JPH11135689A - Radiating slug having cavity recess, its forming method, and semiconductor package material using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radiating slug having a cavity recess in which the rear is flat, the dimensional precision of the depth of the cavity recess is high, and productivity can be improved, and its forming method or the like. SOLUTION: A metal plate 1 is subjected to pressure-shaping divided into a plurality of times by press working, in a state such that the rear face 2 is retained by a flat block. Thereby a cavity recess 3 having a specified depth (m) is formed. A boundary part 8 between a bottom surface 5 and a side surface 6 and a boundary part 9 between the side surface 6 and a surface 7 of recess periphery are formed as rectangular corner angles. The entire rear face 2 is formed flat. After that, the metal plate 1 is cut into segments as radiating slugs. Thus radiating slug S having the cavity recess 3 are formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat dissipation slag having a cavity recess for mounting a semiconductor chip, a method of forming the same, and a semiconductor package material using the same. This makes it possible to improve the depth and other dimensional accuracy and increase productivity.

[0002]

2. Description of the Related Art In a semiconductor package, in order to release heat generated from a semiconductor chip to the outside, a heat dissipation slag made of a metal plate such as copper / copper alloy or aluminum mounted on the semiconductor chip is provided on one side and a mold is provided on the other side. Generally, it is provided so as to be exposed.

There are several types of heat dissipation slags. Conventionally, the heat dissipation slag is roughly divided into two types: a heat dissipation slag itself having no cavity recess for engaging and mounting a semiconductor chip, and a heat dissipation slag itself. Some have a cavity recess in which a semiconductor chip can be engaged and mounted.

The former heat dissipation slag is formed on a printed circuit board having a cavity opening (the printed circuit board referred to in the present application includes a TAB tape) so that the central portion of the heat dissipation slug is exposed from the cavity opening. The semiconductor chip is fixed to the surface of the planar heat dissipation slag exposed in the cavity opening (see, for example, JP-A-4-245668,
JP-A-4-245669, JP-A-4-313257, JP-A-5-3268, JP-A-6-97609,
See JP-A-6-163760 and JP-A-6-163376.

[0005] The heat dissipation slag is formed by joining a cavity recess of the heat dissipation slag itself to the back surface of a printed circuit board having a cavity opening so that the heat dissipation slag itself is exposed from the cavity opening of the board. A semiconductor chip is engaged and mounted on the bottom surface of the cavity recess of the slag (for example, Japanese Patent Publication No. Sho 6
3-54223, JP-A-9-22964,
(See Japanese Patent Application Laid-Open No. 9-22962, filed by the same person as the present application).

[0006]

The present invention belongs to the latter,
The heat dissipation slag itself has a cavity recess in which a semiconductor chip can be engaged and mounted later. As this kind of conventional heat dissipation slug with cavity recess,
As shown in FIG. 22, a metal plate 1 is etched to dissolve and remove a portion serving as a cavity concave portion to form a cavity concave portion 3, and as shown in FIG. 23, the metal plate 1 is pressed from the surface. And locally bends from the front side to the back side, and the recessed portion is used as the cavity recess 3.

However, in the formation of the cavity concave portion 3 by the etching process, it takes too much time to form the cavity concave portion 3, and it is difficult to obtain the precision of the depth of the concave portion for dissolution and removal, and the depth m tends to vary. . For this reason, when the semiconductor chip 17 is later engaged and mounted in the cavity recess 3, the height of the semiconductor chip 17 becomes uneven in each case, and the printed circuit board bonded to the surface around the semiconductor chip 17 and the cavity recess 3 is formed. It was difficult to smoothly perform wire bonding between the 14 circuit terminals.

On the other hand, the formation of the cavity concave portion 3 by pressing a metal plate is described in Japanese Patent Application Laid-Open No. 9-22962, in which the cavity concave portion is formed by pressing a metal plate separately from the etching method. Cavity down ball grid using the formed heat dissipation slag
An example of an array is shown.

