Semiconductor device, insulating sheet, and manufacturing method of semiconductor device

Abstract

To prevent a thermally conductive material from entering an unintended region even in a case where a change in attitude of a semiconductor device or vibration occurs, in a structure using a metal having fluidity as the thermally conductive material.SOLUTION: An electronic apparatus has a thermally conductive material (31) formed between a radiator (50) and a semiconductor chip (11). The thermally conductive material (31) has fluidity at least at a time of operation of the semiconductor chip (11). In addition, the thermally conductive material (31) has electric conductivity. The thermally conductive material (31) is surrounded by a seal member (33). A capacitor (16) is covered by an insulating portion (15).SELECTED DRAWING: Figure 1A

Description

Technical Field

[0001] The present disclosure relates to a technology for improving the cooling performance of semiconductor devices.

Background Art

[0002] Semiconductor chips that function as a Central Processing Unit (CPU), a Graphics Processing Unit (GPU), etc. are thermally connected to a radiator such as a heat sink or a heat pipe and are cooled. There are many electronic devices that use grease as a heat conductive material provided between the semiconductor chip and the radiator.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, as the heat generation amount of the semiconductor chip increases, it becomes difficult to sufficiently cool the semiconductor chip due to the thermal resistance of the grease. In the semiconductor device of Patent Document 2, instead of grease, a metal that liquefies by the heat during the operation of the semiconductor chip is used as a heat conductive material between the semiconductor chip and the radiator. By using such a metal, the thermal resistance between the semiconductor chip and the radiator can be reduced, and the cooling performance of the semiconductor chip can be improved.

[0005] In a structure that uses a metal with fluidity as a heat conduction material, in order to fully exhibit the cooling performance, it is important to limit the range in which the heat conduction material spreads even when the posture of the semiconductor device changes or vibration occurs. Also, when pressing the heat sink against the semiconductor chip, it is important that the force sufficiently acts on the semiconductor chip. That is, the adhesion between the semiconductor chip and the heat sink is also important.

Means for Solving the Problem

[0006] An example of the electronic device proposed in the present disclosure includes a semiconductor chip, a first region disposed below the semiconductor chip and being the region where the semiconductor chip is mounted, a substrate having a second region which is a region where a conductor element including at least one of a circuit pattern and an electrical component is provided, a heat sink disposed above the semiconductor chip, and a heat conduction material between the heat sink and the semiconductor chip. The electronic device further includes a seal member surrounding the heat conduction material and an insulating portion covering the conductor element. The heat conduction material has conductivity and has fluidity at least during the operation of the semiconductor chip. According to this electronic device, the seal member and the insulating portion can limit the range in which the heat conduction material spreads. In this electronic device, the insulating portion is, for example, a portion where an insulating material is cured or a sheet formed of an insulating material.

[0007] Another example of the electronic device proposed in the present disclosure includes a semiconductor chip, a first region disposed below the semiconductor chip and being the region where the semiconductor chip is mounted, and a substrate having a second region provided with a conductor element including at least one of a circuit pattern and an electrical component. The electronic device further includes a heat sink disposed above the semiconductor chip, and a thermal conductive material between the heat sink and the semiconductor chip. The electronic device further has an insulating portion covering the conductor element. The thermal conductive material has conductivity and fluidity at least during operation of the semiconductor chip. The distance from at least a part on the upper surface of the insulating portion to the lower surface of the heat sink is greater than the distance from the upper surface of the semiconductor chip to the lower surface of the heat sink. According to this electronic device, the range in which the thermal conductive material spreads can be limited to a region where no conductor element exists. Also, the adhesion between the heat sink and the semiconductor chip can be ensured.

[0008] An example of the semiconductor device proposed in the present disclosure includes a semiconductor chip, a first region disposed below the semiconductor chip and being the region where the semiconductor chip is mounted, and a substrate having a second region provided with a conductor element including at least one of a circuit pattern and an electrical component, and an insulating sheet covering the conductor element. According to this semiconductor device, the range in which the thermal conductive material spreads can be limited to a region where no conductor element exists.

[0009] Another example of the semiconductor device proposed in the present disclosure includes a semiconductor chip, a first region disposed below the semiconductor chip and being the region where the semiconductor chip is mounted, and a substrate having a second region provided with a conductor element including at least one of a circuit pattern and an electrical component, and an insulating portion covering the conductor element. The height of at least a part on the upper surface of the insulating portion with respect to the substrate is smaller than the height of the upper surface of the semiconductor chip with respect to the substrate. According to this semiconductor device, the range in which the thermal conductive material spreads can be limited to a region where no conductor element exists. Also, the adhesion between the heat sink and the semiconductor chip can be ensured.

[0010] The insulating sheet proposed in the present disclosure has a semiconductor chip and a substrate disposed below the semiconductor chip, and has a first region which is a region where the semiconductor chip is mounted, and a second region provided in the substrate where a conductor element including at least one of a circuit pattern and an electrical component is provided. It is an insulating sheet for attaching to a semiconductor device. This insulating sheet has an upper wall located above the conductor element and an inner wall located inside the upper wall and descending from the upper wall, and has a housing portion covering the conductor element and an attached portion connected to the inner wall and located at a position lower than the upper wall. According to this insulating sheet, the range in which the heat conductive material spreads can be limited to a region where no conductor element exists. Further, even when the height difference between the conductor element and the semiconductor chip is small, the insulating sheet can be attached to the substrate relatively easily.

[0011] An example of a method for manufacturing a semiconductor device proposed in the present disclosure includes a step of preparing a substrate having a first region which is a region disposed below the semiconductor chip and where the semiconductor chip is mounted, and a second region provided in the substrate where a conductor element including at least one of a circuit pattern and an electrical component is provided, and a step of covering the conductor element with an insulating portion. In the step of covering the conductor element with the insulating portion, the height of the upper surface of the insulating portion with respect to the substrate is made smaller than the height of the upper surface of the semiconductor chip with respect to the substrate. According to this method, the range in which the heat conductive material spreads can be limited to a region where no conductor element such as an electrical component exists. Further, the adhesion between the heat sink and the semiconductor chip can be ensured.

