JPH09162238A - Terminal electrode on circuit board, formation thereof, circuit board, and semiconductor module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make smooth flows of sealing resin in facedown bonding of a semiconductor device by using a circuit board that has stepped terminal electrodes with steps. SOLUTION: A circuit board 2 for facedown bonding of a semiconductor device 4 has stepped terminal electrodes 1. For example, the terminal electrode 1 has two or more steps 2a and 2b against the flow of molding resin 7. The height of the step 2a is less than half the average particle size of the filler in the molding resin, whereas that of the step 2b is greater than half the average particle size of the filler. Bump electrodes 5 on pads of the semiconductor device 4 are electrically connected with terminal electrodes 1 on the circuit board 2 through junctions 6 of conductive adhesive or solder. Since the terminal electrodes 1 on the circuit board 2 do not form a vertical barrier against the resin flow, the filler is well distributed in the molding resin 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a terminal electrode on a circuit board for mounting a semiconductor device face down (surface mounting), a method for forming the terminal electrode, the circuit board, and a semiconductor device mounting body using the same. It is a thing.

[0002]

2. Description of the Related Art As electronic devices have become smaller and thinner in recent years, the speed of LSI chips, the degree of integration, and the number of pins have been increased. Packaging technology has advanced. Therefore, LSI
Various shapes and structures have also been proposed for chip packages (Nikkei Electronics 1993 No. 8-2 n
o. 587, “Pushing the Leading Edge in High Density Packaging of LSI Packages”, pp. 93-99). A mounting method using face down (a type of surface mounting) is one of them.

Specific examples of conventional face-down mounting methods and semiconductor device mounting bodies will be described below. As a circuit board used in the conventional face-down mounting method, for example, the one shown in FIG. 17 can be considered. It is a face-down mounting method that the protruding electrodes of the semiconductor device are mounted downward on this circuit board, and a mounting body in which the semiconductor device is actually mounted on the circuit board is shown in FIG. Twenty.

Next, a method of making a circuit board used in the face-down mounting method will be described. Normal,
In the case of printed circuit board terminal electrodes, laminated glass
A copper foil is attached on an epoxy substrate, a resist film with a circuit pattern removed is formed thereon, the exposed portion of the copper foil is dissolved with an etching solution, and finally the resist is peeled off. In this way, only copper circuit patterns are formed on the glass epoxy substrate. The copper wiring film thickness at this time, that is, the thickness of the copper foil is usually 18 μm. Further, if necessary, by plating nickel on the copper wiring and then gold plating, oxidation and corrosion of the wiring surface can be suppressed, and stable wiring can be formed.

In the case of a terminal electrode of a ceramic substrate, a wiring conductor is printed by screen printing after stacking the green sheets or after firing the green sheet, and the wiring conductor is set to 600-1.
The wiring is formed by firing at 000 ° C. The wiring film thickness at this time is about 15 μm for copper and about 5 μm for gold. This is a value determined by the settings of the screen plate, the printing machine, and the viscosity of the conductor paste. Here as well, after further nickel plating, gold plating can be performed. Also,
The material of the wiring paste is Au, Cu, Ag, AgP
d etc.

There is also a wiring forming method similar to that of a printed circuit board for a ceramic substrate. This is a method in which after electroless copper plating is performed on a ceramic substrate, a resist film having a circuit pattern is formed thereon, the exposed portion of the copper plating is dissolved by an etching solution, and finally the resist is peeled off. According to this method, only the copper circuit pattern is formed on the ceramic substrate. Also in this case, the copper wiring can be plated with nickel and then plated with gold.

