JP2000286277A - Vacuum printer and vacuum printing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decrease air bubbles left behind in a seal resin without lowering manufacture efficiency and causing a large sum for equipment investments by a method, wherein there are provided a drying chamber for drying a matter to be printed and a printing chamber provided at a latter stage of this drying chamber and for print-supplying a resin to the matter to be printed in vacuum. SOLUTION: The interior of a carry-in chamber 10 penetrates the interior of a printing chamber 20 via a carrying port 12, and the carry-in chamber 10 serves both as a drying chamber for drying in a vacuum and a matter to be printed before sealing. A resin supplier 27 supplies a resin appropriately onto a stencil printing plate 23 in the printing chamber 20. When a matter to be printed 1 is carried into the interior of the carry-in chamber 10, an opening and closing door 13 is made in a closed state, when a valve 53 is made in a closed state, a valve 57 is made in an open state, and an internal pressure of the carry-in chamber 10 is equalized with the internal pressure of the printing chamber 20 by activating a vacuum pump 60. In addition, since the vacuum chamber 10 is used as a vacuum drying chamber, in view of a reduction in a drying time, a vacuum level may be set higher than that of the printing chamber 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum printing apparatus and a vacuum printing method, and more particularly, to filling holes in a printed wiring board used for various electronic devices, various electronic components mounted on the wiring board, and semiconductor elements. The present invention relates to a vacuum printing apparatus and a vacuum printing method for manufacturing an electronic component by performing sealing.

[0002]

2. Description of the Related Art Conventionally, various methods have been devised for filling holes in printed wiring boards and for sealing semiconductor elements mounted on a substrate. Among these methods, a method of performing printing using a stencil and performing filling and sealing is often used because the sealing shape can be stabilized, and mass production and the economical efficiency of the apparatus are excellent. When the printing method using a stencil is performed under normal atmospheric pressure, air bubbles remain in the resin or between the substrate and the parts and the resin, and when the resin is cured as it is, the air bubbles remain, so that quality is reduced. Causes a problem. Therefore, in order to eliminate these inconveniences, a defoaming step for eliminating these remaining air bubbles by using a vacuum or a pressure reducing means after printing is required.

[0003] Further, even if the substrate contains moisture or the like, it is considered that by performing this defoaming step, it is possible to remove moisture contained in the substrate. , Too high vacuum (for example, 30 torr or less)
If the defoaming step is performed for a long time (for example, 10 minutes or more), appearance defects such as collapse of the sealing resin shape occur. Therefore, the defoaming step is usually performed under a low degree of vacuum (for example, 30 torr or less) and in a short time (for example, 2 to 10 minutes), and if it remains in the resin, the reliability of the packaging is significantly reduced. It was suppressed to such an extent that only bubbles having such a size were removed.

On the other hand, a vacuum printing method in which printing is performed under vacuum using a stencil has been proposed. As described above, in a printing method performed under normal atmospheric pressure, only a degree of vacuum of about 30 torr can be used as a degree of vacuum in a defoaming step after sealing. Since printing is performed in a state where the stencil and the substrate are in contact with each other before and after printing, and the shape of the sealing resin is not destroyed, a high degree of vacuum of 0.01 to 30 torr or less can be used. Therefore, when the vacuum printing method is used, there is an advantage that smaller bubbles can be removed and moisture can be removed.

[0005]

Generally, when an electronic component such as a semiconductor element is sealed, the electronic component is mounted on a substrate in the atmosphere. However, after the electronic component is mounted on the substrate, vacuum printing is performed. Until the sealing is performed, there is moisture absorption of constituent materials of the substrate (for example, moisture absorption of the substrate itself, moisture absorption of the filler in the through-hole portion, and die bonding adhesive for fixing the electronic component to the substrate). In flip chips,
There is moisture absorption in a portion where an organic substance exists, such as when the bump is connected with a conductive paste and when the bump is connected and fixed with an anisotropic conductive paste or an anisotropic conductive sheet. Furthermore, organic materials used for fixing electronic components and the like include residual volatile substances (eg, solvents or low-boiling components).

As described above, the vacuum sealing method has an advantage that sealing can be performed under a high degree of vacuum. However, an electronic component containing moisture or a residual volatile substance is removed under an atmosphere of a high degree of vacuum. , A boiling point drop and a rise in vapor pressure occur, and these are evaporated, vaporized, or sublimated to become gas and released into a vacuum atmosphere.

When electronic components are placed in a vacuum atmosphere, they do not immediately become gas and are released into the vacuum atmosphere. Therefore, when the electronic component is sealed using the vacuum printing method before the moisture and the remaining volatile substances are completely released into the vacuum atmosphere, the moisture and the remaining volatile substances are released into the sealing resin. It will be. In this case, the moisture and residual volatile substances released into the sealing resin due to the viscosity and the viscosity ratio of the sealing resin become bubbles in the sealing resin, float on the resin, and break down to the resin surface. Since the gas is released into a vacuum atmosphere, it takes a considerable time to completely remove moisture and residual volatile substances released into the sealing resin.