Since the cavity recess 3 is formed by one press working, the productivity is good and the accuracy of the depth of the cavity recess 3 is easily obtained. Therefore, there is also an advantage that the height of the semiconductor chip 17 becomes uniform and the wire bonding operation can be performed smoothly.

However, the heat release slag S formed by this press working is
As described above, the metal plate 1 is formed on the back surface 2 of the cavity recess 3.
Side, that is, on the side opposite to the cavity concave portion 3 (FIG. 23, see, for example, FIG. 1 of Japanese Patent Application Laid-Open No. 9-22962). For this reason, there is a problem that even if an attempt is made to attach the heat radiation fins 22 to the back surface 2 of the heat radiation slag S, the contact surface is small and the heat radiation fins 22 cannot be attached well.

Further, each cavity recess 3 of the heat radiation slag S formed by the above-mentioned etching method or press processing method.
The boundary 8 between the bottom surface 5 and the side surface 6 is formed into a curved surface by dissolution removal or bending (see FIGS. 22 and 23 described above).
Therefore, the semiconductor chip 1 is provided on the bottom surface 5 of the cavity recess 3.
In order to make the flat surface necessary for engaging and mounting the groove 7, it is necessary to form the cavity 3 with an extra space t1.

In the press working method, the cavity recess 3
The boundary 9 between the side surface 6 of the concave portion and the surface 7 around the concave portion is also formed in a curved surface, so that the side surface 6 of the concave portion 3 and the surface 7 around the concave portion are formed.
The distance t2 from the printed circuit board 17 to be bonded to the substrate also increases.
(See FIG. 23 above). Therefore, there is also a problem that the bonding wire 18 to be mounted later on the semiconductor chip 17 becomes longer.

The present invention has been made to solve the above problems in a conventional heat dissipation slag having a cavity recess. That is, an object of the present invention is to facilitate the mounting of the radiation fins, to make the height of the semiconductor chip to be later engaged and mounted in the cavity recess uniform, and to perform the wire bonding smoothly, and to realize the semiconductor chip and the printed circuit board. A heat dissipating slag having a cavity concave portion capable of shortening a bonding wire between circuit terminals and improving productivity, a method of forming the same,
And a semiconductor package material using the same.

[0014]

[Means for Solving the Problems]

A A first aspect of the heat dissipation slag having a cavity recess according to the present invention is a structure in which the entire back surface 2 of the cavity recess 3 is formed into a flat shape under pressure.

B The second aspect of the heat dissipation slag having the cavity recess according to the present invention is that the cavity recess 3 has a predetermined depth m, and the bottom surface 5 and the side surface 6 of the cavity recess 3 and the side surface 6 and the surface around the recess. The structure is formed by pressing at the corners orthogonal to each other at the boundary portions 8 and 9 with respect to.

C The third aspect of the heat dissipation slag having a cavity recess according to the present invention is that the cavity recess 3 having a predetermined depth m is flat on the entire back surface 2 and the bottom surface 2, the side surface 6, and the side surface 6 of the cavity recess 3. Each of the boundary portions 8 and 9 between the metal and the surface 7 around the concave portion has a structure formed by pressing at orthogonal corners.

D The fourth aspect of the heat dissipation slag having the cavity concave portion according to the present invention is that the cavity concave portion 3 is formed by pressing the metal plate 1 a plurality of times while supporting the back surface 2 of the metal plate 1 on a flat surface. The cavity recess 3 has a predetermined depth m and the back surface 2
The entire structure is formed flat and formed at orthogonal corners at boundaries 8 and 9 between the bottom surface 2 and the side surface 6 of the cavity concave portion 3 and the side surface 6 and the surface 7 around the concave portion. .

E In the method of forming a heat radiation slag having a cavity concave portion according to the present invention, the metal plate 1 is formed by pressing a plurality of times by press working while the back surface 2 is supported by the flat base 4. As a result, the cavity recess 3 has a predetermined depth m.
Then, the boundaries 8 and 9 between the bottom surface 5 and the side surfaces 6 and the side surfaces 6 and the surface 7 around the concave portion are formed at orthogonal corners, and the entire back surface 2 is formed flat. The heat dissipating slag S is cut into individual pieces.

