JP2000299559A - Power module substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent peeling of a conductive pattern from a ceramic board which is caused by the difference in thermal expansion coefficient between the ceramic board and the conductive pattern. SOLUTION: Related to a power module substrate 10 where a conductive pattern 12 is formed at least on one surface of a base body 11 comprising a ceramic board, a peeling-preventive means 13 which prevents peeling of the conductive pattern 12 from the base body 11 is formed at least at outer end part which is the end part on the peripheral side of the base body 11 among the end part of the conductive pattern 12, and the peeling-preventive means 13 at the outer end part is so formed as to cover the outer end part of the conductive pattern 12 of the base body 11, including the peripheral part of the base body 11. The peeling-preventive means 13 is formed of, for example, a resin material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power module substrate, and more particularly, to a power module substrate for use in, for example, an electronic component used for a control system of an actuator and through which a large current flows.

[0002]

2. Description of the Related Art Conventional power module substrates include 1
For example, as shown in FIG. 14, a metal conductive pattern 212 made of copper or aluminum is joined to both sides of a ceramic plate 211 which is an insulating material for use in an electronic component configuration through which a large current of 0 amperes or more flows. Is used.

[0003] Such a power module substrate 210
In the electronic component 200 configured by using the conductive pattern 212, for example, the conductive pattern 212 formed on one surface side of the ceramic plate 211 is used.
A semiconductor element 201 made of a silicon chip is mounted thereon by bonding with a solder 202. Further, an electrode (not shown) formed on the upper surface of the semiconductor element 201 and the conductive pattern 212 are formed of a wire 20 made of aluminum or the like.
3 and a lead terminal 204 is connected to the conductive pattern 212 via a solder 202. Further, on the lower surface of the conductive pattern 212 formed on the other surface side of the ceramic plate 211, a heat radiating plate 205 formed of, for example, an aluminum plate is joined via a solder 202.

[0004]

In the power module substrate 210 as described above, the mounted semiconductor element 2
01 and the conductive pattern 212, a large current flows, thereby generating heat. However, since the coefficient of thermal expansion of copper or aluminum constituting the conductive pattern 212 is higher than that of the ceramic plate 211, the ceramic plate 211 and the conductive pattern 2
12, a thermal stress is generated between the ceramic plate 211 and the conductive pattern 212, causing a problem that the conductive pattern 212 is separated from the ceramic plate 211. The peeling of the conductive pattern 212 tends to occur particularly at the outer end of the conductive pattern 212 on the side of the peripheral edge of the ceramic plate 211, which causes a decrease in the reliability of the power module substrate 210.

[0005] Therefore, there is a strong demand for the development of a power module substrate that can prevent the conductive pattern from peeling off from the ceramic plate due to the difference in thermal expansion coefficient between the ceramic plate and the conductive pattern.

[0006]

Means for Solving the Problems In order to solve the above-mentioned problems, a power module substrate (1) according to the present invention is a power module substrate formed by forming a conductive pattern on at least one surface of a base made of a ceramic plate. In the substrate, a peeling prevention member for preventing peeling of the conductive pattern from the base is formed at least at an outer end of the conductive pattern, which is an end on the peripheral side of the base, and peeling of the outer end is performed. The prevention member is characterized in that it is formed so as to cover the outer end of the conductive pattern of the base including the peripheral edge of the base.

The peel prevention member is made of, for example, a resin material or an insulating material having a coefficient of thermal expansion substantially equal to or near the coefficient of thermal expansion of the substrate.

Further, the power module substrate (2) according to the present invention is a power module substrate formed by forming a conductive pattern on at least one surface of a base made of a ceramic plate. A peel prevention member for preventing the peeling of the substrate, the peel prevention member including an insulating layer having a thermal expansion coefficient substantially equal to or near the thermal expansion coefficient of the base, and being disposed only on the surface of the conductive pattern. It is characterized by being established.

The conductive pattern is connected to, for example, an electrode of a semiconductor element mounted on a base via a bonding material, and the peeling preventing member is composed of, for example, only the insulating layer. In this case, a separation preventing member is provided at a position on the surface of the conductive pattern opposite to the base, avoiding a joint portion with the bonding material.

[0010] The peel prevention member may include, for example, a clad material having at least the insulating layer and a conductive layer formed on the surface of the insulating layer opposite to the conductive pattern so as to be exposed to the outside; An example in which the above-described insulating layer is provided in a frame shape along the outer end portion on the outer end portion which is the end portion on the peripheral edge side of the base in the conductive pattern. As the insulating layer, for example, a layer made of ceramic is used.

Further, the power module substrate (3) according to the present invention is a power module substrate in which a conductive pattern is formed on at least one surface of a base made of a ceramic plate. Is characterized in that a peeling preventing means for preventing the peeling of the conductive pattern from the base by inserting the conductive pattern is formed.

[0012] The peeling preventing means is, for example, a groove provided on the surface side of the conductive pattern on the base and into which the conductive pattern is fitted, and a projection protruding from a position on the base where the conductive pattern is formed. I have. When the peeling prevention means is a convex portion, the conductive pattern has a concave portion fitted to the convex portion, and is provided in a state where the concave portion is fitted to the convex portion.

