JPH07254631A - Electronic circuit device and manufacture thereof - Google Patents

Abstract

PURPOSE:To realize complete fusion bonding of an electronic circuit device onto a substrate by providing a protrusion having a melting point higher than that of a protruding contact facing a terminal electrode on a substrate and setting the height of the protrusion lower than that of the protruding contact. CONSTITUTION:Protrusions 3 are provided in same direction as protruding contacts 2 on the same surface of a substrate 6 as the protruding contacts 2 facing terminal electrodes 7 are provided. The protrusion 3 has melting point higher than that of the protruding contact 2 and the height of the protrusion 3 is set equal to or lower than the height for allowing positive electrical connection of all protruding contacts with the terminal electrodes 7 at the time of fusion thereof but higher than the height which causes mutual contact and short circuit of fused protruding contacts 2. This method realizes fusion bonding of an electronic circuit device, e.g. an LSI 1, having a plurality of protruding contacts 2 onto the substrate 6 without causing insufficient contact or short circuit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic circuit device and a manufacturing method thereof, and a structure of an electronic circuit device having a plurality of projecting contact portions for electrical connection with a terminal electrode group on a device substrate, and a structure thereof. The present invention relates to a manufacturing method, and more particularly, to an electronic circuit device that can be manufactured and joined at low cost and has no connection failure or contact short circuit, and a manufacturing method thereof.

[0002]

2. Description of the Related Art In recent years, LSIs with many input / output terminals have been
A structure is adopted in which protruding contacts (bumps) on a hemisphere are formed on the SI electrodes by soldering or the like, and the protruding contacts (bumps) are melt-bonded to the terminal electrodes on the substrate for electrical connection. For a typical method of melting this protruding contact,
For example, a continuous reflow method as described in the specification of Japanese Patent Application No. 3-216953 is known.

FIG. 7 is a process flow chart showing a continuous reflow method which is a method of bonding an electronic circuit device according to a conventional technique to a substrate. The continuous reflow method will be described below in the order of FIG.

First, the terminal electrodes 7 of the substrate 6 and the corresponding protruding contacts 2 of the LSI 1 are aligned with each other (see FIG. 7).
(A)). Next, the LSI 1 is mounted on the substrate 6 (see FIG. 7).
(B)).

Next, the substrate 1 on which the LSI 1 is mounted in the previous step is conveyed by the belt conveyor 19 and
It is carried into the heating furnace 20 (FIG. 7C). Finally, the substrate 6
The LSI 1 and the surface-mounted electronic component 17 mounted thereon are heated to melt the solder and the protruding contact 2 of the surface-mounted electronic component 17 (FIG. 7D).

When the protruding contact 2 is melted, the tip portion of the protruding contact 2 wets and spreads on the terminal electrode 7 of the substrate 6, and LSI
The protruding contact 2 is crushed by the weight of 1
The so-called sinking of the LSI 1 occurs, which lowers the height. The amount of subsidence is finally determined by the balance between the own weight of the LSI 1 and the viscous force of the melted protruding contact (group).

[0007]

Problems to be solved when the electronic circuit device and the substrate are joined by the above-mentioned conventional technique will be described below with reference to FIG.
Or let's explain with reference to FIG.

FIG. 8 is a side view of the electronic circuit device for explaining that a contact failure between the substrate 6 and the protruding contact 2 occurs when the substrate 6 is warped. FIG. 9 is a side view of the electronic circuit device showing that the weight 8 is placed and corrected when the substrate 6 is warped as shown in FIG. Figure 1
0 is a side view of the electronic circuit device in which a contact short circuit occurs when the weight 8 is placed as shown in FIG. FIG. 11 shows
It is a side view of an electronic circuit device which has a radiation fin 4.

The above-mentioned prior art relates to a technique for heating the protruding contact 2 to melt-bond it to the substrate 6. However, if the substrate 6 is warped, there is a problem in that a connection may be insufficient as shown in FIG.

Therefore, as shown in FIG. 9, there is a case where a weight 8 having an appropriate weight is placed and reflowed in consideration of a warp of the substrate 6 and a dimensional error such as a height variation of the protruding contact 2 before melting.

