JP2002314039A - LSI package structure - Google Patents

Abstract

(57) [Problem] To provide a package structure capable of connecting a carrier substrate on which electronic components such as memory ICs are mounted and a wiring substrate with a larger number of terminals. A carrier substrate includes a rigid portion on which a memory IC is mounted, and a flexible portion having one end physically and electrically connected to the rigid portion. The flexible portion 101 includes a solder connection portion in which a plurality of electrodes are two-dimensionally arranged on the lower surface on the other end side to which the rigid portion 102 is not connected, and the flexible portion 101 extends upward from the solder connection portion to the rigid portion 102. It has a bent portion 103 that bends toward it. The electrodes of the solder connection portion and the electrodes provided on the wiring board 13 are connected by solder balls 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an LSI package structure, and more particularly to a structure for mounting a carrier substrate on which electronic components such as a memory IC are mounted on a wiring substrate.

[0002]

2. Description of the Related Art In order to mount electronic components such as memory ICs at high density and to efficiently cool electronic components, electronic components are mounted on a carrier substrate instead of directly on a wiring substrate. There is a mounting method in which this carrier substrate is arranged on a wiring substrate. FIGS. 27 and 28 show a conventional structure in which a carrier substrate on which a plurality of memory ICs are mounted is mounted on a wiring substrate. In FIG. 27, the connector 20 is used, and the contact 2 is used.
1, the carrier substrate 105 and the wiring substrate 13 are electrically connected. In FIG. 28, the carrier substrate 105 and the wiring substrate 13 are directly connected by soldering by the leads 22 without using a connector.

On the other hand, as a mounting structure capable of high-density mounting without the need for a clip lead or the like, Japanese Patent Application Laid-Open No.
A hybrid IC disclosed in Japanese Patent Application Laid-Open No. 4 (Kokai) No. 4 is proposed. Here, as shown in FIG. 29, a plurality of component mounting portions 30 are arranged alternately on the flexible substrate so that the component mounting portions 30 are adjacent to each other between the component mounting portions 30. A wiring portion 31 to be electrically connected is formed, and the wiring portion 31 is bent so that each component mounting portion 30 is meandered so as to be perpendicular to the surface of the mounting board 32, and the lead of the first component mounting portion 30 is formed. 30a and the lead 3 of the last component mounting section 30
0b is connected to the mounting board 32. Further, the wiring portions 31 on the side remote from the mounting substrate 32 are electrically connected collectively by the connection line 33, and the wiring portions 31 on the side near the mounting substrate 32
There is also proposed a structure in which the groups are mounted on the same land 34 formed on the mounting board 32 and electrically connected collectively.

[0004]

In the structure shown in FIG. 27, the electrodes arranged in a row below the carrier substrate 105 and the contacts 21 are in contact with each other. Can be said to be about 0.5 mm. If the width of the carrier substrate 105 is 50
In the case of mm, 100 terminals are limited on one surface, and 200 terminals are limited even if both surfaces are added. Further, when the connector 20 is used, the length of the contact 21 causes an increase in signal noise, which causes a problem in high-speed operation.

According to the structure shown in FIG. 28 in which the carrier substrate 105 and the wiring substrate 13 are directly connected by soldering by the leads 22 without using a connector, the signal noise can be reduced. However, since the structure is such that the leads 22 are connected to the electrodes arranged in a line below the carrier substrate 105, the number of terminals that can be taken out has the same problem as the structure of FIG. 27. It is difficult to heat and melt the soldered portion, which causes deterioration in manufacturability.

On the other hand, the structure shown in FIG. 29 is a structure in which the lead 30a of the first component mounting section 30 and the lead 30b of the last component mounting section 30 are connected to the mounting board 32. Since there is a limit to the number of leads that can be taken out from 30 in one row, there is a problem similar to the structure shown in FIGS. Since the structure to which the connection lines 33 and the lands 34 are added aims at connecting a plurality of component mounting units 30 in parallel,
The same number of electrodes as the leads 30a and 30b are provided in a portion where the group of wiring portions 31 closer to the mounting substrate 32 is in contact with the mounting substrate 32.

An object of the present invention is to provide a package structure capable of connecting a carrier substrate on which electronic components such as memory ICs are mounted and a wiring substrate with a larger number of terminals.

Another object of the present invention is to provide a package structure in which a carrier substrate can be easily detached from a wiring substrate.

[0009]

According to an LSI package structure of the present invention, in a structure in which a carrier substrate on which electronic components such as a memory IC are mounted is mounted on a wiring substrate, the carrier substrate includes a rigid portion on which the electronic components are mounted. And a connection member physically and electrically connected to the rigid portion, wherein the connection member has a solder connection portion in which a plurality of electrodes are two-dimensionally arranged on a part of the lower surface. And a bent portion that is bent upward on the way from the solder connection portion to the rigid portion, and an electrode of the solder connection portion of the connection member and an electrode provided on the wiring board are connected by a solder ball. It is characterized by having been done. Here, a structure in which one rigid portion is connected to only one end of the connection member may be used, or a structure in which one rigid portion is connected to both ends of the connection member. Further, the connecting member may be entirely made of a material having flexibility, a portion having the solder connecting portion on the lower surface is made of a non-flexible material, and the other portions are made of a flexible material. It may be composed of a sexual material.