Further, the power module substrate (4) according to the present invention is a power module substrate formed by forming a conductive pattern on at least one surface of a base made of a ceramic plate. Characterized in that there is provided a peeling preventing means which is formed in a state where a part of the conductive pattern is removed and which prevents peeling of the conductive pattern from the base.

The peeling preventing means may be formed, for example, in a large number of holes penetrating the conductive pattern, or at least one of the surface of the conductive pattern on the substrate side and the side surface and the surface opposite to the substrate side. And a groove formed at an end in the width direction of the conductive pattern at intervals along the end. Alternatively, at the end of the conductive pattern, even if the separation preventing means is formed by an inclined portion formed so as to be inclined such that the thickness of the end is thinner than the thickness near the center in the width direction of the conductive pattern. Good. Further, when the peeling prevention means comprises holes, a material having a coefficient of thermal expansion substantially equal to or near the coefficient of thermal expansion of the substrate may be embedded in the holes.

In the power module substrate (1) according to the present invention, of the ends of the conductive pattern formed on at least one side of the base made of a ceramic plate, at least an outer end has a peel preventing portion formed thereon. Since the peeling prevention member at the end is formed so as to cover the outer end of the conductive pattern of the base including the peripheral edge of the base, at least the outer end of the conductive pattern is favorably connected to the base by the peeling preventive member. It is held in a joined state. Therefore, when the conductive pattern is made of a material having a higher coefficient of thermal expansion than the base, even if the power module substrate generates heat, the outer end of the conductive pattern is outside the base due to the difference in the coefficient of thermal expansion between the base and the conductive pattern. Even if you try to expand
Since the outward expansion is suppressed by the separation preventing member, at least the outer end portion of the conductive pattern is prevented from being separated from the base.

Further, in the power module substrate (2) according to the present invention, the separation preventing member for preventing the conductive pattern from being separated from the base made of the ceramic plate has a thermal expansion coefficient substantially equal to or near the coefficient of thermal expansion of the base. The power module substrate generates heat when the conductive pattern is made of a material having a higher coefficient of thermal expansion than the substrate because the insulating layer having the expansion coefficient is provided and disposed only on the surface of the conductive pattern. However, the peel preventing member on the surface of the conductive pattern does not expand as much as the conductive pattern. Therefore, outward expansion of the surface of the conductive pattern is suppressed by the peeling prevention member, and peeling of the conductive pattern from the base is prevented. Further, since the separation preventing member is provided only on the surface of the conductive pattern, the separation preventing member can be formed together with the processing of the conductive pattern.

In the power module substrate (3) according to the present invention, the conductive pattern is fitted on the surface of the base made of a ceramic plate, on which the conductive pattern is formed, to prevent peeling of the conductive pattern from the base. In the case where the conductive pattern is made of a material having a higher coefficient of thermal expansion than that of the base, and the separation preventing means is formed of a groove into which the conductive pattern is fitted, the power module substrate generates heat and the conductive pattern will expand. Also, the outward expansion is restricted by the peeling prevention means. Further, in the case where the concave portion is formed in the conductive pattern, the thickness of the bottom portion of the concave portion is reduced, so that the expansion of the entire conductive pattern is smaller than that of the conductive pattern having a uniform thickness. Therefore, peeling of the conductive pattern from the base is prevented.

Further, in the power module substrate (4) according to the present invention, the conductive pattern is formed in such a state that a part of the conductive pattern is removed to prevent the conductive pattern from peeling off from the base made of the ceramic plate. Since the separation preventing means is provided, when the conductive pattern is made of a material having a higher coefficient of thermal expansion than that of the base, even if the power module substrate generates heat and expands the conductive pattern, the amount of the expansion is one of the conductive pattern. It is absorbed by the peeling prevention means consisting of the part where the part is removed. Therefore, since the outward expansion of the conductive pattern is prevented, peeling of the conductive pattern from the base can be prevented.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the power module substrate according to the present invention will be described below with reference to the drawings. FIG. 1 is a side sectional view showing a power module substrate according to Embodiment (1).

As shown in FIG. 1, the power module substrate 10 includes a base 11 made of a ceramic plate and a base 1.
The conductive pattern 12 includes a conductive pattern 12 formed on both surfaces thereof and a peel prevention member 13 formed on an outer end of the conductive pattern 12 on the peripheral edge side of the base 11. The base 11 is made of a ceramic having a low coefficient of thermal expansion (linear expansion coefficient α) such as alumina, for example.
Is formed using a metal having a higher coefficient of thermal expansion than the base 11, such as aluminum or copper.

The peel preventing member 13 is made of a thermosetting resin material such as an epoxy resin, and covers the outer ends of the conductive patterns 12 on both surfaces of the base 11, that is, the conductive patterns 1
2 and the side surface 12a on the peripheral edge side of the base 11 and the base 1
One surface (hereinafter, this surface is referred to as a lower surface) 12b and the opposite surface (hereinafter, this surface is referred to as an upper surface) 12c and the side surface 12a side include the peripheral portion of the base 11. It is formed to cover. The separation preventing member 13 is, for example, masked on the base 11 having the conductive patterns 12 formed on both surfaces, except for the portion where the separation preventing member 13 is formed.
In this state, the substrate 11 is formed by immersing the vicinity of the periphery of the base 11 in a liquid resin, applying the resin to the vicinity of the periphery, and then curing the resin.

