JP2977889B2 - IC resin sealing method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for resin-sealing an electronic component such as an IC provided on a circuit board with a thermosetting resin according to the present invention.

[Conventional technology]

In recent years, the development of small and thin electronic devices such as IC cards and portable electronic computers has been rapidly progressing. In such electronic devices, it is required that electronic components such as IC chips housed therein are mounted in a small and thin shape in order to maintain a small and thin shape. In the following description, the conventional IC
The example is a card and an IC module stored in the IC card.

FIG. 6 is an external view of a conventional IC card, FIG. 7 is a sectional view taken along line AA of FIG. 6, FIG. 8 is an external view showing a card base of the IC card, and FIG. FIG. 10 is a sectional view showing a sealing method, and FIG. 10 is an external view showing a conventional IC module.

In FIG. 6, the IC card 30 has a plurality of data input / output terminals 33a on the surface, and the overall shape is determined by the plastic card base 31 shown in FIG.

As shown in FIG. 7, the card base 31 has a recess 31
a is formed, and in this concave portion 31a, an IC chip 43 such as a CPU and a memory chip is bonded to the circuit board 33,
An IC module 32 having a resin sealing portion 34 formed on an IC chip 43 is housed and fixed.

The IC card 30 is configured by storing and fixing the IC module 32 in the concave portion 31a of the card base 31, and then covering both sides of the card base 31 with the oversheet 35. In addition, overseat 35
Are provided with various patterns 35a.

The relationship between the elements shown in FIG. 7 is as follows.
The top surface of the sealing portion 34 is in contact with the bottom surface of the concave portion 31a to regulate the thickness, and the outer periphery of the circuit board 33 is engaged with the inner periphery of the concave portion 31a to regulate the planar position.

Generally, the IC card 30 has a thickness of about 0.8 mm, and needs to have a certain degree of flexibility to withstand bending in order to prevent the IC card 30 from being broken by an external force received when being carried or used. Therefore, the flexibility of the card base 31 is of course necessary, and the IC module 32 is made of a resin having high rigidity and excellent moisture resistance so that the bending of the IC chip 43 and disconnection of the bonding wire do not occur. It is necessary to seal with.

Moreover, as described above, the upper surface of the sealing portion 34 abuts against the bottom surface of the concave portion 31a of the thin card base 31, and the thickness of the sealing portion 34 is regulated, so that the outer shape of the sealing portion 34 is reduced so that the thickness does not vary. Must be managed. Therefore, in the potting sealing method of dropping the molten resin onto the IC chip, which has been frequently used in the past, since the thickness of the sealing portion 34 tends to vary,
The sealing portion 34 of the IC module 32 was optimally formed by a transfer molding method using a thermosetting resin having good shape accuracy and high rigidity.

With reference to FIG. 9, a conventional method of resin sealing an IC chip by transfer molding will be described.

In FIG. 9, reference numeral 36 denotes a lower mold, and an IC is provided on an upper surface thereof.
The circuit board 33 to which the chip 43 is bonded is mounted.
Reference numeral 37 denotes an upper mold having a cavity 37a formed therein. The upper mold 37 is fixed to the lower mold 36 so that the cavity 37a covers the upper surface of the IC chip 43.

A gate groove 39a and a runner groove 40a are formed in the upper mold 37, and the mating surface of the upper mold 37 and the lower mold 36 and the upper mold
In the mating surface of 37 and circuit board 33, resin 38 is cavity
The runner 40 and the gate 39 leading to 37a are configured, and a so-called side gate transfer molding method is realized.

The sealing portion 34 applies the heated and molten resin 38 to the plunger 41.
An IC module formed by filling the cavity 37a with the resin 38 that has been injected into the runner 40 and passed through the gate 39, and after the resin 38 has hardened, the upper mold 37 is removed to form the sealing portion 34. 32 is removed.

However, since the gate 39 is formed on the mating surface of the upper mold 37 and the circuit board 33 as described above, the gate is connected to the sealing portion 34 on the circuit board 33 of the IC module 32 as shown in FIG. There is a problem that the remaining 34a is formed.

