JP2001189331A - Resin-sealing method for integrated circuit and mask plate for thick-film printing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealing method for an integrated circuit, as well as a mask plate for thick-film printing which allows easy sealing of an IC chip, etc., with a prescribed height by thick film printing. SOLUTION: A substrate 30 is fixed on a print table 21, and a mask plate 22 comprising a hole 221A, which is formed so that at least the opening part on the upper surface side comprises a ruggedness with prescribed intervals at outer perimeter, while a step part is so provided that the opening area on the upper surface side is smaller that that on the lower surface is fixed to a plate frame. Then the plate frame is stacked on the print table 21, a sealing resin 40 is allowed to flow over the mask plate 22. The sealing resin 40 above the mask plate 22 is injected/filled into the hole 221 of the mask plate 22 by a squeegee 24 for print-coating on the substrate 30. After the mask plate 22 is dismounted, the sealing resin 40 on the substrate 30 is hardened.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small circuit element, such as an IC module, in which a small integrated circuit is mounted on a substrate and sealed with a resin, and more particularly to a method and a method for resin sealing of an integrated circuit. The present invention relates to a mask plate for thick film printing as a jig at the time.

[0002]

2. Description of the Related Art Today, with the spread of computers, IC
Instruments using ultra-small arithmetic storage elements, such as cards, have also been used frequently. This ultra-small arithmetic storage element is printed wiring on a sheet substrate such as a glass epoxy sheet and the IC chip is bonded to the sheet substrate, and then the printed wiring of the sheet substrate and the terminals of the IC chip are wire-bonded. To make an IC module.

As shown in FIG. 11, this IC module has an IC chip 11 on the upper surface of a substrate 10 made of, for example, a glass epoxy sheet. The IC module has printed terminals 12 formed as input / output terminals of the IC module by printed wiring on the lower surface or the upper surface of the substrate 10, and the IC chip 11 and required printed wiring are connected by connection wires 13 such as gold wires. Have been. The IC chip 11 and the connection wires 13 are protected by being covered with a resin 14.

As described above, when the IC chip 11 attached to the substrate 10 and the connection wires 13 connected to the IC chip 11 are protected by being embedded in the sealing resin 14, potting and transfer molding are used. Then, thick film printing has been used.

[0005] In this potting, a liquid sealing resin is put in a container, and the sealing resin is put into an IC chip 11.
For example, the sealing resin dropped on the substrate 10 is heated and cured to cover the IC chip 11 and the connection wires 13 with the sealing resin 14.

In the transfer molding, the IC chip 11 is sealed with a sealing resin by sandwiching the substrate 10 on which the IC chip is mounted with a mold and injecting and solidifying a resin into a cavity formed around the IC chip 11. It is covered with 51.

[0007] Thick film printing, which has recently been used, uses a mask plate having a through hole at the position of an IC chip. In this thick film printing, the sealing resin that has flowed on the mask plate is poured into the through-hole with a squeegee, and FIG.
As shown in FIG. 2, after filling the through hole 15 with the sealing resin 14, the mask plate 16 is removed from the substrate 10, and the resin on the substrate 10 is cured to perform resin sealing of the IC chip 11.

[0008]

As described above, resin sealing by potting makes it possible to relatively easily perform resin sealing of a small IC chip. However, IC
When the height and size of the sealing resin are restricted, as in the case of an IC module for a card, there is a drawback that it is difficult to form the shape and thickness of the sealing resin within a predetermined range. .

Further, in transfer molding, since the shape and size of the resin are regulated by a mold, the shape and size of the sealing resin are regulated precisely to the prescribed shape and the like of the sealing resin. The range can be easily set. However, it takes time and trouble to manufacture the mold, and when the size of the sealing body becomes small, if the amount of resin for sealing the IC chip becomes small, it will remain on the mold runner, etc. However, there is a disadvantage that the use amount of the entire sealing resin cannot be reduced even if the necessary amount of the sealing resin is small.

