JPH10247702A - Ball grid array package and printed board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the heat radiating property, by a method wherein a heat radiating board in excellent thermal conductivity is junctioned with the bottom face side of the semiconductor element mounting part of a resin substrate having the semiconductor element mounting part on the top face side, with the junctioning pad of a solder ball on the bottom face side. SOLUTION: A ball grid array package 10 is provided with a resin substrate 13 having the mounting part of a semiconductor element 11 on the top face side thereof while having a solder ball junctioning pad on the bottom face side thereof. On the other hand, a heat radiating board 21 in excellent thermal conductivity is junctioned with the bottom face side of the semiconductor element mounting part of the resin substrate 13. Resultantly, the heat dissipated from the bottom face of the semiconductor element 1 is radiated to a printed substrate 41 in almost the shortest distant path. Besides, the heat radiating board 21 formed of a material in excellent thermal conductivity such as copper, etc., also takes a planar shape at the lower thermal resistance, thereby enabling the semiconductor element 11 to efficiently radiate the heat to the printed wiring board 41.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a printed board on which electronic components of a BGA package are mounted.

[0002]

2. Description of the Related Art As shown in FIG.
An electronic component 90 of a GA) package has a semiconductor element 91 mounted on a substrate 92, and has a solder ball 93 at the bottom of the substrate 92 for connection to the outside. In FIG.
Reference numeral 4 denotes a bonding wire, and reference numeral 95 denotes a resin mold. And the BGA type electronic component 90
The printed wiring board 96 is connected via the solder balls 93.

The heat generated from the semiconductor element 91 passes through a first path released from the resin mold 95 to the outside air and a second path released from the solder balls 93 via the printed wiring board 96. Released to the atmosphere. Also, as the density of electronic components has increased, heat dissipation from electronic components has become a particularly important issue, and improving heat dissipation characteristics has become an important technical issue.

[0004]

However, both the first path discharged from the resin mold 95 to the outside air and the second path discharged from the solder balls 93 to the atmosphere via the printed wiring board 96 have a low thermal resistance. If it is large as it is, the heat dissipation is not good, and it does not sufficiently respond to the increase in the heat generation of the semiconductor element. The present invention has been made in view of such a conventional problem, and has as its object to provide a ball grid array package having excellent heat dissipation and a printed board having the ball grid array package mounted thereon.

[0005]

According to a first aspect of the present invention, there is provided a ball grid array package mounted on a printed wiring board via solder balls, wherein the package has a semiconductor element mounting portion on an upper surface side and the lower surface has a semiconductor element mounting portion. A ball grid array, comprising: a resin substrate having pads for bonding solder balls; and a heat radiating plate having good heat conduction is bonded to a lower surface of the semiconductor substrate mounting portion of the resin substrate. In the package.

What is particularly noteworthy in the present invention is that a heat radiating plate having good heat conduction is joined to the lower surface side of the semiconductor element mounting portion of the resin substrate. By providing such a heat sink, heat generated from the lower surface of the semiconductor element is
Heat can be dissipated along a path of almost the shortest distance passing through the thickness of the resin substrate and the thickness of the heat sink. Then, through a heat sink formed of a material having good heat conductivity and having a plate shape with low thermal resistance, the printed circuit board can be mounted externally (atmosphere or when mounted on a printed circuit board, The same can be used to release heat. In addition, the structure in which the heat radiating plate is joined to the resin substrate is very simple, and has the advantages of easy manufacture and little increase in cost.

As the material of the heat sink, there are metals such as aluminum, copper, copper tungsten, and Kovar. In addition, it is preferable that a thermal via be provided between the semiconductor element mounting portion of the resin substrate and the heat sink to promote heat conduction. This is because thermal resistance between the lower surface of the semiconductor element and the heat sink can be significantly reduced by the thermal via.

Next, a second aspect of the present invention is a ball grid array package mounted on a printed wiring board via solder balls, wherein an opening is provided at a mounting position of a semiconductor element and the lower surface is provided with the opening. A resin substrate having pads for solder ball bonding, and a metal block mounted in an opening of the resin substrate and having the semiconductor element mounted on an upper surface and having a lower surface open to the outside air. It is in the ball grid array package.