In the vacuum printing method as well, it is preferable that each step be shortened from the viewpoint of manufacturing cost, and the step of sealing the electronic component is usually about 2 to 10 minutes. During this time, the time during which the electronic component is in a vacuum state is about 1 to 8 minutes, so it is difficult to completely remove moisture and residual volatile substances released into the sealing resin. The state in which the moisture and the remaining volatile substances are released into the sealing resin is a state in which bubbles are formed in the sealing resin, which causes a problem of lowering the reliability of the package.

The present invention has been made in view of the above circumstances, and improves the reliability of a package by reducing bubbles remaining in a sealing resin without reducing manufacturing efficiency and incurring a large capital investment. It is an object of the present invention to provide a vacuum printing apparatus and a vacuum printing method that can perform the printing.

[0010]

In order to solve the above-mentioned problems, a vacuum printing apparatus according to the present invention is a vacuum printing apparatus for printing a printing material under a vacuum, comprising: a drying chamber for drying the printing material; A printing chamber provided downstream of the drying chamber and for supplying a resin to a substrate under vacuum. Further, the vacuum printing apparatus according to the present invention is provided between the printing chamber and the drying chamber, is separated or opened from the printing chamber via a first opening / closing door, and is provided via a second opening / closing door. And a transfer chamber for carrying the printing medium provided from the drying chamber. The vacuum printing apparatus according to the present invention is characterized in that the transfer chamber dries the printing object by vacuum drying. Also,
The vacuum printing apparatus according to the present invention is characterized in that the drying chamber dries the printing material by hot air drying. Further, the vacuum printing apparatus according to the present invention, wherein the printing chamber includes a printing machine that prints a resin with a squeegee using a stencil,
Two squeegees are provided, and printing is performed using different squeegees when performing forward printing and returning printing. The vacuum printing method according to the present invention is a vacuum printing method in which printing of a printing material is performed under vacuum, and a drying step of drying the printing material, and after the drying process, printing and supplying a resin to the printing material under vacuum. And a printing step. In the vacuum printing method according to the present invention, the drying step is a step of performing vacuum drying. In the vacuum printing method according to the present invention, the drying step is a step of performing hot air drying. Further, in the vacuum printing method according to the present invention, the printing step is performed by setting and holding an arbitrary degree of vacuum at the time of forward printing, between the end of forward printing and the start of backward printing, and at the time of backward printing. It is characterized by being.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a vacuum printing apparatus and a vacuum printing method according to an embodiment of the present invention will be described in detail with reference to the drawings. [First Embodiment] FIG. 1 is a side view schematically showing the configuration of a vacuum printing apparatus according to a first embodiment of the present invention to which the vacuum printing method according to the first embodiment of the present invention is applied. However, in order to facilitate understanding, cross-sectional views are interlaced.

As shown in FIG. 1, a vacuum printing apparatus according to a first embodiment of the present invention includes a loading chamber 10 for loading a printing material, a printing chamber 20 for printing a printing material, and a printed printing material 20. And an unloading chamber 30 for unloading. Loading room 10
Is provided with a carrying port 11 for carrying in the printing material from outside, and a carrying port 12 for carrying out the carried printing material to the printing room. The inside of the carry-in room 10 and the inside of the printing room 20 penetrate through the carrying port 12. The loading chamber 10 is also used as a drying chamber for performing vacuum drying of the printing material before sealing.
The carry-out chamber 30 is provided with a transport port 31 for carrying in the printing material from the printing room 20 and a transport port 32 for carrying out the printing material to the outside. The inside of the carry-out room 30 and the inside of the printing room 20 penetrate through the carrying port 31.

An opening / closing door 13 for shutting off (separating) or opening the outside and the loading room 10 is provided at the transport opening 11.
The transport opening 12 is provided with an opening / closing door 14 for shutting off (separating) or opening the carry-in room 10 and the printing room 20. In addition, an opening / closing door 33 for shutting off (separating) or opening the printing room 20 and the unloading room 30 is provided in the transport opening 31, and the opening 30 is shut off (separating) between the unloading 30 and the outside in the transport opening 32. An opening / closing door 34 for opening is provided. Door 13,1
4, 33, 34 have a structure that can withstand the pressure difference between the inside and outside. For example, sealing that can maintain airtightness is provided. When the doors 13, 14, 33, 34 are in the closed state, the carry-in room 10, the printing room 20, and the carry-out room 30 are sealed, and airtightness can be maintained. In the present embodiment, the loading chamber 10 is also used as a vacuum drying chamber as described above,
Since the loading chamber is used for removing moisture and residual volatile substances from the printing material, it is preferable that the loading chamber has a pressure-resistant structure that can withstand a degree of vacuum of about 0.1 torr.

