JP3200670B2 - Method of forming body part of resin molded package type electronic component - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a main body of a resin molded package type electronic component.
The present invention relates to a device in which thin burrs along a mold parting line do not remain around a molded main body.

[0002]

2. Description of the Related Art Many resin-mold packaged electronic components are manufactured in the form of a strip-shaped manufacturing frame called a lead frame, or such a strip-shaped frame that is continuous in the longitudinal direction. It is manufactured using a hoop-shaped manufacturing frame having a form.
Electronic components that can be manufactured using the manufacturing frame in this way include not only ICs, LSIs, transistors, diodes, light emitting diodes (LEDs), photodiodes, but also tantalum solid capacitors.

The manufacturing frame F is, for example, shown in FIG.
As shown in FIG. 2, side frame portions 2 having step feed holes 1 at equal intervals, lead portions 3 and 4 extending from the side frame portion 2 in the frame width direction, and a tip portion of one of the lead portions 3 Chip bonding part 5 provided in
And a wire bonding portion 6 for connecting a chip (not shown) bonded to the chip bonding portion 5 at the tip of the other lead portion. A plurality of pairs of leads 3 and 4 extending integrally are connected by a tie bar 7 parallel to the side frame 2 to maintain support rigidity. This type of manufacturing frame F has a common form as a frame used for manufacturing a so-called single-in-line type electronic component having a form in which two leads extend from the electronic component main body 8. Examples of such a single in-line type electronic component include a light emitting diode and a photodiode. In order to manufacture a single-in-line type transistor, three lead portions corresponding to each main body are required.

[0004] In the manufacture of electronic components using this type of manufacturing frame F, the following process steps are sequentially performed. First, in the chip bonding process, the electronic component chip, which is the functional center of the electronic component to be manufactured,
The manufacturing frame F is bonded to each chip bonding portion 5 while being stepped.

Next, in the wire bonding step,
The chip bonded as described above and the wire bonding portion 6 on the frame are connected by a gold wire or the like. Next, the frame F that has completed the above process is
The main body 8 is formed by enclosing the core of the electronic component, which is sent to the resin molding device and includes the bonded chip or the gold wire connecting the chip and the wire bonding portion, with the mold resin.

An apparatus for performing such a resin molding process has upper and lower molds which sandwich the manufacturing frame F. Each of the molds is formed with a cavity in which the electronic component body 8 to be molded is divided into two by a center plane in the thickness direction of the frame F, and the introduced manufacturing frame F is positioned at a predetermined position. In the state where the mold is clamped while being sandwiched between the upper and lower molds, a runner groove or a gate groove formed on the mold in a cavity space defined by a closed cavity of each mold, A thermosetting resin is injected. The thermosetting resin injected into the cavity space in this way is cured after a predetermined time has elapsed by the heat applied to the mold. When the resin cures in the cavity space in this way, the mold opening for opening the upper and lower molds is performed. Then, a step of removing the thin burrs remaining so as to extend along the gate breaking line and the mold parting line of the formed main body is performed.

In the above resin molding process,
The state immediately after the mold opening is shown in FIGS. As is clear from this figure, the resin cured in the gate groove connected to the runner groove of the mold is integrally connected to the top of the molded main body 8, and the mold Thin burrs 9 formed by curing the resin that has entered the minute gaps formed by the mating surfaces of the upper and lower molds remain in the peripheral portion along the ringing line.

In order to form a complete outer shape of the main body portion 8 by feeding the molten resin to every corner in the mold cavity space, the thin burr 9 needs a little more resin than the volume in the mold cavity space. It is inevitably formed to feed. Then, the gate resin 10 and the thin burrs 9 must be removed as a matter of course.

The removal of the gate resin 10 is cut and removed in a step called gate break. However, the thickness of the connecting portion of the gate resin 10 to the molded portion main body 8 is relatively thick, such as 0.1 to 0.2 mm. It may remain as a projection or crack on the cut surface, which adversely affects the appearance quality of the main body.

Next, the thin burr 9 is cantilevered from the periphery of the molded body 8 and is flexible because it is thin. Therefore, the thin burr 9 is removed by, for example, a shearing action using a punch. Is impossible. Therefore, the removal of such thin burrs 9 has conventionally been dissolved and eliminated by chemical treatment, blown off by a water jet,
Alternatively, the method has to be removed by liquid honing.

All of the above-mentioned methods of chemical treatment and removal of thin burrs by water jet or liquid honing require large-scale equipment. In particular, when removing by chemical treatment, a cleaning treatment step is further required. Becomes As a result, there is a problem that the manufacturing equipment becomes complicated and the manufacturing cost increases accordingly.

