JPH0749150B2 - Substrate heating device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating device for controlling a temperature distribution on a substrate having partially different heat capacities.

Conventional technology In the technology trend of high-density mounting of electronic parts on a printed circuit board (hereinafter abbreviated as “board”) as represented by home appliances, the soldering method of elements using a reflow furnace is adopted. Is being done. Here, the heating method will be described by taking the soldering method using the reflow furnace as an example.

The reflow method is different from the conventional flow method in which the board on which the element is mounted is dipped in the molten solder bath, and the element is placed after applying cream solder consisting of fine solder particles and paste to the board at a predetermined position, and then infrared rays are applied. This is done by heating, melting and soldering.

A general reflow furnace is shown in FIG. On the conveyor 1 which moves at a constant speed v, the substrate 2 on which the elements are mounted is heated by the heating element 3 which continues to generate a constant amount of heat. The first half A of the furnace is a preheating section, which normally heats the substrate 2 to around 150 ° C. Then, a temperature of about 250 ° C. is generated in the heating part of the latter half B to perform soldering, and then the product is cooled by fan blowing or the like and taken out.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in the conventional heating furnace, the furnace length of the preheating section is long, and it takes about 5 to 8 times the actual furnace length of the heating section for actual soldering. (A thermocouple is attached to a representative point on the substrate to measure the temperature change process in the conventional furnace, and the results are shown in FIG. 4.)

Furthermore, if the type or size of the board is changed, the temperature rise characteristics of the board will change, resulting in a large difference in solderability.
It is necessary to change the furnace conditions for each substrate. In addition, the heating efficiency of the furnace is extremely poor in a system in which one substrate is flown through the furnace in a fixed space.

In view of the above problems, the present invention significantly reduces the space of the furnace to increase the area productivity, simultaneously heats multiple types, and significantly improves the heating efficiency of the substrate, thereby improving the soldering efficiency and the element. The present invention provides a substrate heating device that realizes stable quality of a substrate including the substrate.

Means for Solving the Problems In order to solve the above problems, a substrate heating apparatus of the present invention is a furnace main body in which a preheating part having an inlet and a heating part having an outlet are partially communicated, and a preheating part. A preheating unit substrate holding device for holding a plurality of substrates which is built in the heating unit, a plurality of heating blocks each including a heating device and a heating unit substrate holding device to form the heating unit, and a furnace main body, and an inlet Substrate carry-in device that can move in the substantially opening direction of, and close to the furnace body,
It has a substrate unloading device arranged substantially in the opening direction of the outlet, a substrate transfer device in the vicinity of the furnace body and the substrate unloading device, and a fluid transfer mechanism to be in fluid communication with the preheating part and to the preheating part. It has a structure provided with a preheating heat source and a duct which fluidly connects the preheating heat source and the preheating section.

Operation The present invention, by virtue of the above-described configuration, simultaneously preheats a plurality of substrates in a space-saving manner, and simultaneously performs substrate heating according to the type of substrate by a plurality of heating blocks, thereby greatly improving mass productivity and improving heat capacity. Simultaneous heat treatment of different kinds of substrates is performed with high efficiency and accuracy.

Example An example of the present invention will be described below with reference to the drawings. FIG. 1 shows a substrate heating apparatus according to an embodiment of the present invention, in which 11 is a substrate and 12 is a substrate chuck section 12.
A substrate loading device having a, 13 is a furnace body, 14 is a preheating part of the furnace body, a preheating part substrate holding device for holding a plurality of substrates 11 at the same time, 22 is a heating part of the furnace body 13, and a heating device 15
A heating block having a heating unit substrate holding device 16 and 17, a substrate take-out device, and a substrate transfer device 18. Further, 19 is a preheating heat source, and 20 is a duct which fluidly connects the preheating heat source 19 and the preheating section.

The operation of the substrate heating apparatus configured as described above will be described in detail below. As shown in FIG. 1, the substrate 11
Is a substrate loading device having a chuck portion 2a and capable of moving itself.
By means of 12 it is introduced into the preheating part through the inlet 21 of the furnace body 13. By feeding hot air generated by the preheating source 19 into the preheating unit through the duct 20 having a blowing function, the temperature of the substrate 1 held in the preheating unit for a certain period of time by the preheating unit substrate transfer device 14 is maintained. To raise.