In the case where the entire connecting member is made of a flexible material, the rigidity is fixed to the surface of the connecting member opposite to the solder connecting portion, so that the flatness of the solder connecting portion can be secured, and the reliability of the solder connection can be secured. Performance can be improved. Further, when a rigid body whose lower surface is fixed to the opposite surface of the solder connection portion in the connection member and whose side surface processed into the shape along the bent portion is fixed to the bent portion is provided, the flatness of the solder connection portion is improved. The shape of the bent portion can be maintained at the same time as the property is secured, and the deformation of the carrier substrate can be prevented. Further, if a heat generating plate having a power supply terminal is fixed to the surface of the connection member opposite to the solder connection portion, the flatness of the solder connection portion can be ensured and detachment of the carrier substrate can be easily performed. At this time, if a lower surface is fixed to the upper surface of the heat generating plate, and a side surface is provided with a rigid body fixed to an upper portion of the bent portion of the connection member,
Deformation of the carrier substrate can also be prevented. Further, in a configuration in which one rigid portion is connected to both ends of the connection member, a top cover having one end fixed to the upper end of one rigid portion and the other end fixed to the upper end of the other rigid portion is provided. Also, the carrier substrate can be prevented from being deformed.

On the other hand, in the case of a connection member in which the portion having the solder connection portion on the lower surface is made of a non-flexible material, the flatness of the solder connection portion is secured as it is. Further, when a rigid body whose lower surface is fixed to the opposite surface of the solder connection portion of the connection member and whose side surface is fixed to the rigid portion is provided, the shape of the bent portion can be maintained, and the deformation of the carrier substrate is prevented. be able to. Furthermore, if a heat generating plate having a power supply terminal is fixed to the surface of the connection member opposite to the solder connection portion, attachment and detachment in units of the carrier substrate becomes easy.
At this time, when the lower surface is fixed to the upper surface of the heat generating plate and the side surface is provided with a rigid body fixed to the upper portion of the bent portion of the connection member, deformation of the carrier substrate can be prevented. Further, in a configuration in which one rigid portion is connected to both ends of the connection member, a top cover having one end fixed to the upper end of one rigid portion and the other end fixed to the upper end of the other rigid portion is provided. Also, the carrier substrate can be prevented from being deformed.

[0012]

According to the LSI package structure of the present invention, a plurality of electrodes are two-dimensionally arranged on a part of a lower surface of a connection member physically and electrically connected to a rigid portion for mounting an electronic component. The solder connection part is provided, and the electrode of the solder connection part and the electrode arranged on the wiring board are connected by the solder ball, so that the carrier board and the wiring board can be connected with a larger number of terminals. . In addition, since a part of the connection member is bent upward, the rigid portion for mounting the electronic component can be perpendicular to the wiring board, and high-density mounting is possible. Further, according to the configuration including the heat generating plate, the solder connection portion can be easily heated, and can be easily detached from the wiring substrate in units of individual carrier substrates.

[0013]

FIG. 1 is a longitudinal sectional view showing an LSI package structure according to a first embodiment of the present invention, and FIG. 2 is a side view thereof. The carrier substrate 10 on which a plurality of memory ICs 11 are mounted is made of a rigid flexible substrate having a flexible portion 101 and a rigid portion 102. The rigid portion 102 is a normal printed wiring board material (FR4), and the flexible portion 101 is made of polyimide as an insulating material and copper is used as an inner wiring. The rigid flexible substrate can be manufactured by sandwiching a flexible portion in a laminating step in a process of manufacturing a printed wiring board, and is a widely used material.

The memory IC 11 has, for example, TSOP '(T
hin-Small-Outline-Packag
e) the rigid portion 10 of the carrier substrate 10
2 is mounted by soldering. The electric signal of the memory IC 11 is connected to the inner layer wiring of the rigid part 102, and further connected to the inner layer wiring of the flexible part 101. The inner layer wiring of the flexible portion 101 is divided into a power supply layer and a signal layer, and has a structure adjusted to a desired impedance (for example, 50Ω). On the lower surface of the flexible portion 101 on the side where the rigid portion 102 is not connected, there is a solder connection portion in which electrodes for electrically connecting to the wiring board 13 are arranged in a grid pattern. The electrode and the electrode of the wiring board 13 are
They are connected by solder balls 12.

When the width of the carrier substrate 10 is 50 mm and the electrode interval is 1 mm, about 50 electrodes can be arranged in one row.
It becomes possible to arrange 400 electrodes.

The flexible portion 101 includes the bent portion 10
3, the rigid part 102 on which the memory IC 11 is mounted is arranged substantially at right angles to the wiring board 13.

FIG. 3 is a longitudinal sectional view showing a structure in which a plurality of carrier substrates 10 shown in FIG. Since the carrier substrate 10 is substantially perpendicular to the wiring substrate 13, high-density mounting is possible.

FIG. 4 is a longitudinal sectional view showing a structure in which a stiffener A14 made of a highly rigid material is fixed to the surface opposite to the solder connection portion of the flexible portion 101 in the structure shown in FIG. The material of the stiffener A14 is a metal (a material obtained by plating nickel on copper or a stainless steel material), a ceramic (for example, alumina ceramic), or the like, and has a thickness of about 1 mm. The material of the stiffener A is desirably close to the coefficient of linear expansion of the wiring board 13 in order to reduce the thermal stress on the solder ball 12. When the FR4 material is used for the wiring board 13, the coefficient of linear expansion of the FR4 is about 16 ppm. Therefore, a material close to this value, for example, copper (about 16 pp
Materials having m) as a base material are preferred. Flexible part 10
A thermoplastic adhesive or a thermosetting adhesive (for example, an epoxy adhesive) is used for fixing the stiffener A14 to the stiffener A14. When the carrier substrate 10 is connected to the wiring substrate 13 by soldering, the stiffener A14 is arranged in advance on the opposite surface of the flexible portion 101 from the solder connection portion, so that the flatness of the solder joint surface of the flexible portion is ensured and stable. Solder connection becomes possible.

