JP5371564B2 - Semiconductor module and method for manufacturing semiconductor module - Google Patents

Description

  The present invention has a heat spreader in which a semiconductor element is mounted on the upper surface side, and an insulating layer formed of a resin composition is bonded to the lower surface of the heat spreader, and is formed of a metal sheet on the lower surface of the insulating layer. The present invention relates to a semiconductor module to which a metal sheet layer is bonded and a resin mold that exposes a lower surface of the metal sheet layer to cover the semiconductor element and the heat spreader, and a method for manufacturing the semiconductor module.

Conventionally, a semiconductor module in which a semiconductor element is resin-molded has been widely used. Since this semiconductor element generates heat when energized, various heat dissipation means are used to prevent the junction temperature from rising above a certain level. Has been taken.
In general, a member called a heat spreader for quickly removing heat generated from a semiconductor element is provided in the module in a state of contacting the semiconductor element.
The heat spreader is usually formed using a metal block, and the heat spreader itself is formed so that heat generated from the semiconductor element can be quickly diffused. It becomes impossible to take heat away from the element.
Therefore, a method is widely used in which an external member such as a heat radiating fin is attached to the semiconductor module to promote the dissipation of heat from the heat spreader outside the module such as in the atmosphere.

Here, reducing the thermal resistance value between the heat spreader and the heat radiating fins is advantageous for heat dissipation of the semiconductor module, but on the other hand, insulation between the heat spreader and the heat radiating fins is necessary for safety. It is required to secure.
As a result, an insulating layer in contact with the surface opposite to the side on which the semiconductor element of the heat spreader is mounted was formed, and the insulating layer was highly filled with inorganic particles to improve thermal conductivity. 2. Description of the Related Art Conventionally, a semiconductor module formed of a resin composition and formed so that heat can be radiated to the outside through this insulating layer has been used.
In general, a sheet formed of a resin composition highly filled with inorganic particles becomes brittle enough to be handled with care alone, so a metal sheet having excellent thermal conductivity is used as a support material. For example, in Patent Document 1, a metal sheet having an insulating layer laminated on the upper surface side is bonded to the lower surface side of the heat spreader on which the semiconductor element is mounted on the upper surface side, and the insulating layer and the metal sheet are bonded. A semiconductor module having a resin mold that exposes the lower surface of the metal sheet layer and covers the heat spreader and the semiconductor element is described.

  This semiconductor module is formed so that the heat of the heat spreader is transferred to the metal sheet layer through the insulating layer, and the lower surface of the metal sheet layer is exposed on the lower surface of the semiconductor module. The heat inside the module can be efficiently dissipated by, for example, contacting the heat dissipating fins with the metal sheet.

JP 2004-165281 A

  In this type of semiconductor module, heat dissipation is improved by increasing the amount of inorganic particles in the resin composition constituting the insulating layer or by reducing the thickness of the insulating layer. It becomes easy to break and lowers insulation reliability, making it difficult to improve both heat dissipation and insulation.

For example, in the case of the semiconductor module described in Patent Document 1, it is formed by adhering a metal sheet with an insulating layer having a larger area than the lower surface of the heat spreader, and the insulating layer and the metal sheet outside the heat spreader. It is in a state of protruding the layer.
In that case, for example, in the bonding operation between the heat spreader and the insulating layer or the resin mold forming operation, bending stress or shearing force is easily applied to the insulating layer at the edge portion on the outer periphery of the lower surface of the heat spreader. Therefore, it is easy to reduce electrical reliability.

In order to prevent this, when an insulating layer and a metal sheet layer are formed by adhering a metal sheet with an insulating layer that is the same as the lower surface of the heat spreader or a small area to the heat spreader, for example, a metal sheet It becomes difficult to ensure electrical insulation between the heat spreader and the metal sheet layer at the outer edge of the layer.
That is, as shown in FIG. 5, only the thickness of the insulating layer is ensured as the creeping distance from the heat spreader to the metal sheet layer, and there is a possibility that the electric insulation can be expected only to the extent of the space withstand voltage therebetween.