F In the semiconductor package material according to the present invention, the cavity concave portion 3 having the predetermined depth m is formed by orthogonal corners at the boundaries 8 and 9 between the bottom surface 5 and the side surface 6 and the side surface 6 and the surface 7 around the concave portion. The heat radiation slug S, which is formed at a corner and has a structure in which the entire back surface 2 is flat, is joined to a printed circuit board 14 having a cavity opening 15.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION In the above configuration, the metal plate 1 is preferably a copper plate, a copper alloy or aluminum.
Other metal plates may be used as long as they have good thermal conductivity and can be subjected to plastic working. In addition, the printed circuit board 14 referred to here includes
Not only hard and thick general printed circuit boards, but also TA
As described above, a tape for B is also included.

The pressing of the metal plate 1 for forming the cavity recesses 3 is carried out stepwise by pressing in a state where the back surface 2 of the metal plate 1 is supported on a flat base 4 having a flat surface. Pressing and "putting in". That is, the concave portion 3a is gradually deepened not by a single pressurization but by a plurality of pressurizations, so that the cavity concave portion 3 having a predetermined depth m is formed.

The heat dissipation slag S formed in the above structure is desirably coated on the entire surface or at least on the back surface 2 with an antioxidant plating 10 (FIG. 16).
・ See FIG. 17). As the antioxidant plating 10, for example, nickel plating is desirable, but not limited thereto.

It is desirable that the heat dissipation slag S be provided with a partial plating 11 which can be wire-bonded at a necessary portion on the surface 7 around the concave portion (see FIG. 18). The partial plating 11 is desirably silver plating, for example, but is not limited thereto, and may be nickel-gold plating or the like. In the case where the partial plating 11 is applied, the oxidation preventing plating 10 is preferably applied only to the back surface 2 of the heat radiation slag S (see FIG. 19).

Further, the heat radiating slag S is subjected to a roughening treatment on the entire surface including the inside of the cavity concave portion 3 except for the back surface 2 or on the entire surface except for the portion on which the partial plating 11 capable of performing wire bonding with the back surface 2 is applied. It is desirable to form the surface 12 (see FIGS. 20 and 21). The roughened surface 12 is preferably, for example, black oxide, but is not limited thereto, and its thickness is desirably about 1 to 3 μm.

The semiconductor package material 16 refers to a state in which the heat-dissipating slag S having the above structure and cut into pieces is joined to the printed circuit board 14 having the cavity opening 15 (FIG. 1). (See FIG. 2). In this case, the semiconductor chip 17 is shipped without being mounted, and the demand for the semiconductor package material 16 is
Into the cavity 3 and mount the printed circuit board 14
The semiconductor package 20 is formed by wire bonding with the circuit terminals of the above and sealing with a resin mold 19. Thereafter, the semiconductor package 20 may be connected to the motherboard 21 by solder balls (see FIG. 3).

In the heat dissipating slag S according to the present invention, when forming the cavity recess 3, the metal plate 1 is supported on a flat flat base plate 4, and the crushing is performed stepwise by pressing. Put in. " That is, by forming the metal plate 1 by pressing several times instead of pressing once, the concave portion 3a is gradually formed deeply on the surface 7 of the metal plate 1, and the cavity concave portion 3 having a predetermined depth m is formed. Is formed.

For this reason, in the step of forming the cavity concave portion 3, the formation of the cavity concave portion 3 is performed in a shorter time than in the conventional etching method. In addition, by appropriately setting one pressing force and the number of pressurizations according to the material of the metal plate 1 and the width of the cavity concave portion 3, the cavity concave portion 3 having a predetermined depth m can be accurately formed. Will be formed.