Belt conveyors 40, 41, 42, 43, and 44 for transporting a printing material are arranged in a straight line in the loading chamber 10, the printing chamber 20, and the unloading chamber 30, and outside the apparatus. The substrates 1, 2, 3 are conveyed. still,
The above-mentioned 1, 2 and 3 are not the print material itself, but may be, for example, a jig plate on which the print material is placed. In addition, the belt conveyors 40, 41, 42, 43, 44 may be, for example, a feeder provided with a roller rotation mechanism. In addition, examples of the substrate include a substrate having a hole filled with resin, a substrate on which a semiconductor sealed with resin is mounted, and an electronic component sealed with resin.

In the above-described carry-in room 10, printing room 20, and carry-out room 30, an intake pipe 50 provided with a valve 53, a valve 5
, An intake pipe 51 with a valve 55
Are provided. Loading room 10, printing room 20,
And when the discharge chamber 30 is in a vacuum state, the valves 53, 5
4 and 55 are opened, so that the loading room 10 and the printing room 2
0 and the pressure inside the carry-out chamber 30 can be set to the atmospheric pressure.

The carry-in room 10, the printing room 20, and the carry-out room 30 are provided with valves 57, 58, 59, and connected to a pipe 56 connected to a vacuum pump 60. Therefore, when the vacuum pump 60 is operating, the valve 5
By setting 7, 58, 59 to the open state, each of the carry-in room 10, the printing room 20, and the carry-out room 30 can be in a vacuum state. Therefore, the valves 53, 54, 55, 57, 5
The carry-in room 10 and the printing room 2 are adjusted by adjusting the opening degree of 8,59.
0 and the degree of vacuum in the carry-out chamber 30 can be arbitrarily set. In particular, since the loading room 10 is also used for performing vacuum drying, it is preferable that the degree of vacuum of the loading room 10 can be arbitrarily set. In FIG. 1, the vacuum pump 60
Are directly connected to the carry-in room 10, the printing room 20, and the carry-out room 30 via the valves 57, 58, 59, and if necessary, the carry-in room 10, the print room 20, the carry-out room 30 and the vacuum pump 60 are connected. And a tank may be provided between them to shorten the time required to reach a predetermined degree of vacuum.

Next, the inside of the printing room 20 will be described in detail. In FIG. 1, reference numeral 21 denotes a table 22 described later.
It is a table elevating device for raising and lowering and stopping the table, and may have a function of stopping at an elevating speed and an arbitrary position for an arbitrary time if necessary. Also, the table elevating device 21
It is also possible to use a device for raising and lowering the printing stencil instead of. In this case, the above mechanism can be provided.

Reference numeral 22 denotes a table of the printing press, which is not particularly necessary when the printing material 2 is mounted on a jig plate or when the printing material itself is transported. Further, a heater (not shown) may be built-in so as to heat the print substrate 2 as necessary, or a heater may be provided on the upper surface of the table.
Reference numeral 23 denotes a stencil plate for printing, in which holes having a size and a shape corresponding to the supply dimensions are provided at positions corresponding to the resin supply portion of the print substrate 2 in a number corresponding to the supply unit. In FIG. 1, holes 23a, 23b and 23c are provided.

Reference numeral 24 denotes a squeegee moving device.
It is configured to be able to reciprocate in the direction indicated by reference numeral H1 or in the direction indicated by reference numeral H2 along the moving rail 25 horizontally installed in the squeegee, and the reference numerals H1 are applied to the squeegees 26a and 26b. Reciprocating in the direction indicated by H2 or in the direction indicated by the symbol H2. In addition, the squeegee moving device 24 reciprocates the squeegees 26a and 26b in the direction indicated by the reference sign V1 or in the direction indicated by the reference sign V2.
The vertical position of the squeegee 26b is adjusted.
The adjustment of the distance between the a and 26b and the stencil 23 and the adjustment of the contact pressure are performed.

Next, the squeegees 26a and 26b and the stencil 23
Will be described. The contact angle θ between the squeegees 26a and 26b and the stencil 23 is preferably set to an angle smaller than 90 ° so that the resin is pushed into the holes of the printing material and filled. That is, when the tips of the squeegees 26a, 26b are not acute angles but close to 90 °, the squeegees 26a, 26b
It is necessary to make the contact angle θ 90 ° or less by tilting itself. When the tips of the squeegees 26a and 26b are acute angles, the contact angle θ is 90 ° or less even if the squeegees 26a and 26b are vertically arranged. In the present embodiment, printing is performed in both the case where the squeegee moving device 24 moves in the direction indicated by reference numeral H1 and the case where the squeegee moving device 24 moves in the direction indicated by reference numeral H2. Squeegees 26a and 26b are provided to face each other.