Generally, the card substrate 31 is made of a polyvinyl chloride sheet (hereinafter referred to as PV
A concave portion 31a in which the sealing portion 34 of the IC module 32 is housed.
Are formed by counterbore processing. Therefore, when the remaining gate 34a is formed in the IC module 32 as shown in FIG. 10, a groove 31b for accommodating the remaining gate 34a must be formed in the card base 31 as shown in FIG. Therefore, counterbore processing was very troublesome.

Therefore, in order to prevent the groove 31b from being formed in the card base 31, conventionally, the remaining gate 34a on the circuit board 33 has been mechanically removed.

However, the remaining gate 34a is on the surface 33c of the circuit board 33.
As shown in FIG. 10, when the gate rest 34a 'shown by a dashed line is broken off, the force is reduced to 3
4a, there is a problem that the surface 33c of the circuit board 33 is peeled off, and in some cases, even the circuit pattern is cut off.

Therefore, in order to eliminate the need to form the groove 31b in the card base 31, a transfer molding method capable of sealing the IC chip 32 without forming the gate residue 34a on the circuit board 33 of the IC module 32 has been desired. .

However, Japanese Patent Publication No. 61-46049 proposes a resin encapsulation method that solves the disadvantages of the conventional resin encapsulation method.

This resin sealing method will be described with reference to FIGS.

FIG. 11 is a sectional view showing another conventional resin sealing method, and FIG.
FIG. 11 is an external view of a cavity plate used in the resin sealing method of FIG. 11, and FIG. 13 is an external view of an IC module manufactured by the resin sealing method of FIG.

In this resin sealing method, the cavity plate 42 shown in FIG. 12 is used. A cavity 42b for determining the shape and position of the sealing portion in the cavity plate 42,
Positioning holes for setting this plate 42 on the mold
42a is formed.

In FIG. 11, 37 is an upper mold, 36 is a lower mold having a runner groove 40 and a gate groove 39, 33 is a circuit board on which an IC chip 43 is mounted, and a cavity plate 42 is a cavity plate.
The circuit board 33 is received between the upper mold 37 and the lower mold 36 so as to surround the IC chip 43 at 42b.

Then, by injecting the molten sealing resin 38 with the plunger 41, the sealing resin 38 is inserted into the cavity 42b of the cavity plate 42 through the runner groove 40 and the gate groove 39.
Is filled.

In other words, this resin sealing method uses a runner groove 40 provided on the upper surface of the lower mold 36 to be a mating surface with the cavity plate 42,
This is a so-called side gate transfer molding method in which a sealing resin is filled into the cavity 42b through the gate groove 39.

According to this resin sealing method, the gate groove 39 and the runner groove 40 into which the sealing resin 38 is guided are formed in the cavity plate 42.
As a result, the gate rest 34a on the circuit board 33 does not exist as shown by the dashed line in FIG. 13, and the card base as shown in FIG. The formation of the groove 31b in the 31 is not required.

However, in the resin sealing method using the cavity plate 42, there is a problem that the working process becomes complicated.

That is, since the thermosetting resin has a small heat shrinkage rate and poor release from the mold, the sealing resin is filled in the cavity of the cavity plate which determines the shape of the sealing portion, and the electron on the circuit board is removed. When the component is sealed, the sealing portion and the cavity plate remain attached after the sealing resin is cured. Therefore, when removing the circuit board on which the sealing portion is formed, once remove the circuit board with the cavity plate attached from the mold, separate the circuit board and the cavity plate by hand, and then re-use the cavity plate. It was necessary to attach to the mold. Therefore, it is difficult to automate a series of operations, and the operations are performed manually, resulting in very low production efficiency.

Therefore, the present applicant has proposed a resin sealing method which has solved the above-mentioned disadvantages in Japanese Patent Application Laid-Open No. Hei 2-1397. This method will be described with reference to the drawings. 14 (a) and (b) are cross-sectional views of main parts showing another conventional resin sealing method, and FIG. 15 is an external view of main parts of the resin sealing method shown in FIG. 14 (a). .