The method of applying the sealing resin only to a predetermined portion of the substrate by thick film printing has an advantage that a small amount of the sealing resin can be easily applied and applied only to a necessary portion. However, when the mask plate is removed, the sealing resin flows somewhat and the application range slightly widens, and the center of the resin serving as the sealing body rises due to the viscosity and surface tension of the resin, and the height regulation is strict. In some cases, it was sometimes difficult to make the height within the regulation range. Although it is conceivable to increase the opening of the through hole in the mask plate, the volume sealed by the resin is similarly increased, and the same result is obtained.

Particularly, as in the case of an IC module for an IC card, the height from the lower surface of the sheet-like substrate to the upper end surface of the sealing resin is equal to 0. If the height of the IC module is already close to the regulation value before the resin sealing of the IC chip is restricted to a few millimeters, the resin-sealed thickness cannot be finished within the regulated range, and the resin sealing is performed. After that, there is a drawback that the upper end of the sealing resin needs to be polished.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method of sealing an integrated circuit which can easily seal an IC chip or the like at a predetermined height by thick film printing. An object of the present invention is to provide a mask plate for thick film printing.

[0013]

In order to achieve the above object, a method of sealing an integrated circuit resin according to the present invention comprises fixing a substrate on a printing table, and opening at least an upper surface side opening at a predetermined distance in an outer peripheral portion. After fixing a mask plate having a perforated hole formed in an uneven shape with a plate frame, the plate frame is overlaid on the printing table, and a sealing resin is poured over the mask plate,
The sealing resin on the mask plate is injected and filled into the through holes of the mask plate with a squeegee and printed and applied to the substrate. After the mask plate is removed, the sealing resin on the substrate is cured.

The present invention also provides a thick-film printing mask plate having a through-hole, injecting and filling a sealing resin into the through-hole, and printing and applying the same to a substrate. The opening is formed in an irregular shape at a predetermined interval on the outer peripheral portion.

In the present invention, the width of the concave portion of the concave and convex portion in the outer peripheral portion of the through hole of the mask plate is such that when the sealing resin filled in the convex portion is thermally cured, the adjacent convex portions are filled. The width is set so that the sealing resins can be connected to each other.

In the present invention, the through hole is formed such that the opening area on the upper surface side is smaller than the opening area on the lower surface side.

According to the present invention, the through holes of the mask pair are formed in a concavo-convex shape (for example, a shape like a gear) having at least an opening on the upper surface side at a predetermined interval on the outer peripheral portion. The amount of the sealing resin filled in the through-holes can be reduced while covering the required area. Then, when the mask plate is removed from the substrate and the sealing resin filled in the convex portions is thermoset, the viscosity of the sealing resin filled in the adjacent convex portions becomes low, and between the convex portions having little resin. Spread and become connected by surface tension. In this case, the resin flows into the recessed regions of the through holes that are not originally filled with the resin, and is connected to each other, so that the thickness of the connection portion between the protrusions is reduced.

Further, by using a mask in which a through-hole having an opening area on the upper surface side smaller than an opening area on the lower surface side is used, the amount of the sealing resin filled in the through-hole can be reduced while covering a required area on the substrate. I can do it. Then, when the mask plate is removed from the substrate, it is possible to reduce the rise of the sealing resin applied on the substrate. In addition, by reciprocating the squeegee head, the sealing resin can be reliably injected and filled into the through-hole that expands inside, and the sealing resin can be applied to the substrate.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a method for sealing a resin of an integrated circuit by thick film printing and a mask plate for thick film printing used in the method according to the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing an external configuration of a thick film printing apparatus to which the resin sealing method for an integrated circuit according to the present invention is applied. As shown in FIG. 1, this thick film printing apparatus 20 includes a printing table 21 which can be moved in a horizontal direction, a mask plate 22 having a plurality of through-holes having a shape described later, and a printing table 2.
1. A frame 23 fixed above the mask plate 22 and movable in the vertical direction, and a mask plate 22 fixed to the frame 23 is positioned above the mask plate 22 and movable in the vertical and horizontal directions. It has a squeegee head 24 as a main component.

The squeegee head 24 has two squeegees 241 and 242 that can be finely adjusted up and down and that are arranged substantially in parallel with each other.