  In the semiconductor module shown in FIG. 5, if the resin mold adheres well to the end face of the insulating layer or the metal sheet layer, the insulation by the resin mold can be expected. It is difficult to bond the resin mold with a small area of the end face of the metal sheet layer, and it is difficult to expect insulation reliability because it may be peeled inadvertently even if bonded. Absent.

That is, the conventional semiconductor module has a problem that it is difficult to improve the heat dissipation while suppressing the deterioration of the insulation reliability.
The present invention has been made in view of the above problems, and a semiconductor module that has improved heat dissipation while suppressing a decrease in insulation reliability, and has excellent heat dissipation while suppressing a decrease in insulation reliability. An object of the present invention is to provide a semiconductor module manufacturing method capable of manufacturing a semiconductor module.

A heat spreader semiconductor element is mounted on the upper surface, a lower surface to be bonded is Ru insulating layer of said heat spreader is formed by a tree fat composition, the metal is formed by a metallic sheet Ru is adhered to the lower surface of the insulating layer sheet a layer, a manufacturing method of a semiconductor module for producing a semiconductor module Ru and a resin mold which is formed so as to expose the lower surface of the metal sheet layer covering the semiconductor element and the heat spreader, the lower surface of the heat spreader A first insulating layer having a shape corresponding to the first insulating layer, the metal sheet layer formed so as to have a smaller area than the lower surface of the first insulating layer, and disposed in the center of the lower region on the lower surface, and the metal sheet Forming a laminate having a shape corresponding to the upper surface of the layer and comprising a second insulating layer bonded to the upper surface and the lower surface of the first insulating layer Bonding the upper surface of the first insulating layer in the laminate to the lower surface of the heat spreader to form the insulating layer comprising the first insulating layer and the second insulating layer; and the first insulating layer outside the metal sheet layer And a step of forming the resin mold so as to adhere to the lower surface of the layer .

In the semiconductor module of the present invention, the metal sheet layer is formed so that the insulating layer has a smaller area than the area covering the lower surface of the heat spreader, and is disposed at the center of the lower surface of the heat spreader.
That is, since the insulating layer is spread outside the metal sheet layer, the creeping distance from the heat spreader to the metal sheet layer is ensured by the extent to which the insulating layer spreads.
In addition, since the lower surface of the insulating layer and the resin mold are bonded, the insulation reliability between them can be further improved.

Sectional drawing which shows the structure of the semiconductor module of one Embodiment. The side view which shows one formation method of an insulating layer. The side view which shows the mode of the inside of the apparatus used for manufacture of a semiconductor module. The side view which shows the other formation method of an insulating layer. Sectional drawing which shows the structure of the semiconductor module outside this invention.

The preferred embodiments of the present invention will be described below.
FIG. 1 is a view showing a cross section of a semiconductor module according to the present embodiment. As shown in FIG. 1, the semiconductor module 1 of the present embodiment has a semiconductor element 50 mounted on the upper surface side. The insulating layer 10 is bonded to the lower surface of the heat spreader 30 and the upper surface of the metal sheet layer 20, and the metal sheet layer 20 is interposed through the insulating layer 10 so as to be located at the center of the lower surface of the heat spreader 30. Are glued together.
And in the semiconductor module which concerns on this embodiment, the lower surface of the said metal sheet layer 20 is exposed, and the resin mold 90 which covers the said semiconductor element 50 and the said heat spreader 30 is given.

And since the said metal sheet layer 20 is formed so that the said insulating layer 10 may become an area smaller than the area which covers the lower surface of the said heat spreader 30, the said resin mold 90 is in the outer side of the metal sheet layer 20. The heat spreader 30 is covered from the lower surface side.
The resin mold 90 covers the heat spreader 30 from the lower surface side in a state of being bonded to the lower surface of the insulating layer 10 outside the metal sheet layer 20.