In the power module substrate 10 configured as described above, the peeling preventing member 13 is formed so as to cover the outer ends of the conductive patterns 12 on both surfaces of the base 11 including the peripheral edge of the base 11. Therefore, the base 11
The outer ends of the conductive patterns 12 on both sides of the substrate 11 are held in a state where they are satisfactorily joined to the base 11 by one peel prevention member 13. Moreover, since the peeling prevention member 13 is made of a thermosetting resin material, the bonding state between the outer end of the conductive pattern 12 and the base 11 is firmly maintained.

Therefore, even when the power module substrate 10 generates heat and the outer end of the conductive pattern 12 tries to expand outward from the base 11 due to the difference in the coefficient of thermal expansion between the base 11 and the conductive pattern 12, Since the expansion is suppressed by the prevention member 13, the outer end of the conductive pattern 12 that is most easily peeled can be reliably prevented from peeling, and the reliability of the power module substrate 10 can be improved.

Next, an embodiment (2) of the power module substrate according to the present invention will be described with reference to side sectional views shown in FIGS. 2 (a) and 2 (b). As shown in FIG. 2A, the power module substrate 20 according to the embodiment (2) differs from the power module substrate 10 according to the embodiment (1) in that the peel prevention member 21 It is made of an insulating material having a coefficient of thermal expansion substantially equal to or near the coefficient of thermal expansion of the ceramic plate to be constituted. Examples of such an insulating material include glass ceramic, aluminum nitride, and silicon nitride.

As in the case of the embodiment (1), the exfoliation preventing member 21 is formed by masking a portion other than the exfoliation preventing member 21 on the base 11 on which the conductive patterns 12 are formed on both surfaces. The base 11 is formed by immersing the vicinity of the periphery of the base 11 in a paste prepared by mixing a material having a low coefficient of thermal expansion such as a resin, an organic solvent, and the like, and further firing the paste.

In the power module substrate 20 having the above-described structure, the peeling preventing member 21 also applies the outer ends of the conductive patterns 12 on both sides of the base 11 to the base 11.
Because it is formed so as to cover the periphery of the
Conductive patterns 12 formed on both sides of base 11
The outside end of the base 11 is
It is maintained in a state of being well joined. Moreover, since the peel prevention member 21 has a low thermal expansion coefficient substantially equal to or in the vicinity of the base 11, even if the power module substrate 10 generates heat, it does not expand much.

Therefore, the base 11 and the conductive pattern 12
When the outer end of the conductive pattern 12 tries to expand outward from the base 11 due to the difference in thermal expansion coefficient between the base 11 and the base 11, the expansion is suppressed by the peel prevention member 21.
The outer end of the conductive pattern 12 can be prevented from peeling off.

In the embodiment (1) and the embodiment (2), the separation preventing members 13 and 21 are formed of the conductive pattern 1.
Although the example in which the anti-separation members 13 and 21 are provided only at the outer end of the conductive pattern 12 is only required to be formed at least at the outer end of the end of the conductive pattern 12, the present invention is not limited to this example. For example, as shown in FIG. 2B, it is also possible to form an anti-peeling member 21 at an end other than the outer end of the conductive pattern 12 so as to cover this end. In this case, in a place where the end portions of the conductive pattern 12 are adjacent to each other, for example, the paste for forming the separation preventing member 21 between the end portions is filled and baked, so that the end portion of the conductive pattern 12 is formed. The covering peel preventing member 21 can be formed.

In the power module substrate 20 shown in FIG. 2B, all ends of the conductive pattern 12 are held in a state in which they are satisfactorily joined to the base 11 by the separation preventing member 21. The peeling of the conductive pattern 12 can be almost certainly prevented, and the reliability can be further improved.

Next, an embodiment (3) of a power module substrate according to the present invention will be described with reference to a side sectional view shown in FIG. As shown in FIG. 3, the power module substrate 30 according to the embodiment (3) is different from the power module substrate 10 according to the embodiment (1) in that the peel prevention member 31 is provided on the surface of the conductive pattern 12. And that the separation preventing member 31 is formed of an insulating member having a thermal expansion coefficient substantially equal to or near the thermal expansion coefficient of the base 11.

That is, in this embodiment (3), the peel preventing member 31 is formed so as to cover the entire surface of the conductive pattern 12 formed on both surfaces of the base 11, that is, the side surface 12a and the upper surface 12c. Further, the peeling prevention member 31 is constituted only by an insulating member. The peel prevention member 31 in this embodiment is formed using a paste containing an insulating material having a low coefficient of thermal expansion such as glass ceramic, aluminum nitride, or silicon nitride, similarly to the peel prevention member 21 of the embodiment (2). ing.

Here, when an electronic component is manufactured using the power module substrate 30, the conductive pattern 12
And an electrode (not shown) of the semiconductor element formed on the base 11 are connected via a bonding material (not shown) made of, for example, a wire. For this reason, the peel prevention member 31
Are formed on the surface of the conductive pattern 12 at positions avoiding the joint with the bonding material. Such a peel prevention member 31 is formed in the same procedure using a paste prepared by mixing an insulating material such as glass ceramic, a resin, an organic solvent, and the like described in the embodiment (2).