Reference numeral 27 denotes a resin supply device for appropriately supplying resin onto the stencil 23 in the printing room 20.
, The resin is supplied to the resin supply device outside. This device may be equipped with a heating device (not shown) so that the resin can be heated if necessary. Further, the resin supply device 27 is provided outside the printing room 20, but it is necessary to supply the resin to the stencil in the printing room due to its structure. This is because it is necessary to supply a resin that is replenished outside the printing room and fed into the printing room 20. Reference numeral 28 denotes a resin supply nozzle connected to the resin supply device 27, which is a portion for discharging the resin onto the stencil 23 from the resin supply device 27, and is configured to be able to heat the resin as necessary. Good.

Incidentally, the resin supply nozzle 28 is
A plurality may be provided between the squeegee 26a and the squeegee 26b. Further, the resin supply nozzle 28 may be configured to be movable. In this case, before the squeegees 26a and 26b move in the direction indicated by reference numeral H1 in FIG. 1 and return to their original positions, the resin supply nozzles 28 move the squeegees 26a and 26b.
After moving from outside the moving range of the squeegee and discharging the resin onto the stencil 23 located in front of the squeegee,
It returns to the original position outside the movement range of 6b. In FIG. 1, reference numeral 29 denotes a resin discharged from the resin supply nozzle 28 onto the stencil 23. Discharge position is squeegee 2 moving forward
It is on the stencil 23 located in front of 6a, 6b.

Next, a vacuum printing method applied to the vacuum printing apparatus according to the first embodiment of the present invention will be described in detail with reference to FIG. First, regarding the loading room 10, the opening and closing door 14 is closed, and the opening and closing door 13 is opened. Also,
Regarding the carry-out room 30, the open / close door 34 is closed and the open / close door 33 is open. Further, the vacuum pump 60 is operated,
The valves 53, 58, 59 are opened, and the valves 54, 5
5, 57 are closed. By doing so, the pressure in the carry-in chamber 10 is set to the atmospheric pressure, and the printing room 20 and the carry-out room 3
0 is adjusted to a predetermined degree of vacuum.

In this state, the belt conveyors 40 and 41 are operated, and the printing material 1 is carried into the carry-in room 10 through the carrying port 11. When the printing medium 1 is loaded into the loading chamber 10, the open / close door 13 is closed, the valve 53 is closed, and the valve 57 is opened, and the internal pressure of the loading chamber 10 is reduced by operating the vacuum pump 60. To the internal pressure of Since the vacuum chamber 10 is used as a vacuum drying chamber, the degree of vacuum may be set higher than that of the printing chamber 20 from the viewpoint of shortening the drying time.

After the internal pressure of the loading chamber 10 becomes equal to the internal pressure of the printing chamber 20, the opening and closing door 14 is opened, and the belt conveyors 41 and 42 are driven to move the printing material 1 to the printing chamber 2.
0. When the printing object 1 is moved by the belt conveyor 42 and reaches a predetermined position on the table elevating device 21, the table elevating device 21 raises the table 22 and moves the printing object 1 to a predetermined position, that is, the upper surface of the printing material 2 is printed. It is raised to a position where it comes into contact with the back surface of the stencil 23.
In FIG. 1, the reference numeral 2 is given to the printed material after ascending.

When the printing medium 2 rises to the predetermined position, the resin supply position 27 discharges the resin 29 in front of the squeegee 26b on the stencil 23, that is, in the direction indicated by the symbol H1 for the squeegee 26b. When the resin 29 is discharged,
The squeegee moving device 24 lowers the squeegee 26b until it contacts the stencil 23, and after the squeegee 26b contacts the stencil 23, moves in the direction indicated by reference numeral H1 in the figure, and starts printing. As the squeegee 26b moves,
The resin 29 is filled in the holes 23 a to 23 c formed in the stencil 23.

Outgoing path printing (the squeegee 26b is designated by the reference
In the printing room 20 after the end of the return pass printing (printing in the case where the squeegee 26a is moved in the direction indicated by the symbol H2 in the figure) after the end of the printing when the printing is performed in the direction marked with. The vacuum degree is 30 torr higher than the vacuum degree during forward printing.
At least r, the pressure is lowered to a predetermined degree of vacuum. In addition, 10to
When printing with a degree of vacuum higher than about rr or a degree of vacuum less than 10 torr, air bubbles in the resin may not be completely removed, for example, a resin unfilled portion remains in a hole, an element periphery, a coil line, and the like. These bubbles and unfilled parts are 10 torr
This is the remaining portion of the air having a degree of vacuum less than that, and even after the vacuum is released (after returning to the normal pressure), a gap of about several millimeters of air remains. In this sense, the degree of vacuum is preferably higher than 5 torr, particularly preferably about 1 torr. Thereafter, the degree of vacuum in the printing chamber 20 is adjusted and maintained at a predetermined degree of vacuum that does not exceed the degree of vacuum during forward printing. This is adjusted by opening and closing the valve 54. During the adjustment of the degree of vacuum, the squeegee 26b is raised and the squeegee 26a is lowered.