The heat spreader 30 is cut from a thick plate formed of a metal such as copper into a rectangular shape when viewed from above, and is accommodated in the semiconductor module 1 so that the planar direction thereof is the horizontal direction. The semiconductor element 50 is fixedly mounted with solder 40 at the center.
The semiconductor element 50 is smaller than the heat spreader 30. In the present embodiment, the semiconductor element 50 is mounted on the heat spreader 30 in a bare chip state.
Then, one end of the bonding wire 60 is bonded to the terminal portion of the lead frame 70 that extends through the case 80 that forms the outer shell of the semiconductor module 1 of the present embodiment, and the other end of the bonding wire 60 is the semiconductor. Bonded to the upper surface of the element 50.
The other terminal portion provided on the lead frame 70 is soldered to the upper surface of the heat spreader 30 exposed around the semiconductor element 50. In the semiconductor module 1 of the present embodiment, the bonding wire 60 is used. Constitutes a terminal part and a counter electrode to which are bonded.
That is, the semiconductor module 1 in the present embodiment is formed so that the heat spreader 30 itself is energized.

The metal sheet layer 20 is formed of a metal sheet 20a such as copper or aluminum, and is formed using, for example, a foil having a thickness of 10 to 300 μm or a plate having a thickness exceeding 300 μm.
And the shape in the top view is formed so as to be a rectangular shape having a smaller area than the lower surface of the heat spreader 30, and the metal sheet layer 20 is positioned at the center of the lower surface of the heat spreader 30. It is bonded via the insulating layer 10.

The insulating layer 10 disposed between the heat spreader 30 and the metal sheet layer 20 is made of a resin composition highly filled with inorganic particles, and the lower surface of the heat spreader 30 It is formed in a size having substantially the same area.
More specifically, a layer 11 in contact with the lower surface of the heat spreader 30 (hereinafter also referred to as “first insulating layer 11”), and a layer in contact with the lower surface of the first insulating layer 11 and in contact with the upper surface of the metal sheet layer 20. 12 (hereinafter also referred to as “second insulating layer 12”), and the first insulating layer 11 is formed so that the shape of the first insulating layer 11 when viewed from above is substantially the same as the lower surface of the heat spreader 30. .

The first insulating layer 11 having a shape corresponding to the lower surface of the heat spreader 30 is bonded to the lower surface of the heat spreader 30 with its outer edge aligned with the outer edge of the lower surface of the heat spreader 30.
On the other hand, the second insulating layer 12 has substantially the same top view shape as the upper surface of the metal sheet layer 20 and is adhered to the metal sheet layer 20 so as to cover substantially the entire upper surface of the metal sheet layer 20. Yes.

Therefore, the insulating layer 10 formed by the first insulating layer 11 and the second insulating layer 12 is formed so that only the upper surface side of the metal sheet layer 20 is thick, and outside the second insulating layer 10 The thickness is reduced by the thickness of the layer 12.
That is, when the thickness of the first insulating layer 11 is t1, and the thickness of the second insulating layer 12 is t2, the insulating layer 10 on the upper surface side of the metal sheet layer 20 has a thickness of (t1 + t2), and its periphery is t1 It has only a thickness.

The lower surface of the first insulating layer 11 is bonded to the resin mold 90 on the outer side of the metal sheet layer 20.
That is, the resin mold 90 covers the heat spreader 30 from the lower surface side with the same thickness as the stepped thickness (t2) shown above, and the lower surface of the resin mold 90 and the metal sheet layer 20 are formed on the lower surface of the semiconductor module. Is substantially flush with the lower surface of the plate.

In addition, when it approaches the area of the lower surface of the heat spreader 30, the creeping distance is shortened and the electrical reliability is lowered.
In such a point, it is preferable to form the insulating layer 10 having a size corresponding to the lower surface of the heat spreader 30 as illustrated above and cover the lower surface of the heat spreader 30 without exposing the metal sheet layer 20. The creeping distance, that is, the distance from the outer edge of the insulating layer 10 is preferably 2 mm or more.
On the other hand, when the metal sheet layer 20 is formed in a state that is too small with respect to the lower surface of the heat spreader 30, it is disadvantageous for heat dissipation.
Therefore, the metal sheet layer 20 is preferably formed such that the distance from the outer edge of the insulating layer 10 is 5 mm or less.
If the metal sheet layer 20 is required to have a larger area while ensuring electrical reliability, the outer edge of the metal sheet layer 20 is formed 2 mm inside the outer edge of the insulating layer 10. You can do so.

