JP3002174B2 - Electronic component package and method of forming the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a package comprising a stiffener or a heat spreader in which a storage portion for storing an electronic component is formed in a metal plate.

[0002]

2. Description of the Related Art With the miniaturization of information devices in recent years, the packages of electronic components typified by semiconductor integrated circuits and hybrid circuits have also been reduced in size and density . As a technique for supporting these, a stiffener having a storage portion for storing electronic components has come to be used. Since the stiffener requires rigidity, a metal plate is used. Further, in the above-mentioned semiconductor integrated circuit, a heat spreader is used in combination with a heat spreader for heat dissipation because the amount of heat generation increases with the increase in density. These are generally referred to as packages.

[0003] Further, as a configuration of a package, a heat spreader having a function as a cover is adhesively bonded to a stiffener accommodating electronic components. FIG. 4 shows an example. That is, the stiffener 30 has a concave portion formed only on one surface of the metal plate to form a storage portion 30a, and an electronic component 31 formed of a semiconductor integrated circuit is stored in the storage portion 30a. Then, a plurality of terminals (not shown) of the electronic component 31 and a plurality of terminals of a printed wiring board (not shown) provided on the upper surface of the stiffener 30 are connected by bonding wires or the like.

Further, the upper surface of the stiffener 30 is covered with a heat spreader 32 so as to cover the storage portion 30a. The heat spreader 32 is also formed of a metal plate having a good heat conductivity, and prevents the heat of the electronic component 21 from being generated. The heat is dissipated and the electronic components 31 and the bonding wires are protected.

[0005]

However, since the stiffener 30 and the heat spreader 32 described above are usually subjected to a punching process by a known press, the stiffener 30 and the heat spreader 32 need not be punched like a heat spreader 32 shown in a circle in FIG. Is formed at the opposite end 32a with a burr 33 or is shaped like a knife edge. However, the end 32a of the heat spreader 32 is gripped by the hand 34 when performing an operation of covering the upper surface of the stiffener 30. Therefore, there is a risk that the burr or knife edge of the end 32a may damage the hand 34. There was a problem with work safety. Also, manufacture stiffeners 30 and heat spreaders 32
When even one another mutually damaging the burr 33 and the knife edge is by contact, there is a problem causes deterioration of value as a product.

As a means for solving these problems, burrs are usually eliminated by using a barrel. However, in the stiffener 30 and the heat spreader 32 which require high-precision flatness, the burrs are deformed by an impact at the time of operating the barrel. The required quality is obtained, for example, because the tiny stones and abrasives used in the barrel adhere and remain even after cleaning, so they cannot be used as packages for electronic components that require fine precision. There is a problem that cannot be solved. As another means, there is a method of chamfering a burr or a knife edge end 32a. However, in addition to an increase in the number of steps, a long time is required for the processing, which inevitably increases the cost. There is a problem. Further, there is a problem that a required flatness is hindered because stress is applied to the work at the time of chamfering.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and provides an electronic package capable of providing a package capable of ensuring work safety and having an outer edge corner formed into a substantially arc shape at the time of punching. An object of the present invention is to provide a method for processing a component package.

[0008]

In order to achieve the above object, according to the first aspect of the present invention, there is provided a storage device for storing electronic components.
For electronic components having a metal lid for covering a part
A half-punch punch and the half-punch punch
The first die with a slightly smaller similar hole
Using one side of the metal plate installed on the first die
Press the above half punch to perform half punching
Thus, a concave portion is formed on one surface and the upper surface is formed on the other surface.
After forming a similar convex part slightly smaller than the concave part,
Punch pressed from the convex side and punch larger than the concave
Using a second die having a hole, the recess is formed with the hole
Put the metal plate on the second die so that it is more inside
Install and hit the convex with the punch from the convex side
Form the above lid with the outer edge corners pulled out and rounded into a substantially arc shape
Characterized in that it.

The invention described in claim 2 is the same as the invention described in claim 1.
Wherein the protrusion formed on the other surface side of the metal plate
The substantially arc-shaped portion at the outer edge corner of the part is formed during the half blanking
The substantially arc-shaped portion formed on the one surface side is formed by the punch
It is characterized in that it is formed at the time of punching .

