JP3258564B2 - Semiconductor device and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device and a method of manufacturing a semiconductor device, and more particularly to a bonding structure between a support substrate having a ground plane function and / or a heat radiation function and a support function of a conductor circuit, and a circuit board.

[0002]

2. Description of the Related Art Semiconductor devices such as ICs and LSIs are connected to circuit patterns on a mounting board by using solder or the like.
In recent years, in response to miniaturization of elements and miniaturization of devices, S
A method called a BC method for connecting a semiconductor package on a circuit board using a solder ball has been proposed. According to this method, the circuit pattern on the mounting board is positioned, mounted, heated and fixed, and is attracting attention because it is easy to mount.

As an example of this, as shown in FIG. 14, a semiconductor chip 202 is connected face-down on a TAB tape 201 having a circuit pattern M formed on both sides, and a support 203 made of a metal plate is adhered to the periphery thereof. A so-called TBGA (Tape Ball) in which a solder ball 204 is disposed on the back surface via a via hole H formed in the TAB tape 201 and the front surface side is sealed with a sealing resin 205, while being fixed via an agent. Grid Aray) method.

[0004] In recent years, with the increase in the speed of information processing equipment, ultra-high frequencies have been used for the operation of semiconductor devices. However, when an ultrahigh-frequency signal is transmitted through the transmission path (lead) of the circuit pattern on the TAB substrate, there is a problem that a so-called crosstalk phenomenon occurs in which a signal leaks to an adjacent lead.

To solve such a problem, a conductive support substrate is fixed to the insulating tape side of the TAB substrate, and predetermined leads of the circuit board are connected to the support substrate through through holes. Stuff has been proposed.

[0006]

However, in this method, the electrical connection between the TAB substrate and the supporting substrate is difficult.
It is provided through a via hole penetrating the TAB substrate. In this structure, in order to establish electrical conduction between the front and back surfaces of the TAB substrate, electroconductive plating is performed on the inner surface of the via hole or a conductive layer is formed by filling a silver paste which is an example of a conductive paste. Need to
There is a problem that the number of man-hours increases and production efficiency decreases.

Further, in this method, when a TAB substrate and a supporting substrate on which a semiconductor chip is mounted are joined using a prepreg which is an example of an insulating adhesive, the TAB substrate and the supporting substrate are interposed between the TAB substrate and the supporting substrate. Due to the misalignment, misalignment occurs between the electrode pads of the semiconductor chip and the leads,
There is a problem that a bonding failure occurs.

Furthermore, when forming a ground plane or a power plane, it is difficult to align circuit patterns on both sides, the cost is high, and there is a limit to high integration and high precision.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a highly reliable semiconductor device which is easy to manufacture and can be easily mounted even in high integration and high precision. Aim.

In other words, there is provided a semiconductor device capable of reducing man-hours such as forming a conductor layer on both substrates when joining a TAB substrate and a supporting substrate, maintaining positional accuracy and improving joining strength. The purpose is to provide.

[0011]

Therefore, a first feature of the present invention is that a circuit board having a plurality of leads constituting a conductive circuit pattern on the back side of an insulating member; A semiconductor device comprising: a support substrate that is attached to a front surface side, and at least the attachment surface side forms a conductor layer; and a semiconductor chip that is electrically connected to the circuit board. In addition to having at least one through hole in a predetermined area, the support substrate has a protrusion protruding on the back side of the circuit board at a position corresponding to the through hole, and a solder ball is provided at a tip of the protrusion. It has been arranged.

Preferably, at least the circuit board side of the support board constitutes a ground plane, and the connection between the ground plane, the leads and the solder balls is formed in a through hole provided at a position corresponding to the lead. This is achieved by inserting a projection and fixing a solder ball to the tip of the projection.

Preferably, the insulating member of the circuit board is made of a polyimide tape or a glass cloth epoxy board.

Further, the support substrate is characterized in that a metal film layer containing nickel or palladium is formed on the entire surface.

Still further, the support substrate is characterized in that a concave portion for mounting a semiconductor chip is formed at the center.

Further, the insulating member of the circuit board is provided with an opening for mounting a semiconductor chip in the center, and a lead protruding inward from a peripheral edge of the opening.