FIG. 5 shows a heating plate 17 having a built-in heating element instead of the stiffener A14 in the structure shown in FIG.
FIG. 3 is a longitudinal sectional view showing a structure in which is fixed to the upper surface of the flexible portion 101 (the surface opposite to the solder connection portion). The heat generating plate 17 is provided with a heat generating resistor (for example, tantalum nitride) in a film shape on an insulating plate material (for example, alumina ceramic). The heating resistor is formed by a method such as sputtering or thick film printing. When a metal such as copper is used as the material of the heat generating plate 17, the heat generating resistor may be formed after forming the insulating film. Further, a metal power supply terminal 18 is provided to supply power to the heating element. The power supply terminal 18 has a pin shape or a plate shape, and is fixed to the heating resistor by soldering or using a filter material. The solder or filler used here is
A material having a higher melting point than the solder ball 12 is used.
When a material equivalent to the solder ball 12 is used, it is fixed with an insulating material so that the power supply terminal 18 does not fall off even if it is melted. By supplying power from the power supply terminal 18 to the heating element of the heating plate 17, the solder balls 12
Can be heated and melted at a temperature higher than the melting temperature of the solder ball 12 (for example, the melting temperature is 183 ° C. when using Sn63 / Pb 37 wt% solder). By doing so, the carrier substrate 10 can be detached. As shown in FIG. 3, even when a plurality of carrier substrates 10 are mounted on the wiring substrate 13, only a specific carrier substrate can be detached.

FIG. 6 is a longitudinal sectional view showing that a stiffener B15 having a shape along the surface opposite to the solder connection portion of the flexible portion 101 and the bent portion 103 is fixed in the structure shown in FIG. By fixing the stiffener B15 having the shape along the bent portion 103 to the upper surface of the flexible portion 101, the shape of the bent portion 103 can be maintained, and the carrier substrate 10 can be prevented from being deformed. The thickness of the stiffener B15 is a thickness that can maintain the bent shape of the flexible portion 101,
For example, when the radius of curvature of the bent portion 103 is 2 mm, the thickness is preferably about 4 mm. The material of the stiffener B15 may be a rigid body, but does not require high rigidity because it is not thin like the stiffener A, and may be a plastic molded material. Stiffener B15 and flexible part 1
For fixing with 01, a thermoplastic adhesive or a thermosetting adhesive is used.

FIG. 7 shows one side of the upper surface of the heat generating plate 17 (the portion where the power supply terminal 18 is not provided) and the bent portion 103 of the flexible portion 101 in the structure shown in FIG.
It is a longitudinal cross-sectional view which shows that the stiffener C16 which fixes the upper part of this is provided. The material of the stiffener C16 is preferably a plastic mold material or the like. With such a structure, deformation of the carrier substrate 10 can be prevented. The stiffener C16 may be fixed to the entire upper surface of the heat generating plate 17. In this case, the power supply terminal 18 is set to a length sufficiently protruding from the upper surface of the stiffener C16.

FIG. 8 shows the structure shown in FIG. 1 in which the angle of the bent portion 103 is changed so that the wiring board 13 and the rigid portion 1 are formed.
It is a longitudinal cross-sectional view which shows that the angle between 02 was made smaller than 90 degrees. With this structure, the mounting height of the carrier substrate 10 can be made lower than the structure shown in FIG.
Further, in this structure, a structure in which the stiffeners A, B, and C shown in FIGS. 4, 5, 6, and 7, and a heat generating plate are attached is also possible.

FIGS. 9A to 9D are longitudinal sectional views showing an assembly process of the LSI package structure according to the present embodiment. FIG. 9A shows a memory IC on one side of a carrier substrate 10.
11 shows a process for mounting the solder balls 11 and the solder balls 12.
Memory IC 1 on rigid portion 102 of carrier substrate 10
The cream solder is printed and supplied onto the pad on which the memory IC 1 is mounted, and the memory IC 11 is mounted. Also flexible 10
The solder ball is mounted by printing and supplying cream solder or flux on the pad on which the solder ball 12 is mounted. In this state, heat reflow, for example, in the case of Sn63 / Pb37wt% as a solder material to be used,
By heating at 200 ° C. to melt the solder, the carrier substrate 10 of the memory IC 11 and the solder balls 12 is formed.
Is completed.

Next, as shown in FIG. 9B, the carrier substrate 10 is inverted, and the memory IC 11 is mounted similarly.
The stiffener A14 shown in FIG. 4 and the heat generating plate 17 shown in FIG. 5 may be fixed thereafter.

Next, as shown in FIG. 9C, the flexible portion 101 is bent at the bending portion 103. When bending, it is processed so as to be sandwiched between molded dies and the like. Heating (for example, 100 ° C) to facilitate processing
It is also possible to do. In order to maintain the shape of the processed flexible portion 101, the stiffener B1 shown in FIG.
5 is fixed in this step.

Finally, the carrier board 10 is mounted on the wiring board 13 as shown in FIG. The cream solder is printed and supplied onto the pads of the wiring board 13, the carrier board is mounted, and heating reflow is performed. Note that the carrier substrate 10 may be overturned during the heating reflow, but the carrier substrate 10 may be supported by a jig. If the solder balls 12 are crushed during the heating reflow due to the weight of the carrier substrate 10, a method of using the solder balls 12 containing copper balls can be considered. Also,
In order to secure the height of the solder ball 12, a spacer may be provided between the flexible part 101 and the wiring board 13.

