JPH106471A - Screen printing equipment - Google Patents

Abstract

(57) Abstract: In a manufacturing process of an electronic component, a printed board, and the like, an insulating resin layer for sealing a mounted chip component or the like is formed with high precision and efficiently by printing. SOLUTION: A screen plate 13 on which a printing pattern for performing predetermined printing on a printed body 1 such as an electronic component is formed.
A stage 11 disposed opposite to the screen plate 13 and on which the printed body 1 is mounted and fixed on the facing surface 15; and driving at least one of the screen plate 13 and the stage 11 to print the opposed interval. It comprises an interval setting mechanism 20 that adjusts according to the thickness of the body 1 and an elastic member 21 disposed on the electronic component mounting surface 15. Variations in the thickness of the printing body 1 are absorbed by the elastic deformation of the elastic member 21, and uniform printing is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screen printing apparatus, and more particularly to a screen printing apparatus suitable for printing an insulating resin layer for sealing a chip component mounted on a lead frame in a manufacturing process of an electronic component or a printed circuit board. It relates to a screen printing device.

[0002]

2. Description of the Related Art A screen printing apparatus is capable of forming a printing layer having a large thickness, being capable of being applied to a printing material having a hard or soft or curved surface due to the flexibility of a printing plate, and being capable of applying various inks. It has features such as being able to be used. Due to the above-described features, this screen printing apparatus is also variously employed in a manufacturing process of an electric component, an electronic component, and the like. For example, in the manufacturing process of a printed circuit board, a process of printing an etching agent on a copper-clad substrate for forming a circuit conductor portion, a process of printing cream solder on a soldered portion of the circuit conductor portion, or a circuit conductor portion, etc. It is used in the resist printing process for

[0003] This screen printing apparatus is also used in the manufacturing process of electronic parts and the like to print and form an insulating resin layer for sealing and electrically insulating and mechanically protecting a chip mounted on a lead frame. Have been. As shown in FIGS. 4 to 6, a conventional screen printing apparatus 100 is provided with a stage 101 horizontally supported by a support rod 102 and on which the electronic component 1 is mounted and fixed, and arranged opposite to the stage 101. Screen version 103,
And a squeegee 104.

Although details of the electronic component 1 are omitted, a lead frame 2 in which a large number of lead terminal pieces are stamped and formed on a conductive metal plate, a predetermined circuit and the like are integrated and formed, and the lead terminal pieces are electrically connected to each other. And the chip component 3 mounted in a state of being connected to the chip component 3. The electronic component 1 is supplied to a screen printing apparatus 100 as described later, and a sealing resin layer 4 covering the chip component 3 is formed by printing. The sealing resin layer 4 is formed by printing with a resin ink 107 made of a thermoplastic resin such as an epoxy resin.

[0005] The stage 101 has a main surface 105 facing the screen plate 103 as a mounting surface for the electronic component 1, and although not described in detail, a positioning portion and a fixing portion are provided, so that the supplied electronic component 1 is provided. Is fixed in the state where it is positioned.

The screen plate 103 is made of a thin metal plate having elasticity in the thickness direction and mechanical resistance and chemical resistance, for example, and has a printed pattern corresponding to the sealing resin layer 4 of the electronic component 1 formed thereon. Consisting of a so-called metal mask. The screen plate 103 is tightly stretched by its surroundings being held by a frame member 106, and is mounted on a printing machine (not shown). The screen plate 103 is moved parallel to and away from the stage 101 by a setting drive mechanism (not shown) of the printing press main body while being kept parallel to the stage 101.

The screen printing apparatus 100 may be configured such that the screen plate 103 is of a fixed type and the stage 101 is of a movable type. In this case, stage 101
Is driven in a direction of coming into contact with and separating from the screen plate 103 by an appropriate setting drive mechanism. The stage 10
In order to enable continuous production of the electronic component 1, for example, the electronic component 1 is also configured as a movable type in which a plurality of components are attached to a rotary table.

The squeegee 104 slides while pressing the plate surface of the screen plate 103 by a drive mechanism (not shown).
07 from the printed pattern to the lead frame 2 of the electronic component 1
Push up and push out. In addition, the screen printing apparatus 100 is also provided with an ink return member and the like, which are interlocked with the squeegee 104, although not shown.

