JPH0754837B2 - Integrated circuit structure - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an integrated circuit structure, and more particularly to an integrated circuit structure suitable for packaging a module in which IC chips are integrated at high density.

[Conventional technology]

With the trend toward miniaturization in semiconductor device manufacturing technology and the increase in the number of integrated circuit elements on a single device, miniaturization is also required for signal connections between these devices and external signal connections such as power supply. It For this reason, it is necessary to provide an integrated circuit package having a connection structure in which reliability of signal connection is improved and defective elements can be easily replaced.

For example, in the integrated circuit structure described in JP-A-59-165446, a metal pad is formed on the surface of a polyimide resin that covers the internal wiring of a single integrated circuit element (hereinafter referred to as an IC chip). By fixing the input / output pins related to the terminal member to the pad and inserting them into the through holes of the printed circuit board, the connection is miniaturized.

[Problems to be solved by the invention]

As seen in the above-mentioned prior art, for the signal connection between IC chips and the signal connection with an external circuit, the mounting distance is miniaturized by the input / output pin connection. But,
With the high integration of IC chips, the single pin connection area tends to increase.
An input / output pin structure capable of sufficiently absorbing the increasing thermal deformation difference between both members of the printed wiring board is required.

However, if the I / O pins are fixed to the IC chip side and then inserted into the through holes of the printed wiring board all at once, the I / O pins are required to have a certain rigidity, and therefore thermal deformation is sufficient. It is difficult to adopt an input / output pin that can absorb a large amount of flexibility.

The present invention has been made in order to solve the above-mentioned problems of the prior art, and when connecting a ceramic substrate and a printed wiring board with a plurality of terminal members, it is possible to efficiently connect a large number of terminal members. It is an object of the present invention to provide an integrated circuit structure pair having high signal connection reliability, which can absorb thermal deformation exerted on the connection portion by the flexible structure of the input / output pin itself related to the terminal member.

[Means for solving problems]

In order to achieve the above object, the structure of an integrated circuit structure according to the present invention is such that one or a plurality of integrated circuit elements are mounted and metal pads for connecting the integrated circuit elements to an external circuit are formed. An integrated circuit structure comprising: a ceramics substrate made of; and a printed wiring board having inner layer wiring, wherein the ceramics substrate and the printed wiring board are electrically connected by a plurality of terminal members. A plurality of flexible I / O pins solder-bonded to the through-hole plating of the printed wiring board, the end portions of the plurality of I / O pins and the metal pads of the ceramic substrate being the I / O pins; It is joined by using a solder material having a melting point lower than that of the solder material between the through hole plating.

In addition, in the present invention, contrary to the conventional procedure of fixing the input / output pin to the IC chip side and inserting the input / output pin into the through hole of the printed wiring board, the input / output pin alone In this state, first, it is fixed to the through hole of the printed wiring board and then soldered to the metal pad on the IC chip side.

Since the I / O pin is handled independently, the flexibility of insertion and joining work is increased, and the shape and structure of the I / O pin is made to have a large flexibility, so that the difference in thermal deformation between both ends of the I / O pin can be improved. Can be fully absorbed.

[Action]

In an integrated circuit structure in which resin pads with a large number of IC chips or metal pads on the surface of the ceramics board and through holes of the printed wiring board are connected by input / output pins, the temperature of each member rises due to the heat generated by the IC chips due to energization. receive.
At this time, since the respective structural members at both ends of the input / output pin have different linear expansion coefficients, a thermal deformation difference occurs between the respective structural members. This thermal deformation difference increases in proportion to the size of the IC chip mounting dimension. If the bending rigidity of the input / output pin is large, the thermal deformation difference concentrates on the connecting portion at both ends of the input / output pin and damages the connecting portion.

If the flexibility of the input / output pin is made sufficiently large as in the present invention, the thermal deformation difference can be absorbed by the bending deformation of the input / output pin, and the stress load on the input / output pin connecting portion can be reduced. .

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 to 6.

FIG. 1 is a configuration diagram showing a connection structure and connection method of an integrated circuit structure according to an embodiment of the present invention.

As shown in FIG. 1, an integrated circuit element or IC chip 5
Are mounted on a plurality of solder balls 6 which are electrically connected to each other on the upper surface of the ceramic substrate 1. On the other hand, one or more (more than one in the figure) ICs
In order to connect the chip 5 to an external circuit, a metal pad 8 which electrically connects the solder ball 6 and the surface layer and inner layer wiring of the ceramic substrate 1 is provided on the back surface of the ceramic substrate 1.

The sealing cap 2 was mounted on the ceramic substrate 1.
The IC chip 5 is sealed via a sealing means 7.

