JPS63196046A - Resin coating method for electronic component - Google Patents

Abstract

PURPOSE:To enable a substrate part to be coated with high precision by a method wherein electronic parts are dipped into a resin solusion vessel up to specified position to be moved therein. CONSTITUTION:Electronic parts 2 with the substrate part 10 thereof turned downward are dipped into a resin solution vessel 31 in the specified depth and then moved in the specified direction in the vessel 31 to accelerate the adherence of resin solution to the substrate part 1a while the electronic parts 2 are picked up uprightly from the resin solution vessel 31. Through these procedures, the substrate part 1a can be coated with resin smoothly subjected to neither any irregularities such as step difference nor any inner bubbling etc., at all.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a method for coating electronic components, such as hybrid ICs, module electronic components, radial type electronic components, etc., on which various circuit components constituting electronic circuits are mounted, with a molten resin. ■Prior art] Electronic components such as hybrid ICs are made by forming a predetermined wiring pattern on a substrate made of a ceramic plate, etc., and also having a substrate on which circuit components such as resistors, capacitors, integrated circuits, etc. are mounted, and the substrate. It has a plurality of terminal parts extending from the board part, and is coated with an electrically insulating resin in order to insulate and protect the wiring pattern on the board part and the circuit components mounted thereon. It has become. This coating resin is used in powder form and liquid form, and when coating with powder resin, conventional methods that aim to automate the work are It has been used since. However, when using a liquid coating material,
This process has not been automated, and the coating has been done manually by dipping the substrate of the electronic component into a molten resin bath. [Problems to be solved by the invention] By the way, as mentioned above, when coating with liquid resin manually, not only is the work efficiency poor, but the resin liquid has a high viscosity. for,
Various circuit components are mounted, and it is difficult to spread the resin liquid over the entire board with large irregularities and coat it with a uniform film, and it is also difficult to control the depth of dipping into the resin bath. It is difficult to do this, and there are drawbacks such as the so-called dipping separation accuracy cannot be strictly performed. The present invention has been made in view of the above points, and an object thereof is to provide a resin coating method for electronic components that enables resin coating to be applied to a board portion with high precision. be.

