JPH0536742A - Resin sealing method for electronic components - Google Patents

Abstract

PURPOSE:To provide a resin sealing method for electronic components which is capable of reducing stress produced on sealing resin. CONSTITUTION:A partitioning jig 30 is mounted on a high voltage IC 14, which is divided into a plurality of blocks. The partitioning jig 30 comprises a partitioning board 32 which divides the high voltage IC 14 and a supporting board 34 which supports the partitioning board 32 and formed with 'Teflon(R)'. To resin-seal the high voltage IC 14, epoxy resin 24 is potted at first for each block. After the resin 24 is heated and cured, the partitioning jig 30 is removed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention seals an electronic component such as a semiconductor element mounted on a long substrate used in an electrostatic recording head of an electrostatic printer or an electrostatic plotter with resin. It is about the method.

[0002]

2. Description of the Related Art An electrostatic printer or an electrostatic plotter forms an electrostatic latent image on an electrostatic recording paper by an electrostatic recording head, visualizes it with toner, and fixes it to print. The electrostatic recording head used in these devices is shown in FIG.
As shown in FIG. 5, the side plate is formed by resin-sealing the tip of the substrate 50 on which a large number of recording electrodes 52 are formed on the front and back surfaces, and the tip is polished and finished. A high voltage IC 54 and a drive common power supply board 56 are mounted on both sides of the board 50.

By the way, in the case of a large electrostatic plotter, for example, an apparatus for printing on A0 size paper, the width of the substrate in the longitudinal direction is about 1 m, and 7200 on one side during this period.
A total of 14,400 recording electrodes 52 are formed on both the front and back surfaces. Along with this, a large number of high voltage ICs 54 for applying a high voltage to the recording electrodes 52 are mounted on the substrate 50 at high density.

[0004]

As described above, the substrate 50 is used.
High voltage IC54 placed on top with high density
In the case of resin encapsulation (COB), even if an attempt is made to apply thermosetting resin 64 such as epoxy resin onto the individual high voltage ICs 54, the resin will flow in all directions, and as shown in FIG. Resin sticks to each other, resin 64
Will be integrated. Therefore, a large stress is generated in the resin due to the contraction of the resin when curing the resin, the heat generation of the high voltage IC, and the expansion and contraction of the resin due to a change in the environmental temperature. Due to the large stress generated in the resin, the high voltage IC 54 and the bonding wire 72 are damaged or the substrate 50 is deformed. As described above, the conventional method has a problem particularly when the semiconductor elements arranged in high density on the substrate are sealed with resin.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a resin sealing method for electronic components, which can reduce the stress generated in the sealing resin.

[0006]

A method for resin-sealing an electronic component according to the present invention for achieving the above object is a method for resin-sealing an electronic component arranged on a substrate, using a partitioning jig. After partitioning the electronic component, the electronic component is sealed with a resin, and after the resin is cured, the partitioning jig is removed.

Further, it is desirable that the partition jig is made of polytetrafluoroethylene or a metal whose surface is treated with fluorine.

[0008]

According to the present invention, the electronic device is divided into a plurality of blocks, for example, by a partitioning jig, and each block is resin-sealed so that the resin in each block flows out to the other side. Prevent.

Further, when the partition jig is made of polytetrafluoroethylene or the surface thereof is made of fluorinated metal, the partition jig has low adhesiveness and friction resistance.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a diagram for explaining a resin sealing method for an electronic component according to an embodiment of the present invention, and FIG. 2 is a schematic perspective view of a partitioning jig used in the resin sealing method for the electronic component.

The elongated substrate 10 shown in FIG. 1 is used as an electrostatic recording head of an electrostatic printer or an electrostatic plotter. Electrodes 12 are formed on the surface of the substrate 10 at a high density by an etching method or the like, and the electrodes 12 are used as needle electrodes for forming an electrostatic latent image on electrostatic recording paper. In addition, the substrate 10 has a high voltage IC 14,
A drive common power supply board 16 and a component 18 such as a resistor and a capacitor are mounted. IC14 for high voltage
Is for applying a high voltage necessary for forming an electrostatic latent image on the electrostatic recording paper, and a large number of electrodes 12 are arranged in the longitudinal direction of the substrate 10 due to the high density of the electrodes 12. . Matrix wiring is provided on the common driving power supply substrate 16. The high voltage IC 14 includes the bonding wire 22 for the electrode 12 and the common power supply substrate 16 for driving.
It is connected to the matrix wiring.

In order to protect the high voltage IC 14 and the bonding wire 22, it is necessary to seal them with a resin 24. In the resin sealing method of this embodiment, first, the partitioning jig 30 is attached to the high voltage IC 14 on the substrate 10.
Is attached and the high voltage IC 14 is divided into a plurality of blocks. Then, a thermosetting resin 24 such as an epoxy resin is potted for each block.