Brief Description of Drawings

[0012]

Figure 1A

Figure 1B

Figure 2

Figure 3A

Figure 3B

Figure 3C

Figure 4

Figure 5A

Figure 5B

Figure 6

Figure 7

Figure 8

Figure 9A

Figure 9B

Embodiments for Carrying Out the Invention

[0013] Hereinafter, the semiconductor device and the electronic device proposed in the present disclosure will be described. In this specification, as an example of the semiconductor device and the electronic device proposed in the present disclosure, the semiconductor device 10 and the electronic device 1 will be described. The electronic device proposed in the present disclosure can be applied to, for example, a game machine, a development machine for executing various programs under development (for example, a game program), and an information processing device different from the game machine (for example, a personal computer, a server device, a control device for a transport vehicle).

[0014] In the following description, the direction indicated by X1-X2 in FIG. 1 is referred to as the horizontal direction, and the directions indicated by Z1 and Z2 are referred to as the upward and downward directions, respectively. These directions are used to explain the relative positional relationship of the elements (parts, members, portions) of the electronic device 1, and do not specify the posture of the electronic device 1 during use.

[0015] [Basic Configuration] As shown in FIG. 1A, the electronic device 1 includes a semiconductor device 10, a circuit board 2, and a heat sink 50. In the description of this specification, the circuit board 2 is disposed below the semiconductor device 10, and the heat sink 50 is disposed above the semiconductor device 10.

[0016] The semiconductor device 10 includes a semiconductor chip 11 and a substrate (package substrate) 17 located below the semiconductor chip 11. The semiconductor chip 11 functions as a CPU, a GPU, or the like. The semiconductor chip 11 is flip-chip mounted, for example, on the upper surface 17a of the substrate 17 (see FIG. 1B). That is, a plurality of solder bumps 18 formed on the lower surface of the semiconductor chip 11 and bumps (not shown) formed on the substrate 17 are soldered. The gap between the semiconductor chip 11 and the substrate 17 is filled with underfill 23. The underfill 23 is formed of, for example, resin and is cured between the semiconductor chip 11 and the substrate 17. The method of mounting the semiconductor chip 11 on the substrate 17 may be wire bonding, tape bonding, or the like.

[0017] In addition to the semiconductor chip 11, a plurality of electrical components are mounted on the upper surface 17a of the substrate 17. In the example shown in FIGS. 1A and 1B, a plurality of capacitors 16 are mounted on the substrate 17. In this specification, in the semiconductor device 10, the region where the semiconductor chip 11 is disposed is referred to as a first region A1 (see FIGS. 1A and 2), and the region around the semiconductor chip 11 where a plurality of electrical components such as capacitors 16 are disposed is referred to as a second region A2 (see FIGS. 1A and 2). In the second region A2, a circuit pattern (including through-holes and vias) may be formed together with or instead of the mounting of the capacitors 16. A stiffener 14 described later is attached to the outer peripheral edge of the substrate 17. The second region A2 is a region between the inner surface of the stiffener 14 and the side surface of the semiconductor chip 11. An insulating portion 15 described later is formed in the second region A2.

[0018] The stiffener 14 is a square frame made of metal and is attached to the outer peripheral edge of the substrate 17. As the material of the stiffener 14, for example, aluminum, copper, or the like can be used. For attaching the stiffener 14 to the substrate 17, an adhesive or solder may be used. The warping of the substrate 17 can be reduced by the stiffener 14. A first region A1 and a second region A2 are defined inside the stiffener 14.

[0019] As shown in FIG. 1A, the substrate 17 is mounted on the circuit board 2 of the electronic device 1. For example, a Ball Grid Array (BGA) 19 is formed on the lower surface of the substrate 17. That is, a plurality of solder bumps arranged in a grid pattern are formed on the lower surface of the substrate 17. The BGA 19 is soldered to the conductor pads formed on the circuit board 2. The method of mounting the substrate 17 on the circuit board 2 is not necessarily limited to the one using the BGA 19, and various other mounting methods may be adopted. For example, a Pin Grid Array (PGA) having pin-shaped lead terminals or a Land Grid Array (LGA) having electrodes arranged in an array may be used. In addition to the BGA 19, a plurality of capacitors 21 may be mounted on the lower surface of the substrate 17.

[0020] The heat sink 50 is, for example, a heat sink and has, as shown in FIG. 1A, a plate-shaped heat receiving portion 50a and fins 50b. The fins 50b are formed, for example, on the upper side of the heat receiving portion 50a. As the heat receiving portion 50a, a vapor chamber composed of a plate-shaped container and a working fluid contained in the container may be used. As another example, the heat sink 50 may include a heat pipe. The heat sink 50 may be biased toward the semiconductor chip 11 by an elastic member (for example, a spring) not shown. Further, the electronic device 1 may have a cooling fan not shown that forms an air flow toward the heat sink 50.

[0021] [Thermal Conductive Material] As shown in FIG. 1A, the lower surface 50c of the heat sink 50 faces the upper surface 11a of the semiconductor chip 11. A heat conductive material 31 is disposed between the lower surface 50c of the heat sink 50 and the upper surface 11a of the semiconductor chip 11. The heat conductive material 31 is in direct contact with the lower surface 50c of the heat sink 50 and the upper surface 11a of the semiconductor chip 11. The heat sink 50 and the semiconductor chip 11 are thermally connected by the heat conductive material 31.

[0022] The heat conductive material 31 is a material having fluidity. More specifically, the heat conductive material 31 is a material having fluidity at least during the operation of the semiconductor chip 11. Preferably, the heat conductive material 31 is in a liquid or paste state at least during the operation of the semiconductor chip 11. The heat conductive material 31 may be a material that generates fluidity during the operation of the semiconductor chip 11 but does not have fluidity at room temperature (for example, 20 ° C) when the semiconductor chip 11 is not operating. That is, the heat conductive material 31 may be a material that generates fluidity by the heat generated by the operation of the semiconductor chip 11. The non-operation of the semiconductor chip 11 is, for example, during manufacturing, during transportation, or when the power of the electronic device is off. In contrast, the heat conductive material 31 may be a material having fluidity even when the semiconductor chip 11 is not operating. That is, the heat conductive material 31 may be in any state such as liquid, paste, powder, plate, block, etc. when the chip is not operating.