In the power module substrate 30 described above,
Since the separation preventing member 31 is made of an insulating material having a thermal expansion coefficient substantially equal to or near the thermal expansion coefficient of the base 11 and is disposed only on the surface of the conductive pattern 12, the power module substrate 30 When the heat is generated, the base 11 expands without being suppressed by the separation preventing member 31, and the separation preventing member 31 on the surface of the conductive pattern 12 also expands to substantially the same extent as the base 11.

However, since the base 11 and the separation preventing member 31 are made of a material having a low coefficient of thermal expansion, the expansion area is small and does not expand as much as the conductive pattern 12. As a result, the expansion of the conductive pattern 12 to the outside of the surface is prevented by the separation preventing member 31.
As a result, the conductive pattern 12 can be suppressed to substantially the same degree as the base 11, so that it is difficult for the conductive pattern 12 to be separated from the base 11.

As described above, the power module substrate 30
Even if heat is generated, the outward expansion of the conductive pattern 12 can be suppressed by the peeling prevention member 31, so that the conductive pattern 12 can be prevented from peeling from the base 11, and a highly reliable power module substrate. 30 can be realized.
Further, since the separation preventing member 31 is formed only on the surface of the conductive pattern 12, the separation preventing member 31 can be formed together with the pattern processing of the conductive pattern 12, and the manufacturing process can be simplified.

Next, an embodiment (4) of a power module substrate according to the present invention will be described with reference to a side sectional view shown in FIG. In the power module substrate 40 according to the embodiment (4) shown in FIG. 4, the difference from the power module substrate 30 of the embodiment (3) is that the thermal expansion coefficient of the base 11 is substantially equal to or smaller than that. The point is that a ceramic material patterned in a predetermined shape in advance is used for the separation preventing member 41 made of an insulating material having a nearby coefficient of thermal expansion.

That is, the peeling prevention member 41 is preliminarily formed in a pattern on the upper surface 12c of the conductive pattern 12 so as to be formed at a position avoiding the joint portion with the bonding material.
The conductive patterns 12 are provided on the upper surface 12c of each of the conductive patterns 12 formed on both surfaces of the base 11, for example, by being adhered with an adhesive. This peel prevention member 41 also
Similar to the peel prevention member 31 of the embodiment (3), the base 1
Since it is made of an insulating material having a coefficient of thermal expansion substantially equal to or near the coefficient of thermal expansion of 1, the effect of preventing the conductive pattern 12 from peeling from the base 11 can be obtained.

Next, an embodiment (5) of a power module substrate according to the present invention will be described with reference to a side sectional view shown in FIG. The power module substrate 50 according to the embodiment (5) is different from the power module substrate 40 according to the embodiment (4) in that the peel prevention member 51 is substantially equal to the coefficient of thermal expansion of the base 11 or An insulating layer 51a having a thermal expansion coefficient in the vicinity thereof, and a conductive layer 5 laminated on the surface of the insulating layer 51a opposite to the conductive pattern 12.
1b, and a substrate 1
1 upper surface 12c of conductive pattern 12 formed on one surface side
Only in that the peeling prevention member 51 is formed.

The conductive layer 51b of the clad material constituting the peel-prevention member 51 is formed of a material which can be satisfactorily bonded to the aforementioned bonding material. Examples of such a material include 42 alloy, which is an alloy of aluminum, nickel and iron. The conductive layer 51b is provided so as to be exposed to the outside.

In the power module substrate 50 configured as described above, the separation preventing member 51 includes the insulating layer 51a having a thermal expansion coefficient substantially equal to or near the thermal expansion coefficient of the base 11, and Upper surface 1 of conductive pattern 12
2c, the power module substrate 5
Even if 0 generates heat, the insulating layer 51a of the separation preventing member 51 only expands slightly to the same extent as the base 11.
Therefore, similarly to the case of the embodiment (4), the outward expansion of the conductive pattern 12 is suppressed to substantially the same level as that of the base 11 by the insulating layer 51a of the separation preventing member 51. The peeling of the pattern 12 can be prevented.

On the other hand, the conductive layer 51b of the peel prevention member 51
Is formed on the surface of the insulating layer 51a opposite to the conductive pattern 12 so as to be exposed to the outside, that is, on the outermost surface of the power module substrate 50, the conductive pattern 12 and the bonding material It is not necessary to pattern-form the insulating layer 51a in order to join the layers. Also, the conductive layer 51b does not need to be patterned in a predetermined shape. Even if the conductive layer 51b is provided on the entire surface of the insulating layer 51a, the conductive layer 51b and the bonding material can be securely bonded without affecting the peeling prevention function. Therefore, the power module substrate 50 of this embodiment can prevent the conductive pattern 12 from peeling off, and can provide the peeling prevention member 51 more easily.

In the embodiment (5), the example in which the clad material is formed by the two layers of the insulating layer 51a and the conductive layer 51b has been described. However, the insulating layer and the conductive layer which can be bonded to the bonding material are formed. If it is provided and this conductive layer is provided in a state where it is exposed to the outside, it may be composed of two or more layers. In the embodiment (5), the base 11
Although the peeling prevention member 51 is provided only on the upper surface of the conductive pattern 12 formed on one surface side, in another embodiment,
Needless to say, the separation preventing member may be provided also on the upper surface of the conductive pattern 12 formed on the other surface side of the base 11.