The present invention has been made under the above circumstances, and simplifies manufacturing equipment by completely eliminating the need for gate break processing and thin burr removal processing for a main body formed by a resin molding process. It is an object of the present invention to provide a new method of forming a main body of a resin-molded package-type electronic component, which can achieve a reduction in manufacturing cost and an improvement in appearance quality of a resin package main body of the electronic component. .

[0013]

Means for Solving the Problems To solve the above problems, the present invention takes the following technical means. That is, the present invention is a method of forming a main body of a resin-molded package-type electronic component by performing a resin molding process on a predetermined portion of a manufacturing frame using upper and lower molds sandwiching the manufacturing frame. As the manufacturing frame, a frame having a sub-frame portion surrounding a portion where the main body portion is to be formed is used, and the main body portion and the main body portion are formed in a region surrounded by the sub-frame portion. A step of integrally forming a rigidity removing portion connected to the entire periphery or a part of the peripheral portion through a continuous thin portion by injecting a resin through a gate provided in the rigidity removing portion, and Removing the rigidity removing portion from the main body portion by punching.

[0014]

According to the method of the present invention, not only the main body of the resin-molded package type electronic component to be manufactured but also the rigidity removing portion connected to the periphery of the main body through a thin portion by the resin molding process. Molded integrally. Therefore, the upper and lower molds to be used are formed with a main body cavity corresponding to the main body of the electronic component, and a rigidity removing cavity arranged so as to surround a part or all of the periphery thereof. Will be. Between the cavity for the main body portion and the cavity for the rigidity removing portion in one or both of the molds, the top portions are formed so as to oppose each other via a minute gap when the upper and lower molds are clamped. The ribs will be arranged. Then, resin is injected into the cavity space for the rigidity removing portion and the cavity space for the main body portion in the mold clamped state from a gate formed so as to be connected to the cavity for the rigidity removing portion.

Since the rigidity removing portion cavity space and the main body portion cavity space communicate with each other through a thin gap, even if the gate is connected to the rigidity removing portion cavity space as described above, As a result, the resin introduced into the rigidity removing portion cavity space is also supplied into the main body portion cavity space via the gap.

When the mold is opened after the above-described resin molding process, the rigid-removed portion is integrally formed around the electronic component body having a predetermined shape via a thin portion. Since the rigidity removing portion has literally rigidity, when a force in the frame thickness direction is applied to the rigidity removing portion by, for example, a die punch, the thin portion is easily cut by the shearing force.

Since the above-mentioned thin portion can have a very small thickness of, for example, 0.03 mm, even if the thin portion is sheared as described above, the appearance of the resin package main body is of a high quality. Is not a problem that worsens.

As described above, according to the method of the present invention, the appearance defect caused by cutting off the gate portion as in the conventional case is completely absent in the main body of the resin molded package type electronic component finally formed. Since no thin burrs in the form of cantilever are formed immediately after the mold is opened, there is no need for a process for removing such thin burrs, which has been very troublesome in the past. The result is a simplified result.

Further, the removal of the rigidity removing portion can be easily performed by combining with a tie bar cutting step in the form of a punching punch for cutting a tie bar connecting between the leads of the manufacturing frame. The implementation of the method of the present invention does not significantly complicate the manufacturing process.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the method of the present invention will be specifically described below with reference to the drawings. FIG. 1 shows an example of a manufacturing frame F having an additional configuration for implementing the method of the present invention in manufacturing an electronic component similar to that already described in the description of the related art. The manufacturing frame F includes a side frame portion 12 provided with feed holes 11 at equal intervals, a plurality of pairs of lead portions 13 and 14 extending from the side frame portion 12 in the frame width direction. A chip bonding portion 15 formed at the front end portion, a wire bonding portion 16 formed at the front end of each other lead portion 14, and the lead portions 13 and 1;
This is similar to the frame F for the conventional manufacturing method shown in FIG. 11 in that it has a tie bar 17 extending in parallel with the side frame portion 12 while connecting the four.

However, in the manufacturing frame F of this embodiment, as shown in FIG. 1, an electronic component core comprising the chip bonding portion 15 and the wire bonding 16 is formed in cooperation with the tie bar 17. This is different from the conventional frame F in FIG. 11 in that a sub-frame portion 18 surrounding a region to be formed in a rectangular shape is provided. The manufacturing frame F is manufactured by punching a thin metal plate having a thickness of about 0.2 mm, for example.

In the chip bonding step and the wire bonding step, the manufacturing frame F sequentially bonds a predetermined electronic component chip (not shown) to the chip bonding portion 15 in the same manner as described above. A wire bonding process is performed to connect the bonded chip to the wire bonding portion 16 on the frame with a gold wire or the like. Next, in the resin molding process, the above-described chip bonding portion 15, wire bonding portion 16 or a resin molding process for forming the main body 19 by covering the core of the electronic component consisting of the chip and the bonding wires bonded as described above with resin.
The resin molding step is performed by a first mold and a second mold that are arranged to face each other with the frame F interposed therebetween.

