JP2001291729A - Method for sealing semiconductor element with resin by stencil printing, and stencil printing plate and squeegee used therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To only seal a semiconductor element with a resin by stencil printing on a hybrid integrated circuit board on which electronic parts are mounted in a hybrid state and the height of the parts is made higher than that of the semiconductor element to be sealed with the resin. SOLUTION: A stencil has a recessed groove 7 extended in the advancing direction of a squeegee 9 on its contacting surface with the squeegee 9, and an inserting hole 6 formed through part of the bottom face of the groove 7 for inserting a sealing resin. The stencil is arranged on the hybrid integrated circuit board 4 in which the semiconductor element 1 and electronic parts 2 are respectively mounted on the area corresponding to the groove 7 of a substrate and on the other area of the substrate 3. The height of the parts 2 may become higher than that of the element 1, and the element 1 is sealed with the sealing resin by printing the resin by means of the squeegee 9 having a projecting section 10 which can be put in the groove 7 by putting the projecting section 10 in the groove 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid mounting of a semiconductor element to be sealed with a resin and an electronic component having a mounting height higher than that of the semiconductor element and requiring no resin sealing. The present invention relates to a method of encapsulating the semiconductor element on a hybrid integrated circuit substrate with a resin by stencil printing, and a stencil and a squeegee used in the method.

[0002]

2. Description of the Related Art In recent years, miniaturization, weight reduction, and thinning of electronic components have made remarkable progress with the development of electronic devices such as mobile phones and notebook computers.

In particular, the demand for thinner semiconductor elements and semiconductor packages is more severe than that of peripheral parts, and the development speed is faster.

Further, the use of so-called "lead-free solder" which does not use lead due to environmental problems has increased the reflow temperature of reflow soldering, and after sealing semiconductor elements, the SMT (Surface) Mounting Technolog
(y: surface mounting technology), when reflow soldering is performed, the sealing resin cannot withstand the temperature, often causing problems such as cracks. In addition, some semiconductor elements themselves cannot withstand such high temperatures.

Conventionally, therefore, peripheral components such as capacitors, diodes, chip resistors and the like are firstly subjected to reflow soldering on a substrate, and after the reflow soldering, a semiconductor element is bonded to the substrate with a resin or the like. It is common to wire bond and seal with a liquid sealing material.

[0006]

However, a hybrid integrated circuit board on which electronic components such as a chip aluminum electrolytic capacitor and a chip coil, which are mounted at a higher mounting height than a semiconductor element, are mounted. In addition, stencil printing cannot be performed using a stencil formed by a conventional flat plate.

As a method of sealing only a semiconductor element on such a hybrid integrated circuit board with a resin, a method of applying a sealing resin with a dispenser device is known. As compared with the method, there is a problem that the application speed is extremely slow and the running cost is increased.

Therefore, the present invention provides a hybrid integrated circuit board on which electronic components having a higher mounting height than a semiconductor element to be resin-sealed are mounted in a hybrid manner, and only the semiconductor element is resin-sealed by stencil printing. It is an object of the present invention to provide a stencil printing resin sealing method for a semiconductor element, and a stencil and a squeegee used in the method.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a semiconductor device which is to be sealed with a resin and an electronic component which has a higher mounting height when mounted on the board than the semiconductor element and is not sealed with a resin. A method of sealing the semiconductor element mounted on the hybrid integrated circuit board hybrid mounted on the resin by stencil printing using a squeegee, wherein a concave groove extending in the squeegee advancing direction is formed on a squeegee contact surface. The semiconductor element is mounted on a stencil in which an insertion hole for inserting the sealing resin is formed in a part of the groove bottom surface of the groove, and the groove is formed in a region corresponding to the groove on the substrate. The squeegee is disposed on a hybrid integrated circuit board on which the electronic component having a high mounting height is mounted in a region other than the concave groove corresponding region, and a squeegee having a convex portion fitted in the concave groove is provided. Part fits in the groove The sealing resin is printed Te, the semiconductor element is achieved by a stencil printing method of resin-sealing for a semiconductor device characterized by resin sealing.