Next, an embodiment (6) of a power module substrate according to the present invention will be described with reference to a side sectional view shown in FIG. As shown in FIG. 6, in the power module substrate 60, the difference from the power module substrate 40 according to the embodiment (4) is that the thermal expansion coefficient is substantially equal to or near the thermal expansion coefficient of the base 11. Anti-peeling member 61 formed of insulating layer 61a having an
On the outer end of each of the conductive patterns 12 on both sides of the conductive pattern 12 in the form of a frame along the outer end.

The peel prevention member 61 is formed by attaching a ceramic material formed in a predetermined frame shape in advance to the upper surface 12 c of the conductive pattern 12 formed on both surfaces of the base 11.
For example, it is provided by being adhered with an adhesive. Therefore, the power module substrate 60 according to Embodiment (6)
As in the case of the power module substrate 50 according to the embodiment (5), the separation preventing member 61 can be easily provided.

The peel prevention member 61 is made of an insulating material having a coefficient of thermal expansion substantially equal to or near the coefficient of thermal expansion of the base 11 and is provided on the outer end of the conductive pattern 12. Even if the module substrate 60 generates heat and the conductive pattern 12 tries to expand outward, the peeling preventing member 61 causes the outer end of the conductive pattern 12 to be attached to the base 1.
Press toward 1 to suppress expansion. Therefore, peeling of the conductive pattern 12 from the base 11 is prevented. Further, in order to provide the peeling prevention member 61 on a part of the conductive pattern 12,
At the time of joining the conductive pattern 12 and the bonding material, the separation preventing member 61 does not hinder the joining, and the joining can be performed smoothly.

Next, an embodiment (7) of a power module substrate according to the present invention will be described with reference to a side sectional view shown in FIG. As shown in FIG. 7, a power module substrate 70 according to the embodiment (7) has a conductive pattern 12 formed on both surfaces of a base 11 made of a ceramic plate. Separation preventing means 71 for preventing the conductive pattern 12 comprising the groove 11a into which the conductive pattern 12 can be fitted on the existing surface;
Is formed.

The peeling preventing means 71 in this embodiment (7) comprises a groove 11a into which the conductive pattern 12 is fitted, and is formed on both surfaces of the base 11. The depth of the groove 11a is set, for example, within the range of the thickness of the conductive pattern 12, but is set substantially equal to the thickness of the conductive pattern 12, and the surface exposed to the outside of the conductive pattern 12 is
When the power module substrate 70 is substantially flush with 1, the expansion of the conductive pattern 12 can be strongly restricted even when the power module substrate 70 generates heat.

The base 11 provided with the separation preventing means 71 is formed by, for example, processing a ceramic using a mold so that the thickness x of the peripheral portion of the base 11 is about 0.6 mm to 1 mm.

In the power module substrate 70 described above,
Since the separation preventing means 71 composed of the groove 11 a into which the conductive pattern 12 is fitted is provided on the surface of the base 11 on which the conductive pattern 12 is formed, even if the conductive pattern 12 tries to expand due to the heat generated by the power module substrate 70, the separation is prevented. The outward expansion of the conductive pattern 12 is restricted by the preventing means 71. Therefore, the conductive pattern 12 can be prevented from peeling off from the base 11, and a highly reliable power module substrate 70 can be realized. Further, since a new material is not required for forming the separation preventing means 71, the material cost does not increase by forming the separation preventing means 71.

Next, an embodiment (8) of a power module substrate according to the present invention will be described with reference to a side sectional view shown in FIG. As shown in FIG. 8, the power module substrate 80 is different from the power module substrate 70 according to the embodiment (7) in that the separation preventing means 81 formed on the substrate 11 It is composed of a convex portion 11b partially formed at a position where the substrate 12 is formed, and is characterized in that such a peeling preventing means 81 is formed on one surface side of the base 11.

The conductive pattern 12 formed on one surface side of the base 11 has a concave portion 12d fitted into the convex portion 11b of the peeling preventing means 81, and is provided in a state where the concave portion 12d is fitted into the convex portion 11b. ing. The height of the projection 11b is set, for example, within the range of the thickness of the conductive pattern 12. The base 11 provided with the separation preventing means 81 is formed by, for example, processing a ceramic using a mold.

In the power module substrate 80 according to the embodiment (8), the conductive pattern 12
Is formed, the thickness of the conductive pattern 12 at the bottom of the recess 12d is smaller than that of the other portions. Therefore, the expansion of the entire conductive pattern 12 can be suppressed as compared with the case where the thickness of the conductive pattern 12 is uniform. In addition, the expansion of the conductive pattern 12 is regulated by the presence of the peeling prevention means 81.

Therefore, even if the power module substrate 80 generates heat, the conductive pattern 12 can be prevented from peeling off from the base 11, and the reliability can be improved. Also in this embodiment, it is not necessary to add a new material for forming the peeling prevention means 81, so that an increase in material cost due to the provision of the peeling prevention means 81 can be prevented.

In this embodiment (8), the base 1
In the case where the conductive patterns 12 are formed on both surfaces of the substrate 11, the peel preventing means 81 is formed only on one surface of the substrate 11, but in another embodiment, the peel preventing device 81 is also formed on the other surface of the substrate 11. Means 81 may be formed. In this case,
The peeling of the conductive patterns 12 on both surfaces of the base 11 can be prevented.