[0027]

FIG. 10 is a longitudinal sectional view showing an LSI package structure according to a second embodiment of the present invention, and FIG. 11 is a side view thereof. The carrier substrate 10 on which a plurality of memory ICs 11 are mounted is made of a rigid-flexible substrate including two rigid portions 102 and a flexible portion 101 interposed therebetween. The rigid part 102 is made of a normal printed wiring board material (FR4), the flexible part 101 is made of polyimide as an insulating material, and copper is used as an inner layer wiring. The rigid flexible substrate can be manufactured by sandwiching a flexible portion in a laminating step in a process of manufacturing a printed wiring board, and is a widely used material.

The memory IC 11 is, for example, TSOP (Th
in-Small-Outline-Package)
It is of a type, and is mounted on the rigid portion 102 of the carrier substrate 10 by soldering. The electric signal of the memory IC 11 is connected to the inner layer wiring of the rigid part 102, and further connected to the inner layer wiring of the flexible part 101. The inner layer wiring of the flexible portion 101 is divided into a power supply layer and a signal layer, and has a structure adjusted to a desired impedance (for example, 50Ω). On one surface of the flexible portion 101, electrodes for electrically connecting to the wiring board 13 are arranged in a grid pattern, and the electrodes and the electrodes of the wiring board 13 are connected by solder balls 12.

When the width of the carrier substrate 10 is 50 mm and the electrode spacing is 1 mm, about 50 electrodes can be arranged in one row.
It becomes possible to arrange 400 electrodes.

The flexible portion 101 is bent at about 90 degrees at two bending portions 103, and the memory I
The two rigid portions 102 on which the C11 is mounted have a structure arranged substantially at right angles to the wiring board 13.

FIG. 12 shows the carrier substrate 10 shown in FIG.
FIG. 5 is a longitudinal sectional view showing a structure in which a plurality of are mounted on a wiring board 13. Since the carrier substrate 10 is substantially perpendicular to the wiring substrate 13 and the two rigid portions 102 share one flexible portion 101, FIG.
In this case, higher-density mounting is possible.

FIG. 13 is a longitudinal sectional view showing a structure in which a stiffener A14 made of a highly rigid material is fixed to the surface opposite to the solder connection portion of the flexible portion 101 in the structure shown in FIG. The material of the stiffener A14 is a metal (a material obtained by plating nickel on copper or a stainless steel material), a ceramic (for example, alumina ceramic), or the like, and has a thickness of about 1 mm. The material of the stiffener A is desirably close to the coefficient of linear expansion of the wiring board 13 in order to reduce the thermal stress on the solder balls 12.
When four materials are used, the linear expansion coefficient of FR4 is about 16 pp
m, a material close to this value, for example, copper (about 16p
pm) is preferred. Flexible part 1
For fixing the stiffener A14 to the stiffener 01, a thermoplastic adhesive or a thermosetting adhesive (for example, an epoxy adhesive) is used. When the carrier substrate 10 is connected to the wiring substrate 13 by soldering,
By arranging the stiffener A14 in advance on the surface opposite to the solder connection portion of the flexible portion 101, the flatness of the solder joint surface of the flexible portion 101 is ensured, and stable solder connection becomes possible.

FIG. 14 shows the structure shown in FIG. 13, in which a heating plate 17 having a built-in heating element instead of the stiffener A14 is provided on the upper surface of the flexible portion (opposite the solder connection portion).
FIG. 3 is a vertical cross-sectional view showing a structure fixed to the device. The heat generating plate 17 is provided with a heat generating resistor (for example, tantalum nitride) in a film shape on an insulating plate material (for example, alumina ceramic). The heating resistor is formed by a method such as sputtering or thick film printing. When a metal such as copper is used as the material of the heat generating plate 17, the heat generating resistor may be formed after forming the insulating film. Further, a metal power supply terminal 18 is provided to supply power to the heating element. The power supply terminal 18 has a pin shape or a plate shape, and is fixed to the heating resistor by soldering or using a filter material. The solder or filler used here is a material having a higher melting point than the solder ball 12. When a material equivalent to the solder ball 12 is used, it is fixed with an insulating material so that the power supply terminal 18 does not fall off even if it is melted. By supplying power from the power supply terminal 18 to the heating element of the heating plate 17, the solder connection portion connected to the wiring board 13 can be heated and melted by the solder ball 12, and the melting temperature of the solder ball 12 ( For example, when a solder of Sn63 / Pb 37 wt% is used, the carrier substrate 10 can be detached by heating to a melting temperature of 183 ° C. or higher. As shown in FIG. 12, even when a plurality of carrier boards 10 are mounted on the wiring board 13, only a specific carrier board can be detached.

FIG. 15 is a longitudinal sectional view showing that the stiffener B15 having a shape along the opposite surface of the solder connection portion of the flexible portion 101 and the two bent portions 103 is fixed in the structure shown in FIG. is there. Bending part 1
The flexible part 1
01, the bent portion 103
Of the carrier substrate 10 can be maintained.
Can be prevented from being deformed. The thickness of the stiffener B15 is a thickness that can maintain the bent shape of the flexible portion 101, and for example, the curvature radius of the bent portion 103 is 2 m.
In the case of m, the thickness is preferably about 4 mm. Stiffener B15
The material may be a rigid body, but does not need high rigidity because it is not thin like stiffener A, and may be a plastic molded material. For fixing the stiffener B15 to the flexible portion 101, a thermoplastic adhesive or a thermosetting adhesive is used.