[Means for Solving the Problems 1] In order to achieve the above-mentioned object, the present invention provides an electronic component having a board portion on which various circuit components are mounted, and a terminal portion extending from the board portion. , in a method for resin coating the board part together with circuit components mounted thereon by dipping the board part in a resin liquid bath, with the board part of the electronic component facing downward;
The electronic component is dipped in a resin liquid tank, and while the electronic component is dipped to a certain depth in the resin liquid tank,
By moving the electronic component in a predetermined direction within the tank, adhesion of the resin liquid to the substrate part is promoted, and when the electronic component is taken out from the resin liquid tank, the electronic component is pulled up straight. This is its characteristic. [Operation 1] The electronic component is dipped into a resin liquid tank with its substrate facing vertically. During dipping into the resin liquid tank, the electronic components should be moved at a gentle speed to a certain position from the time the electronic components reach the liquid level until they are buried to a predetermined depth. For example, it becomes possible to achieve strict accuracy in the parting position of the electronic component. Then, while dipped in the resin liquid tank in this way, the electronic component is vibrated or swung back and forth, left and right, or up and down, and further moved in a manner that combines each of the above operations. The resin liquid can be easily spread around the entire substrate part on which the circuit components are mounted and which has large irregularities on the surface, and it is possible to prevent problems such as the generation of air bubbles inside. Then, when taking out the electronic component, by pulling it up in a straight state, the thickness of the resin coating layer becomes uniform,
The surface can be finished smoothly. [Example] Hereinafter, an example of the present invention will be described in detail based on the drawings. The electronic component coated with resin by the coating method of the present invention has a structure as shown in FIG. That is, the workpiece 1 has a substrate portion 1a made of a plate made of ceramic or the like, and a plurality of terminal portions 1b, lb, ... protruding from the substrate portion 1a, and a predetermined wiring pattern is formed on the substrate portion 1a. At the same time, various circuit components 2, 2 . ... is mounted, and its surface has a large unevenness. In this manner, the substrate portion 1a on which various circuit components 2 are mounted is coated with a covering layer 3 having good electrical insulation and heat resistance, such as phenol resin. Here, as described above, the apparatus for carrying out the coating method on the substrate portion 1a is configured as shown in FIG. In the figure, reference numeral 10 indicates a workpiece placement section, and reference numeral 11 indicates a reversing section, and a workpiece support tray 12 to be supported is placed on the workpiece placement section 10. As shown in FIGS. 3 and 4, the workpiece support tray 12 has a plurality of protrusions 13 having a rectangular cross section in the longitudinal direction of the base portion 13.
a, 13a, . At the same time, the left and right sides of the spring plate piece 14 are formed with holding walls 14b, 14b rising vertically along the side wall surface of the protrusion t3a, and both ends thereof are bent diagonally in a direction approaching each other. The attracting part 14c,
14c. The terminal portion 1b of the workpiece 1 is inserted through the lead-in portion 14c and is erected so as to be sandwiched between the holding wall portion 14b and the protrusion 13a. Next, the reversing section 11 has an inverting table 16, and as shown in FIG. It has side wall portions 18b erected on both left and right sides of the wall portion 113a, and a locking wall portion 18c is formed at the upper end. When the workpiece support tray 12 is inverted, it is restricted by the locking wall portion 18c and is held so as not to fall off the inversion table 1B. In order to transfer the workpiece support tray 12 holding the workpiece 1 in an upright state from the workpiece placement part 10 to the reversal table 18 in the reversal part 11, a transport hook 17 is provided as shown in FIG. The transport hook 17 can engage with a handle 18 attached to the workpiece support tray 12. The conveyance hook 17 is attached to the conveyance guide block 13, and the conveyance guide block 19 can be reciprocated along the guide rod 21 by a driving means (not shown) such as a timing belt. It has become. Further, as shown in FIG. 7, a motor 22 for driving the reversal is mounted on the base 1ia of the reversing section 11, and the motor 22 is connected to the reversing table 18 via a timing belt 23. It is connected to the rotation shaft 24. Therefore, when the motor 22 is operated, the reversing table 18 is in the state shown by the solid line in the same figure and in the state shown by the dashed line.
It is configured to allow rotational displacement between the 80° inverted state and the 80° inverted state. As is clear from FIG. 7, a connecting rod 25 is vertically provided on the lower surface of the base 11a of the above-mentioned reversing section 11, and the tip of the connecting rod 25 is fixed to a lifting platform 26. . The lifting platform 26 is driven up and down by a pole screw 28 driven by a motor 27 for driving up and down. In order to control the amount of feed of the reversing section 11 by the pole screw 28, the pole screw 28 is
An encoder 29 for detecting the rotation angle of 8 is attached. Furthermore, as shown in FIG. 8, a reflective liquid level sensor 30 is attached to the lower surface of the base 11a, and this liquid level sensor 30 allows the detection of the temperature between the workpiece 1 and the resin liquid level. It is configured to be able to detect intervals. The resin liquid tank 31 is disposed below the reversing part 11, and the resin liquid tank 31 is connected to the inner tank 32 as shown in FIG.
The inner tank 32 and the outer tank 33 are connected to each other by a communication passage 34, and the inner tank 32
The height of the wall is lower than that of the outer tank 33. For this reason, the resin liquid in the resin liquid tank 31 flows from the outer tank 33 into the inner tank 33 via the communication path 34, forming a continuous circulation flow that overflows from the upper part of the inner tank 33 to the outer tank 32. In order to forcibly form this circulating flow, a stirring blade 35 is attached to the communication path 34, and the stirring blade 35 is rotationally driven by the stirring motor 3B. ing. Further, in order to swing the work 1 when dipping the work 1 in the resin liquid tank 31, the reversing part 11 is engaged with the base part 11a at the lowered position, as shown in FIG. 1O. A swinging lever 38 is provided that swings about a support shaft 37.
8 around the support shaft 37,
The workpiece 1 is designed to be oscillated in the horizontal direction. The other end of the swing lever 38 is connected to the swing motor 3.