Next, an embodiment (9) according to the present invention will be described with reference to perspective views shown in FIGS. 9 (a) and 9 (b). FIG.
As shown in (a), the power module substrate 90 according to the embodiment (9) has the conductive patterns 12 formed on both surfaces of the base 11. Is provided with a separation preventing means 91 formed in a state where a part of the conductive pattern 12 is removed.

In the embodiment (9), the separation preventing means 9 is used.
Reference numeral 1 denotes a large number of holes 12e penetrating the conductive pattern 12. The hole 12e is provided at a position avoiding the joint with the bonding material. The number, size (diameter), and the like of the holes 12e are set in consideration of the amount of current flowing through the conductive pattern 12.

In the power module substrate 90, since the conductive pattern 12 is provided with the separation preventing means 91 comprising a large number of holes 12e, the power module substrate 9
Even if the conductive pattern 12 expands due to the generation of heat, the expanded portion is absorbed by the separation preventing means 91. as a result,
The outward expansion of the conductive pattern 12 can be prevented, and the base 11
Since the conductive pattern 12 can be prevented from peeling off from the substrate, a highly reliable power module substrate 90 can be realized. Further, since it is not necessary to add a new material for forming the separation preventing means 91, the material cost does not increase due to the separation preventing means 91.

The hole 12e of the peeling preventing means 91 formed in the conductive pattern 12 has a thermal expansion coefficient substantially equal to or near the thermal expansion coefficient of the base 11 in the hole 12e as shown in FIG. A low-thermal-expansion material 92 having a specific modulus may be embedded. The low thermal expansion coefficient material 92 is embedded by putting a paste prepared by mixing an insulating material such as glass ceramic, a resin, an organic solvent, and the like described in the above-described embodiment (2) into the hole 12 e of the peeling prevention means 91. The baking amount may be adjusted according to the degree of expansion of the conductive pattern 12.

In the power module substrate 90, the substrate 9
0 generates heat, the conductive pattern 12 is formed by the low thermal expansion coefficient material 92 embedded in the hole 12 e of the peeling prevention means 91.
Is suppressed, and even if expanded, the expanded portion is absorbed by the hole 12e of the separation preventing means 91 itself. Therefore, peeling of the conductive pattern 12 from the base 11 can be reliably prevented.

Next, an embodiment (10) of a power module substrate according to the present invention will be described with reference to a side sectional view shown in FIG. As shown in FIG. 10, the power module substrate 100 according to the embodiment (10) is different from the power module substrate 90 according to the embodiment (9), except that a part of the conductive pattern 12 is removed. The anti-peeling means 101 configured in the above-described manner includes side surfaces 12 a, lower surfaces 12 b,
Groove 12 formed on at least one surface of upper surface 12c
f. Here, for example, the conductive pattern 1
A groove 12f (peeling preventing means 101) is provided on the upper surface 12c of the second.

In the power module substrate 100, even if the heat is generated and the conductive pattern 12 expands, the expansion is absorbed by the groove 12f serving as the separation preventing means 101. For this reason, the peeling of the conductive pattern 12 from the base 11 can be prevented, and the peeling preventing means 101 can be formed by processing the conductive pattern 12 itself. Nothing.

In the embodiment (10), the separation preventing means 1
01 is the conductive pattern 12 formed on one surface side of the base 11
Although the example formed only in was described, in another embodiment,
The separation preventing means 101 may also be formed on the conductive pattern 12 formed on the other surface of the base 11. In this case, an effect of preventing the conductive patterns 12 on both surfaces of the base 11 from being peeled can be obtained.

In still another embodiment, as shown in FIG. 11, a separation preventing means 101 comprising a groove 12f may be formed on a lower surface 12b of a conductive pattern 12, or in still another embodiment, The peel preventing means 101 may be formed on all of the side surface 12a, the lower surface 12b, and the upper surface 12c of the conductive pattern 12. In any of these cases, the expansion of the conductive pattern 12 is absorbed by the groove 12f of the peeling prevention means 101, as in the case of the embodiment (10), so that the peeling of the conductive pattern 12 from the base 11 is ensured. The effect that can be prevented is obtained.

Next, an embodiment (11) of a power module substrate according to the present invention will be described. 12A and 12B are plan views showing a main part of a conductive pattern in a power module substrate according to Embodiment (11), wherein FIG. 12A shows a state before the separation preventing means is provided, and FIG. The state of is shown.

The power module substrate according to the embodiment (11) is different from the power module substrate 100 according to the embodiment (10) in that the conductive pattern 1
Anti-peeling means 1 constituted in a form in which a part of 2 is removed
Reference numeral 11 denotes a point formed by a groove 12g formed at an end of the conductive pattern 12 in the width direction at intervals along the end. That is, the conductive pattern 12 is provided with
1, the width is not constant. The peeling prevention means 111 is formed, for example, by subjecting the conductive pattern 12 in the state shown in FIG.

Even in such a power module substrate, when the heat is generated and the conductive pattern 12 expands,
Since the expansion is absorbed by the groove 12 g constituting the peeling prevention means 111, the conductive pattern 1
2 can be prevented from peeling off. Also conductive pattern 1
Since the separation preventing means 111 can be formed by processing the 2 itself, there is no increase in material cost.