FIG. 16 shows a stiffener C16 for fixing one side of the upper surface of the heat generating plate 17 (the portion where the power supply terminal 18 is not provided) and the upper portions of the two bent portions 103 of the flexible portion 101 in the structure shown in FIG. It is a longitudinal cross-sectional view which shows that is provided. The material of the stiffener C16 is preferably a plastic mold material or the like. With such a structure, deformation of the carrier substrate 10 can be prevented. The stiffener C16 may be fixed to the entire upper surface of the heat generating plate 17. In this case, the power supply terminal 18 is set to a length sufficiently protruding from the upper surface of the stiffener C16.

FIG. 17 is characterized in that, in the structure shown in FIG. 10, a top cover 19 for mechanically connecting and holding the upper ends of the right and left rigid portions 102 is provided. The top cover 19 has a shape provided with two grooves sandwiching the upper end of the rigid portion 102, and may be made of plastic mold or metal (for example, aluminum or the like). With this structure,
Deformation of the carrier substrate 10 can be prevented, and the shape can be maintained.

FIGS. 18 (a) to 18 (d) are longitudinal sectional views showing an assembly process of the LSI package structure according to the present embodiment. FIG. 18A shows a process of mounting the memory IC 11 and the solder balls 12 on one side of the carrier substrate 10, and applying cream solder on pads on the rigid portions 102 at both ends of the carrier substrate 10 where the memory IC 11 is mounted. Printing is supplied, and the memory IC 11 is mounted. Also, cream solder or flux is printed and supplied onto the pad on which the solder ball 12 is mounted on the flexible portion 101,
Mount the solder balls. In this state, heat reflow, for example, as a solder material to be used, Sn63 / Pb37wt
%, By heating at 200 ° C. to melt the solder, the joining of the memory IC 11 and the solder balls 12 to the carrier substrate 10 is completed.

Next, as shown in FIG. 18B, the carrier substrate 10 is inverted, and the memory IC 11 is mounted similarly. The stiffener A14 shown in FIG. 13 and the heating plate 17 shown in FIG. 14 may be fixed thereafter.

Next, as shown in FIG. 18C, the flexible portion 101 is bent at two bending portions 103. When bending, it is processed so as to be sandwiched between molded dies and the like. Heating (for example, 100 ° C.) may be considered to facilitate processing. The stiffener B15 shown in FIG. 15 and the stiffener C16 shown in FIG. 16 are fixed in this step in order to maintain the shape of the processed flexible portion 101.

Finally, as shown in FIG. 18D, the carrier board 10 is mounted on the wiring board 13. Wiring board 13
The cream solder is printed and supplied on the pad, and the carrier substrate 10 is mounted, and heating reflow is performed. If the solder balls 12 are crushed during the heating reflow due to the weight of the carrier substrate 10, a method of using the solder balls 12 containing copper balls can be considered. Also,
In order to secure the height of the solder ball 12, a spacer may be provided between the flexible part 101 and the wiring board 13.

[0041]

Third Embodiment FIG. 19 is a longitudinal sectional view showing an LSI package structure according to a third embodiment of the present invention, and FIG. 20 is a side view thereof. The carrier substrate 10 on which a plurality of memory ICs 11 are mounted is composed of two rigid portions A102, one rigid portion B104, and two flexible portions 101 sandwiched between the rigid portions A and B. Made of rigid-flexible substrates. Rigid part A102 and rigid part B1
Reference numeral 04 denotes a normal printed wiring board material (FR4), and the flexible portion 101 uses polyimide as an insulating material and copper as an inner layer wiring. The rigid flexible substrate can be manufactured by sandwiching a flexible portion in a laminating step in a process of manufacturing a printed wiring board, and is a widely used material.

The memory IC 11 stores, for example, TSOP (Th
in-Small-Outline-Package)
Rigid part A102 of the carrier substrate 10.
Solder mounted. The electric signal of the memory IC 11 is connected to the inner wiring of the rigid part A102, and further connected to the rigid part B104 via the inner wiring of the flexible part 101. Rigid part A1
02, the rigid part B104, and the flexible part 101
Are divided into a power supply layer and a signal layer, and have a structure adjusted to a desired impedance (for example, 50Ω). On the lower surface of the rigid portion B104, electrodes for electrically connecting to the wiring board 13 are arranged in a grid pattern, and the electrodes and the electrodes of the wiring board 13 are connected by solder balls 12.

When the width of the carrier substrate 10 is 50 mm and the electrode interval is 1 mm, it is possible to arrange about 50 electrodes per row.
It becomes possible to arrange 400 electrodes.

The flexible portion 101 includes the bent portion 10
3, the rigid part A102 on which the memory IC 11 is mounted is arranged at a substantially right angle to the wiring board 13.

FIG. 21 shows the carrier substrate 10 shown in FIG.
FIG. 5 is a longitudinal sectional view showing a structure in which a plurality of are mounted on a wiring board 13. That the carrier substrate 10 is substantially perpendicular to the wiring substrate 13 and that two rigid portions A102
Since one rigid portion 104 is shared, higher density mounting is possible than in the case of FIG.