[0010] It is preferable that the stencil is formed with a recess for accommodating an electronic component having a higher mounting height than the semiconductor element.

The stencil has a through hole through which an electronic component having a higher mounting height than the semiconductor element can penetrate, and the recessed groove has a side wall facing the squeegee abutting surface of the stencil. It may be formed so as to protrude.

A plurality of the semiconductor elements are mounted in a region corresponding to the groove on the substrate so as to form a line in a straight line, and an insertion hole corresponding to each semiconductor element is formed in a groove of the groove. It may be formed at the bottom.

It is preferable that the insertion hole formed in the groove bottom of the groove of the stencil has an interval of at least 0.2 mm or more with the side wall of the groove.

It is another object of the present invention to provide a stencil in which a recessed portion for accommodating an electronic component which does not require resin sealing is formed on a surface of the stencil facing the substrate, and a sealing resin is scraped on a squeegee contact surface of the stencil. Characterized in that the groove is formed and an insertion hole for inserting the sealing resin is formed in a part of the groove bottom of the groove.

Further, the stencil of the stencil has a through hole through which an electronic component on the substrate can penetrate, and a groove for scraping a sealing resin on the squeegee contact surface of the stencil. The groove forms the groove. This is also achieved by a stencil characterized in that the opposing side walls are formed so as to protrude from the squeegee contact surface of the stencil.

Further, the object of the present invention is attained by a squeegee in which a convex portion that fits into the above-mentioned concave groove is formed on a contact surface with the stencil.

The "semiconductor element to be sealed with resin"
The term means that a semiconductor bare chip (naked element) mounted on a substrate is subjected to wire bonding or mounted by bumps. Therefore, "the mounting height is higher than that of the semiconductor element" means that the mounting height is higher than the height of the semiconductor element including the wire bonding. The “mounting height” means the height from the mounting surface of the board to the top end of the mounted component.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings. Throughout the drawings, the same components are denoted by the same reference numerals.

FIG. 1 is a side view (a) and a plan view showing a hybrid integrated circuit board 3 in which a semiconductor element 1 and an electronic component 2 having a mounting height g higher than that of the semiconductor element 1 are mounted on a board 3 in a hybrid manner. (B). As shown in FIG. 1, the semiconductor electronic components 2 are arranged on a substrate 3 so as to form a line in a straight line along a traveling direction X of a squeegee (not shown). The electronic components 2 that do not require resin sealing are mounted in rows on both sides along the rows of the semiconductor elements 1. Electronic component 2
Is similar to the prior art in that soldering is performed prior to a semiconductor element by reflow soldering, and thereafter, a bare chip constituting the semiconductor element 1 is mounted on a substrate 3 and wire-bonded.

FIG. 2 is a partial cross-sectional perspective view showing the stencil 5 mounted on the hybrid integrated circuit board 4. As shown in FIG. 2, the stencil 5 has an insertion hole 6 corresponding to the position of the semiconductor element 1 requiring sealing. The insertion hole 6 is formed at a groove bottom of a concave groove 7 formed on a squeegee abutting surface (a surface on which the squeegee abuts) of the stencil 5. On the substrate facing surface of the stencil 5 (the surface on the side facing the substrate), a housing recess 8 capable of housing the electronic component 2 is formed. Such a stencil 5 can be produced by laminating a plurality of metal plates formed by etching and performing groove processing or through-hole processing.

The squeegee 9 for the stencil 5 is as follows.
As shown in FIGS. 3 and 4, a convex portion 10 that fits into the concave groove 7 is formed. When the protrusion 10 of the squeegee 9 is fitted into the groove 7 of the stencil 5, a gap a (FIG. 3) of at least 0.1 mm or more is formed between the protrusion 10 and the side wall of the groove 7. It is preferable to configure. This is because if the gap a is smaller than 0.1 mm, the squeegee 9 cannot move smoothly due to the flow resistance of the resin sandwiched between the side end surface of the squeegee 9 and the side wall of the housing recess 8. Also, the insertion hole 6 is formed such that the squeegee 9 can contact at least 0.1 mm or more on both sides in the groove width direction at the groove bottom of the concave groove 7.
Is preferably formed. This is because a squeegee support surface b (FIG. 3) of at least 0.1 mm is required on both sides of the insertion hole 6 in order to support the squeegee 9 at the groove bottom of the concave groove 7. This is because the sealing resin pressed between the groove 9 and the side wall of the concave groove 7 flows into the insertion hole 6, and the filling amount of the sealing resin varies.