Next, an embodiment (12) of a power module substrate according to the present invention will be described with reference to a side sectional view shown in FIG. The difference between the power module substrate 120 and the power module substrate according to the embodiment (11) is that the peeling preventing means 121 is provided at the end of the conductive pattern 12 so that the thickness of the end is smaller than that of the conductive pattern 12.
Is formed by an inclined portion 12h formed in a state of being inclined so as to be thinner than the thickness near the center in the width direction. Here, the slope of the end of the conductive pattern 12 is formed such that the lower surface 12b of the conductive pattern 12 is wider than the upper surface 12c.

The separation preventing means 121 composed of the inclined portion 12h as described above is used, for example, for the conductive pattern 12 in the state shown in FIG.
It is formed by masking c and performing a wet etching process.

In the power module substrate 120, the thickness of the end portion of the conductive pattern 12 is made smaller than the thickness of the central portion due to the formation of the separation preventing means 121. Therefore, even when the power module substrate 120 generates heat, expansion of the end of the conductive pattern 12 is suppressed to a small value. Therefore, the conductive pattern 12 is less likely to peel from the base 11.
The peeling preventing means 1 is formed by processing the conductive pattern 12 itself.
21 can be formed, so that there is an advantage that the material cost is not increased.

FIG. 13 shows the separation preventing means 121.
Although an example in which the conductive pattern 12 is formed only on one surface side of the base 11 is shown, in the power module substrate according to another embodiment, the conductive pattern 12 formed on the other surface side of the base 11 is formed. This conductive pattern 1 is used to prevent peeling.
Needless to say, the peel prevention means 121 may be formed on the second.

[0071]

As described above, according to the power module substrate according to the present invention, at least one of the ends of the conductive pattern formed on at least one side of the base made of the ceramic plate has a peel preventing member. Is formed, and the anti-peeling member at the outer end is formed so as to cover the outer end of the conductive pattern of the base including the peripheral portion of the base, so that the conductive pattern has a higher coefficient of thermal expansion than the base. In the case where the conductive pattern is made of a material, even if the power module substrate generates heat, the peeling prevention member can suppress outward expansion of the conductive pattern. Accordingly, since at least the outer end portion of the conductive pattern can be prevented from peeling off from the base, a highly reliable power module substrate can be realized.

Further, according to the power module substrate of the present invention, the separation preventing member for preventing the conductive pattern from being separated from the base made of the ceramic plate has a thermal expansion coefficient substantially equal to or near the coefficient of thermal expansion of the base. When the conductive pattern is made of a material having a higher thermal expansion coefficient than that of the base, the power module substrate is heated by the configuration including the insulating layer having an expansion coefficient and disposed only on the surface of the conductive pattern. Even when the conductive pattern does not expand as much as the conductive pattern, the outward expansion of the surface of the conductive pattern can be suppressed. Therefore, peeling of the conductive pattern from the base can be prevented, and reliability can be improved.

Further, according to the power module substrate of the present invention, the conductive pattern is provided on the surface side of the conductive pattern of the base made of the ceramic plate, and the conductive pattern is provided on the side of the conductive pattern. When the power module substrate is made of a material having a higher coefficient of thermal expansion, even if the power module substrate generates heat, the outward expansion of the conductive pattern can be restricted by the peeling prevention means, or the expansion of the entire conductive pattern can be reduced. . As a result, peeling of the conductive pattern from the base can be prevented, and electrical reliability can be improved.

Further, according to the power module substrate of the present invention, the conductive pattern is formed in a state where a part of the conductive pattern is removed to prevent the conductive pattern from peeling off from the base made of the ceramic plate. When the conductive pattern is made of a material having a higher coefficient of thermal expansion than that of the base body, even if the power module substrate generates heat and the conductive pattern expands, the amount of the expansion is reduced by the structure provided with the peeling preventing means. Therefore, peeling of the conductive pattern from the base can be prevented. Therefore, a power module substrate with improved electrical reliability can be realized.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a power module substrate according to an embodiment (1) of the present invention.

FIG. 2A is a side sectional view showing a power module substrate according to a second embodiment of the present invention, and FIG. 2B is a side sectional view showing a modification of the second embodiment.

FIG. 3 is a side sectional view showing a power module substrate according to an embodiment (3) of the present invention.

FIG. 4 is a side sectional view showing a power module substrate according to an embodiment (4) of the present invention.

FIG. 5 is a side sectional view showing a power module substrate according to an embodiment (5) of the present invention.

FIG. 6 is a side sectional view showing a power module substrate according to an embodiment (6) of the present invention.

FIG. 7 is a side sectional view showing a power module substrate according to an embodiment (7) of the present invention.

FIG. 8 is a side sectional view showing a power module substrate according to an embodiment (8) of the present invention.

9A is a perspective view showing a power module substrate according to an embodiment (9) of the present invention, and FIG. 9B is a perspective view showing a modification of the embodiment (9).

FIG. 10 is a side sectional view showing a power module substrate according to an embodiment (10) of the present invention.

FIG. 11 is a side sectional view showing a modification of the embodiment (10).

FIG. 12 is a plan view of a main part for describing a conductive pattern in a power module substrate according to an embodiment (11) of the present invention.
(B) is a diagram showing a state after the separation preventing means is provided.

FIG. 13 is a side sectional view showing a power module substrate according to an embodiment (12) of the present invention.