FIG. 22 is a longitudinal sectional view showing that the stiffener A14 is fixed to the surface opposite to the solder connection portion of the rigid portion B104 and the inner surface of the rigid portion A102 in the structure shown in FIG. The stiffener A14 is connected to the surface opposite to the solder connection portion of the rigid portion B104 and the rigid portion A1.
By fixing the bent portion 103 to the inner side surface of the flexible substrate 101, the shape of the bent portion 103 of the flexible portion 101 can be maintained, and the deformation of the carrier substrate 10 can be prevented. The material of stiffener A14 is plastic mold,
It is a metal (for example, aluminum) or the like that is easy to process, and a thermoplastic adhesive or a thermosetting adhesive is used for fixing the stiffener A14 to the upper surface of the rigid portion B104 and the inner surface of the rigid portion A102.

FIG. 23 is a longitudinal sectional view showing a structure in which a heating plate 17 containing a heating element is fixed to the surface of the rigid portion B104 opposite to the solder connection portion in the structure shown in FIG. The heat generating plate 17 is provided with a heat generating resistor (for example, tantalum nitride) in a film shape on an insulating plate material (for example, alumina ceramic). The heating resistor is formed by a method such as sputtering or thick film printing. Heating plate 17
When a metal such as copper is used as the material for the first step, the heating resistor may be formed after forming the insulating film. Further, in order to supply electric power to the heating element, a metal power supply terminal 1 is provided.
8 are provided. The power supply terminal 18 has a pin shape or a plate shape, and is fixed to the heating resistor by soldering or using a filter material. The solder or filler used here is a material having a higher melting point than the solder ball 12. When a material equivalent to the solder ball 12 is used, it is fixed with an insulating material so that the power supply terminal 18 does not fall off even if it is melted. By supplying power from the power supply terminal 18 to the heating element of the heating plate 17, the solder connection portion connected to the wiring board 13 can be heated and melted by the solder ball 12, and the melting temperature of the solder ball 12 ( For example, Sn63 / Pb37wt
% Of the solder, the melting temperature is heated to 183 ° C. or higher, so that the carrier substrate 10 can be detached. As shown in FIG. 21, even when a plurality of carrier substrates 10 are mounted on the wiring substrate 13, only a specific carrier substrate can be detached.

FIG. 24 shows a structure shown in FIG. 23, in which a stiffener B15 for fixing one side of the upper surface of the heat generating plate 17 (the portion where the power supply terminal 18 is not provided) and the inner surface of the rigid portion A102 is provided. FIG. With this structure, it is possible to maintain the shape of the bent portion 103 of the flexible portion 101,
Deformation of the carrier substrate 10 can be prevented. The material of the stiffener B15 may be a plastic mold material or the like. The stiffener B15 may be fixed to the entire upper surface of the heat generating plate 17. In this case, the power supply terminal 18 is set to a length sufficiently protruding from the upper surface of the stiffener B15.

FIG. 25 is a longitudinal sectional view showing that the top cover 19 for mechanically connecting and holding the upper ends of the right and left rigid portions A102 in the structure shown in FIG. 19 is provided. With this structure, deformation of the carrier substrate 10 is prevented,
It is possible to maintain the shape.

FIGS. 26 (a) to 26 (d) are longitudinal sectional views showing an assembly process of the LSI package structure according to the present embodiment. FIG. 26A shows a process of mounting the memory IC 11 and the solder balls 12 on one side of the carrier substrate 10. Cream solder is placed on the pads on the two rigid portions A102 of the carrier substrate 10 where the memory IC 11 is mounted. Printing is supplied, and the memory IC 11 is mounted. The cream solder or the flux is printed and supplied on the pad of the rigid portion B104 on which the solder ball 12 is mounted, and the solder ball is mounted. In this state, heating reflow, for example, in the case of using Sn 63 / Pb 37 wt% as a solder material to be used, heating at 200 ° C. to melt the solder completes the joining of the memory IC 11 and the solder balls 12 to the carrier substrate 10.

Next, as shown in FIG. 26B, the carrier substrate 10 is inverted, and the memory IC 11 is mounted in the same manner. The heating plate 17 shown in FIG. 23 may be fixed thereafter.

Next, as shown in FIG. 26C, the flexible portion 101 is bent at two bent portions 103. When bending, it is processed so as to be sandwiched between molded dies and the like. Heating (for example, 100 ° C.) may be considered to facilitate processing. The stiffener A14 shown in FIG. 22 and the stiffener B15 shown in FIG. 24 are fixed in this step in order to maintain the shape of the processed flexible portion 101.

Finally, the carrier board 10 is mounted on the wiring board 13 as shown in FIG. Wiring board 13
The cream solder is printed and supplied on the pad, and the carrier substrate 10 is mounted, and heating reflow is performed. Note that the carrier substrate 10 may be overturned during the heating reflow, but the carrier substrate 10 may be supported by a jig. If the solder balls 12 are crushed during the heating reflow due to the weight of the carrier substrate 10, a method of using the solder balls 12 containing copper balls can be considered.
It is also conceivable to provide a spacer between the flexible part 101 and the wiring board 13 to secure the height of the solder ball 12.

Although the present invention has been described with reference to some embodiments, the present invention is not limited to the above embodiments, and various other additions and changes are possible. For example, although a memory IC has been described as an electronic component, the present invention is also applicable to mounting of other types of electronic components such as a CPU, and a plurality of different types of electronic components are mixed in one rigid unit 102. May be implemented.

[0055]

According to the present invention, in a package structure in which a carrier substrate on which a plurality of electronic components such as memory ICs are mounted on a wiring substrate, a large number of signals can be connected by employing the structure of the present invention. Low noise,
A package that enables high-speed operation can be realized. Further, detachment can be easily performed for each carrier substrate.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an LSI package structure according to a first embodiment of the present invention.