Inside the sealing cap 2, a heat transfer means 3 is provided between the inner surface of the cap ceiling plate 2a and the IC chip 5, so that the heat generated by the IC chip 5 is transmitted to the cap ceiling plate 2a. Further, on the sealing cap 2, a cooling jacket 4 is attached which circulates a fluid which is transmitted to the cap ceiling plate 2a and absorbs heat to promote cooling of the IC chip 5.

A single module is constituted by the ceramic substrate 1, the sealing cap 2, the IC chip 5, the heat transfer means 3, the cooling jacket 4, and the like.

On the other hand, the printed wiring board 10 having the inner layer wiring is provided with a large number of through holes, and the flexible I / O pins 9 associated with a large number of terminal members are inserted into the through holes. These are connected by soldering, and these many input / output pins 9 are used as external signal transmission parts for electrical connection between the inside of the module and the printed wiring board 10 or between the modules.

Then, as shown in FIG. 1, a single or a plurality of modules and a printed wiring board 10 are opposed to each other as shown by thick arrows, and a large number of metal pads 8 and a printed wiring board formed on the back surface of the ceramics board 1 are arranged. A large number of input / output pins 9 fixed to the 10 side are soldered. As the solder material, a solder material having a melting point lower than that of the solder material between the input / output pin 9 and the through hole plate 11 of the printed wiring board 10 is used.

As a result, the solder connection between the input / output pin 9 and the metal pad 8 on the rear surface of the ceramic substrate 1 can be performed without damaging the solder connection of the input / output pin 9 on the printed wiring board 10 side. Not only that, the ceramic substrate 1 is directly heated by infrared rays or the like, or the method of blowing hot air between the ceramic substrate 1 and the printed wiring board 10 is used to solder the input / output pins 9 and the metal pads 8. The joint can be removed, and the module can be replaced.

That is, by the above connection method, a large number of input / output pins 9 can be easily simultaneously joined on the surface of the metal pad 8 of the ceramics substrate 1, and the input / output pin structure can be made extremely soft. The structure can be easily modified.

According to this embodiment, since a large number of input / output pins, which are signal connecting means with the circuit in the module, can be simultaneously connected on the metal pad surface, the pin connection becomes easy. Further, at the time of connection, the connection surfaces can be brought into contact with each other to be soldered, pressing force is not required, and the input / output pin itself can have a flexible structure. As a result, the thermal deformation exerted on the connection portion can be absorbed by the deformation of the input / output pin itself, and the stress of the solder joint portion of the input / output pin, which is the weakest portion, can be reduced.

An example in which the input / output pins have a flexible structure will be described with reference to FIGS. 2 and 3.

FIG. 2 is a sectional view showing a connection structure of terminal members of an integrated circuit structure according to another embodiment of the present invention, and FIG. 3 is a terminal of an integrated circuit structure according to still another embodiment of the present invention. It is sectional drawing which shows the connection structure of a member. In each of these figures,
The parts having the same reference numerals as those in the figure are the same parts as those in the previous embodiment, and therefore their explanations are omitted.

In the embodiment shown in FIG. 2, a large number of thin wires are bundled and inserted into the through holes of the printed wiring board 10, and the through holes are attached.
And a terminal member is formed as the thin wire pin 12 by soldering.

According to the embodiment shown in FIG. 2, the same effect as that described in the embodiment shown in FIG. 1 is expected, and in particular, since the thin wire pin 12 has a flexible structure having a large flexibility, the thermal deformation of the connecting portion is prevented. The absorption is effective.

Next, in the embodiment shown in FIG. 3, the terminal member which is inserted into and fixed to the through hole of the printed wiring board 10 is attached to the ceramic board 1.
The spiral member 14 is formed in a spiral shape between the printed wiring board 10 and the printed wiring board 10. The portion to be inserted into the through hole forms a pin having a substantially true value, and is securely fixed by the through hole filling solder 13.

According to the embodiment of FIG. 3, the same effect as that of each of the embodiments of FIGS. 1 and 2 described above can be expected, and the spiral machining of the member can be performed both before and after inserting the member into the through hole. It is possible to do.

It goes without saying that the spiral member 14 functions as a flexible structure terminal member having sufficient elasticity.

By the way, as the IC chip is highly integrated, the thickness of the printed wiring board 10 is increased, and the through hole portion for inserting the input / output pin becomes longer. For this reason, the wettability of the solder in the solder joint between the input / output pin and the through hole is significantly reduced, and there is a possibility that a connection failure may occur.

Therefore, an example in which the rise of the solder in the gap between the input / output pin and the through hole is promoted will be described below.

FIG. 4 is a sectional view showing a connection structure of terminal members of an integrated circuit structure according to still another embodiment of the present invention, and FIGS. 5 to 7 are all shapes of input / output pins related to the terminal members. FIG.