Subsequently, return printing is performed using the squeegee 26a. After printing on the return path is completed, the table 22 is lowered by the table elevating device 21, and the printing material 2 is separated from the stencil 23. At this time, the lowering speed of the table 22 or the resting time at an arbitrary position is adjusted in order to prevent a shape defect due to a resin break.

Next, the door 33 is opened. Then, when the table 22 is lowered and the printing material 2 is placed on the belt conveyor 42, the belt conveyors 42 and 43 are driven, and the printing material 1 is carried from the printing room 20 to the carry-out room 30. When the loading into the unloading chamber 30 is completed, the opening / closing door 33 is closed, the valve 59 is closed, and the valve 55 is opened to set the pressure in the unloading chamber 30 to atmospheric pressure.

When the pressure in the carry-out chamber 30 becomes atmospheric pressure, the open / close door 34 is opened, and the belt conveyors 43 and 44 are driven to carry out the printing material 3 to the outside. Thereafter, by repeating the series of operations described above, printing can be performed extremely efficiently and the quality can be stabilized.

[Second Embodiment] FIG. 2 is a top view schematically showing the configuration of a vacuum printing apparatus according to a second embodiment of the present invention to which the vacuum printing method according to the second embodiment of the present invention is applied. However, in order to facilitate understanding, cross-sectional views are interlaced. In FIG. 2, reference numeral 90 denotes a loading / unloading chamber for loading and unloading a substrate to be printed, and has a pressure-resistant structure capable of maintaining airtightness. This loading / unloading room 90
Is also used as a vacuum drying chamber for removing moisture and residual volatile substances from the printed material before and after printing. The loading / unloading chamber 90 is provided with an opening / closing door 91 for loading a printing material from the outside and an opening / closing door 92 for unloading the printing material from the outside, and loading / unloading the printing material with a printing room 130 described later. An opening / closing door 93 for carrying out is provided.
These doors 91, 92, and 93 have the same structure and sealing as the doors shown in the first embodiment.

Further, belt conveyors 110, 111, 112, 113 are arranged on a straight line passing through the doors 91, 92. Further, belt conveyors 120 and 121 are arranged on a straight line passing through the door 93 and orthogonal to the belt conveyors 110, 111, 112 and 113. 6, 100, 101, 102, 103, 10
4 is a belt conveyor 110, 111, 112, 113
This is the printing material placed on the top.

Next, the inside of the printing room 130 will be described. The printing room 130 is a printing room in which a printing device is provided, and has a pressure-resistant structure capable of maintaining airtightness. 13
Reference numeral 1 denotes a squeegee moving device, which is similar to the squeegee moving device 24 in FIG. This squeegee moving device 1
Reference numeral 31 is movable in directions indicated by reference numerals H10 and H11 in the drawing along a moving rail 132 horizontally arranged in the printing room 130.

133a and 133b are squeegees similar to the squeegees 26a and 26b described in the first embodiment. 134 is a stencil similar to the stencil 23 described in the first embodiment, and 135 is a hole formed in the stencil 134. 136 is a resin supply device, and 137 is a resin supply nozzle. These are the same as the resin supply device 27 and the resin supply 28 described in the first embodiment. However,
The resin supply nozzle 137 includes squeegees 133a and 133b.
The resin can be supplied to a predetermined position on the stencil 134 in accordance with the movement of the squeegees 133a and 133b.

Further, the above-mentioned loading / unloading chamber 90 and printing chamber 130 are provided with an intake pipe 141 having a valve 152 and an intake pipe 140 having a valve 151, respectively. When the loading / unloading chamber 10 and the printing room 20 are in a vacuum state, the pressure inside the loading / unloading room 90 and the printing room 130 can be set to the atmospheric pressure by opening the valves 152 and 151.

In the loading room 90 and the printing room 130,
Valves 171 and 172 are provided and connected to a pipe 160 connected to a vacuum pump 180. Therefore, when the vacuum pump 160 is operating, the valves 172, 17
1 to the open state, the loading / unloading chamber 90 and the printing room 1
30 can be in a vacuum state. Therefore, the degree of vacuum in the loading / unloading chamber 90 and the printing chamber 130 can be arbitrarily set by adjusting the opening degrees of the valves 151, 152, 171, and 172. In FIG. 2, the vacuum pump 160 is directly connected to the loading / unloading chamber 90 and the printing chamber 130 via the valves 171 and 172. However, if necessary, the loading / unloading chamber 90 and the printing chamber 130 and the vacuum pump 160
And a tank may be provided between them to shorten the time required to reach a predetermined degree of vacuum.