Further, the squeegee 9 is designed such that the squeegee 9 does not come into contact with the top wall 8a of the accommodation recess 8 when the projection 10 is in contact with the groove bottom of the recess groove 7. However, the gap c (FIG. 3) between the squeegee 9 and the top wall 8a of the accommodation recess 8 is 0.1 to 3
mm. If the gap is smaller than 0.1 mm, the squeegee 9 may come into contact with the top wall 8a of the housing recess 8 depending on the adjustment of the pushing amount. This is because a large amount remains on the top wall 8a, drops down toward the insertion hole 6, flows into the insertion hole 6, and causes a problem at the time of later printing.

As shown in FIG. 5, the stencil 5 as described above is arranged such that the grooves 7 correspond to the rows of the semiconductor elements 1 and the insertion holes 6 are positioned at the positions of the semiconductor elements 1. The squeegee 9 is placed along the groove 7 and the squeegee 9 is moved along the groove 7 to perform stencil printing. At this time, it is sufficient that the sealing resin G for printing is filled only in the groove 7 of the stencil 5. The sealing resin G is injected into the semiconductor element 1 through the insertion hole 6 and then cured to complete the resin sealing G (FIG. 6).

By encapsulating the semiconductor element with resin in this manner, even if electronic components having a higher mounting height than the semiconductor element to be resin-encapsulated are hybrid mounted, the semiconductor element can be stencil printed. Only the resin can be sealed.

In order to improve printing efficiency, for example, as shown in FIGS. 7 and 8, stencil printing is performed simultaneously on one substrate, but also on a plurality of substrates using one stencil. Is also possible. In the figure, the arrow X direction is the direction in which the squeegee moves, that is, the printing direction. Thus, if the pattern design on the substrate is devised, the printing efficiency can be further improved by the method of the present invention.

The groove 7 formed in the stencil 5 preferably extends from one end of the stencil 5 to the other from the viewpoint of printing efficiency, but is not limited thereto. Various forms can be adopted depending on the form extending to the end of the stencil 5 or the number of semiconductor elements and electronic parts mounted on the hybrid integrated circuit board.

In connection with this, in the above embodiment, a plurality of semiconductor elements are arranged so as to form a row.
Such an arrangement is not necessarily required. For example, a case where only one semiconductor element is mounted on a substrate may be used. In that case, a concave groove is formed in the stencil only at a portion corresponding to the one semiconductor element, and an insertion hole is formed there.

The electronic components having a higher mounting height when mounted than the semiconductor elements are not limited to the case where they are arranged in rows as shown in the figure. Such an electronic component may be mounted in an area other than the area corresponding to the concave groove of the substrate.

Further, in a region corresponding to the concave groove of the substrate,
Although an electronic component having a higher mounting height at the time of mounting than a semiconductor element to be resin-sealed is not arranged, it is not hindered to arrange an electronic component having a lower mounting height than the semiconductor element. When an electronic component with a low mounting height is mounted in a region corresponding to the groove, a recess (not shown) that can accommodate the electronic component with a low mounting height is formed in the groove of the stencil. good.

Further, it is preferable to form a thin projection 6a on the periphery of the insertion hole 6 on the surface of the stencil 5 in contact with the substrate 3. This is to prevent the sealing resin from going around the lower part of the stencil 5 and to improve the cutting of the sealing resin when removing the stencil 5 from the substrate 3 (to eliminate stringing of the resin).