As described above, in this embodiment, since the heat spreader 30 is energized, the insulation reliability with respect to the insulating layer 10 is strongly required. In this way, the insulation of the two-layer structure is provided on the lower surface side of the heat spreader 30. By forming the layers, even if pinholes or the like are formed in each of the first insulating layer 11 and the second insulating layer 12, the formation positions thereof coincide with each other from the lower surface of the heat spreader 30. It is possible to sufficiently reduce the possibility that a pinhole that penetrates to the upper surface of the sheet layer 20 is formed.
A method for adhering the upper and lower surfaces of the insulating layer 10 to the lower surface of the heat spreader 30 and the upper surface of the metal sheet layer 20 is not particularly limited, but the first insulating layer 11 is attached to the lower surface of the heat spreader 30. After the forming step and the step of forming the second insulating layer 12 on the upper surface of the metal sheet 20x for forming the metal sheet layer 20, the lower surface of the first insulating layer 11 and the upper surface of the second insulating layer 12 A method of adhering the material is an easy method with excellent workability.

In the semiconductor module as shown in Patent Document 1 (Japanese Patent Laid-Open No. 2004-165281) in which an insulating layer and a metal sheet layer having a larger area than the lower surface of the heat spreader are formed, the insulating layer and the metal As a specific method for forming the sheet layer, a method in which a metal sheet with an insulating layer is adhered to the lower surface of the heat spreader is usually employed.
In that case, stress is easily applied in the direction in which the insulating layer is refracted at the edge portion on the outer periphery of the lower surface of the heat spreader, and the insulating layer is easily cracked in this portion, so that the electrical reliability is easily lowered.

  On the other hand, when carrying out the step of forming the first insulating layer 11 and the step of forming the second insulating layer 12 as described above, for example, on a support material such as a resin film subjected to a release treatment. Even when a method is adopted in which the first insulating layer 11 formed in this manner is adhered and transferred to the lower surface of the heat spreader 30, the first insulating layer 11 is substantially the same shape as the lower surface of the heat spreader, so that the edge portion 30e of the heat spreader There is little risk of cracking in the first insulating layer 11, and electrical reliability is easily secured.

Further, even when the metal sheet 20x on which the second insulating layer 12 is formed and the first insulating layer 11 bonded to the lower surface of the heat spreader 30, the second insulating layer 12 is the first insulating layer 11 Since the outer edge of the second insulating layer 12 comes into contact with the first insulating layer 11 because it is in contact with the central portion, the second insulating layer 12 is formed of the resin composition. Unlike the case where the edge of the heat spreader is in contact with the conventional semiconductor module, it is possible to suppress the concentration of stress on the edge portion.
That is, the semiconductor module 1 of the present embodiment can prevent the insulating layer 10 from cracking and can improve insulation reliability.

In addition, since the insulating layer 10 can be prevented from cracking, the resin composition forming the insulating layer 10 can be highly filled with inorganic particles so as to impart high thermal conductivity.
Further, if a resin having a dielectric constant higher than that of the resin composition used for forming the insulating layer 10 is used for the resin mold 90, the electric field strength can be increased by allowing the mold resin having a high dielectric constant to be present in the vicinity of the edge portion. Can be relaxed.
Therefore, by setting it as such an aspect, the insulation reliability of the semiconductor module 1 can be improved further.
This dielectric constant can be obtained by performing measurement at 1 MHz, for example, using a generally used dielectric constant measuring apparatus.

As described above, in the semiconductor module 1 of this embodiment, the adhesive surface A is formed between the lower surface of the first insulating layer 11 and the resin mold 90.
On the bonding surface A, since bonding between the resin compositions is performed, it is easy to exert an excellent adhesive force between the resin mold 90 and the heat spreader 30.
Therefore, it is possible to suppress the possibility that peeling occurs on the adhesive surface A and creeping discharge occurs from the edge portion 30e of the heat spreader 30 to the outer edge portion of the metal sheet layer 20.