What is particularly notable in the present invention is that the semiconductor element is mounted not on a resin substrate but on a metal block, and the metal block has a lower surface directly open to the outside air. For this purpose, an opening for disposing a metal block is provided at the mounting position of the semiconductor element on the resin substrate. By mounting the semiconductor element on the metal block as described above, the lower surface of the semiconductor element and the outside air (the printed wiring board when mounted on a printed wiring board, the same applies hereinafter) are connected by a metal block having low thermal resistance. ,
The heat radiation is very good.

As the material of the metal block, there are metals such as aluminum, copper, copper tungsten, and Kovar. The shape of the metal block is defined in claim 1.
As described in No. 1, there is a plate-like body joined to the lower surface of the resin substrate (see FIG. 2). Such a shape has the advantages of being extremely simple, easy to manufacture, and of little increase in cost.

According to another aspect of the present invention, the metal block has an exposed portion mounted on the lower surface of the resin substrate, and the metal block protrudes upward from the exposed portion. Some include an element mounting portion that passes through the opening (see FIG. 3). In this structure, as shown in FIG. 3, since the step between the upper surface of the resin substrate and the upper surface of the semiconductor element can be reduced or eliminated, the length of the bonding wire can be reduced and the connection can be reduced. Can be easier.

A third aspect of the present invention relates to a ball grid array package mounted on a printed wiring board via solder balls, wherein the package has a semiconductor element mounting portion on the upper surface side and the lower surface side has the semiconductor element mounting portion. A resin substrate having pads for joining solder balls, a semiconductor element mounted on the semiconductor mounting portion, a resin coating covering the semiconductor element, and In a ball grid array package, a heat dissipation block for promoting heat release is provided.

In the present invention, it should be particularly noted that
The heat radiation block is provided near the upper part of the semiconductor element (see FIG. 4). As a result, the thermal resistance of the upper part of the semiconductor element is reduced, and heat radiation upward is promoted. The heat radiating block may be embedded in a resin mold. However, the heat radiating block can be further increased by exposing the heat radiating block to the outside or by connecting to a heat radiating fin.

According to a fourth aspect of the present invention, the heat dissipation block extends not only above the semiconductor element but also in the lateral direction to increase the externally exposed area on the lateral side. There is a structure provided with a portion and a connecting portion for generating a heat flow between the thick portion and the heat radiation block main body (see FIG. 6). With this configuration, heat radiation not only from above but also from the side is promoted, and the amount of heat radiation is further increased.

It is preferable that the lower surface of the heat radiating block and the semiconductor element are electrically insulated from each other via a high heat conductive resin or a high heat conductive resin sheet. This is because the heat resistance between the semiconductor element and the heat radiating block is reduced by the action of the high heat conductive resin or the high heat conductive resin sheet, and the heat radiation is further promoted.

In addition, as described in claim 6, claim 1
By joining the heat radiating plate similar to that of the invention to the lower surface side of the semiconductor element mounting portion of the resin substrate, heat radiation from the lower surface can be further promoted as described above. And claim 7
As described above, it is preferable to provide a thermal via between the heat sink and the semiconductor element mounting portion of the resin substrate to promote heat conduction. This is because thermal resistance between the lower surface of the semiconductor element and the heat sink can be significantly reduced by the thermal via.

Further, in the ball grid array package according to the present invention, a heat radiation block may be provided close to an upper part of the semiconductor element via a resin coating covering the semiconductor element. preferable. As described in the third to fifth aspects, the heat radiation block can promote upward heat radiation.

The radiating block is extended in the lateral direction, and has a thick portion for increasing the externally exposed area on the lateral side, and There is a connecting part which generates a heat flow between the heat radiating block body and the heat radiating block main body (see the description of claim 4 for the operation and effect). It is preferable that the lower surface of the heat radiating block and the semiconductor element are electrically insulated through a high heat conductive resin or a high heat conductive resin sheet. 5)).

Further, as described in claim 11, the metal block of the ball grid array package according to any one of claims 8 to 10 is bonded to the lower surface of the resin substrate as described above. There is a plate-like body (see the description in claim 2 for the function and effect).

According to a twelfth aspect of the present invention, in the ball grid array package according to any one of the eighth to tenth aspects, the metal block comprises:
An exposed portion mounted on the lower surface of the resin substrate and an element mounting portion projecting upward from the exposed portion and passing through the opening can be constituted. ).