As a result, the productivity of the heat dissipating slag S having the cavity concave portion 3 is improved, and a predetermined depth m
When the semiconductor chip 17 is engaged and mounted in the cavity concave portion 3, the height of the semiconductor chip 17 does not become uneven,
Wire bonding with the circuit terminals of the printed circuit board 14 joined to the surface 7 around the concave portion can be smoothly performed.

The radiating slag S is different from that obtained by the conventional press working method in that the back surface 2 of the metal plate 1 is supported by the flat flat base plate 4 while being applied only once from the front surface 7 of the metal plate 1. Instead of the pressure, the pressure is formed several times and is gradually depressed to form a deep recess 3a. As a result, the concave portion of the metal plate 1 gradually moves to the periphery of the concave portion 3a, so that the metal plate 1 does not swell on the back side of the cavity concave portion 3 and the entire back surface 2 has a flat heat radiation. Slag S will be formed. Therefore, the heat release slag S
Has a wide and flat back surface 2 and the radiation fins 2
2 can be securely mounted, and the heat radiation effect can be further enhanced (see FIG. 3).

Further, the heat dissipating slag S is different from those formed by the conventional etching method and pressing method in that the shape of the cavity concave portion 3 is changed to the boundary portion 8 between the bottom surface 5 and the side surface 6 and the side surface 6 and the surface 7 around the concave portion. Is formed at a right-angled corner, and does not become a curved boundary as in the related art (see FIGS. 9 and 10).

As a result, the size of the cavity recess 3 is such that the flat bottom surface 5 necessary for engaging and mounting the semiconductor chip 17 can be formed to have a necessary and sufficient size. Unlike this, it is not necessary to form the cavity concave portion in an extra size to obtain a required flat surface.
Similarly, the surface 7 around the concave portion for joining the printed circuit board 14
Also, unlike the conventional one in which the boundary between the side surface and the surface around the concave portion is a curved surface, the boundary is formed immediately and immediately continuously from the side surface 6 of the cavity concave portion 3 and is not separated. Therefore, the semiconductor chip 17 to be mounted later and the printed circuit board 14
The shortest wire 18 is also required by bonding between the circuit terminals (see FIGS. 1 and 2).

When the cavity 3 is formed, if there is any possibility that the cavity 3 may swell to the rear surface 1 due to a difference in plasticity due to the type of the metal plate 1 or an error in the pressing force, the swelling portion is removed. It is enough to finish the surface by grinding. In the figure, reference numeral 13 denotes a pressing die of a press machine.

[0033]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As an embodiment for forming a heat radiation slag S according to the present invention, here, a copper plate 1 having a thickness of 0.8 mm is formed on a metal plate.
This shows a case where a cavity recess 3 having a square shape with a side of 14.0 mm and a depth of 0.46 mm is formed.

As the copper plate 1, a horizontally long one having a length that can be cut into individual pieces to obtain a plurality of heat dissipation slags S is used. The copper plate 1 is placed on a flat base platen 4 having a flat surface, and the central portion of a part to be later formed into individual pieces is pressed by a press using a press die 13 having a different shape for each stage. "Put in".

The pressing of the metal plate 1 by this press machine is performed only once by pressing the metal plate 1 to a predetermined size.
Do this in several steps instead of deepening. here,
Pressing is performed five times using a press machine with a pressing capacity of 250 t.

That is, in the first stage, the surface 7 of the metal plate 1 is pressurized by using a pressing die 13 having a hemispherical lower end, thereby forming a concave portion 3a having a shallow hemispherical shell shape and a depth of about 0.3 mm. It is formed (see FIGS. 4 and 11).

In the second stage, the same portion is pressed by using a hemispherical pressing mold 13 having a slightly flat lower end, so that the bottom surface 5 has a slightly flattened shape with a shallow hemispherical shell having a flat shape.
A concave portion 3a having a depth of 35 mm is formed.
reference).

In the third stage, the same portion is pressed with a pressing die 13 having a lower end portion having four side surfaces except for four corners and a lower end surface being flat, so that the bottom surface 5 is flat and deep. A recess 3a having a thickness of about 0.4 mm is formed.
3).

