JPS63155790A - Method of applying adhesive for chip parts - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for applying adhesive for chip components, and more specifically, the present invention relates to a method for applying an adhesive for chip components. The present invention relates to an adhesive method for chip components that detects and re-transfers the untransferred portions so that adhesive is applied to all the portions that require transfer.

[Conventional technology]

2. Description of the Related Art In recent communication equipment, home appliances, and the like, so-called light, thin, short, and small products are preferred, and in particular, for example, portable video cameras and the like are desired to be further miniaturized.

For this reason, high-density mounting is required for the printed circuit boards used for mounting electronic components in the above-mentioned home appliances, etc., and one way to achieve this high-density mounting is to Double-sided mounting is used to mount various electronic components.

On the other hand, conventional electronic components such as resistors or capacitors have lead wires extending from both end faces in the direction of the central axis of a cylindrical shape, and these lead wires are bent appropriately and printed. The device was inserted into a hole (through hole, etc.) formed on the board and soldered using an automatic solder bath.

However, when trying to perform high-density mounting as described above, with conventional electronic components that have lead wires, the lead wires protrude to the back side when mounted from the top side of the printed circuit board.
It is not possible to mount other electronic components on the back side in this protruding place.

Therefore, to deal with such cases, leadless parts (chip parts) that do not have lead wires have come to be used, and there are two known types of leadless parts: square chip parts and cylindrical chip parts. ing.

As shown in Figure 6, this cylindrical □-shaped chip component has a cylindrical shape with a diameter of 2 mm and a length of 5 mm, for example, and a belt-shaped solder is attached along the circumference at the left and right ends of the cylinder. Part 1
02 and 103 are formed respectively.

When mounting such cylindrical chip components on both sides of a printed circuit board, an appropriate adhesive is first applied to a position on one surface where the chip components are to be mounted. Next, by feeding predetermined cylindrical chip parts from a parts feeder to the adhesive-coated area, for example, several hundred cylindrical chip parts are applied to the above-mentioned adhesive-coated apparatus.

After temporarily adhering the cylindrical chip to the printed circuit board in this manner, the adhesive is further placed in a thermosetting oven to harden the applied adhesive, thereby firmly adhering the printed circuit board and the cylindrical chip component.

After the cylindrical chip components are bonded and cured on one side of the printed circuit board in this way, other components are mounted on the other side, and then soldered using an automatic solder bath.

[Problem to be solved]

By the way, as mentioned above, in the case of high-density mounting, several hundred cylindrical chip parts may be mounted on one side of a printed circuit board, and in such cases adhesive is applied to the transfer pins, and then printed. Transfer the adhesive to the substrate. At that time, the adhesive may not be sufficiently transferred to the printed circuit board, and even if cylindrical chip parts are supplied from the parts feeder and attempted to be bonded, they may not be able to be bonded and the cylindrical chip parts may fall off. be.

In such a case, conventionally, a person visually confirms the unmounted parts (that is, the parts where the parts are missing), and a worker separately mounts the missing parts by hand.

However, such means were inefficient and not very desirable.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention provides an adhesive application method for chip components, in which chip components are temporarily bonded and held on a printed circuit board with an adhesive, and then soldered in a solder bath. , a first step of applying adhesive to the tip of the first transfer pin, a second step of transferring the adhesive adhered in this first step to a printed circuit board prepared in advance, and a second step of applying adhesive to the tip of the first transfer pin. After the process, a third step re-transfers the transferred tip of the first transfer pin onto a previously prepared transfer sheet.
A fourth step of inspecting the retransferred part after this third step to check the amount of adhesive adhered, and determining the amount of adhesive adhered at the time of retransfer based on the check result of this fourth step. At the location on the printed circuit board where it is determined that
and a fifth step of applying adhesive using a transfer pin, and the chip components are bonded after the adhesive has been applied to all predetermined adhesive application locations. .

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS The adhesive coating method for chip components according to the present invention will be explained below with reference to an illustrated embodiment.

FIG. 1 is a flowchart showing a method of applying an adhesive for chip components according to the present invention, and FIGS. 2 to 5 are diagrams showing an adhesive applying apparatus for chip components and its adhesive application method.

As shown in FIG. 1, first, a printed circuit board is brought in and prepared for transfer.

Next, as shown in FIG. 2, a large number of transfer pins 4a, 4 made of stainless steel, for example, are implanted on the lower surface of the support plate 3.
b, 4c, . . . are moved downward.

Below this, a flat container 1 is placed with a sufficient amount of sticky adhesive 2, and the transfer pins 4a, 4 are arranged.
．． The tips of b, . . . are brought into contact with the surface of this adhesive 2. Then, this transfer pin 4a.

Adhesives 2a, 2b, 2c, . . . are attached to the tips of 4b, 4c, . . . , respectively.

With this adhesive adhered, the transfer bottles 4a, 4b, 4c, . . . of the support plate 3 are brought into contact with the upper surface of the printed circuit board 5, as shown in FIG.