In addition, since the resin mold 90 extends to the lower surface side of the heat spreader 30, the heat spreader 30 in the semiconductor module 1 is firmly fixed, and physical destruction is also suppressed.
That is, in the case where the resin mold does not reach the lower surface side of the heat spreader, when the separation occurs between the side surface of the heat spreader and the resin mold, a deterrent that prevents the heat spreader portion from falling off the semiconductor module is provided. Although depending mainly on the adhesive force on the upper surface side of the heat spreader, in the semiconductor module 1 according to the present embodiment, the resin mold 90 wraps around to the lower surface side of the heat spreader 30, and the first insulating layer 11. Therefore, even if peeling occurs between the side surface of the heat spreader 30 and the resin mold 90, it is possible to sufficiently prevent the heat spreader 30 from falling off.

  That is, it can be said that the semiconductor module 1 in the present embodiment is superior to the conventional semiconductor module not only in insulation reliability but also in reliability in physical strength.

  The first insulating layer 11 and the second insulating layer 12 are formed of a resin composition in which inorganic particles are highly filled in a polymer component in order to quickly transfer the heat of the heat spreader 30 to the metal sheet layer 20 side. Yes.

The polymer component is not particularly limited, and a commonly used resin can be used alone or mixed, and a rubber component or the like can be added as necessary.
Examples of this resin include thermoplastic resins and thermosetting resins. Among these resins, examples of thermoplastic resins include polyolefin resins such as polyethylene resins, polypropylene resins, and ethylene-vinyl acetate copolymer resins, polyvinyl chloride resins, Examples include phenoxy resin, acrylic resin, polyamide resin, polyamideimide resin, polyimide resin, polyetheramideimide resin, polyetheramide resin, and polyetherimide resin.
Examples of the thermosetting resin include an epoxy resin and a phenol resin.
The rubber includes natural rubber, polyisoprene rubber, styrene-butadiene copolymer rubber, polybutadiene rubber, ethylene-propylene copolymer rubber, ethylene-propylene-diene copolymer rubber, butadiene-acrylonitrile copolymer rubber. , Isobutylene-isoprene copolymer rubber, chloroprene rubber, silicon rubber, fluorine rubber, chlorosulfonated polyethylene, polyurethane rubber and the like.

Especially, it is suitable to use an epoxy resin for the polymer component used for forming the insulating layer 10 because it exhibits excellent adhesiveness and heat resistance.
Moreover, a room temperature solid epoxy resin is preferred.
This room temperature solid epoxy is preferable because when the room temperature liquid epoxy resin is used, when the insulating layer 10 is heated to bond the metal sheet layer 20 and the heat spreader 30, the viscosity of the epoxy resin is preferred. It is because there is a possibility that the epoxy resin may ooze out from the edge portion of the metal sheet layer 20 due to excessive reduction.
In the case where the oozing of the epoxy resin is severe, for example, an epoxy resin film is formed on a portion where the metal sheet layer 20 should be exposed, such as the lower surface side of the metal sheet layer 20, and the thermal resistance between the heat sink and the radiator May increase.

On the other hand, if the viscosity does not decrease to some extent when adhering to the adherend (metal sheet 20a, heat spreader 30), a gap or the like tends to occur between the adherend and the insulating layer 10, and the metal sheet layer 20 from the heat spreader 30 side. There is also a risk of decreasing the thermal conductivity to the side.
This epoxy resin has a normal temperature solid bisphenol having an epoxy equivalent of 450 to 2000 g / eq in that the resin composition for forming the insulating layer 10 can be imparted with appropriate flowability to suppress these problems more reliably. A type epoxy resin and a novolac type epoxy resin having a softening point between 87 ° C. and 93 ° C. with a polyfunctional room temperature solid having an epoxy equivalent of 160 to 220 g / eq (bisphenol A type epoxy resin / novolak type epoxy resin) = It is preferable to use what is mixed by the mass ratio used as 40/60-60/40.
In addition, this epoxy equivalent can be calculated | required by JISK7236.