Next, a vacuum printing method applied to a vacuum printing apparatus according to a second embodiment of the present invention will be described in detail with reference to FIG. First, the opening / closing door 93 is closed, the valve 152 is opened, and the pressure inside the loading / unloading chamber 90 is set to the atmospheric pressure. In this state, although not shown in the drawing, the printing medium is arranged in the printing room 130. Next, the door 92 is opened, and the belt conveyor 113,
The printing medium 104 is carried into the carry-in / carry-out chamber 90 by driving the 112. At this time, the printing object 101 that has been printed first
With the opening / closing door 91 on the carry-out side of the carry-in / carry-out room 90 in the open state, the belt conveyors 111 and 110 are driven to carry the outside.

Next, the opening / closing door 9 on the loading side of the loading / unloading chamber 90.
2 and the door 91 on the carry-out side are closed, and the valve 152 is closed.
Is closed, the valve 172 is opened, and the vacuum pump 180 is operated to make the degree of vacuum in the loading / unloading chamber 90 equal to the degree of vacuum in the printing chamber 130. The vacuum chamber 10
Is used as a vacuum drying chamber, the degree of vacuum may be set higher than that of the printing chamber 20 from the viewpoint of shortening the drying time.
During this operation, a printing operation similar to the printing operation described in the first embodiment is performed in the printing room 130.

When the printing operation is completed, the opening / closing door 93 of the loading / unloading chamber 90 is opened, and the printed material on which printing has been completed is driven by the belt conveyors 121 and 120 so that the printing chamber 13 is driven.
0 to the carry-in / carry-out room 90. As a result, the printing medium carried out of the printing room 130 is denoted by reference numeral 102 in FIG.
To the position marked with, followed by the belt conveyor 11
1 and 112, the printing material moves to the position denoted by reference numeral 101, and the printing material at the position denoted by reference numeral 103 moves to the position denoted by reference numeral 102 and prints by driving the belt conveyors 120 and 121. It is carried into the chamber 130.

Thereafter, the production is performed efficiently by repeating the above-mentioned operations. In addition, a mechanism (not shown) for wrapping around the back of the stencil as needed to wipe off the resin is provided, so that the back surface of the stencil is washed after the printing material is detached after printing and before contact with the next printing material. Just do it. Further, it is also possible to connect a device in another process before and after the device and form a production line in conjunction with the device. For example, the pre-process is a circuit board manufacturing process or a semiconductor mounting and connection process, and the post-process is a resin curing and inspection process.

The number of chambers for transporting substrates is one if it is configured as in the second embodiment. However, the configuration as in the first embodiment usually simplifies the apparatus. in this case,
It is also possible to provide a plurality of chambers so that the pressure can be raised and lowered stepwise as a transfer chamber.

[Third Embodiment] Next, a vacuum printing apparatus according to a third embodiment of the present invention will be described. FIG. 3 is a side view showing a part of the configuration of the vacuum printing apparatus according to the first embodiment of the present invention to which the vacuum printing method of the present invention is applied.
However, in order to facilitate understanding, cross-sectional views are interlaced. In FIG. 3, reference numeral 70 denotes a drying chamber provided in a stage preceding the loading chamber 10. The drying chamber 70 is formed by, for example, hot air, far infrared rays, or a combination thereof. In the present embodiment, the case of hot air drying will be described as an example.
The temperature of the drying chamber 70 is in the range of 100 to 200 ° C., particularly 1
20-160 ° C is preferred. The drying time is 5-2.
A range of 4 hours, especially 1 to 8 hours is preferred.

The drying chamber 70 has an inlet pipe 73 for introducing hot air into the drying chamber 70 and an outlet pipe 7 for discharging the introduced hot air.
4 are provided. The introduction tube 73 and the discharge tube 74 are provided with a valve 75 and a valve 76, respectively, so that the introduction amount and the discharge amount of the hot air can be freely controlled. Also, 71 is a drying room 7
A belt conveyor for carrying the printing material 1 into
Reference numeral 2 denotes a belt conveyor provided in the drying chamber 70.
The belt conveyor naturally has heat resistance to the hot air introduced into the drying chamber 70. In addition, outside and drying room 7
Opening and closing doors 77, 7 for shutting off (separating) or opening 0
8 are provided. By closing these to close the inside and outside of the drying chamber 70, the temperature inside the drying chamber 70 can be stabilized and maintained at a predetermined temperature.

Next, a vacuum printing method applied to a vacuum printing apparatus according to a third embodiment of the present invention will be described in detail with reference to FIG. First, the printing material 1 is carried into the drying chamber 1 by the belt conveyors 71 and 72 with the opening and closing doors 77 and 78 opened, and the drying chamber 70 is first opened.
The printing material 1 disposed in the belt conveyor 72, 4
Unload by 0. Next, the open / close doors 77 and 78 provided in the drying chamber 70 are closed, and the valve 75 is opened to introduce hot air into the drying chamber 70. At this time, the valve 76
May be opened to introduce hot air while discharging hot air. Hot air is introduced to set the temperature in the drying chamber 70 to a predetermined temperature, for example, 150 ° C.