[0007]

The above-mentioned conventional terminal electrode of the circuit board has a structure as shown in the sectional view of FIG. 16 and has the following problems. Usually, when mounting a semiconductor device face down on a terminal electrode of a circuit board, in order to enhance the connection reliability between the protruding electrode of the semiconductor device and the terminal electrode of the circuit board, a sealing resin is used between the semiconductor device and the circuit board. Enclose in the gap. At the time of this encapsulation, in the above-mentioned conventional example, the terminal electrode of the circuit board is a wall perpendicular to the encapsulation direction of the encapsulating resin, so that only the liquid component in the encapsulating resin is easily transmitted. In other words, the solid content (filler) can be carried over the height of the vertical portion of the terminal electrode along with the liquid component while being carried by the momentum of the encapsulating resin at the beginning. As the length in the sealing direction becomes longer, the sealing speed of the sealing resin decreases, and the solid content (filler) of the sealing resin accumulates before the vertical portion of the terminal electrode on the circuit board. The above has occurred in each terminal electrode. 18 and 19 specifically show this situation. In each drawing, the terminal electrode on the circuit board is a wall perpendicular to the encapsulation direction of the encapsulating resin, so the filler cannot get over the wall and the terminal electrode on the circuit board It has accumulated in the foreground.

The present invention has been made to solve such a problem, and improves a terminal electrode on a circuit board for improving encapsulation of sealing resin, a method of forming the terminal electrode, and encapsulation of sealing resin. An object of the present invention is to provide a circuit board and a semiconductor device mounting body using them.

[0009]

To achieve the above object, the terminal electrode on the circuit board according to the present invention is characterized in that it has a step-like step. It is preferable that the step has a thickness that is half or less of the average particle diameter of the filler in the sealing resin. With such a configuration, the solid content (filler) in the sealing resin can easily get over the surface of the terminal electrode together with the liquid content.

Furthermore, it is preferable that the stepwise width of the terminal electrodes on the circuit board is at least half the average particle size of the filler in the sealing resin. With this configuration,
If solid content (filler) gets on the step of the terminal electrode,
Since the resin content carries the solid content (filler) on the terminal electrode surface in the horizontal direction with respect to the circuit board, the enclosed speed is not lowered.

Further, in a circuit board on which a semiconductor device is mounted by face-down, a flow auxiliary electrode is provided for improving the encapsulation property of a sealing resin which is sealed between the semiconductor device and the circuit board. And With this configuration, it becomes easy to more surely transfer the sealing resin to the gap interface between the semiconductor device and the circuit board. More preferably, the flow auxiliary electrode is arranged in parallel with or along the inclined direction with respect to the sealing resin enclosing direction. By doing so, the sealing property of the sealing resin can be further improved. It is also preferable to separate the flow assisting electrode from the other terminal electrodes of the circuit board and arrange it at a position irrelevant to electrical conduction.

Further, the method of forming the above-mentioned terminal electrode according to the present invention includes a method by a plating method and a method by an etching method. According to the plating method, first, the resist layer A is formed on the circuit board except the region where the terminal electrode is to be formed, and the average particle of the filler of the sealing resin is formed in the region where the terminal electrode is to be formed by the plating method. A terminal electrode having a thickness not more than half the diameter is deposited. Next, a resist layer B is formed on the formed terminal electrode by removing a small region inward from the outer edge of the terminal electrode by a dimension equal to or more than half the average particle diameter of the filler of the sealing resin, and again by plating. A terminal electrode having a thickness not more than half the average particle diameter of the filler of the sealing resin is deposited on the terminal electrode. Finally, by dissolving or peeling off all the resist films, a terminal electrode having a two-step stepped step can be formed. In addition, by repeating the above steps, a terminal electrode having three or more steps in steps can be formed.

According to the etching method, first, a conductor layer is formed on the entire surface of a circuit board, a resist layer A is formed in a region where a terminal electrode is to be formed, and a region not covered with the resist layer A is formed. Etching is performed so as to remove the conductor layer. Next, the resist layer A is dissolved or peeled off to expose the terminal electrode, and the resist is formed on the terminal electrode in a small area inward from the outer edge of the electrode by a dimension of at least half the average particle diameter of the filler of the sealing resin. The layer B is formed, and the region where the resist layer B is not formed is etched so that a conductor layer having a predetermined thickness remains. Then, by melting or peeling the resist layer B, a terminal electrode having a two-step stepped step can be formed. In addition, a resist layer C is formed in a region including a small region and an electrode lower stage face inward from the outer edge of the electrode upper stage face exposed in the above step by a dimension of half or more of the average particle size of the filler of the sealing resin, A region where C is not formed is etched so that a conductor layer having a predetermined thickness remains, and the resist layer C is melted or peeled off to form a terminal electrode having a three-step staircase-like step. it can. Repeat this process to 4
It is also possible to form a terminal electrode having a step-like step having more than one step.