According to a second feature of the present invention, a circuit board forming step of forming a circuit board by forming a conductive circuit pattern on the back surface side of an insulating member, and forming a conductive circuit pattern on a predetermined area of the circuit board including the conductive circuit pattern. A through-hole forming step of forming at least one through-hole, and a support substrate forming a support substrate having a projection formed in a region corresponding to the through-hole so as to have a protrusion height about the thickness of the circuit board Forming step;
A fixing step of fixing the support substrate to a surface side of the insulating member of the circuit board, and placing a solder ball as an external connection terminal on the projection surface, and heating and melting the solder ball, An external connection terminal forming step for achieving electrical connection between the conductive circuit pattern and the solder ball is provided.

Preferably, the supporting substrate forming step includes an etching step of forming projections on the metal substrate by performing etching processing using photolithography.

Preferably, the supporting substrate forming step comprises:
The method is characterized in that the method includes a step of forming a metal film on the surface after forming the protrusions by using an insulating member.

According to the semiconductor device of the present invention, the projection having the conductor layer formed on the front surface is inserted into the through-hole of the circuit board such as the TAB substrate, so that the electrical conduction between the front and back surfaces of the circuit board is extremely easy. Therefore, conduction can be easily achieved even when a deep via hole is formed.

Furthermore, if the support substrate is formed of a conductive plate, it can be used as a ground plane in addition to the support function, and the heat dissipation function can be improved. In addition, the number of manufacturing steps can be reduced.

Further, a ground plane can be easily formed even in a TBGA type semiconductor device in which a conductor circuit pattern is formed only on one surface of a TAB tape.

Preferably, prior to the formation of the solder ball, a flux layer is formed on the surface of the projection in the via hole, and the solder ball is supplied onto the flux layer and heated to be exposed in the via hole. It becomes a solid solution state with the conductor circuit pattern, and the solder ball can be fixed in the via hole, and mounting can be performed very easily. And, it can be fixed well in the via hole with good selectivity. Finally, a step of removing excess flux may be added. In this way, it is possible to form a solder ball with high precision.

Further, according to the semiconductor device of the present invention, since the semiconductor device is mounted using a circuit board such as an insulating tape having a conductive circuit pattern formed on one surface, it is not necessary to align the masks on the front and rear patterns. Also, no via-hole plating is required, and it is easy to manufacture, highly accurate and inexpensive.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described.
This will be described in detail with reference to the drawings. As shown in FIG. 1, a semiconductor device according to a first embodiment of the present invention is a TBGA type semiconductor device having at least one through hole in a predetermined region of a TAB substrate and a support substrate 4 made of a copper plate. The area corresponding to the through hole is provided with a protrusion 4s protruding from the back surface side of the TAB substrate. By achieving the connection, the support substrate has a function as a ground plane and a heat dissipation function in addition to the function to support the TAB substrate. The projections achieve electrical connection between the conductor circuit pattern 1 and the ground plane.

That is, this semiconductor device comprises a TAB substrate made of an insulating tape 2 having a conductor circuit pattern 1 connected to a semiconductor chip 3 formed on one side, and a copper plate adhered to the back side of the insulating tape. And a support substrate 4 connected to at least one of the conductor circuit patterns on the front surface side via the projections 4s inserted into the through holes H formed in the insulating tape, and to the solder balls 5. It is characterized by being connected. 1s is a bump, and the semiconductor chip is covered with a sealing resin 9. Here, FIG. 1 is a cross-sectional view, FIG. 2 is a plan view as viewed from the back side, and FIG.

Here, the TAB substrate is provided with a conductive circuit pattern 1 on one surface of an insulating tape 2 having an opening in a chip mounting area.
Is formed. Further, the supporting substrate 4 and the TAB substrate are fixed to the TAB substrate at the peripheral portions thereof via an insulating adhesive made of polyimide resin. In addition, a semiconductor chip is fixed to the concave portion formed in the center of the support substrate 4 via the insulating adhesive. The solder balls 5 are formed on the entire surface so as to form a lattice shape, a part of which is connected to the ground plane via the above-described protrusion 4s.
Protected by coating.

FIGS. 4 to 13 show a part of the manufacturing process of this semiconductor device.

First, as shown in FIG. 4, an opening O is formed in a chip mounting area of an insulating tape 2 made of a polyimide resin having a film thickness of 50 μm, and as shown in FIG. 5, a copper foil having a thickness of 18 μm is formed. The copper foil and the insulating tape 2 are patterned by photolithography to form through holes H as shown in FIG. Then, after this, the film thickness is set to 0.
A 5 μm tin plating layer M is formed to form a TAB substrate having a conductor circuit pattern 1 (FIG. 7).