[0023] Due to the fluidity of the heat conductive material 31, the thermal resistance between the upper surface 11a of the semiconductor chip 11 and the lower surface 50c of the heat sink 50 caused by a slight warpage of the upper surface 11a of the semiconductor chip 11 or micro unevenness of the lower surface 50c of the heat sink 50 is reduced, and the cooling performance of the semiconductor chip 11 can be improved. Further, if the heat conductive material 31 has fluidity at room temperature, the heat sink 50 can be separated from the semiconductor chip 11. As a result, for example, when repairing the electronic device 1, after removing the heat sink 50 from the semiconductor device 10, repair work can be performed. Also, the heat conductive material 31 is a material having conductivity, in other words, a material having a high thermal conductivity.

[0024] As the heat conduction material 31, for example, a liquid metal that is liquid at normal temperature can be used. The liquid metal is, for example, one or more low melting point metals selected from the group consisting of Ga (melting point: 29.8 °C, thermal conductivity 40.6 W / mk), In (melting point: 156.4 °C, thermal conductivity 81.6 W / mk), and Sn (melting point: 231.97 °C, thermal conductivity 66.6 W / mk), or an alloy containing one or more of the above low melting point metals can be used. Specific examples of the alloy include In-Ag, Sn-Ag-Cu, In-Sn-Bi, etc. As another example of the heat conduction material 31, a conductive paste may be used. As the conductive paste, a silver paste in which silver powder is dispersed in a resin can be used.

[0025] The heat conduction material 31 is preferably applied over the entire upper surface 11a of the semiconductor chip 11. The heat conduction material 31 may be in contact with a part of the side surface 11b (see FIG. 1B) of the semiconductor chip 11. The area where the heat conduction material 31 is applied on the lower surface 50c of the radiator 50 may be larger than the semiconductor chip 11.

[0026] [Sealing member and insulating part] Since the heat conduction material 31 has fluidity, in order to exhibit cooling performance, it is necessary to limit the range in which the heat conduction material 31 spreads. Also, since the heat conduction material 31 has conductivity, it is necessary to limit the range in which the heat conduction material 31 spreads so that the heat conduction material 31 does not touch the capacitor 16 or the circuit pattern provided in the second region A2. Also, it is not desirable for the heat conduction material 31 to contact other components of the electronic device 1 outside the semiconductor device 10 (outside the stiffener 14). Therefore, the electronic device 1 has the following structure.

[0027] [Insulating part] As shown in FIG. 1A, the semiconductor device 10 has an insulating portion 15 that covers a conductor element provided in the second region A2 (see FIG. 2), that is, a capacitor 16 and a circuit pattern. In an example of the semiconductor device 10, as shown in FIG. 1B, the insulating portion 15 is formed between the inner surface of the stiffener 14 and the side surface 11b of the semiconductor chip 11. The insulating portion 15 is formed over the entire second region A2 and is in contact with the inner surface of the stiffener 14 and the side surface 11b of the semiconductor chip 11. Therefore, the inner peripheral portion of the insulating portion 15 overlaps with the upper side of the outer peripheral portion 23a (see FIG. 1B) of the underfill 23 formed between the semiconductor chip 11 and the substrate 17. The insulating portion 15 is not formed in the first region A1, and the upper surface 11a of the semiconductor chip 11 is exposed from the insulating portion 15.

[0028] The insulating portion 15 is, for example, a resin. More specifically, the insulating portion 15 is a portion where a liquid or gel-like resin has hardened. As the insulating portion 15, for example, an ultraviolet curable resin can be used. The resin is applied so as to cover the conductor elements (that is, the capacitor 16 and the circuit pattern) in the second region A2, and then is cured by receiving ultraviolet rays to form the insulating portion 15. By this insulating portion 15, the heat conductive material 31 can be prevented from contacting the conductor elements in the second region A2.

[0029] As shown in FIG. 1B, the height H2 (the height from the upper surface 17a of the substrate 17) of the upper surface 15a of the insulating portion 15 is smaller than the height H1 (the height from the upper surface 17a of the substrate 17) of the upper surface 11a of the semiconductor chip 11. As a result, the distance from the upper surface 15a of the insulating portion 15 to the lower surface 50c of the radiator 50 is larger than the distance from the upper surface 11a of the semiconductor chip 11 to the lower surface 50c of the radiator 50. Therefore, when the radiator 50 is pushed toward the semiconductor chip 11, interference between the insulating portion 15 and the lower surface 50c of the radiator 50 does not occur, and sufficient adhesion between the radiator 50 and the semiconductor chip 11 can be ensured.

[0030] As shown in FIG. 1B, in the example of the semiconductor device 10, the height of the upper surface 16a of the capacitor 16 (the height from the upper surface 17a of the substrate 17) is smaller than the height H1 of the upper surface 11a of the semiconductor chip 11. The insulating portion 15 preferably covers the upper surface 16a of the capacitor 16. In other words, it is preferable that the entire capacitor 16 is covered by the insulating portion 15. By doing so, it is possible to surely prevent the heat conductive material 31 from touching the capacitor 16. The entire capacitor 16 may be buried in the insulating portion 15.

[0031] Also, as shown in FIG. 1B, the height H3 of the upper surface 14a of the stiffener 14 (the height from the upper surface 17a of the substrate 17) is smaller than the height H1 of the upper surface 11a of the semiconductor chip 11. The height H2 of the upper surface 15a of the insulating portion 15 is smaller than the height H3 of the upper surface 14a of the stiffener 14. Therefore, when the heat sink 50 is pushed toward the semiconductor chip 11, interference between the stiffener 14 and the lower surface 50c of the heat sink 50 does not occur, and sufficient adhesion between the heat sink 50 and the semiconductor chip 11 can be ensured. Different from the example shown in FIG. 1B, the height H2 of the upper surface 15a of the insulating portion 15 may be the same as the height H3 of the upper surface 14a of the stiffener 14.