FIG. 2 is a side view showing an LSI package structure according to the first embodiment of the present invention.

FIG. 3 is a longitudinal sectional view showing a structure in which a plurality of carrier substrates shown in FIG. 1 are mounted on a wiring board.

FIG. 4 is a longitudinal sectional view showing a structure in which a stiffener made of a highly rigid material is fixed to a surface of the flexible portion opposite to a solder connection portion in the structure shown in FIG. 1;

FIG. 5 is a vertical cross-sectional view showing a structure in which a heating plate having a built-in heating element instead of a stiffener in the structure shown in FIG. 4 is fixed to an upper surface of a flexible portion (opposite to a solder connection portion).

FIG. 6 is a longitudinal sectional view showing that a stiffener having a shape along a surface opposite to a solder connection portion of a flexible portion and a bent portion is fixed in the structure shown in FIG. 1;

FIG. 7 is a longitudinal sectional view showing that a stiffener for fixing the upper surface of the heat generating plate and the upper portion of the bent portion of the flexible portion is provided in the structure shown in FIG.

8 is a longitudinal sectional view showing that the angle of the bent portion is changed in the structure shown in FIG. 1 and the angle between the wiring board and the rigid portion is made smaller than 90 degrees.

FIG. 9 is a vertical sectional view showing an assembly process of the LSI package structure according to the first embodiment of the present invention.

FIG. 10 is a longitudinal sectional view showing an LSI package structure according to a second embodiment of the present invention.

FIG. 11 is a side view showing an LSI package structure according to a second embodiment of the present invention.

12 is a longitudinal sectional view showing a structure in which a plurality of carrier substrates shown in FIG. 10 are mounted on a wiring board.

FIG. 13 is a longitudinal sectional view showing a structure in which a stiffener made of a highly rigid material is fixed to the surface of the flexible portion opposite to the solder connection portion in the structure shown in FIG. 10;

FIG. 14 is a longitudinal sectional view showing a structure in which a heating plate having a built-in heating element instead of the stiffener is fixed to the upper surface of the flexible portion (opposite the solder connection portion) in the structure shown in FIG.

FIG. 15 is a longitudinal sectional view showing that a stiffener having a shape along the opposite surface of the flexible portion and the two bent portions is fixed in the structure shown in FIG. 10;

FIG. 16 is a longitudinal sectional view showing that a stiffener for fixing the upper surface of the heat generating plate and the upper portions of two bent portions of the flexible portion is provided in the structure shown in FIG.

FIG. 17 is a longitudinal sectional view showing that a top cover for mechanically connecting and holding upper ends of right and left rigid portions is provided in the structure shown in FIG. 10;

FIG. 18 is a longitudinal sectional view showing an assembly process of an LSI package structure according to a second embodiment of the present invention.

FIG. 19 is a longitudinal sectional view showing an LSI package structure according to a third embodiment of the present invention.

FIG. 20 is a side view showing an LSI package structure according to a third embodiment of the present invention.

21 is a longitudinal sectional view showing a structure in which a plurality of carrier boards shown in FIG. 19 are mounted on a wiring board.

FIG. 22 is a longitudinal sectional view showing that a stiffener is fixed to the surface opposite to the solder connection portion of the rigid portion B and the inner surface of the rigid portion A in the structure shown in FIG.

FIG. 23 is a vertical cross-sectional view showing a structure in which a heating plate having a built-in heating element is fixed to the surface of the rigid portion B opposite to the solder connection portion in the structure shown in FIG. 19;

24 is a longitudinal sectional view showing that a stiffener for fixing the upper surface of the heat generating plate and the inner surface of the rigid portion A is provided in the structure shown in FIG. 23;

25 is a vertical sectional view showing that a top cover for mechanically connecting and holding upper end portions of right and left rigid portions A in the structure shown in FIG. 19 is provided.

FIG. 26 is a vertical sectional view showing an assembly process of the LSI package structure according to the third embodiment of the present invention.

FIG. 27 is a longitudinal sectional view showing an example of a conventional LSI package structure.

FIG. 28 is a longitudinal sectional view showing another example of the conventional LSI package structure.

FIG. 29 is a diagram showing an example of a conventional package structure proposed for a hybrid IC.

[Explanation of symbols]

 10, 105 ... Carrier substrate 101 ... Flexible part 102 ... Rigid part 103 ... Bend part 11 ... Memory IC 12 ... Solder ball 13 ... Wiring board 14 ... Stiffener A 15 ... Stiffener B 16 ... Stiffener C 17 ... Heat generating plate 18 ... Power supply terminal 19: top cover 20: connector 21: contact 22. Lead

Continued on front page F term (reference) 5E336 AA04 AA09 AA16 BB05 BB12 BB15 CC32 CC44 EE01 GG05 GG11 GG23 5E344 AA02 AA12 AA22 BB01 BB02 BB04 DD02 EE06 EE21 EE23 EE26

Claims (29)