Next, as shown in FIG. 8, the cavity region is cut.

Subsequently, as shown in FIG.
Is connected to the conductor circuit pattern 1 via the bump 1s by direct bonding. Here, the leads connected to other signal lines are also connected in the same manner as in the related art.

On the other hand, as shown in FIG. 10, a copper plate is formed by press working to form a support substrate 4 having projections 4s.

Then, as shown in FIG.
Then, a TAB substrate on which the semiconductor chip 3 is mounted is fixed via an insulating adhesive, and a resin is filled by potting so as to cover the semiconductor chip. Then, a flux is printed on the surface of the projection 4s protruding into the through hole H,
A solder ball 5 made of 10% Pb and 90% Sn solder having a diameter of 0.7 mm is supplied, and the surface is fixed to the conductive circuit pattern 1 through a heating process at 320 ° C. for 10 seconds (peak temperature maintaining time).

Finally, if necessary, the substrate is immersed in isopropyl alcohol (IPA) and subjected to ultrasonic cleaning to remove excess flux. In this way, low-cost and highly-accurately arranged solder balls are formed.

The hole pitch and the hole diameter of the via hole are not limited to those in the above-described embodiment, but can be appropriately changed. For example, if the lattice pitch is 1 mm, the hole diameter is 0.55 mm and the lattice pitch is 1.5 mm. If so, the hole diameter can be changed as appropriate to 0.75 mm.

Furthermore, the composition of the solder ball can be appropriately selected. For example, when eutectic solder of Pb 37% Sn 63% is used, the heating temperature in the fixing step may be about 230 ° C.

The connection of the solder ball is stabilized by plating the tip of the projection with palladium or the like.

In the above embodiment, the height of the projection is set to be substantially the same as the surface of the TAB substrate. However, by setting the tip of the projection to a position slightly lower than this, the positioning of the solder ball becomes easy. , And the connection can be stabilized.

Further, when the tip of the projection is slightly protruded from the upper surface of the TAB substrate, the tip of the projection is joined in a state where the solder ball is loaded, so that the positioning of the solder ball becomes easy and stable.

Further, an insulating film may be formed so as to cover the conductive circuit pattern 1 so as to protect the entire surface excluding the solder ball forming region.

Further, instead of the TAB substrate, a rigid substrate such as a glass cloth epoxy substrate may be used. Also, using an uncured resin called prepreg,
A copper foil may be adhered to the surface, cured by heating, and the copper foil may be patterned to form a conductor circuit pattern.

Next, as a second embodiment of the present invention, an example in which the support substrate 14 is formed of an insulating glass epoxy substrate will be described. In this semiconductor device, as shown in FIG. 13, the supporting substrate is formed of an insulating substrate, and after forming the projections 14s, the plating layer 15 is formed on the entire surface. The projection is inserted into a through-hole formed in the TAB substrate to simultaneously connect the conductive circuit pattern 1 and the solder ball, and simultaneously fix the support substrate and the TAB substrate integrally. is there.

This semiconductor device uses a TAB substrate formed in the same manner as in the first embodiment, and connects the tip of the conductor circuit pattern 1 and the semiconductor chip via bonding wires 7. In this example, a flat plate is used as a support substrate.

At the time of mounting, a TAB
The substrate and the semiconductor chip 3 are fixed, and thereafter, wire bonding is performed. Finally, the semiconductor device shown in FIG. 13 is completed by performing resin sealing using the sealing resin 9.

Here, not only the molten solder ball 5 but also
A gap between the through hole of the TAB substrate and the protrusion of the support substrate may be filled with a conductive adhesive called silver paste.

Although the glass cloth epoxy substrate is used in the above embodiment, it goes without saying that another material such as an alumina substrate may be used as long as it has good thermal conductivity.

Furthermore, the conductor layer covering the surface of the supporting substrate such as the plating layer 15 may be formed entirely including the back surface or may be formed partially including the projection.

In addition, the conductor circuit pattern on the surface of the TAB substrate may be covered with an insulating film.

In this semiconductor device, the supporting strength is high and the heat radiation characteristics are good.

