suction collet.

[0049] In the laminated film 11, the metal layer 16 is formed from one of the following: a silver layer, a gold layer, an aluminum layer, or a copper layer. This ensures sufficient heat transfer properties of the metal layer 16, and in the fine bonding piece D, the heat dissipation efficiency of the heat dissipation path P formed by the thermosetting resin layer 15 and the metal layer 16 can be sufficiently increased.

[0050] This disclosure is not limited to the embodiments described above. For example, in the embodiments described above, the adhesive film 14 has a two-layer structure consisting of a thermosetting resin layer 15 and a metal layer 16, but as shown in Figure 5, the adhesive film 14 may have a three-layer structure consisting of a thermosetting resin layer 15 and a metal layer 16. In the example of Figure 5, the adhesive film 14 has a configuration in which a pair of thermosetting resin layers 15, 15 are laminated so as to sandwich the metal layer 16. Even in such a configuration, in the fine bonded pieces D obtained by dicing the adhesive film 14, a heat dissipation path P can be formed by the metal layer 16 and the pair of thermosetting resin layers 15, 15 sandwiching it, as shown in Figure 6.

[0051] Furthermore, according to the configuration in Figure 5, the pickability of the bonding piece D can be more sufficiently ensured even without performing a thermosetting treatment on the thermosetting resin layer 15. In the example in Figure 5, one thermosetting resin layer 15 is provided on one side and one side of the metal layer 16, but multiple thermosetting resin layers 15 may be provided on one side and one side of the metal layer 16.

[0052] In the above embodiment, the support piece Da of a semiconductor device 1 having a dolmen structure was given as an example of application of the bonding piece D, but the application of the bonding piece D is not limited to this. For example, the bonding piece D may be interposed between a heat source and a heat sink in an electronic device instead of a heat transfer material such as TIM (Thermal Interface Material). [Explanation of Symbols]

[0053] 11...Laminated film, 12...Base film, 13...Adhesive film, 14...Bonding film, 15...Thermosetting resin layer, 16...Metal layer, D...Bonding piece, S...Heat transfer particle.

Claims

1. A base film and The base film comprises an adhesive film and a bonding film provided on one side of the base film, The adhesive film comprises a pre-cured thermosetting resin layer containing heat transfer particles made of metal or metal oxide, and a metal layer, and the laminated film is configured by laminating the pre-cured thermosetting resin layer and the metal layer in order from the adhesive film side.

2. The laminated film according to claim 1, wherein the thermal conductivity of the heat transfer particles is 10 W / m·K or more.

3. The laminated film according to claim 1 or 2, wherein the heat transfer particles are metal particles having silver on at least their surface.

4. The laminated film according to any one of claims 1 to 3, wherein the metal layer is formed of a silver layer, a gold layer, an aluminum layer, or a copper layer.

Images