In FIGS. 14 (a), (b) and 15, reference numeral 44 denotes an upper mold having a cavity 44a, 45 denotes a lower mold for mounting a circuit board 33 on which an IC chip 43 is mounted, 50 Is the lower mold 45
In FIG. 15, a gate groove 50a is formed on the upper surface side as shown in FIG. Further, the lower mold 45 has a sealing resin 49 to be described later.
And knockout pins 46, 47, 48 for removing the circuit board 33 from the lower mold 45, and push-up pins 52 for rotating the gate plate 50 upward.

As shown in the figure, the gate plate 50 is connected to the side surface of the cavity 44a of the upper mold 44 with the gate groove 50a facing upward, and a side gate 54 is provided between the gate groove 50a and the upper mold 44.
And a runner 53 between the upper mold 44 and the lower mold 45.
Are respectively constituted.

Next, the resin sealing process will be described. The sealing resin 49 injected by a plunger (not shown)
The cavity 44a is filled through the side gate 54 to seal only the periphery of the IC chip 43.

Next, when the sealing resin 49 filled in the cavity 44a is cured and the sealing portion 34 is formed on the circuit board 33, the upper mold 44 is separated upward. Then, as shown in FIG. 14 (b), the knockout pin 48 is first projected upward, and the runner 5
3. Remove unnecessary sealing resin 49 cured by side gate 54. At this time, as shown in FIG. 15, the gate groove 50a is
Since it is tapered toward 3, only a very small gate residue remains on the side surface of the sealing portion 13.

Next, as shown in FIG. 14 (b), the push-up pins 52 are driven upward, and the gate plate 50 is rotated upward to be separated from the upper surface of the circuit board 33. And knockout pin 4
By projecting 6, 47 upward, a completed IC module can be taken out from the lower mold 45.

[Problems to be solved by the invention]

However, the resin sealing method using the gate plate as described above has the following problems.

That is, since the plate-shaped gate plate is connected to the side surface of the cavity of the upper mold filled with the sealing resin, if the alignment between the upper mold and the gate plate is poor, the sealing resin leaks from the connection portion. However, there is a problem that the outer shape of the sealing portion is deteriorated.

Further, as shown in FIG. 15, the side surface of the cavity of the upper mold in contact with the gate plate (that is, the contact portion between the gate plate 50 and the sealing portion 34 seen in FIG. 15) becomes very thin.
Due to repeated contact between the upper mold and the gate plate, there is a problem that the wear becomes severe and the life of the mold is shortened.

The object of the present invention is to solve the above-mentioned problems, and in a side gate transfer molding method, transfer marks can be continuously formed without leaving a gate mark on a resin substrate on which resin sealing is performed. An object of the present invention is to provide a method of resin sealing an IC chip in which the external shape of a sealing portion is kept clean and a mold is less worn.

[Means for solving the problem]

The resin sealing method of the present invention for achieving the above object is as follows. That is, a circuit board in which an IC chip is mounted on a resin substrate having an electrode pattern is sandwiched by a molding die having a cavity and a gate groove, and a sealing resin is filled from the gate groove into the cavity. In the method of resin-sealing the IC chip inside away from the periphery of the resin substrate, a sealing piece for closing a part of the opening of the gate groove is fitted into the gate groove of the molding die. Filling the sealing resin into the cavity from between the sealing piece and the gate groove, and moving the sealing piece after the sealing resin is cured to form a sealing portion. Removing an unnecessary sealing resin from the stop portion.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 (a) and 1 (b) are cross-sectional views of an essential part showing a method of resin sealing an IC chip according to a first embodiment of the present invention, and FIG. 2 is a sectional view of the IC chip according to the first embodiment of the present invention. FIG. 3 (a) is a cross-sectional view taken along the line BB of FIG. 1 (a), showing a main part external view showing a resin sealing method.