However, if the weight 8 is too light, the above-mentioned connection failure cannot be eliminated, and if it is too heavy, the protruding contact 2 is crushed too much and comes into contact with an adjacent one as shown in FIG. For 8, it is necessary to use one having a well-balanced weight. In addition, since the viscosity of solder rapidly changes with temperature near the melting point, it is necessary to be very careful in adjusting the temperature during reflow. Moreover, since the weight of the weight 8 and the reflow temperature are related to each other, it is difficult to find a condition for optimizing the conditions of both, and it takes a lot of time. .

Further, in the LSI packaged with the radiation fins 4 as shown in FIG. 11, its own weight may be larger than the viscous force of the melted protruding contact. At this time, in the heating furnace with a conveyor as described above. A reflow device that cannot be reflowed and requires a method such as heating the LSI while gripping the LSI and canceling its own weight is required, and the dedicated reflow device causes a cost increase in the manufacturing line. There was a problem that In general, since many components other than LSI are mounted on the substrate, it is the most economical substrate manufacturing method to reflow all components at the same time in a heating furnace with a conveyor.

The present invention has been made to solve the above-mentioned problems of the prior art, and an object thereof is to provide an electronic circuit device such as an LSI having a plurality of protruding contacts without causing a connection failure or a contact chute. An object of the present invention is to provide an electronic circuit device which can be melt-bonded onto the upper surface and can be manufactured and bonded at low cost, and a manufacturing method thereof.

[0014]

In order to achieve the above object, the structure of an electronic circuit device of the present invention comprises one or more protruding contacts facing a terminal electrode on a substrate, and melting the protruding contacts. Then, in an electronic circuit device that can be electrically connected to the terminal electrode of the substrate by fusion bonding, in the same surface as the surface provided with the protruding contact, the direction of the same direction as the protruding contact. The protrusion has a melting point higher than that of the protruding contact, and the height of the protrusion is such that when the protruding contact melts, all the protruding contacts included in the electronic circuit device have the terminals. The height is equal to or lower than the height at which they can be electrically connected to the electrodes, respectively, and when the protruding contacts are melted, if the height is lower than this, the melted protruding contacts come into contact with each other to cause a contact short circuit. Part arises In which it was to be higher than of.

More specifically, in the above electronic circuit device, the protrusion is formed of a brazing material having a melting point higher than that of the protruding contact portion.

More specifically, in the above electronic circuit device, the protrusion is formed of a ceramic material having a melting point higher than that of the protruding contact portion.

Further, in order to achieve the above object, the structure of the method for manufacturing an electronic circuit device of the present invention is such that in the above electronic circuit device, the protruding contact or the protrusion is formed by melting a solder ball. It was done.

Another structure of the method for manufacturing an electronic circuit device according to the present invention is to use a wire bonder to supply a solder wire to the electronic circuit device in a predetermined manner and press-bond the solder wire. The solder wire thus formed is melted to form the protruding contact or the protrusion.

[0019]

According to the present invention, since the protruding contact does not collapse below the height of the protrusion during melting, when the protruding contact is melted, the weight of the reflow weight is overcome by the surface tension of the melted protruding contact. Just make it big,
The reflow temperature condition can be made gentle. Therefore, the man-hours required for determining the reflow condition can be reduced, the manufacturing cost of the weight can be reduced, and the reflow heating furnace can be inexpensive. Also, an LSI such as a radiator fin can be reflowed in a heating furnace with a belt conveyor, and a dedicated reflow device is not required, so that an electronic circuit device with protruding contacts can be economically connected to a substrate.

By providing a protrusion having a melting point higher than that of the protruding contact, even if the protruding contact is melted, the protrusion is not crushed below the height of the protrusion, so that a connection without a defective connection or a defective contact short can be easily obtained. .

Further, since the protrusion can be formed in the same process as that of the protruding contact by forming the protrusion with the same brazing material as that of the protruding contact, the protruding contact type electronic circuit device having the protrusion can be manufactured at low cost. .

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described below with reference to FIGS.