FIG. 14 is a side sectional view showing an example of an electronic component configured using a conventional power module substrate.

[Description of Signs] 10, 20, 30, 40, 50, 60, 70, 80, 9
0, 100, 120 ... Power module substrate 11 ... Bases 11a, 12f, 12g ... Grooves 11b ... Protrusions 12 ... Conductive patterns 12a ... Side surfaces 12b ... Lower surfaces 12c ... Upper surfaces 12d ... Recesses 12e ... Holes 12h ... Inclined portions 13, 21 , 31, 41, 51, 61 ... peeling prevention means material 71, 81, 91, 101, 111, 121 ... peeling prevention means 51 a ... insulating layer 51 b ... conductive layer 92 ... low thermal expansion coefficient material

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Norimitsu Yukimatsu 1-2-28 Goshodori, Hyogo-ku, Kobe City, Hyogo Prefecture Inside Fujitsu Ten Co., Ltd. (72) Inventor Hiromichi Watanabe Goshodori, Hyogo-ku, Kobe City, Hyogo Prefecture 1-2-28 Fujitsu Ten Co., Ltd. (72) Inventor Takafumi Yasuhara 1-2-2-28 Goshodori, Hyogo-ku, Kobe City, Hyogo Prefecture Inside Fujitsu Ten Co., Ltd. (72) Inventor Yuki Wakabayashi Kobe City, Hyogo Goshodori 1-2-28 Fujitsu Ten Limited F term (reference) 5E338 AA18 BB65 BB72 EE27 5E343 AA23 BB24 BB28 GG02

Claims (17)

[Claims] 1. A power module substrate in which a conductive pattern is formed on at least one surface of a base made of a ceramic plate, wherein a separation preventing member for preventing separation of the conductive pattern from the base is provided by the conductive pattern. Of the end portions, at least an outer end portion which is an end portion on the peripheral edge side of the base, the separation preventing member at the outer end includes the outer end portion of the conductive pattern of the base including the peripheral portion of the base. A power module substrate formed to cover. 2. The power module substrate according to claim 1, wherein the peeling prevention member is formed of a resin material. 3. The power module substrate according to claim 1, wherein the separation preventing member is made of an insulating material having a thermal expansion coefficient substantially equal to or near the thermal expansion coefficient of the base. 4. A power module substrate comprising a base made of a ceramic plate and a conductive pattern formed on at least one surface of the base, further comprising: a separation preventing member for preventing separation of the conductive pattern from the base. A power module, wherein the member is provided with an insulating layer having a thermal expansion coefficient substantially equal to or near the thermal expansion coefficient of the base, and is disposed only on the surface of the conductive pattern. Substrate. 5. The conductive pattern is connected to an electrode of a semiconductor element mounted on the base via a bonding material, wherein the peeling preventing member is formed only of the insulating layer. 5. The power module substrate according to claim 4, wherein the conductive pattern is provided on a surface of the conductive pattern opposite to the base, at a position avoiding a bonding portion with the bonding material. 6. The anti-peeling member may be formed of a clad material having at least the insulating layer and a conductive layer formed on a surface of the insulating layer opposite to the conductive pattern and exposed to the outside. The power module substrate according to claim 4, wherein 7. The exfoliation preventing member is formed of only the insulating layer, and a frame is formed along an outer end portion on an outer end portion of the conductive pattern on the peripheral edge side of the base. 6. The device according to claim 5, wherein
The power module substrate as described in the above. 8. The power module substrate according to claim 4, wherein the insulating layer is made of ceramic. 9. A power module substrate in which a conductive pattern is formed on at least one surface of a base made of a ceramic plate, wherein the conductive pattern is fitted on a side of the base where the conductive pattern is formed, and A power module substrate, wherein a separation preventing means for preventing separation of the conductive pattern is formed. 10. The power module substrate according to claim 9, wherein said peeling prevention means comprises a groove provided on a surface side of said conductive pattern on said base and into which said conductive pattern is fitted. 11. The peeling preventing means comprises a convex portion protruding from a position of the base on which the conductive pattern is formed, wherein the conductive pattern has a concave portion fitted to the convex portion,
The power module substrate according to claim 9, wherein the concave portion is provided so as to be fitted into the convex portion. 12. A power module substrate formed by forming a conductive pattern on at least one surface of a base made of a ceramic plate, wherein the conductive pattern is formed by removing a part of the conductive pattern. A substrate for a power module, provided with a separation preventing means for preventing separation of a conductive pattern from a base. 13. The power module substrate according to claim 12, wherein said peeling preventing means comprises a large number of holes penetrating said conductive pattern. 14. The power module according to claim 13, wherein a material having a coefficient of thermal expansion substantially equal to or near the coefficient of thermal expansion of the base is buried in the hole. substrate. 15. The peeling prevention means comprises a groove formed on at least one of a surface, a side surface, and a surface opposite to the substrate side of the conductive pattern. 13. The power module substrate according to item 12. 16. The power module according to claim 12, wherein said peeling preventing means comprises a groove formed at an end in a width direction of said conductive pattern at intervals along said end. Substrate. 17. The peeling preventing means according to claim 1, wherein said conductive pattern has an inclined portion formed at an end portion thereof such that the thickness of said end portion is smaller than a thickness near a center in a width direction of said conductive pattern. The power module substrate according to claim 12, comprising a portion.