[Claims] 1. A structure in which a carrier board on which electronic components are mounted is mounted on a wiring board, wherein the carrier board has a rigid portion on which the electronic components are mounted and a connection physically and electrically connected to the rigid portion. It is composed of members
The connection member has a solder connection part in which a plurality of electrodes are two-dimensionally arranged on a part of the lower surface, and has a bent part that is bent upward on the way from the solder connection part to the rigid part. LS, wherein an electrode of the solder connection portion of the connection member and an electrode provided on the wiring board are connected by a solder ball.
I package structure. 2. The LSI package structure according to claim 1, wherein said connection member is entirely made of a material having flexibility. 3. The L according to claim 2, further comprising a rigid body fixed to an opposite surface of the connection member from the solder connection portion.
SI package structure. 4. A rigid body having a lower surface fixed to a surface of the connection member opposite to the solder connection portion, and a side surface processed into a shape along the bent portion fixed to the bent portion. LSI package structure. 5. The LSI package structure according to claim 2, wherein a heating plate having a power supply terminal is fixed to a surface of said connection member opposite to said solder connection portion. 6. The LSI package structure according to claim 5, further comprising a rigid body having a lower surface fixed to an upper surface of said heat generating plate and a side surface fixed to an upper portion of said bent portion of said connecting member. 7. The LS according to claim 1, wherein a portion of the connection member having the solder connection portion on a lower surface is formed of a non-flexible material, and other portions are formed of a flexible material.
I package structure. 8. The LSI package structure according to claim 7, further comprising a rigid body having a lower surface fixed to an opposite surface of the connection member from the solder connection portion and a side surface fixed to the rigid portion. 9. The LSI package structure according to claim 7, wherein a heating plate having a power supply terminal is fixed to a surface of said connection member opposite to said solder connection portion. 10. The LSI package structure according to claim 9, further comprising a rigid body having a lower surface fixed to an upper surface of said heat generating plate and a side surface fixed to an upper portion of said bent portion of said connecting member. 11. The rigid part according to claim 1, wherein the rigid part is connected to only one end of the connecting member.
An LSI package structure according to the item. 12. The LSI package structure according to claim 1, wherein the different rigid portions are connected to both ends of the connection member. 13. The LSI package structure according to claim 12, further comprising a top cover having one end fixed to an upper end of said one rigid portion and the other end fixed to an upper end of said other rigid portion. 14. A structure in which a carrier board on which electronic components are mounted is mounted on a wiring board.
One rigid part on which the electronic component is mounted, and a flexible part one end of which is physically and electrically connected to the rigid part, and the flexible part is the other end of the rigid part which is not connected to the rigid part. A plurality of electrodes are provided on the lower surface with a solder connection portion arranged two-dimensionally, and a bending portion that bends upward on the way from the solder connection portion to the rigid portion is provided, and the solder connection portion has An LSI, wherein an electrode and an electrode provided on the wiring board are connected by a solder ball
Package structure. 15. A rigid body fixed to a surface of the flexible portion opposite to the solder connection portion.
4. The LSI package structure according to item 4. 16. A rigid body having a lower surface fixed to a surface of the flexible portion opposite to the solder connection portion, and a side surface processed into a shape along the bent portion fixed to the bent portion. LSI package structure. 17. The LSI package structure according to claim 14, wherein a heat generating plate having a power supply terminal is fixed to a surface of said flexible portion opposite to said solder connection portion. 18. The LSI package structure according to claim 17, further comprising a rigid body fixed to an upper surface of said heat generating plate and an upper part of said bent part of said flexible part. 19. A structure in which a carrier board on which electronic components are mounted is mounted on a wiring board.
The rigid part is configured by two rigid parts for mounting the electronic components, and a flexible part whose both ends are physically and electrically connected to the different rigid parts. The electrode includes a solder connection portion arranged two-dimensionally, and further includes a bent portion that is bent upward on the way from the solder connection portion to each of the rigid portions, and the electrode of the solder connection portion and the electrode. An LSI package structure in which electrodes provided on a wiring board are connected by solder balls. 20. A rigid body fixed to a surface of the flexible portion opposite to the solder connection portion.
9. The LSI package structure according to item 9. 21. A rigid body having a lower surface fixed to a surface of the flexible portion opposite to the solder connection portion, and both side surfaces processed into a shape along the bent portion fixed to the bent portion. The described LSI package structure. 22. The LSI package structure according to claim 19, wherein a heat generating plate having a power supply terminal is fixed to a surface of said flexible portion opposite to said solder connection portion. 23. The LSI package structure according to claim 22, further comprising a rigid body fixed to an upper surface of said heat generating plate and an upper portion of said bent portion of said flexible portion. 24. The LSI package structure according to claim 19, further comprising a top cover having one end fixed to an upper end of the one rigid portion and the other end fixed to an upper end of the other rigid portion. 25. In a structure in which a carrier board on which electronic components are mounted is mounted on a wiring board, the carrier board includes:
Two first rigid portions for mounting the electronic component, one second rigid portion having a solder connection portion in which a plurality of electrodes are two-dimensionally arranged on a lower surface, and one of the first rigid portions. And two flexible portions that physically and electrically connect one end of the second rigid portion and the other of the second rigid portion and the other end of the second rigid portion, and Each of the flexible portions includes a bent portion bent upward, and an electrode of the solder connection portion of the second rigid portion and an electrode provided on the wiring board are connected by a solder ball. Characteristic LSI package structure. 26. A lower surface is fixed to a surface of the second rigid portion opposite to the solder connection portion, and both side surfaces are formed of the second rigid portion.
26. The LSI package structure according to claim 25, further comprising a rigid body fixed to the first rigid portions. 27. The LSI package structure according to claim 25, wherein a heat generating plate having a power supply terminal is fixed to a surface of said second rigid portion opposite to said solder connection portion. 28. The LSI package structure according to claim 27, further comprising a rigid body fixed to an upper surface of said heat generating plate and said two first rigid portions. 29. The LSI according to claim 25, further comprising a top cover having one end fixed to an upper end of said one first rigid portion and the other end fixed to an upper end of said other first rigid portion.
Package structure.