As shown in FIG. The swing range can be changed. Furthermore, 42 is a fixed position sensor provided to detect that the swing lever 38 is reliably returned to the normal position when the swing is stopped. The apparatus for carrying out the method of the present invention is constructed as described above, and next, a method for coating electronic components using this apparatus will be explained. First, the motor 36 is rotated to rotate the stirring blade 35 to form a circulating flow in the resin liquid in the resin liquid layer 31 that flows from the inner tank 32 to the outer tank 33 and from the communication path 34 to the inner tank 32. As a result, the resin liquid in the resin liquid tank 31 is kept fluid. On the other hand, the work 1 has its substrate portion 1
The terminal portion tb is erected on the workpiece support tray 12 with the side a facing upward. The work support tray 12 with the work 1 mounted thereon in this manner is placed on the work placement section 10 manually or by an appropriate loading means. In this state, the transport hook 17 is moved toward the workpiece loading section 10, and the handle 18 provided on the workpiece loading section 10 is moved.
engage with. Then, when the transport hook 17 is returned, the workpiece support tray 12 is moved onto the reversing table 16 in the reversing section 11. Therefore, the conveyor hook 17 is attached and detached from the handle 18, and the motor 22 is operated to connect the rotation shaft 24 via the timing belt 23.
By rotating the inverting table 16, the inverting table 16 is inverted by 180@. In this way, the reversing section 11 is reversed, and the workpiece support tray 12
The workpiece 1 mounted on the holder is placed in a state in which the substrate portion 1a faces vertically, and stirring of the resin liquid tank 31 is stopped, and the motor 27 is driven to rotate the ball screw 28 to move the lifting platform 2B. By lowering the workpiece 1, the substrate portion 1a of the workpiece 1 is dipped into the resin liquid tank 31. here,
As shown in FIG. 2, in order to completely cover the substrate portion 1a of the workpiece 1 with the coating layer 3, the coating layer 3 is formed up to a predetermined position at the base of the terminal portion 1b. It is necessary to strictly control the parting accuracy of the resin so that the depth of the inward dipping is always constant. For this purpose, the liquid level in the resin liquid tank 31 is monitored by a liquid level sensor 30 mounted on the base 11a of the reversing section 11. Then, when the reversing part 11 reaches a predetermined height position with respect to the liquid level of the resin liquid tank 31, the liquid level sensor 30 detects this and controls the operation of the motor 27.
By repeating the coating process, the resin liquid tank 3
Even if the liquid level inside the workpiece 1 changes, the depth separation position of the workpiece 1 can be determined with high precision. The depth of dipping may be directly detected by the liquid level sensor 30, or the liquid level sensor 30 may detect when the liquid level reaches a predetermined height from the liquid level. It is also possible to feed the motor 27 by a predetermined feed amount based on this detection signal. By doing the latter, the feeding by the motor 27 is performed at high speed until the liquid level detection signal from the liquid level sensor 30 is input, and the speed of the motor 27 is changed from the time when the liquid level detection signal is input. By lowering the amount, it becomes possible to prevent the resin liquid from splashing up during dipping. If the motor 28 is stopped when the encoder 29 has counted a predetermined number of pulses since the liquid level detection signal was input, the efficiency of the de-dipping operation can be improved. Become. Here, since the resin liquid has a fairly high viscosity, as shown in FIG. 12, it becomes difficult to adhere to the workpiece 1 due to its surface tension when the workpiece 1 is dipped. Also. Since various circuit components 2 are mounted on the substrate portion 1a, its surface has large unevenness, and it is difficult to cause the resin liquid to flow around the unevenness. Therefore, motor 3S
is activated to rotate the eccentric roller 40 and swing the swinging lever 38 about the support shaft 37, so that the workpiece 1 mounted on the reversing section 11 is horizontally moved in the resin liquid tank 31. You will be made to sway. As a result, the surface tension in the resin liquid is destroyed, and the resin liquid comes to wrap around the entire substrate portion 1a of the workpiece 1, forming a coating layer 3 of resin liquid up to the parting line. At the same time, the resin liquid flows around to every corner of the uneven parts of the substrate part 1a, and the coating layer 3
There is no risk of bubbles being generated inside. As described above, the workpiece 1 may not only be swung horizontally around the support shaft 37, but may also be swiveled horizontally within the resin liquid layer 31, for example. Further, it may be moved horizontally in the plate thickness direction or in a direction perpendicular thereto, it may be vibrated in the horizontal or vertical direction, or the above-mentioned operations may be combined. After the work 1 is moved and dipped in the resin liquid for a predetermined period of time as described above, the swinging of the work 1 by the motor 39 is stopped, and the motor 27 is activated to raise the lifting platform 28. The workpiece 1 mounted on the workpiece support tray 12 is pulled up from the resin liquid. Here, the workpiece 1 is pulled up vertically and at a slow speed until the resin liquid adhering to the workpiece 1 runs out, so that the surface of the workpiece 1 can be coated without any difference in level. etc. can be prevented from occurring. After the workpiece 1 is drained of liquid, the rotational speed of the motor 27 is increased to increase the lifting speed. The operation of the motor 27 at this time can be controlled based on the signal from the encoder 23. And, the reversing section 11 is the workpiece placement section! When the height becomes the same as the height position of O, the rotation of the motor 27 is stopped, and the motor 22 is rotated to invert the reversing section 11 by 180'' together with the work supporting tray 12 installed therein. The workpiece 1 returns to the state with its substrate portion 1a facing upward.Then, the workpiece support tray 12
By drying the coating layer 3 on the work l by air drying or the like in that position or in the state taken out from the reversing section 11, the work l can be coated. In the above-mentioned embodiment, a plurality of workpieces 1 are installed in the workpiece support tray 12 in an upright state, and the workpieces 1 are inverted and immersed in the resin liquid tank 31. In short, after dipping the workpiece 1 into the resin liquid tank 31 with the substrate portion 1a facing vertically, the workpiece 1 should be moved in a predetermined direction to perform the resin coating. It goes without saying that the device configuration for carrying out the present invention is not limited to that of the embodiment described above. Effects of the Invention As described in detail above, the present invention provides for dipping an electronic component into a resin liquid tank to a predetermined position with its substrate facing in the vertical direction; I made it move and then pulled it up vertically.
Even if the resin is highly viscous, the resin can be passed around very smoothly, and the dipping accuracy is good, and there are no bubbles inside.
Furthermore, the resin coating can be applied to the surface in a smooth state without unevenness such as steps.