[0032] When conductor elements such as circuit patterns and capacitors 16 exposed on the upper surface 17a of the substrate 17 are formed only in a part of the second region A2, the insulating portion 15 may be formed only in this part of the second region A2. For example, as shown in FIG. 3C, the insulating portion 15 may be separated from the side surface 11b of the semiconductor chip 11. In the example shown in this figure, a seal member 33 described later is disposed between the insulating portion 15 and the side surface 11b of the semiconductor chip 11. Such an insulating portion 15 may be, for example, a portion where a liquid or gel-like resin (specifically, an ultraviolet curable resin) supplied between the seal member 33 and the stiffener 14 is cured.

[0033] [Seal member] The electronic device 1 has a sealing member 33 (see FIG. 1A) that surrounds the heat-conductive material 31. The sealing member 33 has a square opening in plan view, and the heat-conductive material 31 and the semiconductor chip 11 are located inside the sealing member 33 (see FIG. 2). As shown in FIG. 1B, the sealing member 33 is located between the semiconductor device 10 and the lower surface 50c of the heat sink 50, seals the gap therebetween, and holds the heat-conductive material 31 inside the semiconductor device 10. The sealing member 33 is separated from the outer peripheral edge (side surface 11b) of the semiconductor chip 11. For this reason, it is possible to apply the above-described heat-conductive material 31 to the entire upper surface 11a of the semiconductor chip 11. That is, it is possible to continuously apply the heat-conductive material 31 up to the four edge portions of the upper surface 11a.

[0034] The sealing member 33 is disposed, for example, between the upper surface 15a of the insulating portion 15 and the lower surface 50c of the heat sink 50 and is sandwiched between these two surfaces 15a and 50c. The sealing member 33 may be attached to the lower surface 50c of the heat sink 50. The sealing member 33 may be adhered to the lower surface 50c of the heat sink 50, for example. Conversely, the sealing member 33 may be attached to the upper surface 15a of the insulating portion 15. The sealing member 33 may be adhered to the upper surface 15a of the insulating portion 15, for example.

[0035] Further, the sealing member 33 may have a portion located above the capacitor 16 covered by the insulating portion 15. That is, the sealing member 33 may have a portion overlapping the capacitor 16 in plan view of the semiconductor device 10. According to the semiconductor device 10 having such a positional relationship, it is possible to employ the sealing member 33 having a large width in the horizontal direction, and the sealing performance can be improved. A space S in which air exists is formed inside the sealing member 33.

[0036] The sealing member 33 is formed of a material having cushioning properties, for example. That is, the sealing member 33 is formed of a material that allows a change in the thickness of the sealing member 33 in the direction in which the upper surface 11a of the semiconductor chip 11 and the lower surface 50c of the heat sink 50 face each other, that is, in the vertical direction. The material of the sealing member 33 is, for example, rubber, sponge, foamed resin, silicone, or the like. By doing so, even when the heat sink 50 is pressed against the semiconductor chip 11 by an elastic member, the load acting on the semiconductor device 10 through the sealing member 33 can be reduced.

[0037] The position of the sealing member 33 is not limited to the example shown in FIG. 1B. For example, as shown in FIG. 3A, the sealing member 33 may be located between the upper surface 15a of the insulating portion 15 and the lower surface 50c of the heat sink 50 and may avoid the position of the capacitor 16. That is, the sealing member 33 may be arranged so as not to overlap the capacitor 16 in a plan view. By doing so, it is possible to prevent a load from acting on the capacitor 16 from the heat sink 50 through the sealing member 33.

[0038] In still another example, as shown in FIG. 3B, the sealing member 33 may be arranged between the upper surface 14a of the stiffener 14 and the lower surface 50c of the heat sink 50 and may be sandwiched between these two surfaces 14a and 50a. The stiffener 14 is formed of metal and has higher rigidity than the insulating portion 15. Since the sealing member 33 is pressed against the stiffener 14 having high rigidity, the contact pressure between the sealing member 33 and the stiffener 14 can be improved. As a result, the sealing performance by the sealing member 33 can be improved.

[0039] As described above, the insulating portion 15 may be formed at the position of the capacitor 16 and may be separated from the side surface 11b of the semiconductor chip 11. In this case, as shown in FIG. 3C, the sealing member 33 may be located inside the insulating portion 15. And the sealing member 33 may be arranged between the upper surface 17a of the substrate 17 and the lower surface 50c of the heat sink 50 and may be sandwiched between these two surfaces 17a and 50c.

[0040] That is, the inner peripheral surface 33a of the seal member 33 (the surface surrounding the semiconductor chip 11) may be located outside the outer edge of the semiconductor chip 11 and does not need to overlap with the semiconductor chip 11. The outer peripheral surface 33b of the seal member 11 (the surface facing the side opposite to the inner peripheral surface 33a) may be located inside the outer edge of the semiconductor device 10 (in the example of the semiconductor device 10, the outer edge of the stiffener 14).

[0041] [Manufacturing method] An example of the manufacturing method of the electronic device 1 and the semiconductor device 10 will be described.

[0042] First, the semiconductor chip 11, the capacitor 16, and the stiffener 14 are mounted on the substrate 17. The underfill 23 is filled between the semiconductor chip 11 and the substrate 17. A liquid or gel-like ultraviolet curable resin is supplied around the capacitor 16. That is, the ultraviolet curable resin is stored between the stiffener 14 and the semiconductor chip 11. The amount of the resin is such that the upper surface 16a of the capacitor 16 is buried in the resin. The resin is irradiated with ultraviolet rays and cured. Thereby, the insulating portion 15 is obtained. In addition, as shown in FIG. 3C, when manufacturing a structure in which the insulating portion 15 is formed between the seal member 33 and the stiffener 14, after the seal member 33 is attached to the substrate 17, a liquid or gel-like ultraviolet curable resin is supplied between the seal member 33 and the stiffener 14, whereby the insulating portion 15 can be formed.

[0043] Next, as shown in FIG. 4, the heat conductive material 31 is applied to the upper surface 11a of the semiconductor chip 11 and the lower surface 50c of the radiator 50. It is desirable to spread the heat conductive material 31 over the entire upper surface 11a of the semiconductor chip 11 by utilizing the fluidity of the heat conductive material 31. Also, it is desirable to spread the heat conductive material 31 over the entire region corresponding to the semiconductor chip 11 on the lower surface 50c of the radiator 50. The region where the heat conductive material 31 is applied on the radiator 50 is preferably larger than the size of the semiconductor chip 11.