By these methods, a terminal electrode suitable for the present invention can be formed. Further, by mounting the terminal electrode on the circuit board and the semiconductor device by a face-down mounting method and encapsulating a sealing resin between them, a semiconductor device mounting body having a highly reliable connection portion can be obtained. Obtainable.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the present invention will be described below with reference to the drawings. First, the semiconductor device mounting body according to the present embodiment will be described with reference to FIG. FIG.
FIG. 8A is a cross-sectional view of one in which a plurality of semiconductor devices 4 are mounted on the multilayer circuit board 2 (multichip module), and FIG. 8B is a single semiconductor device 4 on the circuit board. It is sectional drawing of what is mounted (chip size package). In FIG. 8A, a plurality of semiconductor devices 4 are mounted on the multilayer circuit board 2 in a face-down manner. The gap between the semiconductor device 4 and the multilayer circuit board 2 is covered with the sealing resin 7
It is filled and sealed by. In FIG. 8B, a single semiconductor device 4 is mounted on the circuit board 2 by face-down. The gap between the semiconductor device 4 and the circuit board 2 is filled and sealed with the sealing resin 7. In addition, also in other embodiments described later, the entire structure of the mounted body of the semiconductor device is the same as that in FIG.

FIG. 1 shows a first embodiment of the present invention. As shown in the cross-sectional view of FIG. 1, the terminal electrode 1 of the first embodiment has a step-like step on a circuit board 2. This step-like step of the terminal electrode 1 is provided in the encapsulation direction of the encapsulating resin, and by providing this step, the terminal electrode does not become a vertical wall, and after encapsulating the encapsulating resin. The dispersion state of is good.

Next, the method of forming the terminal electrode according to the first embodiment will be described with reference to FIG. First, FIG.
As shown in (a), a resist layer A is formed on a portion of the circuit board 2 excluding a region where a terminal electrode is to be formed.
Next, as shown in FIG. 4B, a terminal electrode having a thickness not more than half the average particle diameter of the filler of the sealing resin is formed by plating on the area where the terminal electrode is to be formed on the circuit board 2. Precipitate. This is the first stage of the terminal electrode 1. Next, FIG.
As shown in (c), on the first stage of the terminal electrode 1 formed in FIG. 4 (b), from the outer edge of the terminal electrode, only a size equal to or more than half the average particle size of the filler of the sealing resin is provided. A resist layer B is formed on the inside except for a small region. Next, FIG.
As shown in (d), a terminal electrode having a thickness equal to or smaller than half the average particle diameter of the filler of the sealing resin is deposited on the first stage of the terminal electrode 1 by plating again. And finally, Figure 4
As shown in (e), all the resist films are dissolved or peeled off to expose the terminal electrodes 1 having step-like steps on the circuit board 2 and, if necessary, the circuit board 2 and the terminal electrodes 1 To wash. By the above method, a terminal electrode having a two-step stepped step can be formed. Further, in the above method, by repeating the steps shown in FIGS. 4C and 4D, it is possible to form the terminal electrode 1 having a step difference of three steps or more.

To the terminal electrode 1 according to the first embodiment,
FIG. 9 shows the structure of a mounting body on which the semiconductor device 4 in which the protruding electrodes 5 have a two-step protruding shape is mounted. This is because the protruding electrode 5 formed on the electrode pad portion 11 of the semiconductor device 4 and the terminal electrode 1 having a step-like step on the circuit board 2 by the face-down via the bonding layer 6. It is electrically connected. The gap between the semiconductor device 4 and the circuit board 2 is filled and sealed with the sealing resin 7.
The protruding electrode 5 of the semiconductor device 4 is formed in a two-step protruding shape by a wire-bonding method in order to stably connect with the terminal electrode 1. In FIG. 9, 7 is a sealing resin,
8 is the average particle size of the filler, 9 is the maximum particle size of the filler, and 10 is the minimum particle size of the filler. The arrow indicates the direction of encapsulation of the sealing resin.