According to the present invention, as shown in FIG. 2, a resin package main body 19 enclosing the electronic component core is formed by the resin molding process using the first and second molds as described above. It is characterized by integrally forming a rigidity removing portion 21 connected to a part or the entire periphery of the main body portion 19 through a continuous thin portion 20.

In this embodiment, as shown in FIGS. 2 to 5, the thin portion 20 is formed along the mold parting line on the side or upper portion of the main body 19, and The rigidity removing portion 21 connected to the main body portion 19 through the thin portion 20 has a thickness equivalent to the thickness of the frame F and is formed in a planar area defined by the sub-frame portion 18. I have to.

A closed plane region surrounded by the line along the lower surface of the main body 19 and the tie bar 17 and the sub-frame portion 18 includes a thin portion 22 extending from the lower surface of the main body 19, A thick portion 23 which is integrally continuous and has the same thickness as the frame is formed near the frame members (tie bars 17, lead portions 13, 14 and sub-frame portion 18).

The configuration of a mold for obtaining a molded product as shown in FIG. 2 is as follows, for example. As shown in FIGS. 3 to 5, in the first mold (lower mold) 24, a main body cavity 26 is formed so as to be depressed from a planar mold reference surface 27. .

On the other hand, in the second mold (upper mold) 25, not only is the main body cavity 28 formed in a depressed shape,
Around this, a flat stepped portion 30 is provided via a rib 29.
Are formed. When the molds 24 and 25 are clamped, the mold reference surface 27 of the first mold 24 and the second mold 2
The flat step-down portion 30 of FIG. 5 is suitable for clamping the sub-frame portion 18 of the frame F. Therefore, the inner periphery of the sub-frame portion 18 and the flat opposing surfaces of the two dies 24 and 25 cooperate to form a space for forming the rigidity removing portion 21 having the same thickness as the thickness of the frame F. Will be formed. Thus, the second mold 25 is formed with a gate groove 31 communicating with the rigidity removing portion 21 molding space.

The ribs 29 formed in the second mold 25 so as to surround the cavity 28 for the main body, as shown in FIG.
In a state where the molds 4 and 25 are clamped, the first mold 24
Is formed to face the mold reference surface 27 with a slight gap of, for example, 0.03 mm.

Using the above-described frame F and the mold configuration,
When the molten resin is injected from the gate groove 31 in a state where the mold is clamped as shown in FIGS. 3 to 5, the molten resin first fills the rigid removal portion molding space, and then Through a small gap between the first mold 24 and the mold reference surface 27, the inside of the main body cavity space 2
6, 28, and will eventually fill all of the body cavity space. Thus, the molten resin that fills all the spaces between the molds is cured by the heat applied to the molds.

When the mold is opened after the resin is cured, a molded product as shown in FIG. 2 is obtained. That is, as described above, this molded product includes the thin portion 2 having the body portion 19 and the rigidity removing portion 21 formed in the region inside the sub-frame portion 18 and having the same thickness as the frame.
0 and the rigidity removing portion 2
1 is provided with the gate resin formed by the gate groove 31. The main body 19
Below the lower surface of the thin portion 22 as described above.
And the thick portion 23 are attached to a closed planar area surrounded by the frame member.

The molded product is then subjected to a tie bar cutting step and a sub-frame part cutting step for removing the tie bar 17 and the sub-frame part 18, and at the same time as these processing steps, a rigidity removing part surrounding the main body part 19 Unnecessary parts such as 21 are removed. First, in the tie bar cutting step, as shown in FIG. 6, the tip of the inner punch 32 capable of cutting off the tie bar portion 17a bridging the pair of lead portions 13 and 14 is extended to the vicinity of the main body portion 19. In advance, after supporting the frame F on a die (not shown),
The inner punch 32 is operated in the frame thickness direction. Then, as shown in FIG.
Along with a, the unnecessary resin attached to the tie bar 17a or the pair of lead portions 13 and 14 is removed.

Next, in the sub-frame portion cutting step, FIG.
As shown in FIG. 3, an outer punch 33 capable of cutting the tie bar portion 17b connected to the outside of the lead portions 13 and 14.
Is formed in a portal shape so as to overlap with the sub-frame portion 18 and the rigidity removing portion 21 formed inside the sub-frame portion 18, and the entire frame F is supported by a die (not shown). Is operated in the frame thickness direction. Then, as shown in FIG. 9, each tie bar portion 17b, 17b is cut from each lead portion 13, 14, and at the same time, the rigidity removing portion 21 is separated from the main body portion 19, so that the final form of the electronic component is obtained. Is obtained.