In this thick-film printing apparatus 20, when performing resin sealing for embedding an integrated circuit such as an IC chip in resin, as shown in FIG. 30 is fixedly mounted, and the printing table 21 is moved horizontally to stop at a predetermined position below the plate frame 23. Then, the frame 23
To press the mask plate 22 against the substrate 30.

The mask plate 22 is made of, for example, a metal thin plate, and as shown in FIG.
Reference numeral 21 denotes the I on the substrate 30 fixed to the print table 21.
It is provided in accordance with the position of the C chip. Hereinafter, three configuration examples of the through hole 221 will be described with reference to FIGS. 4, 5, and 6.

The basic configuration 4 of the through hole 221 is a diagram showing a basic configuration of the through hole 221 of the mask plate 22 according to the present invention, FIGS. 4 (a) is a plan view, FIG. 4
FIG. 4B is a cross-sectional view taken along line AA of FIG.
FIG. 7A is a cross-sectional view taken along line BB of FIG.

As shown in the plan view of FIG. 4, for example, the through-hole 221 basically has a columnar shape (circle in a plane) with a radius r around O and has a circular outer peripheral portion 221a. Are formed in an irregular shape having a predetermined interval.
In other words, it is formed in a so-called gear shape. That is, in the uneven portion 222, a plurality of the convex portions 222a and the concave portions 222b are alternately formed at predetermined intervals over the entire outer peripheral portion 221a. When the sealing resin is filled in the through hole 221 having such a shape, only the protrusion 222a as an opening is filled with the resin, and the filling of the recess 222b with the resin is suppressed. The width of the concave portion 222b of the concave-convex portion 222 is such that when the sealing resin filled in the convex portion 222a is thermally cured, the sealing resin filled in the adjacent convex portions 222a is
The width x is set so that connection is possible. Further, the convex portion 222a is formed to protrude from the outer peripheral portion 221a by a length y.

By using the through hole 221, since the resin is not filled in the concave portion 222 b, the amount of the sealing resin filled in the through hole can be reduced while covering a required area on the substrate. Then, the mask plate is removed from the substrate, and the protrusion 2
When the sealing resin filled in 22a is thermally cured, the sealing resins filled in the adjacent protrusions 222a have low viscosity, spread between the protrusions 222a with less resin, and are connected by surface tension. become. In this case, as described later, the resin flows into the recessed portions 222b of the through holes that are not filled with the resin and is connected to each other, so that the thickness of the connection portion between the projections 222a is reduced.

[0027] The second configuration example Figure 5 of the through-hole, a diagram showing a second configuration example of a through hole of the mask plate 22 according to the present invention, FIGS. 5 (a) is a plan view, FIG. 5 ( b)
FIG. 5A is a cross-sectional view taken along line CC of FIG. 5A, and FIG. 5C is a cross-sectional view taken along line DD of FIG.

This through hole 221A is basically formed as shown in FIG.
As shown in FIG. 4A, similar to the through hole 221 shown in FIG.
A basic shape is a columnar shape (circle in a plane) having a radius r with O as the center, and a circular outer peripheral portion 221a is formed in an uneven shape with a predetermined interval on the upper surface side. In other words, it is formed in a so-called gear shape. That is, in the uneven portion 222, a plurality of the convex portions 222a and the concave portions 222b are formed alternately at predetermined intervals over the entire outer peripheral portion 221a. As shown in FIG. 5 (b), the through hole 221A is formed with a step 223 at a substantially central portion in a thickness direction below the concave portion 222b, and is divided into an upper surface side and a lower surface side.
The diameter of the lower opening is larger than the diameter of the upper opening. The step portion 223 is formed by stacking two metal plates having through holes having different diameters.
It is formed at the center in the thickness direction of the through hole 221A in the thin mask plate 22.

By using the through holes 221A, the amount of the sealing resin filled in the through holes can be reduced while covering the required area on the substrate 30, and when the mask 22 is removed from the substrate 30, The swelling of the sealing resin applied thereon can be reduced.

The third configuration example 6 of the through-hole is a diagram showing a third configuration example of the through hole of the mask plate 22 according to the present invention, FIGS. 6 (a) is a plan view, FIG. 6 ( b)
7A is a cross-sectional view taken along line EE of FIG. 6A, and FIG. 6C is a cross-sectional view taken along line FF of FIG.