FIG. 2 shows a second embodiment of the present invention. As shown in the cross-sectional view of FIG. 2, the terminal electrode 1 of the second embodiment has a step-like step on the circuit board 2, and the step is the average particle size of the filler in the sealing resin. The thickness is less than half. The step-like step of the terminal electrode 1 is provided in the sealing resin sealing direction,
Since its thickness is less than half the average particle size of the filler,
The terminal electrode does not form a vertical wall, and the dispersion state after encapsulation of the sealing resin is good.

To the terminal electrode 1 according to the second embodiment,
FIG. 10 shows the structure of a mounting body on which the semiconductor device 4 in which the protruding electrodes 5 have a two-step protruding shape is mounted. This is because the protruding electrode 5 formed on the electrode pad portion 11 of the semiconductor device 4 and the terminal electrode 1 having a step-like step on the circuit board 2 by the face-down via the bonding layer 6. It is electrically connected. The gap between the semiconductor device 4 and the circuit board 2 is filled and sealed with the sealing resin 7.
The protruding electrode 5 of the semiconductor device 4 is formed in a two-step protruding shape by a wire-bonding method in order to stably connect with the terminal electrode 1.

FIG. 3 shows a third embodiment of the present invention. As shown in the cross-sectional view of FIG. 3, the terminal electrode 1 of the third embodiment has a step-like step on the circuit board 2, and the step 2a is the average particle size of the filler in the sealing resin. Is less than half the thickness, and the step width 2b is configured to have a dimension not less than half the average particle diameter of the filler in the sealing resin. Since the step-like step of the terminal electrode 1 is formed in the above-mentioned dimension with respect to the encapsulation direction of the sealing resin, the terminal electrode does not become a vertical wall, and the dispersed state after encapsulation of the sealing resin Will be good.

Next, a method of forming the terminal electrode 1 according to the third embodiment will be described with reference to FIG. First, FIG.
As shown in (a), the conductor layer 3 is formed on the entire surface of the circuit board 2. Next, as shown in FIG. 5B, a resist layer A is formed in the region where the terminal electrode is to be formed. Next, FIG.
As shown in (c), etching is performed so as to remove the conductor layer 3 in the region not covered with the resist layer A. next,
As shown in FIG. 5D, the resist layer A is dissolved or peeled off to expose the conductor layer 3. Next, as shown in FIG. 5E, on the conductor layer 3 formed in FIG.
The resist layer B is formed so as to form a small region inward from the outer edge of the electrode by a dimension that is at least half the average particle diameter of the filler of the sealing resin. Next, as shown in FIG.
Etching is performed so that the conductor layer 3 having a thickness equal to or less than half the average particle diameter of the filler of the sealing resin remains in a region where the resist layer B is not formed on the conductor layer 3. Next, as shown in FIG. 5G, the resist layer B is dissolved or peeled off. Through the steps up to this point, a terminal electrode having a two-step step difference can be formed. Next, as shown in FIG. 5H, on the terminal electrode formed in FIG. A resist layer C is formed on the small area and on the terminal electrode formed in FIG. next,
As shown in FIG. 5 (i), in the region where the resist layer C on the terminal electrode is not formed, the average particle diameter of the filler of the sealing resin is set to the thickness of the terminal electrode formed in FIG. 5 (f). Etching is performed so that a terminal electrode having a thickness equal to or less than half of the above remains. Next, as shown in FIG. 5J, the resist layer C is dissolved or peeled off to expose the terminal electrode 1 having a step-like step on the circuit board 2. By the method described above, the terminal electrode 1 having a three-step stepped step can be formed. Further, by repeating the steps shown in FIGS. 5 (h) to 5 (j) of the above method, 4
It is also possible to form the terminal electrode 1 having a step-like step having more than one step. If necessary, the circuit board 2 and the terminal electrode 1 are washed. The conductor layer formed on the entire surface of the circuit board 2 may be a copper foil adhered material, electroless copper plating, or another conductor.