The substrate 11 retained in the preheating portion for a predetermined time is a substrate unloading device.
It is conveyed to the heating part of the furnace body 13 by the A-direction stroke of 17. In the heating part, original heating of the substrate including reflow soldering is achieved.

The heating unit is provided with a heating unit block 22 in which a heating device 15 represented by an infrared lamp or the like is vertically arranged. A plurality of heating blocks 22 are provided in the height direction or the width direction as shown in FIG. 1, and the substrate 11 is moved in the height direction or the width direction by the B direction stroke or the C direction stroke of the substrate takeout device 17. Move any heating block 22
Set to and heat. When the substrate 11 is heated, the heating intensity of the heating device 15 is partially changed to various settings so that the thermal characteristics of each heating block 22 can be changed.
Therefore, heating of substrates having different heat capacities can be achieved simultaneously.

The substrate 11 that has been heated in the heating section is similarly taken out of the furnace through the outlet 25 by the substrate take-out device 17 and taken out by the substrate carrying device 18.

Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. FIG. 2 shows the heating section of the furnace body 13.
This is an enlarged view of the structure of the heating block 22. The difference from the first embodiment is that a mask 23 is inserted between the substrate 11 and the heating device 15.

The mask 23 is provided with a plurality of holes 24 at appropriate positions,
The radiant heat component generated in the heating device 15 is completely transferred to the substrate 11 in the hole 24 portion, while it is reduced in the portion without the hole 24, in consideration of the local heat capacity change in the electronic component mount on the substrate 11 etc. It has the function of achieving proper and efficient heating. As the mask 23, generally, a method of providing an appropriate hole 24 in a metal plate or the like can be considered, and for the purpose of reflecting heat, a transparent sheet, heat-resistant glass, an acrylic plate, or the like having a heat-reflecting glossy paint printed thereon is used. May be.

In the present invention, the substrate loading device, the heating device, the substrate holding device of the preheating part or the heating part, the substrate unloading device, the substrate transfer device, and the preheating heat source have configurations other than those shown in this embodiment as long as they fulfill their original functions. , You may have a mechanism. Further, the preheating unit holding device may remove the function when it does not necessarily need to move during preheating, and may use a fluid other than air such as N ₂ gas to improve preheating efficiency. Needless to say.

EFFECTS OF THE INVENTION As described above, the present invention can greatly contribute to space saving as a furnace, and can heat various types of substrates with different heat capacities by controlling them with high precision for a short time. The preheating efficiency can be greatly improved as compared with.

[Brief description of drawings]

1 is a perspective view of a substrate heating apparatus according to the first embodiment of the present invention, FIG. 2 is a perspective view of a second embodiment of the present invention, and FIG.
FIG. 4 is a cross-sectional view of the substrate heating apparatus in the conventional example, and FIG. 4 is a diagram showing an actually measured curve of substrate temperature heating characteristics in the conventional example. 11 …… Substrate, 12 …… Substrate loading device, 13 …… Furnace body, 14…
… Preheating part substrate holding device, 15 …… Heating device, 16 …… Heating part substrate holding device, 17 …… Substrate unloading device, 18 …… Substrate transfer device, 19 …… Preheating source, 20 …… Duct, 21 …… Entrance, 22 ...
… Heating block, 23 …… Mask, 25 …… Exit.

Claims (2)

[Claims] 1. A furnace body in which a preheating section having an inlet and a heating section having an outlet are partially communicated with each other, a preheating section substrate holding device which is built in the preheating section and holds a plurality of substrates, and a heating device. And a plurality of heating blocks that respectively include a heating unit substrate holding device to form the heating unit, and are close to the furnace body,
A substrate loading device that is movable in the substantially opening direction of the inlet, a substrate unloading device that is disposed near the furnace body and that is substantially in the opening direction of the outlet, and a substrate transfer device that is near the furnace body and the substrate unloading device. Substrate heating, comprising: a preheating source fluidly connected to the preheating unit and having a fluid transfer mechanism to the preheating unit; and a duct that fluidly connects the preheating source and the preheating unit. apparatus. 2. In the heating section, between the substrate and the heating device,
The substrate heating apparatus according to claim 1, further comprising a mask arranged in substantially the same plane as the substrate.