[0044] Also, a seal member 33 is attached to the lower surface 50c of the radiator 50. Then, the radiator 50 is attached to the semiconductor chip 11, and the radiator 50 is pressed against the semiconductor chip 11 using an elastic member such as a spring. As a result, the lower surface 50c of the radiator 50 comes into close contact with the upper surface 11a of the semiconductor chip 11.

[0045] In addition, in the method of applying the heat conductive material 31 only to one of the upper surface 11a of the semiconductor chip 11 and the lower surface 50c of the radiator 50, when the radiator 50 is attached to the semiconductor chip 11, the heat conductive material 31 is difficult to spread on the other surface, and the thermal resistance between the semiconductor chip 11 and the radiator 50 increases. As shown in FIG. 4, by applying the heat conductive material 31 to both the upper surface 11a of the semiconductor chip 11 and the lower surface 50c of the radiator 50, such a problem can be solved.

[0046] [Modification Example] FIG. 5A is a cross-sectional view showing a modification example of the electronic device 1. FIG. 5B is an enlarged view of FIG. 5A. In these figures, the electronic device 1 has a semiconductor device 110 as a modification example of the semiconductor device 10. In this figure, the same reference numerals are given to the same portions or members as those described so far.

[0047] The semiconductor device 110 has an insulating sheet 115 (see FIG. 5A) as an insulating portion that covers conductor elements such as a capacitor 16 and a circuit pattern. The insulating sheet 115 is a sheet formed of resin. As the material of the insulating sheet 115, for example, engineering plastics such as polycarbonate and polyamide can be used. FIG. 6 is a perspective view of the insulating sheet 115. In FIGS. 5A and 5B, the insulating sheet 115 is shown with its width in the left-right direction reduced compared to the insulating sheet 115 shown in FIG. 6.

[0048] As shown in FIG. 5B, the insulating sheet 115 has a housing portion 115a. A capacitor 16 is disposed inside the housing portion 115a (the space defined by the housing portion 115a and the upper surface 17a of the substrate 17). The housing portion 115a has an upper wall 115b, an inner wall 115c, and an outer wall 115d. The upper wall 115b is located above the capacitor 16. The inner wall 115c is located inside the capacitor 16 (i.e., closer to the center of the semiconductor device 10 with respect to the capacitor 16) and extends downward from the upper wall 115b toward the substrate 17. The outer wall 115d is located outside the capacitor 16 and extends downward from the upper wall 115b toward the substrate 17. Accordingly, a space is formed inside the housing portion 115a for disposing the capacitor 16.

[0049] [Height of the housing portion] As shown in FIG. 5B, the height H4 of the highest portion of the upper surface of the insulating sheet 115 (the highest portion of the upper surface of the upper wall 115b) is smaller than the height H1 of the upper surface 11a of the semiconductor chip 11. By this, the distance from the upper surface of the insulating sheet 115 to the lower surface 50c of the heat sink 50 is larger than the distance from the upper surface 11a of the semiconductor chip 11 to the lower surface 50c of the heat sink 50. Therefore, when the heat sink 50 is pressed toward the semiconductor chip 11, interference between the insulating sheet 115 and the lower surface 50c of the heat sink 50 does not occur, and sufficient adhesion between the heat sink 50 and the semiconductor chip 11 can be ensured.

[0050] As shown in FIG. 5B, the height H3 of the upper surface 14a of the stiffener 14 is smaller than the height H1 of the upper surface 11a of the semiconductor chip 11. The height H4 of the upper surface of the insulating sheet 115 is smaller than the height H3 of the upper surface 14a of the stiffener 14. When the heat sink 50 is pressed toward the semiconductor chip 11, interference between the stiffener 14 and the lower surface 50c of the heat sink 50 does not occur, and sufficient adhesion between the heat sink 50 and the semiconductor chip 11 can be ensured. Different from the example shown in FIG. 5B, the height H4 of the upper surface of the insulating sheet 115 may be the same as the height H3 of the upper surface 14a of the stiffener 14.

[0051] Note that a metal plate having a size adapted to the size of the semiconductor chip 11 may be welded to the lower surface 50c of the heat sink 50. In this case, the height H4 of the upper surface of the insulating sheet 115 may be higher than the height H1 of the upper surface 11a of the semiconductor chip 11. According to this structure, by adjusting the thickness of the metal plate, the distance from the upper surface of the insulating sheet 115 to the lower surface 50c of the heat sink 50 can be made larger than the distance from the upper surface 11a of the semiconductor chip 11 to the lower surface of the heat sink (the lower surface of the metal plate). As a result, interference between the insulating sheet 115 and the lower surface 50c of the heat sink 50 does not occur, and sufficient adhesion between the heat sink 50 and the semiconductor chip 11 can be ensured.

[0052] [Mounting portion] As shown in FIG. 5B, the insulating sheet 115 is attached to the semiconductor device 110. In one example, the insulating sheet 115 has attachment portions 115h and 115i that are attached to the substrate 17 and form the edges of the housing portion 115a. The attachment portions 115h and 115i are attached to the substrate 17 by an adhesive E1. As the adhesive E1, for example, an ultraviolet curable resin can be used.

[0053] As shown in FIG. 5B, the inner attachment portion 115h is connected to the lower end of the inner wall 115c. The attachment portion 115h extends horizontally, for example, from the lower edge of the inner wall 115c and is arranged along the substrate 17. Then, the attachment portion 115h is located between the capacitor 16 and the side surface 11b of the semiconductor chip 11. The position of the attachment portion 115h is lower than the upper wall 115b of the housing portion 115a. According to this shape of the insulating sheet 115, the work for insulating the capacitor 16 from the heat conductive material 31 becomes easy. That is, in the structure illustrated in FIG. 1A, when the difference in height between the upper surface 16a of the capacitor 16 and the upper surface 11a of the semiconductor chip 11 is small, there is a problem that it is difficult to control the height at which the resin is injected so as not to exceed the upper surface 15a of the insulating portion 15. On the other hand, according to the shape of the insulating sheet 115 having the attachment portion 115h at a position lower than the upper wall 115b, even if the difference in height between the upper surface 16a of the capacitor 16 and the upper surface 11a of the semiconductor chip 11 is small, the insulating sheet 115 can be easily attached to the semiconductor device 10. Further, the attachment portion 115h extends in the direction along the surface of the substrate 17. Therefore, the attachment strength of the attachment portion 115h to the substrate 17 can be increased. Note that the attachment portion 115h does not necessarily have to extend in the direction along the surface of the substrate 17. In this case, the lower edge of the inner wall 115c may be adhered to the substrate 17 and function as the attachment portion 115h.