In this case, the main body portion 19 and the rigidity removing portion 2
1 is connected only by the thin portion 20 having a small thickness, and when a force is applied to the rigidity removing portion 21 in the frame thickness direction, the thin portion 20 is easily cut. As described above, the thin portion 20 can be made extremely thin, for example, 0.03 mm, and its width can be made extremely thin, of the same order. In such a state, the thin burr-like material hardly remains around the main body 19 to the extent that it can be visually recognized.

Further, the gate groove 31 for supplying the resin to the cavity space in the mold is not directly communicated with the cavity space for the main body, but is formed in the rigidity removing portion 21 to be finally removed. Since only the communication is performed, the conventional gate breaking step is not required, and the convex roots after the gate break remain on the outer surface of the main body 19, which deteriorates the appearance of the main body. Not even.

FIG. 10 shows an example in which the shape of the frame F to be used in the present invention is improved. In this example, a pair of left and right protruding pieces 34, 34 is sandwiched so as to sandwich the gate groove 31 of the second mold 25 from both sides in plan view.
It extends integrally from the sub-frame portion 18. Naturally, the protruding pieces 34, 34 end before the rib 29 that separates the formation space for the main body 19 and the rigidity removing part 21 from each other. Such a protruding piece 3
1 and 2, when the resin supplied from the gate groove 31 is regulated by the protruding pieces 34, 34, as shown in FIG.
As shown by a virtual line at 0, first, it is introduced into the cavity space for the main body portion, fills the cavity space for the main body portion, and then fills the space for forming the rigidity removing portion 21 via the thin portion 20. . Then, even if the setting of the supply amount of the resin is rough, the formation of a space such as a void or a pinhole in the molded main body 19 is effectively avoided, and the yield of the product is improved. To contribute.

Of course, the scope of the present invention is not limited to the embodiment described above.

Further, in the embodiment shown in FIG. 10, the protruding pieces 34, 34 are provided on the sub-frame portion 18 to restrict the flow of the resin introduced from the gate groove 31, but such a flow of the resin is restricted. Can be performed by providing a projection (not shown) on one of the molds, in addition to providing the protruding pieces 34, 34 on the sub-frame portion 18. Furthermore, in the embodiment, the description has been given on the assumption that the main body of the single-in-line type electronic component having two lead legs is formed. However, the type of the electronic component to be manufactured by using the method of the present invention is of course not limited. .

[Brief description of the drawings]

FIG. 1 is a plan view showing an example of a manufacturing frame used to carry out the method of the present invention.

FIG. 2 is an enlarged plan view of a molded product obtained immediately after performing a resin molding step by the method of the present invention using the manufacturing frame of FIG. 1;

FIG. 3 is a cross-sectional view showing a mold clamping state in the method of the present invention, and is a cross-sectional view taken along line III-III of FIG. 2;

FIG. 4 is an enlarged view of a main part of FIG. 3;

FIG. 5 is a cross-sectional view showing a mold clamping state in the method of the present invention, and corresponds to a cross-sectional view taken along line VV of FIG. 2;

FIG. 6 is a plan view illustrating an unnecessary portion removing step using an inner punch.

FIG. 7 is a plan view showing a state after the process of FIG. 6;

FIG. 8 is a plan view illustrating an unnecessary portion removing step using an outside punching punch.

9 is a plan view showing a state (final form of the electronic component) after the process of FIG. 8;

FIG. 10 is an explanatory view of a modified example of the method of the present invention.

FIG. 11 is a plan view showing an example of a manufacturing frame used in a conventional method.

FIG. 12 is a plan view showing a state after a molding process in a conventional method.

13 is a view in the direction of the arrow XIII in FIG. 12;

[Explanation of symbols]

 F Manufacturing frame 19 Body 20 Thin part 21 Rigidity removing part 24 First mold 25 Second mold 31 Gate groove

Claims (1)

(57) [Claims] 1. A method of forming a main body of a resin-molded package-type electronic component by performing a resin molding process on a predetermined portion of a manufacturing frame using upper and lower molds sandwiching the manufacturing frame. The main body part should be formed as the manufacturing frame.
Use the one provided with the sub-frame portion surrounding the place, in the region surrounded by the sub-frame portion, the main body portion, a thin portion continuous to the entire circumference or a part of the periphery of the main body portion A resin removing portion connected to the rigidity removing portion through a gate provided in the rigidity removing portion, and a step of punching out the rigidity removing portion from the main body portion. A method of forming a main body of a resin mold package type electronic component.