Thus, when an epoxy resin is contained in the resin composition as the polymer component, a thermosetting property can be imparted by further containing an epoxy resin curing agent and a curing accelerator in the resin composition.
The curing agent is not particularly limited, and examples thereof include amine curing agents such as diaminodiphenyl sulfone, dicyandiamide, diaminodiphenylmethane, and triethylenetetramine, phenol novolac resins, aralkyl type phenol resins, and dicyclopentadiene-modified phenols. Resin, phenolic curing agents such as naphthalene type phenolic resin and bisphenolic phenolic resin, acid anhydrides and the like can be used.
Among these, phenol novolac resin and diaminodiphenyl sulfone are preferable in that it is easy to ensure reliability in electrical characteristics.
The curing accelerator is not particularly limited, but amine-based curing accelerators such as imidazoles, triphenyl phosphate (TPP), and boron trifluoride monoethylamine are preferable in terms of storage stability.

As the inorganic particles, those generally used as inorganic fillers can be adopted, and among them, boron nitride particles are excellent in thermal conductivity and can be suitably used.
Moreover, it is preferable to use particles (aggregated particles) obtained by agglomerating plate-like primary particles of boron nitride.
As the aggregated particles, aggregated particles (granular particles) formed in an overall granular state or aggregated particles (aggregated state) exhibiting an aggregated state aggregated to such an extent that the scaly structure of the primary particles of boron nitride can be distinguished. Particles) and the like.

In addition, although depending on the thickness of the insulating layer 10 to be formed, etc., the resin composition can usually contain aggregated particles having an average particle diameter of 10 to 100 μm.
The “average particle diameter” can be determined by, for example, measuring the D50 value by performing particle size distribution measurement using a laser diffraction method.

  Further, as the inorganic component, inorganic particles formed of a substance other than boron nitride (for example, aluminum nitride, silicon nitride, gallium nitride, aluminum oxide, silicon carbide, silicon dioxide, diamond, etc.) can also be included. .

  In addition, the content of the inorganic particles in the resin composition for forming the insulating layer 10 is preferably 50% or more by volume in that the effect of preventing cracking of the insulating layer 10 can be exhibited more significantly. More preferably, it is 55 volume% or more.

  Although not described in detail here, in addition to the polymer component and inorganic particles as described above, the resin composition for forming the insulating layer 10 includes a dispersant, a tackifier, an anti-aging agent, and an antioxidant. In general, rubbers such as processing aids, stabilizers, antifoaming agents, flame retardants, thickeners, pigments, and the like, which are commonly used as plastic compounding chemicals, can be appropriately added.

Further, the first insulating layer 11 and the second insulating layer 12 can be made of different resin compositions.
In addition, although the 1st insulating layer 11 and the 2nd insulating layer 12 can aim at the improvement of thermal conductivity by making thickness thinner, respectively, in that case, electrical insulation is reduced. Become.
In this respect, at least the thickness of the first insulating layer 11 is preferably 50 μm or more.
Further, as described above, if the thickness of the insulating layer 10 is increased, the thermal conductivity is lowered. Therefore, the total thickness of the first insulating layer 11 and the second insulating layer 12 is 300 μm or less. preferable.
That is, it is preferable that the first insulating layer 11 and the second insulating layer 12 each have a thickness of 50 to 150 μm.

  Next, a manufacturing method for manufacturing the semiconductor module 1 as described above will be described with some examples.

First, the first manufacturing method will be described with reference to FIGS.
In the semiconductor module manufacturing method of the present embodiment, as a method of forming the metal sheet layer 20 and the insulating layer 10, a long belt-like sheet made of a metal sheet (for example, copper foil) for forming the metal sheet layer 20 is used. After coating the resin composition for forming the insulating layer 10 to form a film, a cut piece 10x having a shape corresponding to the lower surface of the heat spreader 30 is formed from the film-formed belt-like sheet, and the cut piece 10x And a cut-out piece 10y having a shape corresponding to the metal sheet layer 20 is cut out, and the first insulating layer 11 and the second insulating layer 12 are thereby formed.