After a lapse of a predetermined period of time, for example, eight hours from the start of drying, when the substrate 1 is dried, the opened and closed doors 77 and 78 are opened, and the dried substrate 1 is conveyed by the belt conveyors 72 and 40. While being carried out, the printing material 1 to be dried next is carried into the drying chamber 1 by the belt conveyors 71 and 72. The dried printing material 1 is conveyed into the carry-in room 10 by the belt conveyor 40,
Thereafter, printing is performed by a printing process. The printing process is the same as in the first embodiment.

When the printing object is an electronic component, the steps from the step of mounting the semiconductor element on the substrate and connecting the semiconductor element and the substrate to the step of drying the substrate need not be performed continuously. Further, it is not necessary to perform the process continuously from the process of drying the substrate to the process of vacuum printing and sealing, but within a time (about 8 hours under a normal working environment) that the substrate does not absorb moisture again. It is preferred to do so. Further, in the first embodiment, the printing medium 1 is dried by vacuum drying in the loading chamber 10. However, the drying may be performed using only the drying chamber 70, or the vacuum drying by the loading chamber 10 may be performed. The drying in the drying chamber 70 may be performed together.

[Fourth Embodiment] Next, a vacuum printing apparatus according to a fourth embodiment of the present invention will be described. The vacuum printing apparatus according to the fourth embodiment of the present invention has a configuration in which a drying chamber 70 shown in FIG. 3 is provided at a stage preceding the vacuum printing apparatus according to the second embodiment of the present invention shown in FIG. As in the third embodiment, the drying chamber may be, for example, hot air, far-infrared, or a combination thereof. Also in the present embodiment, when the print target is an electronic component, the steps from mounting the semiconductor element on the substrate and connecting the semiconductor element and the substrate to drying the substrate need to be continuously performed. There is no. Further, it is not necessary to perform the process continuously from the process of drying the substrate to the process of vacuum printing and sealing, but within a time (about 8 hours under a normal working environment) that the substrate does not absorb moisture again. It is preferred to do so. Further, in the first embodiment, the printing medium 1 is dried by vacuum drying in the loading chamber 10. However, the drying may be performed using only the drying chamber 70, or the vacuum drying by the loading chamber 10 may be performed. The drying in the drying chamber 70 may be performed together.

[0048]

Next, an embodiment of the present invention will be described. This example is mainly of the third embodiment of the present invention, and a drying chamber 70 using hot air drying is used. In this embodiment, samples were manufactured as Example 1 and Example 2 using the vacuum printing apparatus according to the third embodiment under different conditions. Example 1 and Example 2
Prepares a substrate on which a semiconductor element is mounted as a printing substrate. That is, an IC chip was adhered to a glass epoxy substrate having a thickness of 0.5 mm on which a circuit was formed, using a die bonding paste, and a wire-bonded IC chip was used, and this was left under an atmosphere of 20 ° C./60% for 3 days.

Examples 1 and 2 prepared using the above-described substrate are as follows. Example 1 After the above-mentioned substrate was subjected to a drying treatment at 125 ° C. for 8 hours, it was sealed with a sealing resin NPR-100 (manufactured by Nippon Rec Co., Ltd.) using a vacuum printer. The printing conditions were as follows: after printing with a printing stencil having a stencil thickness of 0.8 mm and an opening of 10 × 10 mm at a degree of vacuum of 1 torr, returning it to the atmosphere and taking it out, drying with a hot air drier at 100 ° C. for 1 hour, Further, it was dried and cured at 150 ° C. for 3 hours. Example 2 Example 2 is different from Example 1 in that the drying temperature and time were 150 ° C./2 hours, and the other conditions were the same as Example 1.

For comparison with Examples 1 and 2, the following Comparative Examples 1 to 3 were prepared. Comparative Example 1: The substrate was not subjected to the drying treatment, but was subjected to the same vacuum printing and sealing as in Example 1 and was similarly cured. Comparative Example 2: After the substrate was not dried and sealed with the same printing stencil and sealing resin as in the example under the normal atmosphere, the defoaming treatment was performed with a vacuum defoamer at 60 torr / 3 minutes. After the application, printing and drying were performed under the same conditions as in Example 1. Comparative Example 3: After the substrate was dried at 125 ° C. for 8 hours, the same printing, defoaming, and curing treatments as in Comparative Example 2 were performed.

Examples 1 and 2, Comparative Example 1, Comparative Example 2 and Comparative Example 3 were prepared as follows: (1) Appearance (2) Presence or absence of air bubbles (ultrasonic test) (3) Thermal cooling cycle test ( (4 cycles of −40 ° C. to 100 ° C.) (4) Constant temperature and humidity test (maintaining 85 ° C./85% and applying 12 V to electronic components) (5) PCT (Pressure Cooker Test) (121 ° C., 2
Pressure). FIG. 4 is a chart showing the evaluation of the test results of the actually created examples and comparative examples.