[Brief explanation of the drawing]

Fig. 1 is an overall configuration diagram of a coating apparatus showing an embodiment of the present invention, Fig. 2 is an external view of a workpiece showing a state in which a part of the coating layer is cut away, and Fig. 3 is an explanatory diagram of the structure of a workpiece support. ,
FIG. 4 is a sectional view taken along line 17-IT in FIG. 3, FIG. 5 is an explanatory diagram of the structure of the reversing section, FIG. 6 is an explanatory diagram showing the mechanism for transferring the workpiece from the work storage section to the reversing section, and FIG. Figure 8 is an explanatory diagram showing the operating state of the reversing section, Figure 8 is an explanatory diagram of the configuration of the liquid level sensor, Figure 9 is an explanatory diagram of the configuration of the resin liquid tank, and Figure 10 is an explanatory diagram of the configuration of the workpiece swing mechanism. , FIG. 11 is an enlarged plan view of the main part of FIG. 10, and FIG. 12 is an explanatory diagram of the operation. 1: Workpiece, la: Board part, 1b = Terminal part, 2: Circuit component, 3: Coating layer, 1o: Work placement part, 11: Inversion part, 12: 7-way support tray, IB: Inversion table, 3o :
Liquid level sensor, 31: Resin liquid tank.

Claims (1)

[Claims] An electronic component having a board part on which various circuit parts are mounted and a terminal part extended from the board part is prepared by dipping the board part in a resin liquid bath together with the circuit parts mounted thereon. In the method for resin coating, the electronic component is dipped in a resin liquid bath with the substrate portion facing vertically, and the electronic component is dipped to a certain depth in the resin liquid bath. By moving the component in a predetermined direction within the tank, the adhesion of the resin liquid to the substrate is promoted, and when the electronic component is taken out from the resin liquid tank, the electronic component is pulled up straight. Characteristic resin coating method for electronic parts.