  That is, as shown in FIG. 2, after the cut piece 10x is thermally bonded to the lower surface of the heat spreader 30, only the metal sheet 20a is peeled off, and the first insulating layer 11 is formed on the lower surface of the heat spreader 30, The cutout piece 10y having a shape corresponding to the metal sheet layer 20 is bonded to the center of the lower surface of the heat spreader 30, and the insulating layer 10 and the metal sheet layer 20 having a laminated structure of the first insulating layer 11 and the second insulating layer 12 are combined. Can be produced.

More specifically, for example, an epoxy resin composition containing an epoxy resin and nitriding particles is prepared, and this is dispersed in a solvent to prepare a coating liquid having an appropriate viscosity to form an insulating layer. Therefore, it can be set as a resin composition.
Then, for example, a copper foil coil is applied to a continuous coating machine, the coating liquid is applied and then dried to form a film, and the cut pieces 10x and 10y are cut out from the copper foil formed with the film, respectively. After the cut piece 10x is adhered to the lower surface of the heat spreader 30 by hot pressing or the like, the first insulating layer 11 is formed by peeling the copper foil, and then the metal sheet 20a (cut out) having the second insulating layer 12 on the upper surface. The piece 10y) can be bonded by hot pressing or the like to form the insulating layer 10 and the metal sheet layer 20 having a laminated structure.
Then, in the state in which the insulating layer 10 and the metal sheet layer 20 are formed, for example, using a device as shown in FIG. 3, the molten resin is used to cover the semiconductor element and the heat spreader 30 from the lower surface side. The resin mold 90 can be formed.

FIG. 3 is a side view showing the apparatus for forming the resin mold and the semiconductor module before the resin mold is viewed from the side, and the heat spreader 30 and the like are attached to the case 80 accommodated in the mold Z. The resin mold 90 is formed by using the mold resin M.
As a specific example using such an apparatus, for example, the heat spreader 30 in which the insulating layer 10 and the metal sheet layer 20 are formed on the lower surface side on the bottom surface of the mold Z and the semiconductor element 50 is mounted on the upper surface side is accommodated. In addition, the case 80, the lead frame 70, etc. are also accommodated at predetermined positions in the mold Z so that the inflow pressure of the mold resin M acts from the upper surface side to the lower surface side of the heat spreader 30. The method of filling is included.
At this time, since the lower surface of the metal sheet layer 20 is in contact with the bottom surface of the mold Z, the resin is not exposed to the mold resin M and the lower surface of the metal sheet layer 20 is exposed to this portion. A mold 90 can be formed.
In addition, since the lower surface of the first insulating layer 11 constituting the insulating layer 10 is exposed outside the metal sheet layer 20, the first insulating layer 11 is filled with the mold resin M in this state. A resin mold 90 adhered to the lower surface of the layer 11 can be formed.

In addition, in the filling of the mold resin M, the inflow pressure of the mold resin M acts to press the heat spreader 30 downward. As described above, the insulation layer 10 is cracked by the pressure. Therefore, the semiconductor module 1 can be manufactured in a state where a decrease in electrical reliability is suppressed.
Therefore, even if an epoxy resin composition having a high thermal conductivity in which boron nitride particles are highly filled by 50% by volume or more is used in the resin composition constituting the insulating layer, cracking or the like may occur in the insulating layer. It is suppressed and insulation reliability is ensured.

  Here, the mold resin M is filled in advance in a state where the heat spreader 30 and the first insulating layer 11, the first insulating layer 11 and the second insulating layer 12, and the second insulating layer 12 and the metal sheet layer 20 are respectively bonded. However, the present invention is not limited to such a method. For example, the heat spreader 30 and the first insulating layer 11 or the first insulating layer 11 and the second insulating layer 12 are in contact with each other and can be separated. Alternatively, a method may be employed in which the mold resin M is filled in a state in which the mold resin is laminated and these are bonded and integrated by heat and pressure of the mold resin M.