As shown in FIG. 4, in Comparative Examples 2 and 3, in which defoaming treatment was performed after printing and sealing in a normal atmosphere, the appearance was good, so that bubbles in the resin could be removed. However, it is considered that the reliability is lowered because bubbles remain around the chip. Further, it can be seen from FIG. 4 that in Comparative Example 1 performed by vacuum printing, bubbles around the chip did not remain as in Comparative Examples 2 and 3, but the moisture and low moisture contained in the substrate constituent material were low. The volatile components are released as bubbles into the sealing resin in a vacuum atmosphere, and it is considered that the presence of the bubbles prevents improvement in reliability.

In contrast to these Comparative Examples 1 to 3, in Examples 1 and 2 in which the substrate was dried in advance and printing was performed while maintaining the substrate in a dry state, the external shape could be maintained. Needless to say, the reliability was significantly improved as compared with Comparative Examples 1 to 3. Such a remarkable improvement in reliability only requires a drying step before vacuum printing without the necessity of adding a large-scale facility, and has a great technical effect.

In the above embodiment, the single-wafer processing is performed in the drying chamber in the drying step before the vacuum printing step. However, a large number of processing can be performed at once. For example, a multi-stage rack, case, magazine, cassette, or the like may be used, a drying process may be performed while being stored in these, and a single sheet may be transported to a printing room to perform vacuum printing.

[0055]

As described above, according to the present invention, drying is performed before printing under vacuum to remove moisture and residual volatile substances from the printing object. Since moisture and residual volatile substances do not mix as bubbles in the resin thus obtained, there is an excellent effect that the reliability of the package can be improved. Further, since a drying chamber for performing drying (also used as a transfer chamber in the case of vacuum drying) is simply provided in the preceding stage of the printing chamber, the above-described effects can be obtained without incurring a large capital investment, and the manufacturing can be performed. There is an extremely excellent effect that the efficiency is not reduced.

[Brief description of the drawings]

FIG. 1 is a side view schematically showing a configuration of a vacuum printing apparatus according to a first embodiment of the present invention to which a vacuum printing method according to the first embodiment of the present invention is applied.

FIG. 2 is a top view schematically illustrating a configuration of a vacuum printing apparatus according to a second embodiment of the present invention to which the vacuum printing method according to the second embodiment of the present invention is applied.

FIG. 3 is a side view showing a part of the configuration of the vacuum printing apparatus according to the first embodiment of the present invention to which the vacuum printing method of the present invention is applied.

FIG. 4 is a table showing evaluation of test results of the created examples and comparative examples.

[Explanation of symbols]

 Reference Signs List 10 carry-in room (transfer room, drying room) 13 door (second door) 14 door (first door) 20 printing room 23 stencil 26a, 26b squeegee 70 drying room 90 carry-in / out room (transfer room, (Drying room) 130 printing room 133a, 133b squeegee 134 stencil

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Noriko Fujita, Inventor 5-29-21 Senriyama Nishi, Senriyama-nishi, Suita-shi, Osaka 203 Felisimo Senriyama 203 72) Inventor Tsuneichi Hashimoto 1-24 Kitano, Yasu-cho, Yasu-gun, Shiga F-term (reference) 5E314 AA24 CC08 EE02 EE08 FF01 FF21 GG15 GG24 5F061 AA01 BA03 CA12 CB12 DE06

Claims (9)

[Claims] 1. A vacuum printing apparatus for printing a printing material under vacuum, comprising: a drying chamber for drying the printing material; and a drying chamber provided at a subsequent stage of the drying chamber, for printing and supplying resin to the printing material under vacuum. A vacuum printing apparatus, comprising: 2. A printing apparatus provided between the printing room and the drying room, which is separated or opened from the printing room via a first opening / closing door and from the drying room via a second opening / closing door. 2. The vacuum printing apparatus according to claim 1, further comprising a transfer chamber into which the arranged print material is loaded. 3. The vacuum printing apparatus according to claim 2, wherein the transfer chamber dries the printing material by vacuum drying. 4. The vacuum printing apparatus according to claim 1, wherein the drying chamber dries the printing material by hot air drying. 5. The printing room is provided with a printing machine for printing a resin by a squeegee using a stencil, and two squeegees are provided, and printing is performed using different squeegees when performing forward printing and returning printing. The vacuum printing apparatus according to claim 1, wherein: 6. A vacuum printing method for printing a printing material under vacuum, comprising: a drying step of drying the printing material; and a printing step of printing and supplying a resin to the printing material under vacuum after the drying step. A vacuum printing method comprising: 7. The vacuum printing method according to claim 6, wherein the drying step is a step of performing vacuum drying. 8. The vacuum printing method according to claim 6, wherein the drying step is a step of performing hot air drying. 9. The printing step is a step of setting and holding an arbitrary degree of vacuum during forward printing, from the end of forward printing to the start of backward printing, and at the time of backward printing. The vacuum printing method according to claim 6, wherein