The screen printing apparatus 100 configured as described above forms the sealing resin layer 4 on the electronic component 1 by printing according to the process shown in FIG. In other words, the screen printing apparatus 100 is supplied with the electronic component 1 on the electronic component mounting surface 105 of the stage 101 located below the screen plate 103 as shown in FIG. It is placed and fixed in a state where it is placed. Screen printing device 1
00 is the stage 1 until the screen plate 103 is driven downward by the setting drive mechanism and contacts the electronic component 1.
01 approach operation. This screen version 1
Reference numeral 03 denotes a configuration in which the amount of movement is automatically specified according to the specification of the thickness dimension of the electronic component 1.

The screen printing apparatus 100 is supplied with a resin ink 107 in a molten state on a screen plate 103 and, at the same time, drives a squeegee 104 as shown in FIG. The squeegee 104 slides from one side of the screen plate 103 toward the other side, and extrudes the resin ink 107 from the print pattern onto the lead frame 2 of the electronic component 1. In the electronic component 1, the chip component 3 mounted on the lead frame 2 is thereby covered with the resin ink 107.

After that, the screen printing apparatus 100
The screen plate 103 is driven upward with respect to the stage 101 by the operation of the setting drive mechanism as shown in FIG. The screen printing device 100
The squeegee 104 also returns to the initial position in conjunction with the return operation of the screen plate 103, and the ink return member operates to level the resin ink 107.

The electronic component 1 that has undergone the above steps is taken out of the screen printing apparatus 100 and subjected to a drying step of curing the resin ink 107 to form a sealing resin layer 4 that seals the chip component 3.

[0013]

As described above, in the conventional screen printing apparatus 100, the interval between the screen plate 103 and the stage 101 is adjusted by the setting drive mechanism in accordance with the thickness of the electronic component 1. You. However, since the electronic component 1 has a variation in its thickness dimension, a state may occur in which the distance between the stage 101 and the screen plate 103 is not set optimally.

When the electronic component 1 having a thickness less than the specified thickness is supplied, for example, the screen printing apparatus 100 is disposed between the screen plate 103 and the lead frame 2 as shown in FIG. , A gap of Δx occurs. When printing is performed in this state, a part of the resin ink 107 of the screen printing apparatus 100 oozes out of the print pattern via the gap. For this reason,
In the electronic component 1, as shown in FIG. 4D, the oozed resin ink 107 solidifies to form the squeezed resin layer 4a, resulting in a printing failure in which the normal sealing resin layer 4 is not formed.

In the screen printing apparatus 100, for example, when an electronic component 1 having a thickness larger than a specified thickness is supplied, the screen plate 103 is strongly pressed against the electronic component 1 as shown in FIG. As a result, a gap is generated between the central portion and the electronic component 1. When printing is performed in this state, the screen printing apparatus 100 illicitly oozes out of the print pattern via a gap, similarly to the thin electronic component 1 described above. Therefore, the electronic component 1
As shown in FIG. 4D, the resin ink 107 that has oozed out is solidified to form the squeezed resin layer 4a,
A printing failure where a normal sealing resin layer 4 is not formed due to a portion where the resin ink 107 is not filled occurs.

The screen printing apparatus 100 prints each electronic component 1 supplied to the stage 101 while adjusting the distance from the screen plate 103 by, for example, a setting drive mechanism, thereby eliminating the above-described printing failure. Generation can be prevented. However, such a printing method is inefficient and cannot be adopted at all in the mass production process of the electronic component 1. Also, the stage 101
Adjusting the distance between the screen and the screen plate 103 is also very troublesome, and requires skill of an operator.

For this reason, conventionally, the thickness dimension of the electronic component 1 is controlled with high accuracy, and the electronic component 1 on which the sealing resin layer 4 is printed and formed by the screen printing apparatus 100 is appropriately timed by a worker. A sampling inspection was performed to adjust the distance between the stage 101 and the screen plate 103, and a method of determining the electronic component 1 having a printing failure in a later process was adopted. However, such a measure also has a problem that the yield is deteriorated due to a variation in the thickness dimension of the electronic component 1. Therefore, an object of the present invention is to provide a screen printing apparatus that prints an insulating resin layer that seals a mounted chip component or the like with high precision and efficiently in a manufacturing process of an electronic component or a printed board. It is a proposal.