The thickness of the projection 6a is usually 0.05 to 0.5 mm.
3 mm. In the case where the projections 6a are provided, if the stencil 5 has a structure in which the stencil 5 is in contact with the substrate 3 only by the projections 6a, the squeegee may have poor durability against the pressing force. When there is a required distance between the electronic component and an adjacent electronic component, the projection 6a can be formed by digging a groove 6b around an insertion hole on a surface of the stencil 5 in contact with the substrate. If the projection 6a is formed in this manner, the squeegee pressure is reduced by the projection 6a and the portion 6c outside the groove 6b when the pressing force by the squeegee is applied.
And the durability is improved.

Further, in a vacuum atmosphere, an excessive amount of the sealing resin is supplied onto the insertion hole, and thereafter, the resin is exposed to an atmospheric pressure atmosphere, and is filled with a pressure difference which is a difference between the vacuum pressure and the atmospheric pressure. The so-called differential pressure filling method for performing the above method can also be applied to the method of the present invention. In that case, for example, under a vacuum atmosphere, the sealing resin is supplied in an excessive amount such that the sealing resin protrudes into the concave groove of the stencil set on the hybrid integrated circuit board, and a general squeegee having no irregularities is provided on the upper surface of the housing portion. The sealing resin protruding from the groove is scraped off by being moved while being in contact with the groove. Then, the sealing resin remaining in the concave groove may be scraped by the above-described squeegee having the convex portion by performing exposure in an air atmosphere to perform the differential pressure filling.

In the case of the differential pressure filling method, it is possible to use only the stencil of the present invention, that is, a stencil having a concave groove. When exposed to the atmosphere, dents on the resin surface should not be lower than the top surface of the stencil by differential pressure filling, and in the atmospheric pressure atmosphere, the resin that has protruded from the insertion hole of the groove can be scraped off with a squeegee. . Therefore, the squeegee used in a vacuum atmosphere is
Another squeegee in which the degree of protrusion of the protrusion is reduced may be used, or the squeegee used in the atmospheric pressure atmosphere may be used by setting the height position of the squeegee slightly higher. .

Next, a second embodiment of the present invention will be described below with reference to FIG. FIG. 9 is a cross-sectional view showing a state where the stencil according to the second embodiment is set on a hybrid integrated circuit board, with a part thereof being cut away.

As shown in FIG. 10, the stencil 5 'has a through hole 11 through which the electronic component 2 having a high mounting height can penetrate. 12,12
Is different from the first embodiment in that it is formed so as to protrude from the squeegee abutting surface of the stencil 5, and the other points are the same as in the first embodiment. Is omitted.

In the illustrated example, the groove bottom surface 7'a constituting the concave groove 7 'is set at the same height as the squeegee-side surface 5'a of the stencil 5, but the semiconductor element to be sealed with resin is used. The stencil 5 'may be formed above or below the squeegee-side surface 5'a in accordance with the height dimension of 1 or the required height of the sealing resin.

In the stencil 5 according to the second embodiment, it is necessary to control the supply amount of the sealing resin so that the resin to be printed does not climb over the side walls 12 forming the concave groove 6b. There is an advantage that the structure is simplified as compared with the stencil of the first embodiment.

[0038]

As is apparent from the above description, according to the stencil printing resin sealing method for a semiconductor device according to the present invention, an electronic component having a higher mounting height when mounted than a semiconductor device to be resin-sealed. In a hybrid integrated circuit board on which is hybrid mounted, only the semiconductor element can be resin-sealed by stencil printing, and cost reduction can be achieved.

[Brief description of the drawings]

FIGS. 1A and 1B show an embodiment of a hybrid integrated circuit board which is stencil-printed by the method of the present invention, wherein FIG. 1A is a side view and FIG.

FIG. 2 is a partial sectional perspective view showing a first embodiment of a stencil according to the present invention.

FIG. 3 is a partial cross-sectional view showing a state where a squeegee as a component of the present invention is fitted to the stencil of FIG. 2;

FIG. 4 is a partial perspective view showing the squeegee of FIG. 3;

FIG. 5 is a partial sectional view showing a state where stencil printing is performed by the method of the present invention.

FIG. 6 is a side view of the hybrid integrated circuit board in a state where the semiconductor element is resin-sealed by the method of the present invention.