[0010] The invention according to claim 3 provides an electronic component.
Electronic component provided with a metal lid that covers a storage unit to be stored
A package for use according to claim 1 or claim 2.
It is characterized by being formed by a forming method .

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a package according to the present invention will be described in detail based on an embodiment shown in the drawings. FIG.
Shows an example of a package for a semiconductor integrated circuit to which the package according to the present invention is applied. The package 1 includes a stiffener 2 and a heat spreader 3 as a lid . The stiffener 2 is made of a metal material, has rigidity, matches the coefficient of thermal expansion with a wiring board or the like described later, has good thermal conductivity, and
Copper alloy, stainless steel, or aluminum is used as a metal material that can be subjected to plastic working. At the center of the stiffener 2, a storage section 2b formed of a substantially rectangular through hole is formed.

Further, one side of the stiffener 2 has a TA
A wiring board 4 made of B, a flexible printed board, a normal printed board, or the like is bonded and fixed with an adhesive. A window hole having a size substantially the same as that of the housing portion 2b is formed in the wiring board 4, and a number of terminal portions (not shown) having a line width and a pitch of about 37 nm are formed by printed wiring on the periphery of the window hole. ing. Printed wiring is provided between this terminal portion and an external terminal (not shown) provided on the outer edge side of the wiring board 4.

Further, a storage section 2 formed in the stiffener 2
b stores a chip of the semiconductor integrated circuit 5. The semiconductor integrated circuit 5 is fixed to the heat spreader 3 bonded to the other surface of the stiffener 2 by an adhesive in a surface bonding state. What is important in this adhesive fixing is that bubbles are not formed between the semiconductor integrated circuit 5 and the bottom of the concave portion. If the semiconductor integrated circuit 5 generates heat during operation, or if it is heated in the process of assembling the package 1 with the semiconductor integrated circuit 5 and the wiring substrate 4, the heat expands bubbles and may cause the semiconductor integrated circuit 5 to peel off. There is.
For this reason, the central portion of the heat spreader 3 is formed with a warpage of 30 nm or less and a flatness.

On the upper surface of the semiconductor integrated circuit 5, a large number of terminals (not shown) having the same line width and pitch as the terminal portions formed on the wiring board 4 are provided. The terminal portion of the wiring board 4 of the semiconductor integrated circuit 5 is a bonding wire 6
Are electrically connected by Further, a sealing agent 7 is injected into the storage portion 2b of the stiffener 2 to seal the semiconductor integrated circuit 5 and the bonding wire 6.

In order to mount the integrated circuit component configured as described above on a circuit board of an electronic device (not shown), solder balls 8 are arranged on external terminals provided on the outer edge of the wiring board 4, and By heating the circuit board temporarily fixed at a predetermined position, the solder balls 8 are melted to electrically connect the wiring board 4 and the circuit board of the electronic device. On the other hand, when the semiconductor integrated circuit 5 generates heat during operation, the heat is spread from the heat spreader 3.

The heat spreader 3 shown in FIG. 1 described above is formed by punching a metal plate by pressing or the like, and as shown in an enlarged view in a circle, the outer edge corner 3a is rounded in a substantially arc shape. I have. The heat spreader 3 has good thermal conductivity and is made of a copper alloy, stainless steel, or aluminum as a metal material that can be subjected to plastic working. Both corners of the portion 3a are formed in a substantially arc shape.

As a result, no burr or knife edge is generated at the corner 3a when the normal punching is performed, which has been conventionally regarded as a problem. Can be prevented beforehand, and safe work can be achieved. Also, in the manufacturing process of the heat spreader 3, damage to the other heat spreaders 3 due to the burrs and knife edges can be eliminated, and the product value can be increased.

On the other hand, the stiffener 2 is also a heat spreader 3
In the same manner as described above, the outer corners 2a are rounded in a substantially arc shape by applying a special punching process to be described later. Therefore, burrs and knife edges do not occur at the corners 2a, so that safety during operation can be ensured, and damage to other stiffeners during manufacturing can be prevented. The stiffener 2 does not necessarily need to form the corner 2a in a substantially arc shape.