To the terminal electrode 1 according to the third embodiment,
FIG. 12 shows the structure of a mounting body on which the semiconductor device 4 in which the protruding electrodes 5 have a two-step protruding shape is mounted. This is because the protruding electrode 5 formed on the electrode pad portion 11 of the semiconductor device 4 and the terminal electrode 1 having a step-like step on the circuit board 2 by the face-down via the bonding layer 6. It is electrically connected. The gap between the semiconductor device 4 and the circuit board 2 is filled and sealed with the sealing resin 7.
The protruding electrode 5 of the semiconductor device 4 is formed in a two-step protruding shape by a wire-bonding method in order to stably connect with the terminal electrode 1.

FIG. 6 shows a fourth embodiment of the present invention. As shown in the plan view of FIG. 6, in the fourth embodiment, when the circuit board 2 is viewed from directly above, the flow auxiliary electrode 1a is sealed in the sealing resin 7 on the circuit board 2 in the sealing direction. , Parallel to or along the tilt direction. In addition, the flow assisting electrode 1a is arranged such that the longitudinal direction thereof is parallel to the sealing direction of the sealing resin 7 or along the inclined direction. Normally, only the optimized terminal electrode 1 is formed on the circuit board 2. However, in the fourth embodiment, as described above, the terminal electrode 1 is parallel or inclined with respect to the encapsulation direction of the sealing resin. ,
The flow auxiliary electrode 1a is added. With the above configuration, the sealing resin flows along the auxiliary flow electrodes 1a, so that the dispersed state of the sealing resin after encapsulation becomes good. The line width and length of the flow assisting electrode 1a should not be made extremely thick, or if there is no risk of shorting between adjacent parts,
There is no particular limitation.

The flow assisting electrode 1 according to the fourth embodiment
FIG. 14 is a plan view showing the structure of the mounting body when the semiconductor device 4 is mounted on the circuit board 2 provided with a. This is because the protruding electrode 5 formed on the electrode pad portion 11 of the semiconductor device 4 and the terminal electrode 1 on the circuit board 2 are electrically connected via the bonding layer 6 by face down. . As described above, the terminal electrode 1 is provided with the flow auxiliary electrode 1a that is parallel or inclined with respect to the sealing resin sealing direction.
In addition, the gap between the semiconductor device 4 and the circuit board 2 is filled and sealed with the sealing resin 7.

FIG. 7 shows a fifth embodiment of the present invention. As shown in the plan view of FIG. 7, in the fifth embodiment, when the circuit board is viewed from directly above, the flow auxiliary electrode 1b is connected to the terminal electrode 1 which is related to normal optimized electrical conduction. Separately from the above, it is provided at a position that is completely unrelated to electrical conduction, either parallel to the sealing resin enclosing direction or along the inclined direction. With the above configuration, the sealing resin flows along the flow assisting electrode 1b, so that the encapsulating property of the sealing resin becomes good. Flow auxiliary electrode 1b
The line width and length are not particularly limited as long as they are not extremely thick or there is no risk of short-circuiting with the surrounding terminal electrodes having electrical conduction.

The flow assisting electrode 1 according to the fifth embodiment
FIG. 15 is a plan view showing the structure of the mounting body when the semiconductor device 4 is mounted on the circuit board 2 provided with b. This is because the protruding electrode 5 formed on the electrode pad portion 11 of the semiconductor device 4 and the terminal electrode 1 on the circuit board 2 are electrically connected via the bonding layer 6 by face down. . As described above, the flow assisting electrode 1b is added to the circuit board 2 at a position that is completely unrelated to electrical conduction, in parallel or at an inclination with respect to the encapsulation direction of the sealing resin.
The gap between the semiconductor device 4 and the circuit board 2 is filled and sealed with the sealing resin 7.