Moreover, in the said method, the example which cuts out the cut piece 10x for forming the 1st insulating layer 11, and the cut piece 10y for forming the 2nd insulating layer 12 and the metal sheet layer 20 from a common member is shown. For example, these may be cut out from separate members.
For example, since the cut piece 10x for forming the first insulating layer 11 is to peel off the metal sheet 20a later, it is not a copper foil but a polymer film that has been subjected to a release treatment. It is also possible to facilitate peeling after bonding to the heat spreader 30.

Moreover, it can replace with said method and can also employ | adopt the 2nd manufacturing method as shown in FIG.
In the second manufacturing method, a film made of the epoxy resin composition is formed on a polymer film for forming the first insulating layer 11, and the first insulating layer 11 is formed from the polymer film formed with the film. While producing the cut piece 10z for forming the layer 11, the small cut piece 10y which used copper foil as the base material is produced similarly to the 1st manufacturing method.
And after bonding the cut piece 10y to the center part of the cut piece 10z for forming this 1st insulating layer 11 with hot press etc., the base film of the cut piece 10z for forming the 1st insulating layer 11 20b is peeled off to produce a laminated body in which the first insulating layer 11 / second insulating layer 12 / metal sheet layer 20 are laminated, and the die Z of the apparatus shown in FIG. The semiconductor module 1 can be manufactured by setting together with the heat spreader 30 or the like.

  Furthermore, if necessary, the second insulating layer 12 is formed on the polymer film in the same manner as the first insulating layer 11 in the second manufacturing method, and the first insulating layer 11, the second insulating layer 12, and the metal sheet layer 20 are formed. Each of the metal sheets 20a for producing the resin is produced separately, and the resin mold 90 is formed after sequentially adhering to the heat spreader 30, or the resin mold 90 is set in a mold in a separable state, and the resin is obtained. A method of bonding and integrating with the formation of the mold 90 may be adopted.

In the above description, the semiconductor module and the manufacturing method thereof have been described by taking the case where the insulating layer has a two-layer structure as an example. It may be a layer.
In addition, in order to form an insulating layer having a stepped structure with a thin periphery and a thick central portion exemplified in the present embodiment, a sheet having a thin central thickness is formed by injection molding or the like. Thus, it is possible to adopt an embodiment in which this is used for forming the insulating layer.
In addition to the copper foil, various metal sheets such as an aluminum plate can be used for forming the metal sheet layer.
Furthermore, known technical matters in conventional semiconductor modules can be appropriately adopted as long as the effects of the present invention are not significantly impaired.

DESCRIPTION OF SYMBOLS 1 Semiconductor module 10 Insulating layer 11 1st insulating layer 12 2nd insulating layer 20 Metal sheet 30 Heat spreader 40 Solder 50 Semiconductor element 60 Bonding wire 70 Lead frame 80 Case 90 Resin mold M Mold resin P Resin mold apparatus Z Mold

Claims (1)

A heat spreader semiconductor element is mounted on the upper surface, a lower surface to be bonded is Ru insulating layer of said heat spreader is formed by a tree fat composition, the metal is formed by a metallic sheet Ru is adhered to the lower surface of the insulating layer sheet a layer, a manufacturing method of a semiconductor module for producing a semiconductor module Ru and a resin mold which is formed so as to expose the lower surface of the metal sheet layer covering the semiconductor element and the heat spreader,
A first insulating layer having a shape corresponding to the lower surface of the heat spreader, and the metal sheet layer formed to have a smaller area than the lower surface of the first insulating layer and disposed in the center of the lower region of the lower surface; Forming a laminate comprising a second insulating layer having a shape corresponding to the upper surface of the metal sheet layer and bonded to the upper surface and the lower surface of the first insulating layer;
Bonding the upper surface of the first insulating layer in the laminate to the lower surface of the heat spreader to form the insulating layer comprising the first insulating layer and the second insulating layer;
And a step of forming the resin mold so as to adhere to the lower surface of the first insulating layer outside the metal sheet layer .

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