[0054] As shown in FIG. 5B, the outer attachment portion 115i is connected to the lower edge of the outer wall 115d. The attachment portion 115i extends horizontally from the lower edge of the outer wall 115d, for example, and is arranged along the substrate 17. The position of the attachment portion 115i is also lower than that of the upper wall 115b. According to this shape of the insulating sheet 115, the work for insulating the capacitor 16 from the heat conductive material 31 becomes easy. That is, in the structure illustrated in FIG. 1A, when the difference in height between the upper surface 16a of the capacitor 16 and the upper surface 14a of the stiffener 14 is small, there is a problem that it is difficult to control the height at which the resin is injected so as not to exceed the upper surface 15a of the insulating portion 15. On the other hand, according to the shape of the insulating sheet 115 having the attachment portion 115i at a position lower than the upper wall 115b, even if the difference in height between the upper surface 16a of the capacitor 16 and the upper surface 14a of the stiffener 14 is small, the insulating sheet 115 can be easily attached to the semiconductor device 10. Further, the attachment portion 115i extends in a direction along the surface of the substrate 17. Therefore, the attachment strength of the attachment portion 115i to the substrate 17 can be increased. Note that the attachment portion 115i does not necessarily have to extend in a direction along the surface of the substrate 17. In this case, the lower edge of the outer wall 115d may be adhered to the substrate 17 and function as the attachment portion 115i.

[0055] In the structure shown in FIG. 5B, the inner attachment portion 115h is in direct contact with the upper surface 17a of the substrate 17. However, the attachment portion 115h may be indirectly attached to the substrate 17. For example, the attachment portion 115h may be disposed above the outer peripheral portion 23a of the underfill 23 and adhered to the underfill 23. As still another example, the attachment portion 115h may be formed below the underfill 23 and attached to the upper surface 17a of the substrate 17 by the underfill 23. According to this structure, the work process for adhering the attachment portion 115h can be reduced.

[0056] Mounting portions 115h and 115i are provided on the entire edge of the housing portion 115a, and the inside of the housing portion 115a is sealed. As shown in FIG. 6, the insulating sheet 115 is, for example, rectangular with an opening where the semiconductor chip 11 is disposed formed on the inside. The insulating sheet 115 has, for example, four housing portions 115a along the four side surfaces 11b of the semiconductor chip 11 respectively. The insulating sheet 115 has a mounting portion 115h on the entire inner peripheral edge thereof and a mounting portion 115i on the entire outer peripheral edge thereof. Note that the positions of the mounting portions 115h and 115i are not limited to this. For example, at positions where insulation is not required, the edge of the insulating sheet 115 may not be attached to the substrate 17.

[0057] The shape of the insulating sheet 115 is not limited to the example shown in FIG. 6. For example, when electrical components such as the capacitor 16 exist only in one direction or two directions with respect to the semiconductor chip 11, the insulating sheet 115 does not have to be in a shape surrounding the semiconductor chip 11. For example, the insulating sheet 115 may exist only on one or two of the right side, left side, front side, and rear side of the semiconductor chip 11.

[0058] In the structure shown in FIG. 5B, the outer mounting portion 115i is in direct contact with the upper surface 17a of the substrate 17. However, the mounting portion 115i may be indirectly attached to the substrate 17. For example, the mounting portion 115i may be located on the upper surface 14a of the stiffener 14 as shown in FIG. 7. And the mounting portion 115i may be adhered to the upper surface 14a. In this case, it is desirable that the position of the mounting portion 115i is lower than the upper surface 11a of the semiconductor chip 11. By doing so, when the heat sink 50 is pressed against the semiconductor chip 11, the mounting portion 115i does not interfere with the heat sink 50, so that the adhesion between the heat sink 50 and the semiconductor chip 11 can be ensured.

[0059] In yet another example, the insulating sheet 115 may not have the attached portions 115i and 115h. For example, as shown in FIG. 8, an insulating material may be filled inside the accommodating portion 115a of the insulating sheet 115. This insulating material 115M may be a material that functions as an adhesive (for example, an ultraviolet curable resin). In this way, the insulating sheet 115 is attached to the substrate 17 by this insulating material 115M.

[0060] [Sealing member] In the examples shown in FIGS. 5A, 7, and 8, the sealing member 33 is disposed between the upper surface 14a of the stiffener 14 and the lower surface 50c of the radiator 50, and is sandwiched between these two surfaces 14a and 50c. The stiffener 14 is formed of metal and has higher rigidity than the insulating sheet 115. Since the sealing member 33 is pressed against the stiffener 14 having high rigidity, the contact pressure between the sealing member 33 and the stiffener 14 can be improved. As a result, the sealing performance by the sealing member 33 can be improved.

[0061] [Manufacturing method] An example of a manufacturing method of the semiconductor device 110 and the electronic apparatus 1 including the same will be described. First, the semiconductor chip 11, the capacitor 16, and the stiffener 14 are mounted on the substrate 17. Underfill 23 is filled between the semiconductor chip 11 and the substrate 17. Next, the insulating sheet 115 is placed over the capacitor 16. Then, an adhesive is applied to the attached portions 115h and 115i and cured. Thereby, the inside of the accommodating portion 115a is sealed. As the adhesive, an ultraviolet curable resin can be used. The subsequent steps may be the same as the steps for manufacturing the semiconductor device 10 and the electronic apparatus 1 including the same.