[Structure of Electronic Circuit Device and Its Melt Bonding] The structure of an electronic circuit device according to an embodiment of the present invention and the case of melting and bonding it will be described below with reference to FIGS. 1 to 4.

FIG. 1 is a side view of an electronic circuit device according to an embodiment of the present invention. FIG. 2 is a process flow diagram when the electronic circuit device having the structure of FIG. 1A is melt-bonded onto a substrate. FIG. 3 is an enlarged side view of a joint portion when an electronic circuit device according to an embodiment of the present invention is fusion-bonded onto a substrate. FIG. 4 is a process flow diagram when the electronic circuit device having the structure of FIG. 1B is melt-bonded onto a substrate.

The LS of the electronic circuit device shown in FIG.
I1 is connected to the terminal electrode 7 of the substrate for electrical connection,
A plurality of protruding contacts 2 are formed on the connection surface to the substrate. A protrusion 3 having a height lower than or equal to that of the protruding contact 2 is provided on the same surface. Moreover, the protrusion 3 is made of a material having a higher melting point than the protruding contact 2.

FIG. 1B shows another structure of the electronic circuit device according to the embodiment of the present invention, in which the radiation fins 4 are bonded to the upper surface of the LSI 1 (the surface opposite to the substrate connection surface). It shows a structural example in the case of being joined via the portion 5.

Now, a process of fusion-bonding the electronic circuit device shown in FIG. 1A onto a substrate will be described in order of FIG.

First, the protruding contact 2 of the LSI 1 and the terminal electrode 7 of the substrate 6 are aligned (FIG. 2A). Next, the LSI 1 is mounted on the substrate 6 (FIG. 2B).

Next, in order to apply a weight, the weight 8 is attached to the LSI 1
(Fig. 2 (c)). Finally, the device is heated in order to melt the protruding contacts 2 and bond them to the terminal electrodes (FIG. 2 (d)).

In the heating step of FIG. 2D, the heating temperature is set to be higher than the melting point of the protruding contact 2 and lower than the melting point of the protrusion 3. By doing so, the protruding contact 2 spreads wet to the terminal electrode 7, and the LSI 1 and the weight 8
Although it is crushed by the weight of the
And receives the load of weight 8. Therefore, this LSI
The amount of depression of 1 is defined by the protrusion 3.

Now, with reference to FIG. 3, a desirable relationship between the protruding contact and the height of the protrusion will be described. The height of the protrusion 3 is h.

In order to ensure that the protruding contact 2 is electrically connected to the terminal electrode 7, the protrusion 3 must not be too high. Therefore, as shown in FIG. 3A, if the height at which all the protruding contacts 2 can be reliably electrically connected to the terminal electrodes 7 when the protruding contacts are melted and crushed is h ₁ , h ₁ The relationship between h and h must be the following expression (1).

[0033]

## EQU00001 ## h ₁ ≧ h (1) On the other hand, if the projection 3 is too short, the fused bonding materials of the protruding contacts 2 stick to each other at the adjacent protruding contacts 2 and cause a contact short circuit. Therefore,
As shown in FIG. 3B, when the protruding contact 2 is melted,
When the limit of height bonding material protruding contacts 2 and molten more low becomes contact short in contact with each other and h _2, the relationship of h ₂ and h must be the following equation (2).

[0034]

[Number 2] h> h ₂ ... (2) After all, together both the desired relationship between the height of the protruding contact protrusion, it can be seen that must be in the following equation (3).

[0035]

## EQU00003 ## h ₁ ≧ h> h ₂ (3) Next, a case where the electronic circuit device having the structure of FIG. 1B is fusion-bonded will be described in comparison with the above process. That is, this is a step of fusion-bonding the LSI 1 having the radiation fins 4 bonded to the upper surface to the substrate 6.

The following is a description of the order of FIG. First, the protruding contact 2 of the LSI 1 and the terminal electrode 7 of the substrate 6 are aligned (FIG. 4A). Next, the LSI 1 is mounted on the substrate 6 (FIG. 4B).