In the fourth stage, the same portion is pressed by using a pressing die 13 having a lower end portion having approximately four side surfaces and a flat lower end surface, so that the bottom surface 5 is flat and has a depth of about 0. .4
A recess 3a of 2 mm is formed (see FIGS. 7 and 14).

In the fifth stage, the same portion is pressed by using a pressing die 13 having a square lower end of 1.4 mm on a side, four sides, and a flat lower end. This allows
A recess 3a having a square bottom of 1.4 mm, four sides, and a flat bottom surface 5 having a depth of 0.46 mm is formed (see FIGS. 8 and 15).

In the above case, the copper plate 1 is a flat flat base 4
It is placed on top and pressurized, and it is recessed by "putting in" step by step, so that the flesh of the recessed portion moves to the periphery of the recess 3a, and the back surface 2 of the recess 3a does not swell (FIG. 9).

Thereafter, a reference hole is drilled and cut into individual pieces of a required size to form individual heat radiation slags S. As a result, the cavity recess 3 having a predetermined depth is formed quickly and accurately at a predetermined position of the copper plate 1, and a heat radiation slag S having a flat back surface 2 as a whole is formed (see FIG. 10).

The cavity recess 3 formed as described above
Since the boundary 8 between the bottom surface 5 and the side surface 6 and the boundary 9 between the side surface 6 and the surface 7 around the recess are formed at right angles (see FIG. 10), the cavity recess 3 is formed. The bottom surface 5 has a flat surface large enough to engage and mount the semiconductor chip 17 later, and between the semiconductor terminal 17 and the circuit terminals of the printed circuit board 14 joined to the surface 7 around the concave portion. The bonding wire 18 may have the shortest length (see FIGS. 1 and 2).

The pressing force and the number of times of pressurization by the press machine described above are not limited to the above, but the material and thickness of the metal plate 1 to be pressurized, or the dimension of one side of the cavity concave portion 3 to be formed. An optimum numerical value may be set in consideration of the depth and the depth m, etc.

The heat dissipating slag S formed as described above is provided with a nickel antioxidant plating 10 on the flat back surface 2 and a silver partial plating 11 which can be wire-bonded to a required portion on the surface 7 around the concave portion. Except for the portion of the partial plating 11, the surface 7 and each side end surface are formed on the roughened surface 12 of 2 μm in thickness and black oxide (see FIG. 21).

The heat dissipating slag S is thereafter joined to the printed circuit board 14 having the cavity opening 15 with an adhesive 23 to form a semiconductor package material 16 (see FIGS. 1 and 2). Usually, as described above, the semiconductor package material 16 is shipped in a state where the semiconductor chip 17 is not mounted, and a consumer of the semiconductor package material 16 engages and mounts a desired semiconductor chip 17 in the cavity recess 3 and prints. The semiconductor package 20 is wire-bonded to the circuit terminals of the substrate 14 and sealed with a resin mold 19.
(See FIG. 3). Thereafter, the semiconductor package 20 is connected to the motherboard 21 by solder balls (see FIG. 3).

[0047]

As is apparent from the above description, the heat dissipation slag having the cavity recess according to the present invention, the method of manufacturing the same, and the semiconductor package material in which the heat dissipation slag is joined to the printed circuit board have the following effects.

That is, according to the present invention, the cavity recess of the heat radiation slag is formed by supporting a metal plate on a flat flat base plate and applying a plurality of pressurizations by press working to “squeeze” step by step. Accordingly, the cavity is formed to have a predetermined depth.

Therefore, as compared with the conventional etching method, the cavity recess can be formed in a shorter time, thereby improving the productivity and reducing the cost. Accuracy can be increased. As a result, when the semiconductor chips are later engaged and mounted in the cavity recesses, the heights thereof become uniform, so that the wire bonding operation between the semiconductor chips and the circuit terminals of the printed circuit board can be easily and smoothly performed. it can.