FIG. 11 shows a sixth embodiment of the present invention. As shown in the cross-sectional view of FIG. 11, this is a terminal electrode provided with a bump electrode 5 formed on the electrode pad portion 11 of the semiconductor device 4 by face down and a step-like step on the circuit board 2. 1 are electrically connected to each other through the bonding layer 6. The gap between the semiconductor device 4 and the circuit board 2 is filled and sealed with the sealing resin 7. Furthermore, the protruding electrode 5 of the semiconductor device 4 is formed by a plating method.

FIG. 13 shows a seventh embodiment of the present invention. As shown in the cross-sectional view of FIG. 13, the terminal electrode 1 of the seventh embodiment has a step-like step only toward the sealing resin sealing direction on the circuit board 2, and the step 2a
Is a thickness not more than half the average particle diameter of the filler in the sealing resin, and the step width 2b is configured to have a dimension not less than half the average particle diameter of the filler in the sealing resin. Since the step-like step of the terminal electrode 1 is configured as described above only in the encapsulation direction of the encapsulating resin, the terminal electrode does not form a vertical wall, and dispersion after encapsulating the encapsulating resin is not achieved. The condition is good. The gap between the semiconductor device 4 and the circuit board 2 is filled and sealed with a sealing resin 7, and the protruding electrodes 5 of the semiconductor device 4 are wire-bonded by a wire bonding method in order to stably connect with the terminal electrodes. Is formed in a two-step projection shape.

Further, the material of the terminal electrode 1 in each of the above embodiments is not particularly limited, and Cu or Ni, for example, can be considered, and as the forming method, Cu plating, Ni plating, Au plating, etc. can be considered. To be

Further, the electrode pad portion 11 of the semiconductor device 4
The shape of the protruding electrode formed above may be a two-step protruding shape, and the material may be Au or the like.
Further, in each embodiment, the protruding electrode formed on the electrode pad portion 11 of the semiconductor device 4 and the terminal electrode 1 of the circuit board 2 are face down (wireless bonding).
Although the method of joining by
The method is not limited to this, and a method of forming with a wire bonding device is also preferable.

Further, as the bonding layer for bonding the terminal electrode 1 on the circuit board 2 and the protruding electrode 5 formed on the electrode pad portion 11 of the semiconductor device 4, a conductive adhesive, solder or the like is considered. .

[0033]

According to the present invention, since the terminal electrode of the circuit board is provided with the step-like step, the terminal electrode on the circuit board does not become a wall perpendicular to the sealing resin enclosing direction. The dispersion state after encapsulation of the sealing resin becomes good. Also,
By providing a flow auxiliary electrode on the circuit board, the sealing resin is not sealed in the gap between the semiconductor device and the circuit board, and the solid content (filler) is prevented from settling and depositing. It can be sealed well. Further, by mounting the semiconductor device on the terminal electrode or the circuit board having the above-described configuration, the mounting portion of the semiconductor device after encapsulating the sealing resin and the periphery of the terminal electrode have a liquid content and a solid content in the sealing resin. Distribution is better and a reliable connection is obtained.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing a terminal electrode on a circuit board according to a first embodiment of the present invention.

FIG. 2 is a schematic sectional view showing a terminal electrode on a circuit board according to a second embodiment of the present invention.

FIG. 3 is a schematic sectional view showing a terminal electrode on a circuit board according to a third embodiment of the present invention.

4A to 4C are process diagrams for explaining a method of forming the terminal electrode of FIG.

5A to 5C are process diagrams for explaining a method of forming the terminal electrode of FIG.

FIG. 6 is a schematic plan view showing a circuit board according to a fourth embodiment of the present invention.

FIG. 7 is a schematic plan view showing a circuit board according to a fifth embodiment of the present invention.

FIG. 8 is a cross-sectional view showing the overall structure of a mounting body according to each embodiment of the present invention

9 is an enlarged cross-sectional view showing the structure of an electrode connection portion of a mounting body in which a semiconductor device having projecting electrodes having a two-step projecting shape is mounted on the circuit board having the terminal electrodes of FIG. 1;

10 is an enlarged cross-sectional view showing a structure of an electrode connection portion of a mounting body in which a semiconductor device having projecting electrodes in a two-step projecting shape is mounted on a circuit board having the terminal electrodes of FIG.