Finally, the device is heated in order to melt the protruding contacts 2 and bond them to the terminal electrodes (FIG. 4).
(C)).

Here, as compared with the step shown in FIG. 2, there is no step for placing the weight 8, but this is because the radiation fin 4 has the same role as the weight 8 in FIG.
This is because the surface tension of the melted protruding contact 2 is overcome and the protruding contact is crushed to a predetermined height defined by the protrusion 3.

As described in the above embodiments, according to the present invention, the protrusion 3 can set the sinking amount of the LSI 1 at the time of reflow (that is, the crushing amount of the protruding contact 2) to a predetermined value. Bonding of the circuit to the substrate can be easily realized with high reliability without causing disconnection defects and short circuit defects. Further, since the protrusion 3 is formed of the same solder material as that of the protruding contact 2, the protrusion 3 can be formed at low cost.

[Method for Manufacturing Electronic Circuit Device] A method for manufacturing an electronic circuit device according to an embodiment of the present invention will be described below with reference to FIGS. 5 and 6. FIG. 5 is a schematic circuit diagram of the electronic circuit device according to the present embodiment.
FIG. 7 is a manufacturing process flow chart for forming a protrusion 3 and a protrusion 3.

Contrary to FIGS. 1 to 3, the LSI 1 is placed with the bonding surface facing upward. LSI1 has protruding contact 2
Electrode 9 for a protruding contact serving as a base for forming a protrusion and metallization 10 for a protrusion serving as a base for forming the protrusion 3.
Is provided. The projection metallization 10 and the internal circuit of the LSI 1 are not electrically connected.

Hereinafter, description will be made in order of FIG. First, the protruding contact solder balls 11 are mounted on the protruding contact electrodes 9 (FIG. 5A). Next, the solder balls 12 for protrusions are mounted on the metallization 10 for protrusions (see FIG. 5).
(B)). Finally, heating reflow is performed (FIG. 5C).

As described above, the solder balls 12 for protrusions must be made of a material having a higher melting point than the solder balls 11 for protruding contacts. Therefore, by doing so, if the heating temperature in the heating step (FIG. 5C) is set to a temperature higher than the melting point of the solder balls 12 for protrusions, both are melted and the hemispherical protruding contacts 2 and the protrusions 3 are melted. Will be formed.

FIG. 6 is a flowchart of another manufacturing process for forming the protruding contact 2 and the protrusion 3 on the LSI 1 in the electronic circuit device according to this embodiment.

Hereinafter, the order of FIG. 6 will be described. First, the end of the protruding contact solder wire 14 protruding from the tip of the protruding contact wire bonder 13 is heated to be spherical (a heating device is not shown) (FIG. 6A). Next, after pressure bonding is performed on the protruding contact electrode 9, the protruding contact solder wire 14 is pulled off by pulling upward (FIG. 6).
(B)).

Next, this is sequentially performed for all the protruding contact electrodes 9 (FIG. 6C). Next, the same pressure bonding is performed on all the metallizations 10 for protrusions using the protrusion wire bonder 15 and the solder wires for protrusions (FIG. 6D). Finally, heat reflow (Fig. 6)
(E)).

As described in the above-mentioned manufacturing method,
The solder wire 16 for the protrusion is the solder wire 14 for the protruding contact.
Is a material with a higher melting point than that of the heating process (Fig. 6 (e))
If the heating temperature in is higher than the melting point of the solder wire 16 for protrusion, both are melted and the hemispherical protruding contact 2 and the protrusion 3 are formed.

In the above embodiment, the projection 3 is formed on the protruding contact 2
Although an example of forming by the same manufacturing process as the above is shown, in the case of manufacturing these, the manufacturing method of the protrusion 3 and the protruding contact 2 are mixed (for example, the protruding contact 2 is formed by a solder ball and the protrusion 3 is formed by soldering). Wire bonding may be formed or vice versa). Further, both can be formed by a manufacturing method other than the above, such as solder plating and solder vapor deposition.

Further, the protrusion 3 need only have a higher melting point than that of the protruding contact 2, and not only is it formed of a brazing material such as solder as in the above-described embodiment, but also a columnar body made of a material such as ceramic is LS.
It may be formed by a method such as bonding to I1 or forming a protrusion in the LSI manufacturing process.