Further, unlike the conventional press working method, even if the cavity is formed by pressing the metal plate,
It does not bend or bulge to the back side. Thus, since the heat dissipation slag is flat on the entire back surface, the heat dissipation fins can be easily and reliably attached to the back surface, and the heat dissipation effect can be further improved.

Further, unlike the conventional etching method and the conventional press working method, each boundary portion between the bottom surface and the side surface of the cavity concave portion and the side surface and the surface around the concave portion can be formed at right-angled corners. As a result, the cavity concave portion can be formed on a flat bottom surface which is necessary and sufficient in size for engaging and mounting the semiconductor chip, and does not need to be formed in an extra size.

Moreover, the positions of the circuit terminals of the printed circuit board on the surface around the cavity recesses are also close to the cavity recesses, so that the bonding wires between the semiconductor chip and the circuit terminals of the printed circuit board also need to have the shortest length. Will be.

[Brief description of the drawings]

FIG. 1 is an enlarged vertical sectional side view showing an embodiment of a semiconductor package material using a heat dissipation slag having a cavity concave portion according to the present invention.

FIG. 2 is an enlarged vertical sectional side view showing another embodiment of a semiconductor package material using a heat dissipation slag having a cavity concave portion according to the present invention.

FIG. 3 is an enlarged vertical sectional side view showing a state where a semiconductor package using the package material shown in FIG. 1 is joined to a motherboard.

FIG. 4 is an enlarged vertical cross-sectional side view showing a first-stage pressurized state in the method of forming a heat dissipation slag having a cavity recess according to the present invention.

FIG. 5 is an enlarged vertical sectional side view showing a second-stage pressurized state in the method of forming a heat-dissipating slag having a cavity concave portion according to the present invention.

FIG. 6 is an enlarged vertical sectional side view showing a third-stage pressurized state in the method for forming a heat dissipation slag having a cavity concave portion according to the present invention.

FIG. 7 is an enlarged vertical sectional side view showing a fourth stage pressurized state in the method of forming a heat dissipation slag having a cavity concave portion according to the present invention.

FIG. 8 is an enlarged vertical cross-sectional side view showing a fifth-stage pressurized state in the method for forming a heat dissipation slag having a cavity recess according to the present invention.

FIG. 9 is an enlarged vertical sectional side view showing a state after completion of the fifth stage pressurization in the method for forming a heat dissipation slag having a cavity recess according to the present invention.

FIG. 10 is an enlarged longitudinal sectional side view showing the heat dissipation slag after being cut into individual pieces in the method for forming a heat dissipation slag having a cavity concave portion according to the present invention.

FIG. 11 is a plan view of a recess formed by the first-stage pressing shown in FIG. 4;

FIG. 12 is a plan view of a concave portion formed by the second-stage pressing shown in FIG. 5;

FIG. 13 is a plan view of a concave portion formed by the third-stage pressing shown in FIG. 6;

FIG. 14 is a plan view of a concave portion formed by the fourth stage pressing shown in FIG. 7;

FIG. 15 is a plan view of a concave portion formed by the fifth stage pressing shown in FIG. 8;

FIG. 16 is an enlarged vertical sectional side view showing a state in which oxidation preventing plating is applied to the entire surface of the heat dissipation slag shown in FIG. 10;

FIG. 17 is an enlarged vertical sectional side view showing a state in which oxidation preventing plating is applied only to the rear surface of the heat dissipation slag shown in FIG.

18 is an enlarged vertical cross-sectional side view showing a state where a required portion of the surface of the heat radiation slag shown in FIG.

19 is an enlarged vertical cross-sectional side view showing a state in which a required portion of the surface of the heat dissipation slag shown in FIG.

FIG. 20 is an enlarged vertical sectional side view showing a state where an antioxidant plating is applied to the back surface of the heat radiation slag shown in FIG. 10 and the remaining entire surface is a roughened surface.

FIG. 21 is an enlarged vertical cross-sectional view showing a state where the back surface of the heat radiation slag shown in FIG. 10 is plated for antioxidation, the required portion of the surface is partially plated for wire bonding, and the other surface is roughened. It is a side view.