FIG. 11 is an enlarged cross-sectional view showing a structure of an electrode connecting portion of a mounting body according to a sixth embodiment of the present invention.

12 is an enlarged cross-sectional view showing a structure of an electrode connecting portion of a mounting body in which a semiconductor device having projecting electrodes in a two-step projecting shape is mounted on a circuit board having the terminal electrodes of FIG.

FIG. 13 is an enlarged cross-sectional view showing a structure of an electrode connecting portion of a mounting body according to a seventh embodiment of the present invention.

14 is a schematic plan view of a mounting body in which a semiconductor device is mounted on the circuit board of FIG.

15 is a schematic plan view of a mounting body in which a semiconductor device is mounted on the circuit board of FIG.

FIG. 16 is a schematic cross-sectional view showing a terminal electrode on a circuit board according to a conventional example.

FIG. 17 is a schematic plan view showing a circuit board according to a conventional example.

FIG. 18 is an enlarged cross-sectional view showing a structure of an electrode connecting portion of a mounting body in which a semiconductor device having protruding electrodes in a two-step protruding shape is mounted on a circuit board having terminal electrodes of a conventional example.

FIG. 19 is an enlarged cross-sectional view showing a structure of an electrode connecting portion of a mounting body in which a semiconductor device is mounted on a circuit board having a terminal electrode of a conventional example.

FIG. 20 is a schematic plan view of a mounting body in which a semiconductor device is mounted on a conventional circuit board.

[Explanation of symbols]

 1 Terminal Electrode 1a Flow Auxiliary Electrode 1b Flow Auxiliary Electrode Irrelevant to Electrical Conduction 2 Circuit Board 2a Terminal Electrode Step 2b Terminal Electrode Step Width 3 Conductor Layer 4 Semiconductor Device 5 Projection Electrode 6 Bonding Layer 7 Sealing Resin 8 Filler ( Average particle size 9 Maximum particle size 10 Minimum particle size 11 Electrode pad

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masahiro Ono 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (23)