The through hole 221B corresponds to the through hole 221A in FIG.
The point of difference is that the formation position of the step portion 223A is
a in that it is further formed on the outer periphery. Other configurations and functions are the same as those of the through hole 221A in FIG.

That is, the through hole 221B is basically formed by
As shown in FIG. 6A, similarly to the through hole 221 shown in FIG. 4, the basic shape is a columnar shape (circle in a plane) with a radius r centered on O, and the outer peripheral portion 221 of the circle on the upper surface
a is formed in an uneven shape with a predetermined interval. In other words, it is formed in a so-called gear shape. That is, in the uneven portion 222, a plurality of the convex portions 222a and the concave portions 222b are alternately formed at predetermined intervals over the entire outer peripheral portion 221a. Then, as shown in FIG.
In the same manner as the through hole 221A shown below, a step portion 223A is formed at a substantially central portion in the thickness direction below the concave portion 222b and divided into an upper surface side and a lower surface side, and the lower side opening diameter is larger than the upper side opening diameter. Is also formed to be large.

Next, a resin sealing method using the thick film printing apparatus 20 will be described with reference to the drawings. However, in this case, the through hole of the mask plate 22 is the through hole 2 of the configuration shown in FIG.
The case where 21A is used will be described as an example.

As shown in FIG. 7, the substrate 30 is fixed to the
The sealing resin 40 is dropped on the mask plate 22 pressed against
The squeegee head 24 is moved horizontally so that the sealing resin 40 placed on the mask plate 22 is dropped into the through hole 221A by lowering the first squeegee 241 to print the sealing resin 40 on the substrate 30. In this case, the first
The squeegee 241 is a squeegee located behind the squeegee head 24 in the moving direction. After the squeegee head 24 is moved from one end of the plate frame 23 to the other end in this manner, the first squeegee 241 is raised, and the second squeegee 242 is lowered, so that the upper surface of the mask plate 22 Replace the squeegee to be brought into contact.

Then, as shown in FIG. 8, the squeegee head 24 is moved back to perform printing application again, and the sealing resin 40 remaining on the mask plate 22 is dropped into the through-hole 221A to form the sealing resin 40. Is printed on the substrate 30.

When the tips of the squeegees 241 and 242 are brought into contact with the upper surface of the mask plate 22, the first squeegee 241 and the second squeegee 242 are slightly pressed against the mask plate 22. Needless to say, the amount of descent is adjusted. The mask plate 22 is used to manufacture an IC module for an IC card, and five substrates 30 provided with IC chips 31 in two rows with twelve IC chips 11 as one row are arranged and the sealing resin 40 is formed at a time. It is to be printed and applied, and has 120 through-holes 221A having a lower surface side opening diameter of about 7 mm, and the thickness t of the mask plate 22 is a 0.3 mm stainless steel plate.

As described above, when the squeegee head 24 is reciprocated, the sealing resin 40 is filled in the through hole 221A and printed and applied to the substrate 30, not only the central portion of the through hole 221A but also FIG. As shown, the convex portion 222a of the concave / convex portion 222 can be filled with the sealing resin 40. Then, after printing is performed by reciprocating the squeegee head 24, the plate frame 2
The mask plate 22 is removed from the substrate 30 by raising 3.

When the mask plate 22 is removed from the substrate 30 and the sealing resin filled in the projections 222a is thermoset, the viscosity of the sealing resins filled in the adjacent projections 222a decreases. , Spread between the convex portions 222a with little resin, and are connected by surface tension. in this case,
As shown in FIG. 9C, the resin 40 flows into the recessed portions 222b of the through holes not filled with the resin 40, and finally connects to each other as shown in FIG. 9D. In this case, originally resin 4
Since the connection is made in the region of the concave portion 222b of the through hole 221A where 0 is not filled, the thickness of the connecting portion between the convex portions 222a becomes thin.