FIG. 22 is an enlarged vertical sectional side view of a semiconductor package using a heat dissipating slag having a cavity recess formed by a conventional etching method.

FIG. 23 is an enlarged vertical sectional side view of a semiconductor package using a heat dissipating slag having a cavity recess formed by a conventional press working method.

[Explanation of symbols]

S-radiation slag 13-pressing die 1-metal plate 14-printed board 2-back surface 15-cavity opening 3-cavity recess 16-semiconductor package material 3a-recess 17-semiconductor chip 4-plane base 18-bonding wire 5 -Bottom surface 19-Resin mold 6-Side surface 20-Semiconductor package 7-Surface 21-Motherboard 8-Boundary part 22-Radiation fin 9-Boundary part 23-Adhesive 10-Antioxidant plating m-Depth 11-Partial plating t1 -Interval 12-Roughened surface t2-Interval

Claims (10)

[Claims] 1. A heat dissipating slag having a cavity concave portion, wherein the entire back surface 2 of the cavity concave portion 3 has a structure pressed and formed into a flat shape. 2. The cavity recess 3 has a predetermined depth m,
A cavity recess formed by press-forming at orthogonal corners at respective boundaries 8, 9 between a bottom surface 5 and a side surface 6 of the cavity recess 3 and a side surface 6 and a surface 7 around the recess. Heat dissipation slag with. 3. A cavity recess 3 having a predetermined depth m is flat on the entire back surface 2, and a bottom surface 2 of the cavity recess 3 is provided.
, Each boundary portion 8 between the side surface 6 and the side surface 6 and the surface 7 around the concave portion,
9. A heat dissipating slag having a cavity recessed portion, wherein the heat dissipating slag has a structure formed by pressing at orthogonal corners in 9. 4. The cavity recessed portion 3 is formed by pressing a plurality of times while supporting the back surface 2 of the metal plate 1 on a flat surface, so that the cavity recessed portion 3 has a predetermined depth m and the entire back surface 2 is formed. Each boundary portion 8, 9 between the bottom surface 2 and the side surface 6 of the cavity concave portion 3 and the side surface 6 and the peripheral surface 7 around the concave portion.
A heat dissipating slag having a cavity concave portion, wherein the heat dissipating slag has a structure formed at orthogonal corners. 5. The antioxidant plating 10 is applied only to at least the flat back surface 2.
A heat dissipating slag having a cavity recess according to claim 1. 6. A heat dissipating slag having a cavity recess according to claim 1, wherein the surface 7 around the cavity recess 3 is provided with a partial plating 11 capable of wire bonding. 7. A roughened surface 12 including a surface 7 including the inside of the cavity concave portion 3 and a side end surface.
Or a heat-dissipating slag having the cavity concave portion according to 5. 8. The surface 7 including the inside of the cavity recess 3 and the side end surface are roughened surfaces 12 except for a portion of the partial plating 11 on the surface 7 around the cavity recess 3 where wire bonding is possible. A heat dissipating slag having the cavity recess according to claim 1. 9. The metal plate 1 is pressed and formed in a plurality of times by press working in a state where the back surface 2 is supported by the flat base plate 4, so that the cavity concave portion 3 has a predetermined depth m and the bottom surface thereof. The boundary portions 8 and 9 between the side surface 5 and the side surface 6 and the side surface 6 and the surface 7 around the concave portion are formed at orthogonal corners, and the entire back surface 2 is formed to be flat.
A method for forming a heat dissipating slag having a cavity concave portion, wherein the heat dissipating slag is cut into individual pieces. 10. A cavity recess 3 having a predetermined depth m is formed at orthogonal corners at boundaries 8 and 9 between the bottom surface 5 and the side surface 6 and the side surface 6 and the surface 7 around the recess. A semiconductor package material having a structure in which a heat dissipating slag S having a structure formed entirely flat is joined to a printed board 14 having a cavity opening 15.