In FIG. 4, the same reference numerals as those in FIG. 1 are the same parts as those in the embodiment of FIG.

In the embodiment of FIG. 4, the input / output pin 9A related to the terminal member is
Groove 16 that should become a solder flow path in the pin axial direction on the outer periphery of the pin
A plurality of openings are provided, and an opening is provided between the ceramics board 1 and the printed wiring board 10.

With such a pin shape, at the time of solder joining in the through hole of the printed wiring board 10, the through hole filling solder 13 uniformly rises using the groove 16 as a flow path, and an air flow path is secured in the upper opening of the through hole. Through holes are prevented from being blocked by the selective soldering.

In FIG. 4, reference numeral 15 denotes a brazing material connecting the head of the input / output pin 9A and the metal pad 1.

Examples of solder flow paths for the input / output pins are shown in FIGS.

In the example shown in Fig. 5, the solder flow path of the input / output pin 9B is a spiral groove.
It is processed into 17 and solder properly rises along the spiral groove 17 to improve the wettability of the solder joint.

The example in Fig. 6 shows a pipe-shaped flow path at the center of the input / output pin 9C.
18a is processed, and an opening 18b is provided at a position above the through hole.

In the example of FIG. 7, the split pin portion 19 is formed by cutting a plurality of portions of the through hole of the printed wiring board 10 to be soldered in the axial direction of the input / output pin 9D.

According to this pin shape, the solder can rise through the gap in the split pin portion 19 as a solder flow path.

As described above, according to the embodiments of FIGS. 4 to 7, the same effect as that of the embodiment of FIG. 1 is expected, and
When soldering the input / output pins in the through holes, the solder wettability in the through holes is improved, and connection defects can be reduced. As a result, a highly reliable and compact signal connection structure can be obtained.

In each of the above-described embodiments, a large number of input / output pins are soldered to the through holes of the printed wiring board, and then the heads of the input / output pins are connected to the metal pads on the surface of the ceramic substrate. The characteristic points have been explained, but the input / output pins of FIGS.
It is also noted that the present invention can be applied to a joining structure other than the present invention in which the input / output pin is inserted into a through hole of a printed wiring board and soldered after being joined to the metal pad on the surface of the ceramic substrate via 15.

[Effects of the Invention] As described in detail above, according to the present invention, when connecting a printed wiring board of a ceramic substrate by a plurality of terminal members, a large number of terminal members can be efficiently connected, It is possible to provide an integrated circuit structure with high reliability of signal connection, in which thermal deformation exerted on the connection portion can be absorbed by the flexible structure of the input / output pin itself related to the terminal member.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a connection structure and connection method of an integrated circuit structure according to an embodiment of the present invention, and FIG. 2 is a terminal member of an integrated circuit structure according to another embodiment of the present invention. FIG. 3 is a sectional view showing a connection structure, FIG. 3 is a sectional view showing a connection structure of a terminal member of an integrated circuit structure according to still another embodiment of the present invention, and FIG. 4 is another embodiment of the present invention. 5 to 7 are sectional views showing the connection structure of the terminal members of the integrated circuit structure according to the present invention, and FIGS. 5 to 7 are front views showing the shapes of the terminal members. 1 …… ceramics board, 5 …… IC chip, 8 …… metal pad, 9,9A, 9B, 9C, 9D …… input / output pin, 10 …… printed wiring board, 12 …… fine wire pin, 14 …… spiral Member, 16,1
7 ... Groove, 18a ... Flow path, 19 ... Split pin part.

Claims (5)

[Claims] 1. A ceramic substrate on which one or a plurality of integrated circuit elements are mounted and metal pads for connecting the integrated circuit elements to an external circuit are formed, and a printed wiring board having inner layer wiring. An integrated circuit structure comprising these ceramic substrates and a printed wiring board electrically connected by a plurality of terminal members, wherein the plurality of terminal members are soldered to through-hole plating of the printed wiring board. A plurality of flexible I / O pins, the end portions of the plurality of I / O pins and the metal pad of the ceramic substrate having a lower melting point than the solder material between the I / O pins and the through-hole plating; An integrated circuit structure characterized by being joined using a material. 2. The integrated circuit structure according to claim 1, wherein the input / output pin is formed by bundling a plurality of thin wires and soldering them together in a through horn. 3. The integrated circuit structure according to claim 1, wherein the input / output pins are spirally formed between the ceramic substrate and the printed wiring board. body. 4. The input / output pin according to claim 1, wherein the input / output pin is formed with a flow path for allowing the solder to flow during solder joining in a through hole of a printed wiring board. Integrated circuit structure. 5. The input / output pin according to claim 1, wherein the input / output pin is formed in a split pin shape in which a portion to be soldered in a through hole of a printed wiring board is cut into a plurality of pieces. An integrated circuit structure characterized by the above.