[0062] [Further modification example] FIG. 9A is a cross-sectional view showing yet another modification example of the electronic apparatus 1. FIG. 9B is an enlarged view of FIG. 9A. In these figures, the electronic apparatus 1 has a semiconductor device 210 as a modification example of the semiconductor device 10. In this figure, the same reference numerals are given to the same portions or members as those described so far.

[0063] The semiconductor device 210 has an insulating sheet 215 (see FIG. 5A) as an insulating portion that covers conductor elements such as the capacitor 16 and circuit patterns. The insulating sheet 215 is a sheet formed of resin. As the material of the insulating sheet 215, similar to the above-described insulating sheet 115, for example, engineering plastics such as polycarbonate and polyamide can be used.

[0064] [Liquid gasket] As shown in FIG. 9B, the insulating sheet 215 has an upper wall 215b located above the capacitor 16 and an inner wall 215c located inside the capacitor 16. The upper wall 215b and the inner wall 215c constitute a housing portion 215a for housing conductor elements such as the capacitor 16. The insulating sheet 215 is attached to the substrate 17 by a liquid gasket E2. Specifically, a portion to be attached 215h is formed at the lower end of the inner wall 215c, and this portion to be attached 215h is attached by the liquid gasket E2.

[0065] A liquid gasket has fluidity at normal temperature, dries or becomes uniform after being applied to a joint surface, and forms an elastic or adhesive thin layer. Examples of the material of the liquid gasket include phenolic, modified ester, silicone, and acrylic. By using such a liquid gasket, high sealing performance can be ensured between the portion to be attached 215h of the insulating sheet 215 and the substrate 17.

[0066] The portion to be attached 215h formed at the lower edge of the inner wall 215c is bent with respect to the inner wall 215c and is along the upper surface 17a of the substrate 17. The liquid gasket E2 is disposed, for example, between the upper surface 17a of the substrate 17 and the portion to be attached 215h. According to this, it is possible to prevent the liquid gasket E2 from getting on the upper side of the semiconductor chip 11 during the process of assembling the semiconductor device 210, which may affect the thermal conductivity between the semiconductor chip 11 and the heat sink 50.

[0067] [Double insulating sheet] As shown in FIG. 9B, the semiconductor device 210 further has an insulating sheet 225 as a sheet covering conductor elements such as the capacitor 16 and circuit patterns. The insulating sheet 225 is disposed below the insulating sheet 215. The two sheets 215 and 225 overlap. (In the following description, the insulating sheet 215 is referred to as the upper sheet, and the insulating sheet 225 is referred to as the lower sheet.) The lower sheet 225 is also attached to the substrate 17. Specifically, the lower sheet 225 also has an inner wall 225c inside the capacitor 16, and an attached portion 225h formed at the lower edge thereof is attached to the substrate 17.

[0068] A space for accommodating conductor elements such as the capacitor 16 and circuit patterns is formed between the lower sheet 225 and the substrate 17. Therefore, this space is partitioned by a double sheet from the space where the heat conductive material 31 exists. That is, the upper sheet 215 forms a space (inside the accommodating portion 215a) partitioned from the space where the heat conductive material 31 exists, and the lower sheet 225 forms a space inside the accommodating portion 215a, which is partitioned from the space outside the lower sheet 225.

[0069] The lower sheet 225 is made of a material different from the liquid gasket and is attached to the substrate 17. The attached portion 225h of the lower sheet 225 is bent with respect to the inner wall 225c and is along the upper surface 17a of the substrate 17. The lower sheet 225 is attached to the substrate 17 by, for example, an adhesive tape (a tape coated with an adhesive on both sides) disposed between the attached portion 225h and the substrate 17. The method of attaching the lower sheet 225 to the substrate 17 is not limited to the method using the adhesive tape. For example, the attached portion 215h of the lower sheet 225 may be attached by an adhesive applied to the substrate 17.

[0070] As described above, a heat conductive material 31 having fluidity is disposed between the lower surface 50c of the radiator 50 and the upper surface 11a of the semiconductor chip 11. Since the heat conductive material 31 has fluidity, it may come out from between the lower surface 50c of the radiator 50 and the upper surface 11a of the semiconductor chip 11 and adhere to the liquid gasket E2. When it is necessary to remove the radiator 50 and the upper sheet 215 for repairing the electronic device or replacing defective parts, care must be taken in handling so that the liquid gasket E2 to which the heat conductive material 31 adheres does not scatter. In the semiconductor device 210, the lower sheet 225 is disposed below the upper sheet 215 and further covers the capacitor 16 in the accommodation portion 215a. By this, even if the liquid gasket E2 scatters when the radiator 50 and the upper sheet 215 are removed, the range can be limited to a region where the capacitor 16 does not exist.

[0071] The lower sheet 225 and the upper sheet 215 may be formed of different materials. For example, the lower sheet 225 may be formed of a material having a lower rigidity than the upper sheet 215. Also, in the example of the semiconductor device 210, the lower sheet 225 is a thinner sheet than the upper sheet 215. An example of the material of the lower sheet 225 is polyethylene terephthalate, and the lower sheet 225 may have flexibility. By doing so, an increase in cost due to the lower sheet 225 can be suppressed.

[0072] In the example shown in FIG. 9B, the attached portion 225h of the lower sheet 225 is located below the attached portion 215h of the upper sheet 215 and partially overlaps in plan view. A part of the liquid gasket E2 is disposed above the attached portion 225h of the lower sheet 225. The relationship between the two attached portions 215h and 225h is not limited to the example shown in the figure. The attached portion 225h of the lower sheet 225 may be horizontally separated from the attached portion 215h of the upper sheet 215.

[0073] The semiconductor device 210 has a sealing material 33 formed of a cushioning material. In the example shown in FIGS. 9A and 9B, the sealing material 33 is located above the capacitor 16 and is sandwiched between the upper sheet 215 and the lower surface 50c of the heat sink 50. The sealing material 33 is disposed along the inner edge of the upper wall 215b of the upper sheet 215. The position of the sealing material 33 is not limited to the example shown in this figure, and for example, it may be located above the stiffener 14.