[Claims] 1. A terminal electrode on a circuit board on which a semiconductor device is mounted face down, the terminal electrode on the circuit board having a step-like step. 2. The terminal on the circuit board according to claim 1, wherein the terminal electrode on the circuit board has a step-like step having at least two steps in the injection direction of the sealing resin. electrode. 3. The circuit according to claim 1, wherein the step-like step difference of the terminal electrode on the circuit board has a thickness not more than half the average particle diameter of the filler in the sealing resin. Terminal electrodes on the substrate. 4. The step-shaped step width of the terminal electrode on the circuit board is equal to or more than half the average particle diameter of the filler in the sealing resin. Terminal electrodes on the circuit board. 5. A circuit board on which a semiconductor device is mounted by face-down is provided with a flow auxiliary electrode for improving encapsulation of a sealing resin sealed between the semiconductor device and the circuit board. And a circuit board. 6. The circuit board according to claim 5, wherein the flow assisting electrode is disposed in parallel with or along the inclined direction with respect to the encapsulation direction of the sealing resin. 7. A semiconductor device, which is separated from a terminal electrode for connection with a protruding electrode and is located at a position unrelated to electrical conduction,
7. The circuit board according to claim 5, wherein the flow auxiliary electrode is provided. 8. The terminal electrode on the circuit board according to claim 1, wherein the material of the terminal electrode is Cu or Ni. 9. The circuit board according to claim 5, 6 or 7, wherein the material of the terminal electrode and the flow auxiliary electrode on the circuit board is Cu or Ni. 10. The terminal electrode is formed by Cu plating, Ni plating or Au plating.
The terminal electrode on the circuit board according to claim 1. 11. The circuit board according to claim 5, 6 or 7, wherein the terminal electrode and the flow auxiliary electrode on the circuit board are formed by Cu plating, Ni plating or Au plating. 12. A method of forming a terminal electrode on a circuit board for mounting a semiconductor device face down, comprising the step a of forming a resist layer A on the circuit board except a region where the terminal electrode is to be formed. A step b in which a terminal electrode having a thickness not more than half the average particle diameter of the filler of the sealing resin is deposited in a region where the terminal electrode is to be formed by a plating method, and the step b
A step c of forming a resist layer B on the terminal electrode formed by removing a small area inward from the outer edge of the terminal electrode by a dimension equal to or more than half the average particle diameter of the filler of the sealing resin, and plating again. The step d of depositing a terminal electrode having a thickness not more than half the average particle size of the filler of the sealing resin on the terminal electrode, and the step e of dissolving or peeling all the resist films. A method of forming a terminal electrode on a circuit board, the terminal electrode having a stepped step. 13. The method of forming a terminal electrode on a circuit board according to claim 12, wherein the step c and the step d are repeated, and finally the step e is performed. A method of forming a terminal electrode on a circuit board, wherein a terminal electrode having a step in which the thickness of each step is less than or equal to half the average particle diameter of the filler of the sealing resin is formed. 14. A method of forming a terminal electrode on a circuit board for mounting a semiconductor device by face-down, comprising: forming a conductor layer on the entire surface of the circuit board; and forming the terminal electrode. Step b of forming resist layer A in the region
A step c of etching so as to remove the conductor layer in a region not covered by the resist layer A, and a step d of dissolving or peeling the resist layer A to expose the terminal electrode.
And a step e of forming a resist layer B on the terminal electrode in a small area inward from the outer edge of the electrode by a dimension equal to or more than half the average particle diameter of the filler of the sealing resin, and forming the resist layer B. The step is a step-like step of two steps, which includes a step f of etching an unetched region so that a conductor layer having a predetermined thickness remains, and a step g of dissolving or peeling the resist layer B. A method of forming a terminal electrode on a circuit board, wherein a terminal electrode having a step whose thickness is less than or equal to half the average particle size of the filler of the sealing resin is formed. 15. The method of forming a terminal electrode on a circuit board according to claim 14, wherein the outer edge of the upper electrode surface exposed in step g is inward by a dimension not less than half the average particle diameter of the filler of the sealing resin. A step h of forming a resist layer C in an area including a small area and an electrode lower surface, and a step i of etching an area in which the resist layer C is not formed so that a conductor layer having a predetermined thickness remains. A terminal electrode having a three-step step-like step consisting of a step j of dissolving or peeling the resist layer C, in which the thickness of each step is not more than half the average particle size of the filler of the sealing resin. Forming a terminal electrode on a circuit board. 16. The method for forming a terminal electrode on a circuit board according to claim 15, wherein steps h to j are repeated to form a step-like step having four or more steps and each step has a thickness. A method for forming a terminal electrode on a circuit board, the method comprising forming a terminal electrode having a step that is equal to or less than half the average particle diameter of a resin filler. 17. A semiconductor device mounting body, wherein a protruding electrode formed on an electrode pad portion of a semiconductor device and a terminal electrode on a circuit board are electrically connected via a bonding layer, A package of a semiconductor device, wherein the terminal electrode has the structure according to any one of claims 1 to 4. 18. A package of a semiconductor device, wherein a protruding electrode formed on an electrode pad portion of the semiconductor device and a terminal electrode on a circuit board are electrically connected via a bonding layer, The terminal electrode on the circuit board is defined by claim 5, 6 or 7.
A semiconductor device mounting body having the structure described. 19. The projection electrode formed on the electrode pad portion of the semiconductor device has a two-step projection shape.
8. A semiconductor device package according to item 8. 20. The material of the protruding electrode formed on the electrode pad portion of the semiconductor device is Au.
A packaged semiconductor device as described above. 21. The semiconductor device mounting body according to claim 17, wherein the protruding electrode formed on the electrode pad portion of the semiconductor device is formed by a wire bonding device. 22. The semiconductor device mounting body according to claim 17, wherein the protruding electrode formed on the electrode pad portion of the semiconductor device is formed by a plating method. 23. The semiconductor device package according to claim 17, wherein the bonding layer is made of a conductive adhesive or solder.