The partitioning jig 3 used in this embodiment is as follows.
0 will be described. The partitioning jig 30 shown in FIG. 2 is composed of a partition plate 32 that divides the high-voltage IC 14 into a plurality of blocks, and a support plate 34 that supports the partition plate 32. Each high-voltage IC 14 has a U-shape. It is divided into The partition plate 32 includes one high voltage IC 14 in each block. I for high voltage
Since C14 are linearly arranged, the support plate 34 also has a length substantially the same as the length of the substrate 10 in the longitudinal direction. A step portion 32 a is provided at a lower end portion of the partition plate 32 so as to engage with the drive common power supply board 16. The partition plate 32 and the support plate 34 are each formed in a tapered shape using Teflon (polytetrafluoroethylene). Since Teflon has poor moldability, a special molding method such as a sintering method is used.

After potting the sealing resin 24, the resin 24 is cured by heating, and the partitioning jig 30 is removed. Since Teflon is used as the material of the partitioning jig 30, not only the heat resistance is good, but also the adhesiveness and the friction resistance are low. Therefore, the partitioning jig 30 has a very weak adhesive force with epoxy resin, silicone resin or the like, and the partitioning jig 30 is formed in a tapered shape, so that the partitioning jig 30 can be easily removed. be able to. In this way, the resin sealing work of the high voltage IC 14 is completed. The partition jig 30 can be used repeatedly as many times as desired.

To form an electrostatic recording head using the substrates 10 thus manufactured, for example, the surfaces of the two substrates on which the electrodes are not formed are made to face each other, and the electrodes of the respective substrates are arranged in a zigzag pattern. Join so that. Then, a side plate is adhered to the upper portion of the substrate 10 (on the side where the electrodes are formed), and the tip is polished and finished to form an electrostatic recording head.

In the resin sealing method for electronic parts of this embodiment,
After partitioning the high voltage IC into multiple blocks using a partitioning jig, each block is resin-sealed, so the resin flows into the adjacent block, and the resins in the adjacent blocks are stuck together and integrated. Can be prevented. Therefore, even if the resin shrinks when the resin is cured or the resin expands due to heat generation of the high voltage IC, a large stress is not generated in the resin. Therefore, even if stress is generated in the resin due to heat shrinkage or the like, the stress does not damage the IC for high voltage, pull the bonding wire to break the wire, or deform the substrate. Further, since the resin does not flow into the adjacent block, the electronic component can be surely sealed with the resin, and the waste of the resin can be prevented. Furthermore, since it is not necessary to be careful that the sealing resin spreads and is integrated, the resin sealing work becomes easier,
It is also possible to automate the work.

In the above embodiment, the case where the partitioning jig is formed by using Teflon has been described.
The present invention is not limited to this, and the surface of the partitioning jig made of metal may be treated with fluorine. The fluorine treatment on the surface also reduces the adhesiveness and frictional resistance, and makes it easy to remove the partitioning jig from the sealing resin.

In the above embodiment, the case where each high voltage IC is partitioned into a U shape by the partition jig has been described, but the present invention is not limited to this, and the partition jig is not limited to this. For example, each high voltage IC may be formed so as to surround a square. As described above, by completely surrounding the high voltage IC, it is possible to prevent the resin from flowing out to a portion where the resin does not adhere to other parts, a portion which needs to be subjected to a post process, or the like.

Further, in the above embodiment, the case where one block divides one high voltage IC has been described. However, one block divides two or more high voltage ICs.
You may partition.

In addition, in the above embodiment, the case where the present invention is applied to the electrostatic recording head has been described. However, the present invention is not limited to this, and a substrate on which a large number of semiconductor elements are mounted is used. If so, it may not be a recording head such as an electrostatic printer.

[0021]

As described above, according to the present invention, since the electronic component is resin-sealed by using the partitioning jig,
Since resin can be prevented from flowing out to other parts and the resin can be sealed in predetermined blocks, it is possible to prevent large stress from being generated in the resin and damage to electronic parts such as semiconductor elements due to the stress of the sealing resin. Also, it is possible to provide a resin sealing method for an electronic component, which can prevent the deformation of the substrate and is therefore particularly suitable for resin sealing of a semiconductor element or the like mounted on an electrostatic recording head such as a high-quality electrostatic plotter. it can.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a resin sealing method for an electronic component which is an embodiment of the present invention.

FIG. 2 is a schematic perspective view of a partitioning jig used in the resin sealing method for electronic components of the present embodiment.

FIG. 3 is a diagram for explaining a conventional resin sealing method for electronic components.

[Explanation of symbols]

10 substrates 12 electrodes 14 High voltage IC 16 Common power supply board for driving 18 Parts such as resistors 22 Bonding wire 24 Sealing resin 30 Partition jig 32 partition boards 34 Support plate

Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H01L 21/56 R 8617-4M // B29L 31:34 4F

Claims (2)

[Claims] 1. A method of resin-sealing electronic components arranged on a substrate, wherein after partitioning the electronic components with a partitioning jig, the electronic components are sealed with a resin, and after the resin is cured, A resin sealing method for electronic components, characterized in that a partitioning jig is removed. 2. The resin sealing method for an electronic component according to claim 1, wherein the partitioning jig is made of polytetrafluoroethylene or a metal whose surface is treated with fluorine.