First, the configuration of each unit will be described with reference to the drawings. Numeral 1 denotes an upper die, as shown in FIG. 2, a cavity 1a for determining the shape of the sealing portion, a gate groove 1b formed by being connected to one side surface of the cavity 1a, and a guide, as shown in FIG. A hole 1d is provided, and a pot 1c for charging the sealing resin 9 is provided so as to penetrate the upper and lower surfaces. 3 is a pot
This is a plunger for injecting the sealing resin 9 charged in 1c. Reference numeral 2 denotes a lower die which abuts on the lower surface of the upper die 1, and a substrate fixing portion 2 for mounting a resin substrate 5 described later.
a, Runner groove 2 for guiding sealing resin 9 to gate groove 1b
b, Guide pins 4 for positioning the resin substrate 5 are provided. Reference numeral 5 denotes a resin substrate having a metal wiring pattern (not shown), on which an IC chip 6 is bonded to form a circuit substrate. Reference numeral 7 denotes a sealing piece, which is provided on the lower mold 2 so as to be driven up and down by a driving device (not shown). As shown in FIG. 3 (a), the sealing piece 7 has a trapezoidal shape in which both side surfaces are inclined, the tip of which is placed on the resin substrate 5, and the gate groove 1b of the upper mold 1 is formed.
Is inserted into the gate groove 1b so as to block a part of the opening 1e, and the upper surface of the resin substrate 5 corresponding to the gate groove 1b is shielded. Reference numeral 8 denotes an ejector pin for extruding the resin substrate 5 from the substrate fixing portion 2a of the lower mold 2.

Next, the resin sealing step of this embodiment will be described. First, as shown in FIG. 1A, the resin substrate 5 to which the IC chip 6 is bonded is set on the substrate fixing portion 2a of the lower mold 2 while being inserted into the guide pins 4. Next, the sealing piece 7 is set at a predetermined position on the upper surface of the end of the resin substrate 5. Then, the upper mold 1 is pressed against the upper surface of the lower mold 2 so that the cavity is formed.
In step 1a, the IC chip 6 is covered at an inner position away from the peripheral edge of the resin substrate 5, and a sealing piece 7 is fitted into the gate groove 1b to close the resin substrate side of the opening 1e of the gate groove 1b. In this state, the sealing resin 9 is put into the pot 1c, heated and melted, and the sealing resin 9 melted by the plunger 3 is injected into the mold as shown in FIG. groove
The sealing resin 9 that has passed through 2b is filled into the cavity 1a through the space between the gate groove 1b and the sealing piece 7. That is, the gate groove
The sealing resin 9 passing through 1b is filled in the cavity 1a apart from the upper surface of the resin substrate 5. When the sealing resin 9 is cured, the upper mold 1 is separated from the lower mold 2 as shown in FIG. As shown in the figure, a sealing portion 10 formed by a sealing resin 9 seals the IC chip 6 at a position inside the resin substrate 5 away from the peripheral edge, and furthermore, the sealing hardened in the gate groove 1b. All of the resin 9 remains on the upper surface of the sealing piece 7.
Therefore, as shown in FIG. 1B, by pushing up the sealing piece 7, that is, by moving the sealing piece 7, unnecessary sealing can be easily performed from the sealing portion 10 formed on the resin substrate 5. The resin 9 can be removed. Finally, by ejecting the ejector pins 8 upward, the resin substrate 5 is taken out from the basic fixing portion 2a.

In this embodiment, as shown in FIG.
Although the sealing resin 9 is filled in the cavity 1a through the entire upper surface of the above, the present invention is not limited to this, and various modifications are possible. That is, as shown in FIGS. 3 (b) to 3 (d), in FIG. 3 (b), the width of the bottom surface of the gate groove 1b through which the sealing resin 9 passes is reduced and the sealing piece 7 is fitted to thereby reduce the flow rate. The pouring position is adjusted. In FIG. 3 (c), a groove 7a is also formed on the upper surface of the sealing piece 7, and the gate groove is formed.
The cavity 1a is filled with the sealing resin 9 from between the groove 1b and the groove 7a. Further, as shown in FIG. 3 (d), it is possible to form two grooves 7b and 7c on the upper surface of the sealing piece 7. In this case, as shown in the external view of the main part of FIG. 4, the sealing resin 9 flowing through the two grooves 7b and 7c does not directly hit the IC chip 6 but flows to both sides of the IC chip 6, so that the bonding wire Deformation can be prevented.