FIG. 7 is a plan view of a hybrid integrated circuit for explaining another embodiment of the stencil printing resin sealing method for a semiconductor element according to the present invention.

FIG. 8 is a plan view of a hybrid integrated circuit for explaining another embodiment of the stencil printing resin sealing method for a semiconductor element according to the present invention.

FIG. 9 is a sectional view corresponding to FIG. 5 and showing a modification of the stencil shown in FIG. 2;

FIG. 10 is a partial sectional view showing a stencil according to a second embodiment of the present invention together with a squeegee.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 semiconductor element 2 electronic component 3 substrate 4 hybrid integrated circuit board 5 stencil 6 insertion hole 7 concave groove 8 receiving recess 9 squeegee 10 convex portion 11 through hole 12 side wall

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Noritaka Oyama 21-1 Ohatacho, Takatsuki-shi, Osaka Charmancopo Settsu Tomita 301 F-term (reference) 2C035 AA06 FD01 FD42 FF26 4M109 AA01 BA03 CA12 DB17 GA02 5F061 AA01 BA03 CA12 FA02

Claims (8)

[Claims] 1. A hybrid integrated circuit board in which a semiconductor element to be resin-encapsulated and an electronic component having a mounting height higher than that of the semiconductor element and not resin-sealed are mounted on the substrate in a hybrid manner. A method of sealing the mounted semiconductor element with a resin by stencil printing using a squeegee, wherein a groove extending in the squeegee advancing direction is formed on a squeegee contact surface, and a part of the groove bottom surface of the groove is formed. A stencil in which an insertion hole for inserting the sealing resin is formed, the semiconductor element is mounted in a groove corresponding region corresponding to the groove of the substrate, and the stencil is formed in a region other than the groove corresponding region. An electronic component having a high mounting height is mounted on a hybrid integrated circuit board on which the electronic component is mounted, and a squeegee formed with a convex portion that fits into the concave groove fits the convex portion of the squeegee into the concave groove to form a sealing resin. Printing the semiconductor element The stencil printing resin sealing method of a semiconductor device characterized by resin sealing. 2. The stencil printing resin sealing method for a semiconductor element according to claim 1, wherein the stencil has a receiving recess capable of receiving an electronic component having a mounting height higher than that of the semiconductor element. . 3. The stencil has a through hole through which an electronic component having a mounting height higher than that of the semiconductor element can penetrate, and the concave groove has a squeegee abutting on a side wall facing the stencil. 2. The stencil printing resin sealing method for a semiconductor device according to claim 1, wherein the method is formed so as to protrude from a surface. 4. In a region corresponding to the concave groove of the substrate,
A plurality of the semiconductor elements are mounted so as to form a line in a straight line, and an insertion hole corresponding to each semiconductor element is formed at a groove bottom of the concave groove. 3. The method of sealing a stencil printing resin for a semiconductor element according to any one of 3. 5. The groove according to claim 1, wherein the insertion hole formed in the groove bottom of the groove of the stencil has a distance of at least 0.2 mm or more from the side wall of the groove. A stencil printing resin sealing method for a semiconductor element according to any one of the above. 6. A concave portion for accommodating an electronic component that does not require resin sealing is formed on a surface of the stencil facing the substrate, and a concave groove for scraping the sealing resin is formed on a squeegee contact surface of the stencil. 6. A stencil printing resin sealing for a semiconductor element according to claim 1, wherein an insertion hole for inserting said sealing resin is formed in a part of a groove bottom of said concave groove. The stencil used for the method. 7. A squeegee contact surface of a stencil has a through hole through which an electronic component on the substrate can penetrate, and a groove for scraping a sealing resin, and the groove forms the groove. The stencil used for sealing a stencil printing resin of a semiconductor according to any one of claims 1 to 5, wherein opposing side walls are formed so as to protrude from a squeegee contact surface of the stencil. 8. A squeegee for use in a method of sealing a stencil printing resin for a semiconductor element according to claim 1, wherein a projection is formed on a contact surface with the stencil.