[0074] In the example shown in FIGS. 9A and 9B, the sheets 215 and 225 extend horizontally outward beyond the position of the sealing material 33 and each have upper walls 215b and 225b that cover the capacitor 16 and the stiffener 14. The sheets 215 and 225 descend from the outer edges of the upper walls 215b and 225b and each have outer walls 215d and 225d that cover the stiffener 14. The outer walls 215d and 225d are not attached to the stiffener 14 or to the substrate 17. Thereby, the work required for attaching the sheets 215 and 225 to the substrate 17 can be reduced.

[0075] In contrast, the outer walls 215d and 225d may be attached to the stiffener 14 or the substrate 17. For example, the outer wall 215d of the upper sheet 215 may be attached to the substrate 17 by a liquid gasket, and the outer wall 225d of the lower sheet 225 may be attached to the substrate 17 or the stiffener 14 by means different from the liquid gasket (for example, an adhesive or a double-sided sheet).

[0076] The structure of the sheets 215 and 225 is not limited to the examples shown in these figures. For example, the sheets 215 and 225 may have an outer wall located between the stiffener 14 and the capacitor 16, similar to the example shown in FIG. 5B. And the lower edge (the portion to be attached) of the outer wall may be attached to the substrate 17. In this case, the lower edge (the portion to be attached) of the outer wall of the upper sheet 215 is attached to the substrate 17 by a liquid gasket, and the lower edge (the portion to be attached) of the outer wall of the lower sheet 225 may be attached to the substrate 17 by means different from the liquid gasket (for example, an adhesive or a double-sided sheet).

[0077] [Manufacturing Method] An example of a manufacturing method for the semiconductor device 210 and the electronic device 1 including the same will be described. First, the semiconductor chip 11, the capacitor 16, and the stiffener 14 are mounted on the substrate 17. The underfill 23 is filled between the semiconductor chip 11 and the substrate 17. Next, an insulating sheet (lower sheet) 225 is placed over the capacitor 16. Then, the attachment portion 225h is attached to the substrate 17 with an adhesive sheet. Next, the liquid gasket E2 is applied on the substrate 17, and then, an insulating sheet (upper sheet) 215 is placed over the lower sheet 225. Then, the attachment portion 215h of the upper sheet 215 is attached to the substrate 17 with the liquid gasket. The subsequent steps may be the same as the steps for manufacturing the semiconductor device 10 and the electronic device 1 including the same.

[0078] [Summary] In the electronic device 1 described above, the heat conductive material 31 is disposed between the heat sink 50 and the semiconductor chip 11. The heat conductive material 31 has electrical conductivity and has fluidity at least during the operation of the semiconductor chip 11. The seal member 33 surrounds the heat conductive material 31, and conductor elements such as circuit patterns and electrical components are covered by insulating portions (insulating portion 15 or insulating sheets 115, 215, 225). According to this structure, the range in which the heat conductive material 31 spreads can be restricted by the seal member 33 and the insulating portion.

[0079] Also, in the electronic device 1, the heat conductive material 31 is disposed between the heat sink 50 and the semiconductor chip 11. The heat conductive material 31 has conductivity and has fluidity at least during the operation of the semiconductor chip 11. Conductor elements such as circuit patterns and electrical components are covered by insulating portions (insulating portion 15 or insulating sheets 115, 215, 225). The distance from at least a part on the upper surface of the insulating portion to the lower surface 50c of the heat sink 50 is larger than the distance from the upper surface 11a of the semiconductor chip 11 to the lower surface 50c of the heat sink 50. According to this structure, the range in which the heat conductive material spreads can be restricted to a region where no conductor elements such as electrical components exist. Also, the adhesion between the heat sink and the semiconductor chip can be ensured.

[0080] The semiconductor devices 110 and 210 have insulating sheets 115, 215, and 225 that cover conductor elements such as circuit patterns and electrical components. According to this semiconductor device 110 and 210, the range in which the heat conduction material 31 spreads can be limited to a region where no conductor element exists.

[0081] The semiconductor devices 10, 110, and 210 have an insulating portion (insulating portion 15 or insulating sheets 115, 215, and 225) that covers conductor elements such as circuit patterns and electrical components. The height of at least a part of the upper surface of the insulating portion with respect to the substrate 17 is smaller than the height of the upper surface 11a of the semiconductor chip 11 with respect to the substrate 17. According to this structure, while limiting the range in which the heat conduction material 31 spreads to a region where no conductor element such as an electrical component exists, the adhesion between the radiator 50 and the semiconductor chip 11 can be ensured.

[0082] The insulating sheets 115 and 215 have accommodating portions 115a and 215a that have upper walls 115b and 215b located above the conductor element and inner walls 115c and 215c located inside the upper walls 115b and 215b and descending from the upper walls 115b and 215b. Further, the insulating sheets 115 and 215 have attached portions 115h and 215h that are connected to the inner walls 115c and 215c and are located at a position lower than the upper walls 115b and 215b. According to this insulating sheet 115 and 215, the range in which the heat conduction material 31 spreads can be limited to a region where no conductor element exists. Also, even when the height difference between the conductor element (for example, capacitor 16) and the semiconductor chip 11 is small, the insulating sheets 115 and 215 can be relatively easily attached to the substrate.

[0083] An example of a method for manufacturing semiconductor devices 10, 110, and 210 includes a step of covering conductor elements such as circuit patterns and electrical components with an insulating portion (insulating portion 15 or insulating sheets 115, 215, 225). In the step of covering the conductor elements with the insulating portion, the height of the upper surface of the insulating portion with respect to the substrate 17 is smaller than the height of the upper surface 11a of the semiconductor chip 11 with respect to the substrate 17. According to this method, the range in which the heat conduction material 31 spreads can be limited to a region where no conductor elements such as electrical components exist. Further, the adhesion between the heat sink 50 and the semiconductor chip 11 can be ensured.

[0084] Note that the invention according to the present disclosure is not limited to the electronic device, semiconductor device, insulating sheet, and manufacturing method described above, and appropriate changes within the scope that maintains the gist of the invention are included in the scope of the present invention.

Claims

[Claim 1] A semiconductor chip; a substrate disposed below the semiconductor chip, the substrate having a first region in which the semiconductor chip is mounted, and a second region in which conductor elements including at least one of a circuit pattern and an electrical component are provided; and an insulating sheet covering the conductor element. Semiconductor device.

Images