Next, a second embodiment of the present invention will be described with reference to FIGS. 5 (a) and 5 (b). The same components as those in the first embodiment are given the same reference numerals, and the description is omitted. A feature of the present embodiment, which is different from the first embodiment shown in FIGS. 1A and 1B, is that the sealing piece 11 is vertically driven obliquely with respect to the lower mold 2. That is, as shown in FIG. 5 (a), the sealing resin 9 is filled into the cavity 1a from between the gate groove 1b of the upper mold 1 and the sealing piece 11 to form the sealing portion 10. Then, as shown in FIG. 5 (b), the upper mold 1 is separated from the lower mold 2 and the sealing piece 11 is pushed upward to thereby form the sealing portion 10
Unnecessary sealing resin 9 can be removed. At this time,
As shown in FIG. 5 (b), the sealing piece 11 is pushed obliquely upward to the right, so that the sealing piece 11 moves to a position not overlapping with the substrate fixing part 2a, and the resin substrate 5 is moved to the substrate fixing part 2a of the lower mold 2. Can be easily attached and removed from above,
Automation of continuous molding is further facilitated.

In the above embodiments, the IC module of the IC card has been described as an example. However, the present invention is not limited to this. For example, another resin such as a resin-sealed PAC (pad array carrier) may be used. The present invention can also be applied to a sealed semiconductor device.

〔The invention's effect〕

As is apparent from the above description, according to the present invention, a sealing piece for closing the resin substrate side of the opening of the gate groove is fitted into the gate groove of the molding die which sandwiches the resin substrate on which the IC chip is mounted. Since the IC chip is resin-sealed by filling the cavity with the sealing resin from between the sealing piece and the gate groove, all the sealing resin cured in the gate groove remains on the sealing piece and remains on the resin substrate. Without attaching unnecessary sealing resin
IC chips can be sealed with resin. Moreover, as a mold, only a small sealing piece that seals the opening of the gate groove is inserted into the upper and lower two-part mold that is generally used conventionally.
The positioning of the mold and the sealing piece is simplified, resin leakage from the mating portion is prevented, and continuous production can be easily performed.

[Brief description of the drawings]

1 (a) and 1 (b) are cross-sectional views of an essential part showing a method of resin sealing an IC chip according to a first embodiment of the present invention, and FIG. 2 is a sectional view of the IC chip according to the first embodiment of the present invention. FIG. 3 (a) is a sectional view taken along the line BB of FIG. 1 (a),
3 (b) to 3 (d) are cross-sectional views of main parts of a gate groove showing a modification of the present invention, and FIG. 4 is a resin sealing method for an IC using the gate structure shown in FIG. 3 (d). 5 (a) and 5 (b) are cross-sectional views of a main part showing a method of resin sealing an IC chip according to a second embodiment of the present invention, and FIG. 6 is a conventional IC.
FIG. 7 is a sectional view taken along line AA of FIG. 6, FIG.
FIG. 9 is an external view showing a card base of an IC card, FIG. 9 is a cross-sectional view showing a conventional IC chip resin sealing method, FIG. 10 is an external view showing a conventional IC module, and FIG. FIG. 12 is a cross-sectional view showing the resin sealing method of FIG. 12, FIG. 12 is an external view of a cavity plate used in the resin sealing method of FIG. 11, and FIG.
External view of the IC module manufactured by the resin sealing method of FIG. 11,
14 (a) and (b) are cross-sectional views of main parts showing still another conventional resin sealing method, and FIG. 15 is an external view of main parts of the resin sealing method shown in FIG. 14 (a). is there.

Claims (1)

(57) [Claims] 1. A circuit board having an IC chip mounted on a resin substrate having an electrode pattern is sandwiched by a molding die having a cavity and a gate groove, and a sealing resin is filled from the gate groove into the cavity. A method for sealing the IC chip by filling the resin inside the resin substrate at a distance from a peripheral edge of the resin substrate, wherein the sealing is performed to seal a part of an opening of the gate groove in the gate groove of the molding die. Insert the piece,
Filling the sealing resin into the cavity from between the sealing piece and the gate groove, and moving the sealing piece when the sealing resin is cured to form a sealing portion, thereby moving the sealing piece. Removing unnecessary sealing resin from the part.