As described above, the squeegee head 2
4 is reciprocated, the sealing resin 40 is filled in the through hole 221A and printed and applied to the substrate 30. As shown in FIG. 10 (a), the inside of the through hole 221A having a step portion 223 formed in the middle is sufficiently filled. The sealing resin 40 can be injected and filled, and the IC chip 31 and the connection wire 32 can be embedded in the sealing resin 40. At this time, due to the viscosity of the sealing resin 40, a small amount of the sealing resin 40 pulls a thread from a part of the periphery of the opening on the upper surface side of the through hole 221 </ b> A to the upper surface of the mask plate 22. The first squeegee 2 is so arranged that the amount of the sealing resin 40 connected to the upper surface of the plate 22 is as small as possible.
The amount of descent of 41 and the second squeegee 242, particularly the amount of descent of the second squeegee 242, is finely adjusted.

Then, after printing is performed by reciprocating the squeegee head 24, the mask plate 22 is removed from the substrate 30 by raising the plate frame 23 as described above. When the mask plate 22 is removed from the substrate 30, As shown in FIG. 10B, the sealing resin 40 connected to the upper surface of the mask plate 22 is formed.
Is drawn into the sealing resin 40 printed and applied on the substrate 30 due to the viscosity of the sealing resin 40, and when the mask plate 22 is completely separated from the substrate 30, as shown in FIG. The sealing resin 40 slightly expands from the lower surface side opening of the through hole 221A, and the center slightly rises due to the viscosity and surface tension of the sealing resin 40.

The mask plate 22 has through holes 22A.
1 is to reduce the opening area of the upper surface side and to reduce the amount of the sealing resin 40 that draws a thread from the upper opening portion to the upper surface of the mask plate 22 through the through hole
1A compared to the amount filled inside,
The amount of the sealing resin 40 filled in the step portion 223 is made smaller than the printing area, and the upper diameter of the sealing resin 40 is reduced beforehand to be applied to the substrate 30. Therefore, when the mask plate 22 is removed, the amount by which the center height of the sealing resin 40 becomes higher than the thickness of the mask plate 22 is set to 100.
On the contrary, depending on the sealing resin 40, the center height could be made slightly lower than the thickness of the mask plate 22 depending on the sealing resin 40.

As described above, according to the present embodiment, the substrate 30 is fixed on the print table 21, and at least the upper opening is formed in an irregular shape with a predetermined interval on the outer periphery, and Hole 2 formed such that the opening area on the upper surface side is smaller than the opening area on the lower surface side
After the mask plate 22 having the mask 21 is fixed to the plate frame 23, the plate frame 23 is overlaid on the printing table 21, the sealing resin 40 is poured on the mask plate 22, and the mask plate 22 is
The sealing resin 40 on the substrate is injected and filled into the through-holes 221 of the mask plate 22, printed and applied to the substrate 30, and the sealing resin 40 on the substrate 30 is cured after removing the mask plate 22. An extremely thin and relatively small IC chip 31 can be easily embedded in the sealing resin 40 to protect the IC chip 31 and the like. In addition, there is an advantage that not only a thin object such as a circuit module and an entire package of a substrate but also a smooth and large-area sealing can be achieved. In addition, as a through hole 221 of the mask plate 22, the opening on the lower surface is
1, the area of the upper surface opening is made smaller than the area of the lower surface opening, and the amount of resin applied to the substrate 30 is compared with the application area. Since it is slightly reduced, the swelling when the mask plate 22 is removed can be reduced.

Therefore, if thick film printing is performed with the thickness of the mask plate 22 being close to the highest point of the connection wire 32 or the like, the height of the resin-sealed IC module or the like can be reduced to the IC chip 31 and the connection wire. The protection by the sealing resin 40 can be performed very close to a height such as 32. Further, when the thickness of the IC module in which the IC chip 31 is resin-sealed is reduced, and the thickness of the IC module or the like is strictly regulated such as an IC card, the IC chip 31 is sealed by the thickness t of the mask plate 22. By determining the height of the resin 40, IC modules having a specified thickness can be easily and inexpensively mass-produced.

The through holes 221 shown in FIGS.
A and 221B may have one step, but may form two or three steps so that the upper opening area is made smaller than the lower opening area by sequentially reducing the area. The shape of the through-hole is not a circular shape in plan view, but a shape such as a rectangle, which conforms to the shape of the portion on the substrate 30 that requires resin sealing, and the amount by which the upper opening area is smaller than the lower opening area. Is determined by the range and size of resin sealing, the state of the sealing resin 40, and the like.