FIG. 2 shows a second example of the package. The stiffener 12 has a concave portion 12a formed in the center and a bottom portion 12b having a bottom surface having a predetermined thickness. It is formed in a cavity mold. Then, the chip of the semiconductor integrated circuit 5 is housed in the recess 12 a of the stiffener 12, and at least the recess 1
A heat spreader 13 for covering 2a is provided. The heat spreader 13 in this example has the outer edge corner 13 as in the enlarged example shown in the circle, as in the above-described example.
a is rounded in a substantially arc shape. Also, stiffener 12
Similarly to the heat spreader 13, the outer corners 12c are rounded in a substantially arc shape by performing a special punching process described later on the outer shape. Also in this example, since burrs and knife edges do not occur, safety during assembly work can be maintained, and effects such as being able to prevent damage to other heat spreaders and the like in the manufacturing process are the same as those of the above example. The same is true.

Next, the heat sp
A special punching method for the redder 3 or the stiffener 2 will be described with reference to FIG. 3A to 3D show the processing steps. For example, a copper alloy, stainless steel, aluminum, or the like is selected as a material of the metal plate 10 shown in FIG.

As shown in FIG. 3A, the metal plate 10 is placed in a state where it is positioned on a first die 20 of a press machine, and a half punch 21 having a predetermined shape is lowered from one surface side. The metal plate 10 is half-cut. As a result, the metal plate 1
0, a concave portion 10a is formed by pressing on one side,
A projection 10b is formed on the other surface side. At this time, since the shape of the half blanking hole 20a formed in the first die 20 is set to a similar shape slightly smaller than the shape of the half blanking punch 21, the shape of the convex portion 10b is , Are formed in a similar shape slightly smaller than the concave portion 10a. Then, when the half blanking process is performed, as shown in the enlarged view of the circle in FIG. 3A, when the corner portion 10c of the outer edge of the convex portion 10b is sagged, the corner portion 10c becomes substantially arc-shaped. It is formed. At the time of the half blanking, it is desirable that the pressing plate 23 urged upward by the spring 22 be brought into contact in order to secure the flatness of the concave portion 10a.

The metal plate 10 half-punched as described above
Next, the processing shown in FIGS. 3B to 3D is performed. The press die used for this processing has a concave portion 24a for placing the half-blanked metal plate 10 in a positioned state, and a similar shape larger than the concave portion 10a formed by the half-blanking process. At least a second die 24 having a formed hole 24b and a punch 25 having a similar shape smaller than the convex portion 10b are provided. still,
Reference numeral 26 denotes a pressing plate for pressing and pressing around the convex portion 10b.

Then, the half-blanked metal plate 10 is
As shown in FIG. 3B , the concave portion 10a is formed with the hole.
The concave portion 24a of the die 24 is located inside the
Place it in the state where it is positioned. Thereafter, the punch 25 is lowered to press the convex portion 10b of the metal plate 10, and the convex portion 10b
Is pressed down so that the convex portion 10b is depressed and punched out at the same time as shown in FIG . Further, the lowering of the punch 25 is continued, and as shown in FIG.
Push down below b. As a result, heat spreader 3
Is formed. As described above, the outer edge of the heat spreader 3 is sagged during the punching process from the depression of the projection 10b, and the corner 3a is formed in a substantially arc shape.

The human <br/> over preparative spreader 3 as this way the cover body formed, when forming the convex portion 10b by half die cutting the metal plate 10 made of a material, the outer angle portion of the convex portion 10b Is formed in a substantially arc shape, and the upper
By intentionally sagging the corners on the side opposite to the outer edge corners and forming the outer edge corners in a substantially arc shape, the outer edge corners on both surfaces can be made substantially arcuate.

As a result, the heat spreader 3 is free from burrs and knife edges.
When performing the work of covering the heat spreader 3 on the upper surface of the stiffener 2, there is no danger of damaging the hands, and the safety of the work can be ensured. Further, when manufacturing the stiffener 2 and the heat spreader 3, the outer edges of both sides Since the corners are rounded in a substantially arc shape, mutual damage due to contact is prevented beforehand, and the value as a product can be enhanced. Also, the need for a deburring step using a barrel or the like is eliminated, and the process can be shortened. In addition to cost reduction, the required flatness can be secured because the stress on the work is greatly reduced. It has become possible to meet the needs that the packaging industry of various kinds of electronic components has been demanding.