According to a thirteenth aspect, the ball grid array package according to any one of the first, second, or sixth to twelfth aspects is mounted on a printed wiring board. In the printed board, it is preferable that the space between the heat sink or the metal block of the ball grid array package and the printed wiring board is filled with an adhesive or grease having good thermal conductivity. This is because the action of the adhesive or grease having good thermal conductivity can promote heat radiation from the heat sink or the metal block of the package to the printed wiring board via the heat conductive adhesive or grease.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 In this embodiment, as shown in FIG. 1, a part of a printed board 1 in which electronic components of a ball grid array package 10 mounted on a printed wiring board 41 via solder balls 12 are mounted on the printed wiring board 41. FIG. The ball grid array package 10 includes a resin substrate 13 having a mounting portion for a semiconductor element 11 on an upper surface side and a pad (not shown) for bonding a solder ball 12 on a lower surface side.
A radiator plate 21 having good heat conduction is joined to the lower surface side of the semiconductor element mounting portion 3.

On the upper part of the package 10, fins 51 for dissipating the heat of the semiconductor element 11 to the outside air are appropriately arranged. A fan for forced air cooling is appropriately arranged on the fin 51 (the fin 51 and the fan are not essential). In the figure, reference numeral 14 denotes a resin mold for sealing, and reference numeral 17 denotes a bonding wire. And
The space between the heat sink 21 and the printed wiring board 41 of the ball grid array package 10 is filled with an adhesive or grease 42 having good heat conductivity.

The ball grid array package 1 of the present embodiment
Reference numeral 0 denotes a heat radiating plate 21 provided between the printed wiring board 41 and the heat generated from the lower surface of the semiconductor element 11. The heat is radiated to the printed wiring board 41 through a path of the shortest distance passing through the grease 42. And the heat sink 21 is
It is made of a material having good thermal conductivity, such as copper, aluminum, copper tungsten, and Kovar, and has a plate shape with low thermal resistance. Also, an adhesive or grease 42
Is made of a silicon-based resin and has a very good thermal conductivity.
Heat can be efficiently released.

Further, the structure for joining the heat radiating plate 21 to the resin substrate 13 is extremely simple, the manufacturing is easy, and the increase in manufacturing cost can be reduced. (A) of FIG.
The graph shown in (b) shows the allowable heat generation for the element 11 when the conventional ball grid array package 900 shown in FIG. 10 is used and when the ball grid array package 10 of this example is used. (Package 900 is package 1 except for the presence or absence of heat sink 21)
0).

That is, (a) of the figure shows an allowable heat generation amount for the conventional ball grid array package 900, and (b) of the figure shows the allowable heat generation amount of the ball grid array package 10 of the present embodiment.
Shows the allowable calorific value. The left bar graph shows the case where the fins 51 are present, and the right bar graph shows the case where the fins 51 are not present. The thermal resistance of the fin 51 used is 1.5 ° C./W. As shown in the figure, by using the package 10 of this embodiment, the allowable heat generation can be increased by 30% to 80%.

Embodiment 2 In this embodiment, as shown in FIG. 2, the structure of the ball grid array package in Embodiment 1 is changed. That is, the ball grid array package 101 of the present example has a resin substrate 15 having an opening 151 at a mounting position of the semiconductor element 11 and having a pad (not shown) for bonding the solder ball 12 on the lower surface side. Plate-shaped metal block 22 which is mounted in the opening 151 and has the semiconductor element 11 mounted on the upper surface and the lower surface side open to the outside.
And

In the package 101 of the present embodiment, the semiconductor element 11 is mounted not on the resin substrate 15 but on the metal block 22, and the lower surface of the metal block 22 is illustrated via the above-mentioned adhesive or grease having good heat conductivity. The printed wiring board 41 is not joined. for that reason,
An opening 151 for arranging the metal block 22 is provided at the mounting position of the semiconductor element 11 on the resin substrate 15. As described above, the semiconductor element 11 is
The metal block 2 having low thermal resistance is provided between the lower surface of the semiconductor element 11 and the printed wiring board 41 by mounting the
2, the heat radiation is extremely good. The material of the metal block 22 is copper, aluminum, copper tungsten, Kovar, or the like.

As a result, as shown in FIG. 9D, the allowable heat generation of the semiconductor element 11 increases from 97% to 150% as compared with the conventional package 900 shown in FIG. 9A. I was able to. Others are the same as in the first embodiment.

Embodiment 3 As shown in FIG. 3, the present embodiment differs from Embodiment 2 in that the structure of the metal block of the ball grid array package is changed. That is, the metal block 23 of the ball grid array package 102 according to the present embodiment includes the exposed portion 231 mounted on the lower surface of the resin substrate 15 and the exposed portion 2.
And an element mounting portion 232 projecting upward from the base 31 and penetrating the opening 151.