[0050]

According to the present invention, an electronic circuit device such as an LSI having a plurality of protruding contacts can be melt-bonded onto a substrate without any connection failure or contact chute.
Moreover, it is possible to provide an electronic circuit device that can be manufactured and bonded at low cost, and a manufacturing method thereof.

[Brief description of drawings]

FIG. 1 is a side view of an electronic circuit device according to an embodiment of the present invention.

FIG. 2 is a process flow diagram when the electronic circuit device having the structure of FIG. 1A is melt-bonded onto a substrate.

FIG. 3 is an enlarged side view of a joint portion when an electronic circuit device according to an embodiment of the present invention is fusion-bonded onto a substrate.

FIG. 4 is a process flow diagram when the electronic circuit device having the structure of FIG. 1B is melt-bonded onto a substrate.

FIG. 5 shows an LSI in the electronic circuit device according to the present embodiment.
FIG. 3 is a manufacturing process flow chart of forming the protruding contact 2 and the protrusion 3 on the first structure.

FIG. 6 shows an electronic circuit device according to the present embodiment in which an LSI
FIG. 7 is a flow chart of another manufacturing process for forming the protruding contact 2 and the protrusion 3 on the first substrate.

FIG. 7 is a process flow chart showing a continuous reflow method which is a method of bonding an electronic circuit device according to a conventional technique to a substrate.

FIG. 8 is a side view of the electronic circuit device for explaining that contact failure between the substrate 6 and the protruding contact 2 occurs when the substrate 6 is warped.

9 is a side view of the electronic circuit device showing that the weight 8 is mounted and corrected when the substrate 6 is warped as shown in FIG.

FIG. 10 is a side view of the electronic circuit device in which a contact short circuit occurs when the weight 8 is placed as in FIG.

FIG. 11 is a side view of an electronic circuit device having a radiation fin 4.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... LSI 2 ... Protruding contact 3 ... Protrusion 4 ... Radiating fin 5 ... Joining part 6 ... Substrate 7 ... Terminal electrode 8 ... Weight 9 ... Protrusion contact electrode 10 ... Protrusion metallization 11 ... Protrusion contact solder ball 12 ... Protrusion Solder ball 13 ... Wire bonder for protruding contact 14 ... Solder wire for protruding contact 15 ... Wire bonder for protrusion 16 ... Solder wire for protrusion 17 ... Imposition electronic component 18 ... Solder paste 19 ... Belt conveyor 20 ... Heating furnace

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hitoshi Odajima 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa, Ltd.

Claims (5)

[Claims] 1. A method comprising: one or more projecting contacts facing a terminal electrode on a substrate; melting the projecting contact to form an electrical connection with the terminal electrode of the substrate by fusion bonding. In the electronic circuit device that can be provided, a protrusion having a direction in the same direction as that of the protruding contact is provided on the same surface as the surface provided with the protruding contact, and the melting point of the protrusion is higher than the melting point of the protruding contact. The height of is equal to or lower than the height at which all the protruding contacts of the electronic circuit device can be surely electrically connected to the terminal electrodes when the protruding contacts are melted, Moreover, when the protruding contact is melted, the height is higher than the height at which a portion where the protruding contact melts to contact with each other to cause a contact short circuit if the protrusion contact is lower than the height. 2. The protrusion is formed of a brazing material having a melting point higher than that of the protruding contact portion.
Electronic circuit device described. 3. The electronic circuit device according to claim 1, wherein the protrusion is made of a ceramic material having a melting point higher than that of the protruding contact portion. 4. The method for manufacturing an electronic circuit device according to claim 1, wherein the protruding contact or the protrusion is formed by melting a solder ball. 5. A wire bonder is used to supply a solder wire to an electronic circuit device in a predetermined manner for pressure bonding, and then the pressure-bonded solder wire is melted to form the protruding contact or the protrusion. 3. The method for manufacturing an electronic circuit device according to claim 1, wherein the method is molded.