In the above-described forming method, a method of continuously performing the punching and the punching- down processing on the metal sheet 10 which has been half- punched has been exemplified. To further improve the flatness, it steps pushes her a step of punching out the protrusions 10b formed by half blanking the metal plate 10
Each may be separated into a single step. That is, the punching process
Then, the protrusion 10b is punched out and then pushed back once so as to be flush with the surrounding metal plate 10 to house the protrusion 10b (heat spreader 3) in the metal plate 10, and in this state, the metal plate Flat pressing process for entire 10
Then, as shown in FIG. 3 (D), the heat spreader 3 is
b. As described above, the flatness of the heat spreader 3 can be improved by performing the flat pressing once.

In the embodiment described above, a semiconductor integrated circuit such as a CPU is illustrated as an electronic component housed in the recess of the package. However, other electronic components such as a hybrid circuit, an inductor chip, or a register array are used. Is also good. Further, the present invention can be applied to the cavity type heat stiffener integrated stiffener of the cavity type shown in FIG. 2 or an unillustrated squeeze type, and can also be applied to a cover covering the integrated stiffener. Also, in the above-described embodiment, the outer edge corners of both surfaces are made almost the same, but the arc of the outer edge corner of the surface particularly required for performing the work is enlarged, and the various surfaces are reduced. A difference may be provided in the size to be blunted, and the present invention is not limited to these embodiments, and can be variously changed without departing from the present invention.

[0028]

As described above, according to the electronic component package of the present invention, the outer edge of the package made of the stiffener or the heat spreader is formed by the metal plate as described above.
Since blunted in a substantially arcuate shape by forming methods, the thickness
Burrs and knife edges are reliably generated even on thin metal plates.
Raw and prevent, at the time of work to deal with the heat spreader and the stiffener, the safety of the work is Ru can be secured. Furthermore, those
The in manufacturing, it is possible to prevent mutual damage from occurring due to contact. Further, since the deburring step is not required, the step can be shortened, and the required flatness can be ensured because the stress is greatly reduced in addition to the cost reduction.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an electronic component package according to the present invention.

FIG. 2 is an exploded sectional view showing another electronic component package according to the present invention.

FIGS. 3A to 3D are process explanatory views showing a package forming method of the present invention.

FIG. 4 is a cross-sectional view showing a conventional package and a working mode.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 package 2 stiffener 2a corner 3 heat spreader (lid) 3a corner 5 semiconductor integrated circuit 6 terminal 10 metal plate 10a recess 10b protrusion 20 first die 20a half hole 21 half hole punch 24 second die 24a hole Hole 25 punch

Claims (3)

(57) [Claims] 1. A method of forming an electronic component package having a metal cover for covering a storage portion for storing an electronic component, comprising: a half punch; and a similar half punch having a shape slightly smaller than the half punch. Using a first die having holes, pressing the half punch from one surface side of the metal plate installed on the first die to perform a half punching process, thereby forming a concave portion on the one surface. Along with forming a convex portion having a similar shape slightly smaller than the concave portion on the other surface, the concave portion is formed by using a punch pressed from the convex portion side and a second die having a punched hole larger than the concave portion. The lid in which the metal plate is placed on the second die so as to be inside the punched hole, and the convex portion is punched out from the convex portion side with the punch so that the outer edge corner is rounded in a substantially arc shape. For electronic parts characterized by forming a body The method of forming the package. 2. A substantially arc-shaped portion formed on the other surface side of the metal plate at an outer edge corner of the convex portion at the time of the half blanking process and formed on the one surface side. 2. The punch is formed at the time of punching with said punch.
4. The method for forming an electronic component package according to claim 1. 3. An electronic component package comprising a metal lid for covering a storage portion for storing an electronic component, wherein the electronic component package is formed by the forming method according to claim 1. Package for electronic components.