[0018]

A screen printing apparatus according to the present invention that has achieved the above object has a screen printing plate on which a printing pattern for performing a predetermined printing on a printed body is formed;
A stage, which is arranged to face the screen plate and on which the printed body is mounted and fixed on the facing surface, and at least one of the screen plate and the stage is driven to set the facing interval to the thickness of the printed body. It comprises an interval setting mechanism that is set according to the requirements, and an elastic member disposed on the printing body mounting surface of the stage.

According to the screen printing apparatus of the present invention constructed as described above, even if the thickness of the printed material supplied on the stage and subjected to printing varies, the thickness varies. Printing is performed in a stable and uniform state by the elastic member that is elastically deformed. Therefore, the screen printing device efficiently performs high-precision printing on a print.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings. Screen printing device 10 shown in FIGS. 1 to 3 as an embodiment
Is installed during the manufacturing process of the electronic component 1 similarly to the above-described conventional screen printing apparatus 100, and the resin ink 17 is provided.
The sealing resin layer 4 is formed by printing. That is, the electronic component 1 includes a lead frame 2, a chip component 3 on which a predetermined circuit and the like are formed integrally and mounted in a state of being electrically connected to the lead terminal pieces, and a sealing device for sealing the chip component 3. And a resin layer 4. Screen printing device 1
0 denotes a sealing resin layer 4 with resin ink 17 so as to cover the supplied electronic component 1 with the chip component 3.
Is formed by printing.

As shown in FIG. 1, the screen printing apparatus 10 has a stage 11 horizontally supported by a support rod 12 and on which the electronic component 1 is mounted and fixed, and a screen arranged opposite to the stage 11. It has a plate 13 and a squeegee 104. The main surface 15 of the stage 11 facing the screen plate 13 is configured as a mounting surface of the electronic component 1, and the elastic plate 21 is fixedly joined thereto. Although not described in detail, the stage 11 is provided with a positioning portion and a fixing portion on the main surface 15, and fixedly holds the supplied electronic component 1 on the elastic plate 21 in a positioned state.

The screen plate 13 is formed from a thin metal plate having, for example, elasticity in the thickness direction and mechanical resistance, chemical resistance, etc., and has a printing pattern corresponding to the sealing resin layer 4 of the electronic component 1. It consists of a so-called metal mask formed. The outer periphery of the screen plate 13 is held by the frame member 16 in a tightly stretched state. One end of the frame member 16 is rotatably supported by a printer body (not shown). The frame member 16 is vertically moved by the setting drive mechanism 20 as shown by the arrow in FIG. 1, thereby setting the screen plate 13 at a predetermined distance from the stage 11.

Although the details of the setting drive mechanism 20 are omitted,
It is constituted by a drive source and a transmission mechanism such as a step motor for driving the frame member 16 in the vertical direction, and a numerical value setting section having a 10 key or the like. The setting drive mechanism 20 arbitrarily sets the facing distance between the stage 11 and the screen plate 13 by its numerical value setting unit based on the standard thickness dimension of the electronic component 1.

The screen printing apparatus 10 is configured as a movable section by providing the setting drive mechanism 20 on the frame member 16 holding the screen plate 13 as described above, and the stage 11 is configured as a fixed section. Of course, it is good. Further, the screen printing apparatus 10 may be configured such that the stage 11 and the frame member 16 are provided with the setting drive mechanism 20, and these are configured as movable parts. Further, the screen printing apparatus 10 is configured by mounting a plurality of stages 11 on a rotary table in order to enable continuous production of the electronic components 1, and a transport mechanism of the electronic components 1 before and after the stages 11 and an automatic supply mechanism. A take-out mechanism may be additionally provided.

