JPH03214688A - Heat treatment equipment for electronic parts - Google Patents

Abstract

PURPOSE:To prevent the temperature drop of a board effectively by providing at least a pair of carry means for catching the board to carry it, and equipping a means for circulating this carry means inside a heating chamber. CONSTITUTION:For the throwing in of a board 4 into a heating chamber 2, the board 4 is put, in the condition that both end faces are held, on the carry chain 3 sandwiched and supported between a chain rail and a chain guide 8, and is carried in the heating chamber 2 on a tunnel together with the carry chain 3 rotated by a driving power source such as a motor, or the like, and there the drying and fusion of cream solder for joining the chip pats 10 on the board 4 with the conductor circuit 11 on the board 4 are performed by infrared ray heaters 5 and 6 installed in the heating chamber 2. Accordingly, since the carry chain 3 is reciprocated in the heating chamber 2, being caught by a pair of chain rails 9 and guide rails 8, the contact between the atmosphere outside the heating chamber and the carry chain 3 decreases. Hereby, the temperature drop of the part where the carry chain 3 and the board 4 contact with each other can be relaxed as far as possible.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to heating processing equipment for various electronic components, such as reflow equipment for soldering electronic components to printed circuit boards (hereinafter referred to as boards). It relates to a processing device.

[Background Art] With the miniaturization of electronic and electrical devices in recent years, the substrates on which various components used in these devices are mounted have also become smaller and more dense.

By the way, heat treatment devices for electronic components are used in various fields. For example, it is a solder reflow device.

In manufacturing such a mounting board, desired components are soldered onto the board using a reflow apparatus. The prior art will be explained below by taking a reflow apparatus as an example.

Conventionally, a transport section using a carrier-less type transport chain has often been used to transport substrates in a reflow apparatus used for this type of soldering.

An example of the substrate transport section of the conventional reflow apparatus described above will be described below with reference to the drawings.

The substrate transfer section of a conventional reflow apparatus of this type has a structure as shown in FIGS. 3 and 4.

That is, the attachment chain 1 that transports the substrate 4
2 is held between the guideable lower chain rail 13 and the chain presser plate 14, and
2 is driven by a motor, both ends of the board are held on a pair of opposing attachment chains 12, and run through the tunnel of the heating chamber 2, thereby connecting the conductive circuit 11 on the board 4 and the chip component 10. Dry and melt the cream solder, turn it with sprocket 15 on the exit side,
A sprocket 16 installed at the bottom of the heating chamber 2 holds the chain portion and transfers it to the inlet side.

[Problems to be solved by the invention However, with the structure of the prior art,
The temperature distribution of the substrate heated in the tunnel of heating chamber 2 is
As shown in FIG. 5B, the temperature of the portion held by the conveyor chain decreases, causing uneven melting of the cream solder during reflow soldering. Therefore, it is necessary to provide a post-process to inspect and correct these soldering defects, resulting in high running costs and unstable quality and reliability. In other words, since the substrate transport chain is circulated through the lower part of the heating chamber 2 (outside the heating chamber) 3, when it returns, it is cooled by the atmosphere outside the furnace, and the heat loss of the transport chain itself is large. This caused a temperature drop in the substrate, resulting in a problem of lowering the temperature accuracy within the substrate.

In order to solve the problems of the prior art, the present invention prevents the temperature drop of the substrate transport means due to contact with the atmosphere outside the heating chamber, makes the temperature distribution of the substrate uniform, and improves the temperature distribution of the substrate, such as drying cream solder, melting process, etc. An object of the present invention is to provide a heat treatment apparatus that can uniformly heat treat electronic components.

[Means to solve the problem] In order to achieve the above object, the present invention has the following configuration.

That is, the present invention provides an electronic component heat treatment apparatus in which a substrate on which an electronic component is mounted is heat-treated while being continuously conveyed into a heating chamber. A heat processing apparatus for electronic components, characterized in that the apparatus is provided with a means for circulating the conveying means within a heating chamber.

4. In the configuration of the present invention, the heat treatment apparatus is preferably used as a reflow apparatus for melting and fixing solder for reflow of electronic components.

[Function] According to the configuration of the present invention described above, at least one pair of conveyance means for sandwiching and conveying the substrate is provided, and
By providing means for circulating the transport means within the heating chamber, it is possible to reduce the contact of the transport means with the atmosphere outside the heating chamber, and it is possible to effectively prevent a temperature drop of the substrate.