[0045]

As described above, according to the present invention,
The amount of sealing resin applied to the application area is reduced, the rise of the sealing resin when the mask plate is removed is reduced, and the height of the sealing resin can be made extremely close to the thickness of the mask plate. The height of the sealing resin can be easily adjusted to a specified value by using thick film printing. In addition, there is an advantage that not only a thin object such as a circuit module and an entire package of a substrate but also a smooth and large-area sealing can be achieved.

[Brief description of the drawings]

FIG. 1 is a view showing an external configuration of a thick film printing apparatus to which a resin sealing method for an integrated circuit according to the present invention is applied.

FIG. 2 is a diagram showing an example of arrangement of a substrate and a mask plate for implementing the present invention.

FIG. 3 is a plan view showing an example of a mask plate used in the present invention.

FIG. 4 is a diagram showing a basic configuration of a through hole according to the present invention.

FIG. 5 is a diagram showing a second configuration example of the through hole according to the present invention.

FIG. 6 is a diagram showing a third configuration example of the through hole according to the present invention.

FIG. 7 is a diagram showing a thick film printing process according to the present invention.

FIG. 8 is a diagram showing a thick film printing process according to the present invention.

FIG. 9 is an explanatory view of a step of curing the resin in the uneven portion in the through hole according to the present invention.

FIG. 10 is a view showing a step of removing a mask pair for thick film printing according to the present invention.

FIG. 11 is a diagram showing a state of resin sealing of the IC chip.

FIG. 12 is a diagram illustrating a state of conventional thick film printing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 20 ... Thick film printing apparatus 21 ... Printing table 22 ... Mask plate 221, 221A, 221B ... Through-hole 222 ... Concavo-convex part 223 ... Step 23 ... Plate frame 24 ... Squeegee head 241, 242 Squeegee 30 ... Substrate 31 ... IC chip 40 ... sealing resin

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2C035 AA06 FC04 FD01 FD15 FD19 FD52 FF22 FF26 2H114 AB11 AB15 AB17 DA80 EA04 GA11 GA34 GA38 5E314 AA25 BB06 CC06 EE02 FF21 GG26 5F061 AA01 BA03 CA12 DE06

Claims (6)

[Claims] 1. A substrate is fixed on a printing table, and a mask plate having at least an upper surface side opening having a perforated hole formed in a concavo-convex shape having a predetermined interval at an outer peripheral portion is fixed to a plate frame. The plate frame is placed on the printing table, the sealing resin is flowed on the mask plate, and the sealing resin on the mask plate is injected and filled into the through holes of the mask plate by a squeegee, and printed and applied to the substrate. A resin sealing method for an integrated circuit, wherein the sealing resin on the substrate is cured after removing the mask plate. 2. The width of the concave portion of the concave / convex portion in the outer peripheral portion of the through hole of the mask plate is such that when the sealing resin filled in the convex portion is thermoset, the sealing portions filled in adjacent convex portions are filled. 2. The resin sealing method for an integrated circuit according to claim 1, wherein the width is set such that the resins can be connected to each other. 3. The opening according to claim 1, wherein the through-hole has an opening area on the upper surface smaller than an opening area on the lower surface.
Or the resin sealing method of an integrated circuit according to 2. 4. A thick-film printing mask plate having a through-hole, and injecting and filling a sealing resin into the through-hole, and printing and applying it to a substrate. A thick-film printing mask plate formed in a concave and convex shape with a predetermined interval in a portion. 5. The width of the concave portion of the concave / convex portion at the outer peripheral portion of the through hole of the mask plate is such that when the sealing resin filled in the convex portion is thermoset, the sealing portions filled in adjacent convex portions are filled. 5. The mask plate for thick film printing according to claim 4, wherein the width is set such that the resins can be connected to each other. 6. The through hole is formed such that the opening area on the upper surface side is smaller than the opening area on the lower surface side.
Or the resin sealing method for an integrated circuit according to 5.