As a result, as shown in FIG. 9C, the allowable heat generation of the semiconductor element 11 increases from 92% to 150% as compared with the conventional package 900 shown in FIG. 9A. I was able to. Others are the same as the second embodiment.

Fourth Embodiment As shown in FIG. 4, this embodiment is different from the first embodiment in that the structure of the ball grid array package is changed. That is, the ball grid array package 103 of this embodiment is mounted on the resin substrate 13 having the mounting portion of the semiconductor element 11 on the upper surface side and the pad for bonding the solder ball 12 on the lower surface side, and the semiconductor element mounting portion. A semiconductor element 11, a resin coating 14 that covers the semiconductor element 11, and a heat dissipation block 24 that is close to the top of the semiconductor element 11 via the resin coating 14 and that promotes upward heat release are provided. As a result, the thermal resistance to the upper part of the semiconductor element 11 decreases, and heat radiation upward is promoted.

As a result, as shown in FIG. 9 (e), when the fins 51 are attached, heat radiation upward is promoted, and the allowable heat generation of the semiconductor element 11 becomes as shown in FIG. 9 (a). Compared with the conventional package 900 shown in FIG. Others are the same as in the first embodiment.

Fifth Embodiment As shown in FIG. 5, this embodiment is a modification of the third embodiment in which the structure of the ball grid array package is changed. That is, the ball grid array package 1 of this example
In 04, a heat radiating block 24 for promoting heat release above the semiconductor element 11 is provided. as a result,
As shown in FIG. 9F, the allowable heat generation of the semiconductor element 11 can be increased by 137% to 150% as compared with the conventional package 900 shown in FIG. 9A. Others are the same as the third embodiment.

Embodiment 6 In this embodiment, as shown in FIG. 6, the structure of the heat dissipation block of the ball grid array package in Embodiment 4 is changed. That is, in the ball grid array package 105 of this example, the heat radiation block 25
A thick portion 252 extending in the horizontal direction and increasing the externally exposed area on the side portion;
And a connecting portion 253 for generating a heat flow between the heat dissipation block main body 251 and the heat radiation block main body 251.

Therefore, heat radiation not only from above but also from the side is promoted, and the amount of heat radiation is further increased. as a result,
As shown in FIG. 9G, the allowable heat generation of the semiconductor element 11 can be increased by 134% to 158% as compared with the conventional package 900 shown in FIG. 9A. Others are the same as in the fourth embodiment.

Embodiment 7 As shown in FIG. 7, this embodiment is a modification of Embodiment 5 in which the structure of the heat radiation block of the ball grid array package is changed. That is, in the ball grid array package 106 of this example, the heat radiation block 25
A thick portion 252 extending in the horizontal direction and increasing the externally exposed area on the side portion;
And a connecting portion 253 for generating a heat flow between the heat dissipation block main body 251 and the heat radiation block main body 251.

Therefore, heat radiation not only from above but also from the side is promoted, and the amount of heat radiation is further increased. as a result,
As shown in FIG. 9H, the allowable heat generation of the semiconductor element 11 can be increased from 203% to 242% as compared with the conventional package 900 shown in FIG. Others are the same as the fifth embodiment.

Embodiment 8 In this embodiment, as shown in FIG. 8, a thermal via 27 is provided in the resin substrate 13 of the ball grid array package in Embodiment 1. The thermal via 27 can greatly reduce the thermal resistance between the lower surface of the semiconductor element 11 and the heat sink 21. For others,
This is the same as the first embodiment.

[0040]

As described above, according to the present invention, it is possible to obtain a ball grid array package excellent in heat dissipation and a printed board mounted with the ball grid array package.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of an electronic component using a ball grid array package according to a first embodiment.

FIG. 2 is a schematic cross-sectional view of an electronic component using the ball grid array package according to the second embodiment.

FIG. 3 is a schematic cross-sectional view of an electronic component using the ball grid array package according to the third embodiment.

FIG. 4 is a schematic cross-sectional view of an electronic component using the ball grid array package according to the fourth embodiment.

FIG. 5 is a schematic sectional view of an electronic component using the ball grid array package according to the fifth embodiment.

FIG. 6 is a schematic sectional view of an electronic component using the ball grid array package according to the sixth embodiment.