The squeegee 14 is slid by a driving mechanism (not shown) in a state where the leading end of the squeegee 14 presses the plate surface of the screen plate 13.
The resin ink 17 supplied to 3 is extruded from the printed pattern onto the lead frame 2 of the electronic component 1. Although not shown, the screen printing apparatus 10 includes this squeegee 1
An ink return member or the like that is slid in a state where the printing plate surface of the screen printing plate 13 interlocked with 4 is pressed is also provided.

The elastic plate 21 is sufficiently elastically deformed by the application of a slightly large pressing force.
The elastic sheet is made of an elastic sheet material having chemical resistance such as silicon rubber which elastically returns to a natural state when the pressing force is released. Elastic plate 21
Is slightly larger than the external dimensions of the electronic component 1 to be supplied, and is attached and fixed to the electronic component mounting surface 15 of the stage 11.

The screen printing apparatus 10 configured as described above prints the sealing resin layer 4 for sealing the chip component 3 on the electronic component 1A through the process shown in FIG. The thickness of the electronic component 1A is, for example, equal to or slightly smaller than a standard value. As shown in FIG. 2A, the screen printing device 10
The electronic component 1 </ b> A is supplied to the stage 11 which is positioned below the electronic component 1, and is placed and fixed in a state of being positioned on the elastic plate 21 adhered and fixed to the electronic component placing surface 15. The screen printing device 10 includes a stage 11
Is set by the setting drive mechanism 20 such that the distance between the screen plate 13 and the standard is slightly smaller than the standard value of the thickness dimension of the supplied electronic component 1.

When the setting drive mechanism 20 is driven, the screen printing apparatus 10 moves the screen plate 13 to the stage 101.
Is operated downward so as to approach. The screen plate 13 has a gap with respect to the electronic component 1A whose thickness dimension is smaller than the standard because the setting distance between the screen plate 13 and the stage 101 is previously set by the setting drive mechanism 20 as described above. Abuts without a predetermined pressure.

The screen printing apparatus 10 is supplied with the resin ink 17 in a molten state on the screen plate 13 and the squeegee 14 is driven as shown in FIG. The squeegee 14 slides from one side of the screen plate 13 to the other side, and pushes the resin ink 17 from the print pattern onto the lead frame 2 of the electronic component 1A.
In the electronic component 1A, the chip component 3 mounted on the lead frame 2 is thereby covered with the resin ink 17.

Thereafter, in the screen printing apparatus 10, the screen plate 13 is returned upward to the stage 11 by driving the setting drive mechanism 20 as shown in FIG. The screen printing device 10
The squeegee 14 also returns to the initial position in conjunction with the return operation of the screen plate 13, and the ink return member operates to level the resin ink 17.

The electronic component 1A that has undergone the above steps is taken out of the screen printing apparatus 10 and subjected to a drying step of curing the resin ink 17, whereby the electronic component 1A is shown in FIG.
The sealing resin layer 4 for sealing the chip component 3 is formed as shown in FIG. Although the thickness of the electronic component 1A is slightly smaller than the standard, the sealing resin layer 4 on which the print pattern of the screen plate 13 is accurately transferred is formed.

The screen printing apparatus 10 may be supplied with an electronic component 1B having a thickness larger than a standard size due to a variation in the thickness. This electronic component 1B
The sealing resin layer 4 is formed by printing on the chip component 3 mounted on the lead frame 2 through the process of FIG.
The electronic component 1B is, as shown in FIG.
The electronic component is placed and fixed in a state where it is positioned on the elastic plate 21 adhered and fixed to the electronic component mounting surface 15.

The screen printing apparatus 10 is operated downward so that the screen plate 13 approaches the stage 11 when the setting drive mechanism 20 is driven. As described above, the screen printing apparatus 10 is set in advance by the setting drive mechanism 20 so that the opposing distance between the stage 11 and the screen plate 13 is adapted to the electronic component 1A having a thickness slightly smaller than the standard. I have.