As a result, when used as a heat treatment device for melting and fixing solder for reflow of electronic components, it is possible to uniformly dry and melt the cream solder applied to the board. The reflow soldering quality can be improved and stabilized.

[Example] The present invention will be described in more detail below using an example.

In the following embodiment, one embodiment of a reflow apparatus will be described with reference to the drawings as an example of a heat treatment apparatus for electronic components.

FIG. 1 is a schematic cross-sectional view of a reflow apparatus according to an embodiment of the present invention, where 2 is a tunnel-shaped heating chamber of the reflow apparatus 1, and 3 is an endless substrate conveyor, which is used to apply reflow solder. , the substrate 4 on which the chip components are mounted is transported into the heating chamber 2. Reference numerals 5 and 6 indicate infrared heaters that heat the chip component mounting substrate 4 with infrared rays, which heat the conveyor 3 passing through the heating chamber 2 downward and upward from above and below, respectively, and also heat the atmosphere within the heating chamber 2. . Note that 7 is a thermal insulator (insulator) provided around the heating chamber 2.
This is provided to prevent the outside temperature from rising.

The operation of the substrate transport section of the reflow apparatus configured as described above will be described below.

The substrate 4 is introduced into the heating chamber 2 by placing the substrate 4 on the conveyor chain 3 held between the chain rail 10 and the chain guide 8 while holding both ends thereof, and rotating the substrate 4 by a drive source such as a motor. The conveyor chain 6 enters the tourniquet heating chamber 2 together with the conveyor chain 3, and the chip components 10 on the substrate 4 and the conductive circuit 11 on the substrate 4 are bonded by the infrared heaters 5 and 6 installed in the heating chamber 2. Cream solder is dried and melted.

Since the conveyance chain 3 is held between a pair of chain rails 9 and a guide rail 9 and reciprocated within the heating chamber 2,
By reducing the contact between the transport chain 3 and the atmosphere outside the heating chamber, the temperature drop in the portion where the transport chain 3 and the substrate 4 are in contact can be reduced as much as possible.

As described above, according to one embodiment of the present invention, the substrate (4) on which electronic components (for example, chip components 10) are placed is heat-treated while being continuously transported into the heating chamber (2). The apparatus includes at least one pair of conveyance means (for example, conveyance chain 3) for sandwiching and conveying the substrate (4).
is provided, and the conveying means (3) is connected to the heating chamber (2).
This is a heat treatment apparatus for electronic components equipped with a means for circulating the parts (for example, a chain guide 8, a chain rail 9).

[Effects of the Invention] As described above, the present invention provides at least one pair of transport means for sandwiching and transporting the substrate, and also includes a means for circulating the transport means within the heating chamber.
A special effect can be achieved in that the contact of the transport means with the atmosphere outside the heating chamber can be reduced, and the temperature drop of the substrate can be effectively prevented.

In addition, when used as a heat treatment device for melting and fixing solder for reflow of electronic components, it is possible to uniformly dry and melt the cream solder applied to the board, so it is possible to Reflow soldering quality can be improved and stabilized.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view of an embodiment of the reflow apparatus of the present invention;
FIG. 2 is a side view showing an embodiment of the present invention, FIG. 3 is a sectional view of a conventional reflow apparatus, FIG. 4 is a side view of a substrate transfer section of a conventional reflow apparatus, and FIG. 58 is a side view of a conventional reflow apparatus. FIG. 7 is a diagram showing the results of comparing the temperature variations of the chip component mounting substrate when using the transport section and the conventional transport section. 1... Reflow device, 2... Heating chamber, 3...
Conveyance chain, 4... Chip component mounting board, 5,
6... Infrared heater, 7... Thermal insulator, 8...
・Chain guide, 9...Chain rail,
10... Chip component, 11... Conductor circuit. 9

Claims (2)

[Claims] (1) In an electronic component heat treatment apparatus that heats a substrate on which an electronic component is mounted while continuously conveying it into a heating chamber, at least one pair of conveying means for sandwiching and conveying the substrate is provided. What is claimed is: 1. A heat processing apparatus for electronic components, further comprising a means for circulating the conveying means within a heating chamber. (2) The heat treatment device for electronic components according to claim 1, wherein the heat treatment device is a reflow device for melting and fixing solder for reflow of electronic components.