FIG. 7 is a schematic cross-sectional view of an electronic component using the ball grid array package according to the seventh embodiment.

FIG. 8 is a schematic sectional view of an electronic component using the ball grid array package according to the eighth embodiment.

FIG. 9 is a diagram showing an allowable heat generation amount of an element of an electronic component using the ball grid array package according to the first to eighth embodiments together with a case where a conventional ball grid array package is used (the left bar graph indicates a case with fins) , The bar graph on the right shows the case without fins).

FIG. 10 is a schematic cross-sectional view of an electronic component using a conventional ball grid array package.

FIG. 11 is a sectional view of an electronic component using a conventional ball grid array package.

[Explanation of symbols]

 10. . . 10. ball grid array package, . . Semiconductor device, 13. . . 21. a resin substrate; . . Heat sink, 41. . . Printed wiring board,

Claims (13)

[Claims] 1. A ball grid array package mounted on a printed wiring board via solder balls, the resin having a mounting portion for a semiconductor element on an upper surface side and a pad for bonding the solder balls on a lower surface side. A ball grid array package, comprising: a substrate; and a heat radiating plate having good heat conduction is joined to a lower surface side of the semiconductor element mounting portion of the resin substrate. 2. A ball grid array package mounted on a printed wiring board via solder balls, the resin having an opening at a mounting position of a semiconductor element and a pad for bonding the solder ball on a lower surface side. A ball grid array package, comprising: a substrate; and a metal block mounted in an opening of the resin substrate and having the semiconductor element mounted on an upper surface and having a lower surface open to the outside. 3. A ball grid array package mounted on a printed wiring board via solder balls, said resin having a mounting portion for semiconductor elements on an upper surface side and a pad for bonding said solder balls on a lower surface side. A substrate, a semiconductor element mounted on the mounting portion of the semiconductor element, a resin coating covering the semiconductor element, and a heat dissipation block which is close to the upper part of the semiconductor element via the resin coating and promotes upward heat release. A ball grid array package provided. 4. The heat radiation block according to claim 3, wherein the heat radiation block extends in the lateral direction, and has a thick portion for increasing an externally exposed area on a lateral side portion, and the thick portion and the heat radiation block main body. A connection part for generating a heat flow between the ball grid array package and the ball grid array package. 5. The semiconductor device according to claim 3, wherein the lower surface of the heat radiation block and the semiconductor element are electrically insulated via a high heat conductive resin or a high heat conductive resin sheet. And ball grid array package. 6. The ball grid array package according to claim 3, wherein a heat radiating plate having good heat conduction is joined to a lower surface side of a mounting portion of the resin substrate on which the semiconductor element is mounted. A ball grid array package characterized by being made. 7. The semiconductor device according to claim 1, wherein a thermal via for promoting heat conduction is formed between the resin substrate and the semiconductor element mounting portion between the resin substrate and the heat sink. And ball grid array package. 8. The ball grid array package according to claim 2, wherein a semiconductor element is mounted on a mounting portion of the resin substrate on which the semiconductor element is mounted, and a resin coating covering the semiconductor element and a resin coating are provided via the resin coating. A ball grid array package, characterized in that a heat dissipation block is provided adjacent to an upper portion of the semiconductor element and for promoting heat emission upward. 9. The heat radiation block according to claim 8, wherein the heat radiation block extends in the horizontal direction, and has a thick portion for increasing the externally exposed area on the lateral side portion, and the thick portion and the heat radiation block main body. A connection part for generating a heat flow between the ball grid array package and the ball grid array package. 10. The semiconductor device according to claim 8, wherein a lower surface of the heat dissipation block and the semiconductor element are electrically insulated via a high heat conductive resin or a high heat conductive resin sheet. And ball grid array package. 11. The ball grid array package according to claim 2, wherein the metal block is a plate-like body joined to a lower surface of the resin substrate. A ball grid array package characterized by the above-mentioned. 12. The ball grid array package according to claim 2, wherein the metal block comprises: an exposed portion mounted on a lower surface of the resin substrate; A ball grid array package having a semiconductor element mounting portion projecting upward from the exposed portion and penetrating the opening. 13. The method according to claim 1, wherein the control information is stored in the storage device.
13. A printed board comprising the ball grid array package according to any one of claims 12 to 12 mounted on a printed wiring board, wherein the heat sink or the metal block of the ball grid array package is connected to the printed wiring board. A printed board characterized by being filled with an adhesive or grease having good thermal conductivity.