Due to the transfer shown in FIG. 3, the upper surface of the printed circuit board 5 should have the adhesive adhered to all the predetermined adhesive application locations.

Next, as shown in FIG. 4, an inspection sheet 6 made of a translucent material such as thin paper or a transparent material such as cellophane is hung from a supply roller 8 onto a take-up roller ruff and held approximately horizontally with an appropriate tensile strength. Stretch it out so that it looks like this.

On top of the stretched inspection sheet 6, the transfer bin 4a,
4b, 4c, . . . are pressed together.

Then, if any adhesive remains at the tips of these transfer bottles, these adhesives will be retransferred as adhesives 11a and Ilb remaining on the upper surface of the inspection sheet 6 as shown in FIG. becomes.

That is, the adhesive in the portion sufficiently transferred from the transfer bottle to the printed circuit board 5 as described above leaves almost no trace on the inspection sheet 6 shown in FIG. 5.

However, the portion of the adhesive that has not been transferred from the transfer pin to the printed circuit board 5 is the remaining adhesive 1 in FIG.
They are left on the inspection sheet 6 as 1a and Ilb.

As shown in FIG. 4, an image pickup device 9 such as a COD is placed below between the take-up roller 7 and the supply roller 8.
As described above, the remaining locations of the adhesive 11a and Ilb left as traces are read, and these remaining locations are determined as coordinate positions (XY coordinates) on the inspection sheet 6 by appropriate image processing means.

Furthermore, the residual adhesive 11a determined in this way
, 11b, adhesive is applied to the tip of a separately prepared second transfer pin, and this second transfer pin is determined as described above. Apply to the desired location. In this way, it becomes possible to completely apply adhesive to all of the hundreds of areas to which adhesive should be applied.

In this way, once the adhesive has been applied to all the positions to be applied, cylindrical chip parts etc. are applied from a parts feeder (not shown) and temporarily attached, and the adhesive is further hardened in a thermosetting oven. , the cylindrical chip component is temporarily firmly adhered to the printed circuit board 5.

Once the components have been adhered to one side in this way, the printed circuit board is turned over and the necessary electronic components are mounted on the other side.

After the various electronic components have been mounted on both sides of the printed circuit board as described above, the necessary soldering (solder dip) is performed by pouring the printed circuit board into an automatic solder tank (not shown).

Once the solder dipping is completed in this way, a printed circuit board with high-density mounting is completed by correcting solder whiskers and the like.

In this embodiment, the case of a cylindrical chip component has been described, but it is of course applicable to not only a cylindrical chip component but also a rectangular chip component.

〔effect〕

According to the present invention, a plurality of adhesive application locations are reliably checked to detect an unapplied portion of the adhesive, and the adhesive is applied to the unapplied portion using the second transfer bottle.

Therefore, the adhesive can be applied to all the parts where adhesive needs to be applied, so that the chip components can be completely bonded.

[Brief explanation of the drawing]

Fig. 1 is a float chart 1 showing the adhesive application method for chip components of the present invention, Fig. 2 is a side view showing the positional relationship between the transfer bottle and the adhesive, and Fig. 3 is a flowchart showing the adhesive application method for chip components of the present invention. Fig. 4 is a side view showing the case where the transfer pin of the transfer method is pressed against the inspection sheet, Fig. 5 is a side view showing the case where the transfer pin of the transfer method is pressed against the inspection sheet, and Fig. 5 shows the residue left on the inspection sheet by pressure contact, which is not shown in Fig. 4 above. FIG. 6 is a plan view showing the adhesive, and FIG. 6 is a perspective view showing a conventional cylindrical chip component. 2...Adhesive, 4a, 4b, 4c...Transfer pin, 5...
...Printed circuit board, 6...Inspection sheet (transfer sheet) 9...
......Image sensor, 11 a,, 1 l b...Remaining adhesive,
101...Cylindrical chip component, Applicant: NEC Bo1, Electronics Co., Ltd.

Claims (1)

[Scope of Claims] 1. A method for applying adhesive for chip components, in which a chip component is temporarily bonded and held on a printed circuit board with an adhesive, and then soldered in a solder bath. A first step of applying adhesive to the tip of the transfer pin, a second step of transferring the adhesive adhered in this first step to a previously prepared printed circuit board, and a step of transferring the adhesive that has been transferred after this second step. A third step of re-transferring the tip of the first transfer pin onto a previously prepared transfer sheet, and a fourth step of inspecting the re-transferred portion after this third step to check the amount of adhesive attached. , A fifth step of applying adhesive using a second transfer pin to a location on the printed circuit board where it was determined that a large amount of adhesive would adhere during retransfer based on the check results of the fourth step.
1. A method for applying adhesive for chip components, comprising the steps of: and bonding the chip components after the adhesive has been applied to all predetermined adhesive application locations.