Therefore, the screen printing apparatus 10
Screen plate 1 for electronic component 1B with large thickness
3 comes into contact with a pressing force greater than a predetermined pressing force. The electronic component 1B is mounted and fixed on the electronic component mounting surface of the stage 11 via an elastic plate 21. Therefore, a large pressing force applied from the screen plate 13 is applied to the elastic plate 21 via the electronic component 1B.
Is elastically deformed to be absorbed by the elastic plate 21. Since the screen plate 13 abuts on the electronic component 1B without bending as shown in FIG. 3B, no gap is formed between the screen plate 13 and the electronic component 1B.

In this state, the resin ink 17 in a molten state is supplied onto the screen plate 13 in this state, and the squeegee 14 is driven. The squeegee 14 slides from one side of the screen plate 13 to the other side, and pushes the resin ink 17 from the print pattern onto the lead frame 2 of the electronic component 1B. Electronic component 1B
Thus, the chip component 3 mounted on the lead frame 2 is covered with the resin ink 17.

Thereafter, in the screen printing apparatus 10, the screen plate 13 is returned to the stage 11 by the setting drive mechanism 20 being driven upward as shown in FIG. The screen printing device 10
The squeegee 14 also returns to the initial position in conjunction with the return operation of the screen plate 13, and the ink return member operates to level the resin ink 17.

As described above, the screen printing apparatus 10 attaches the elastic plate 21 to the electronic component mounting surface 15 of the stage 11 on which the electronic component 1B is mounted and fixed. Due to the fixing, the screen plate 13 comes into contact with a certain pressing force. Therefore, the screen plate 1 is provided on the electronic component 1B.
The resin ink 17 is supplied from the printing pattern formed on the third resin layer 3, and the precise sealing resin layer 4 is formed by printing.

The present invention is limited to a screen printing apparatus which is employed in the above-described manufacturing process of the electronic component 1 and prints and forms a sealing resin layer 4 for sealing the chip component 3 mounted on the lead frame 2. Of course, the present invention can also be applied to printing of an insulating resist for covering a mounted component or a conductor in a process of manufacturing a printed board, for example. In addition, the screen printing apparatus enables the sealing resin layer 4 to be printed by the same process for not only the same electronic component but also a plurality of types of electronic components having slightly different thickness dimensions.

[0039]

As described above in detail, according to the screen printing apparatus according to the present invention, it is possible to print on a stage a printing material having a different thickness dimension.
The printing plate is kept in constant contact with the printing surface of the printing body by the action of the elastic member without adjusting the distance between the stage and the screen plate each time. Is efficiently performed.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part for explaining a schematic configuration of a screen printing apparatus according to the present invention.

FIG. 2 is a process diagram showing a process of printing and forming a sealing resin layer of an electronic component having a standard thickness dimension by using the screen printing apparatus.

FIG. 3 is a process diagram showing a process of printing and forming a sealing resin layer of an electronic component having a slightly larger thickness dimension than a standard by using the screen printing apparatus.

FIG. 4 is a process diagram showing a process of printing and forming a sealing resin layer of an electronic component using a conventional screen printing apparatus.

FIG. 5 is a vertical sectional view of a main part showing a printing state of an encapsulating resin layer on an electronic component having a smaller thickness dimension than a standard in the screen printing apparatus.

FIG. 6 is a vertical sectional view of a main part showing a printing state of an encapsulating resin layer on an electronic component having a larger thickness than a standard in the screen printing apparatus.

[Explanation of symbols]

1 electronic components (printed body), 2 lead frames, 3 chip components, 4 sealing resin layers, 10 screen printing devices, 11 stages, 13 screen plates, 14 squeegees, 15 stage electronic component mounting surfaces, and holding 16 screen plates Frame member, 17 resin ink, 20 setting drive mechanism, 21 elastic plate

Claims (2)

[Claims] 1. A screen plate on which a printing pattern for performing predetermined printing on a printed body is formed, and a stage which is arranged to face the screen plate and on which the printed body is mounted and fixed on a surface facing the screen plate. An interval setting mechanism that drives at least one of the screen plate and the stage to set an opposing interval between the screen plate and the stage in accordance with the thickness of the printed material; and an elastic member disposed on the printed material mounting surface of the stage. A screen printing apparatus comprising: 2. The screen printing apparatus according to claim 1, wherein the elastic member is a member formed in a sheet shape from silicon rubber.