[0050]

As described above, according to the present invention, it is possible to provide a semiconductor device which is easy to manufacture, has a large supporting strength, and is highly reliable.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a semiconductor device according to a first embodiment of the present invention;

FIG. 2 is a plan view showing the semiconductor device.

FIG. 3 is an enlarged view of a main part showing the semiconductor device.

FIG. 4 is a view showing a manufacturing process of the semiconductor device according to the first embodiment of the present invention;

FIG. 5 is a view showing a manufacturing process of the semiconductor device according to the first embodiment of the present invention;

FIG. 6 is a view showing a manufacturing process of the semiconductor device according to the first embodiment of the present invention;

FIG. 7 is a view showing a manufacturing process of the semiconductor device according to the first embodiment of the present invention;

FIG. 8 is a view showing a manufacturing process of the semiconductor device according to the first embodiment of the present invention;

FIG. 9 is a view showing a manufacturing process of the semiconductor device according to the first embodiment of the present invention;

FIG. 10 is a view showing a manufacturing process of the semiconductor device according to the first embodiment of the present invention;

FIG. 11 is a view showing a manufacturing process of the semiconductor device according to the first embodiment of the present invention;

FIG. 12 is a view showing a manufacturing process of the semiconductor device according to the first embodiment of the present invention;

FIG. 13 is a sectional view showing a semiconductor device according to a second embodiment of the present invention;

FIG. 14 is a plan view showing a conventional semiconductor device.

[Explanation of symbols]

 Reference Signs List 1 conductor circuit pattern 2 insulating tape 3 semiconductor chip 4 support substrate 5 solder ball 6 insulating resin 7 bonding wire 9 sealing resin H via hole (through hole) M tin plating layer 15 plating layer 201 TAB tape 202 semiconductor chip 203 support Body 204 Solder ball 205 Sealing resin

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-7-183336 (JP, A) JP-A 8-162496 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 21/60 H01L 23/34

Claims (9)

(57) [Claims] 1. A circuit board comprising a plurality of leads constituting a conductive circuit pattern on a back side of an insulating member; and a circuit board adhered to a front side of the insulating member. In a semiconductor device comprising: a support substrate forming a conductor layer; and a semiconductor chip electrically connected to the circuit board, the semiconductor device includes at least one through hole in a predetermined region of the circuit board, The semiconductor device according to claim 1, wherein the support substrate includes a protrusion protruding from the rear surface of the circuit board at a position corresponding to the through hole, and a solder ball is disposed at a tip of the protrusion. 2. The support board, wherein at least the circuit board side constitutes a ground plane, and a connection between the ground plane, the lead and the solder ball is formed in a through hole provided at a position corresponding to the lead. 2. The semiconductor device according to claim 1, wherein the semiconductor device is achieved by inserting a solder ball into the tip of the projection. 3. The semiconductor device according to claim 1, wherein the insulating member of the circuit board is made of a polyimide tape or a glass cloth epoxy board. 4. The semiconductor device according to claim 1, wherein the support substrate is formed by forming a metal film layer containing nickel or palladium on the entire surface. 5. The support substrate according to claim 1, wherein a concave portion for mounting a semiconductor chip is formed in the center.
13. The semiconductor device according to claim 1. 6. The circuit board according to claim 1, wherein the insulating member has an opening for mounting a semiconductor chip at a center thereof, and a lead protruding inward from a peripheral edge of the opening. 2. The semiconductor device according to 1. 7. A circuit board forming step of forming a circuit board by forming a conductor circuit pattern on the back surface side of an insulating member, and forming at least one through hole in a predetermined area of the circuit board including the conductor circuit pattern. Forming a support substrate having a projection formed at a position corresponding to the through hole so as to have a projection height about the thickness of the circuit board; and forming the support substrate. A fixing step of fixing to the surface side of the insulating member of the circuit board, placing a solder ball as an external connection terminal on the projection surface, and heating and melting the solder ball,
A method of manufacturing a semiconductor device, comprising: a step of forming an external connection terminal for achieving an electrical connection between the conductive circuit pattern and the solder ball. 8. The method of manufacturing a semiconductor device according to claim 7, wherein said supporting substrate forming step includes an etching processing step of forming projections by performing etching processing using photolithography on said supporting substrate. Method. 9. The method according to claim 7, wherein the step of forming a support substrate includes a step of forming a projection on the support substrate made of an insulating member and then forming a metal film on the surface.
The manufacturing method of the semiconductor device described in the above.