JP2002181634A - Standardized sensor block for measuring temperature profile of reflow furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a standardized sensor block repeatedly usable, in place of various sample boards for measuring temperature profile in a reflow furnace for soldering a printed circuit board. SOLUTION: A sensor module with a thermocouple sensor 1 fixed to a metal plate 2 or the like standardized in shape and dimensions is made attachable to and detachable from a metal plate 4 or the like stardardized in shape and dimensions, on the same condition to prepare a sensor unit. A plurality of sensor units are mounted on two extensible rods to constitute the sensor block slidingly adjustable in the position. Since the temperature in the reflow furnace is measured using the standardized sensor block, the temperature can be measured invariably on the same measuring condition regardless of the model of the reflow furnace and the type of the produced printed circuit board.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sensor unit used in an apparatus for measuring a real-time temperature profile in a reflow furnace used for soldering electronic components mounted on a printed circuit board.

[0002]

2. Description of the Related Art A printed circuit board on which electronic components are mounted is passed through a reflow furnace and soldered. Therefore, the temperature setting in the reflow furnace is very important and always requires accurate setting. For this reason, it is necessary to check the temperature profile at the beginning of each operation at the site.

At present, a thermocouple sensor is fixed at a key point on a real printed board on which electronic components are mounted, and the open end is a wireless temperature data transmitter (Japanese Patent Laid-Open No. 06-281504). To measure the temperature by passing through the reflow furnace.

In this method, a temperature profile must be measured using a real printed circuit board at the beginning of each operation. However, when the printed circuit board is passed through the reflow furnace several times to several tens of times, the printed board is deteriorated, and an error may occur between the first data and the data after several times. Therefore, if the temperature is measured many times using the same printed circuit board, good results are not always obtained.

As a result, at the production site, the printed circuit board that has passed through the reflow furnace a certain number of times is discarded, and a printed board for temperature profile measurement is manufactured using a new actual printed circuit board under the same sensor mounting conditions as before. There must be. This task places a heavy burden on field staff. Also, using a good substrate as a sample and then discarding it is a waste of resources,
As a result, the overall cost is high.

[0006]

According to the present invention, all kinds of printed circuit boards manufactured by using the standardized sensor unit of the present invention are used instead of manufacturing various kinds of printed circuit boards for measuring temperature profiles. Easily measure the temperature profile when needed, corresponding to the printed circuit board of
The OK / NG judgment is immediately displayed on the personal computer screen.

[0007]

According to a first aspect of the invention, a thermocouple sensor is fixed to a ceramic plate, a heat-resistant plastic plate, a metal plate, or the like having a standardized shape and dimensions by a certain method.
Standardized sensor module.

A second aspect of the present invention is a standardized sensor unit capable of easily attaching and detaching a standardized sensor module to and from a metal plate having a standardized shape and dimensions under the same conditions.

According to a third aspect of the present invention, two or more standardized sensor units are attached to two parallel extendable rods, and the sensor units can be easily positioned according to the effective width in the reflow furnace. apparatus.

In a fourth aspect, the open ends of the thermocouples fixed to the respective sensor modules according to the first aspect are respectively connected to connectors dedicated to the thermocouples, and are fixed to the mounting mechanism of the sensor unit. Sensor block that can be connected to the connector of the temperature data transmitter.

[0011]

According to the first aspect of the present invention, regardless of the type of printed circuit board to be soldered through the reflow furnace or the temperature profile in the reflow furnace that is currently set, regardless of the reflow furnace used. Can always be measured faithfully under the same conditions. If the sensor module is damaged or deteriorates, it must be replaced with a new one. However, since it is standardized, it is not necessary to calibrate the temperature data again after replacement. The replacement operation is extremely simple.

According to the third aspect of the invention, the positioning of the plurality of sensor modules can be arbitrarily and easily set using the telescopic rod according to the width of the printed circuit board passing through the inside of the reflow furnace. Temperature distribution in the width direction can be measured finely.

According to the fourth aspect, the sensor block and the existing data transmitter can be easily connected by the dedicated connector, so that the handling operation becomes very simple.

[0014]

Embodiments of the present invention will be described below. FIG. 1 shows an example of a standardized sensor module. The thermocouple sensor is fixed at the center between two polyimide plates having a diameter of 25 mm and a thickness of 2 mm. As the thermocouple, a K-type (chromel / alumel) wire diameter of 0.2 mm was used. The open end is connected to a heat-resistant connector dedicated to a K-type thermocouple.

FIG. 2 shows an example of a standardized sensor unit. This is a unit in which the sensor module of FIG. 1 is fixed to a metal plate whose shape and dimensions are standardized by a certain method.

If necessary, a plurality of sensor units are used depending on the shape and dimensions of the printed circuit board.

FIG. 3 shows an example of a sensor block. This is an example in which two standardized sensor units are used. One of the sensor units is A, and the telescopic rod 2
Secure the book. Another sensor unit B is fixed to the ends of two extending and contracting rods. The sensor unit A has a mechanism to which a metal fitting for fixing the connector dedicated to the thermocouple is attached. The positions of the two sensor units are adjusted by a telescopic bar in accordance with the printed circuit board to be soldered.

[0018]

As described above, according to the present invention,
The sensor block is passed through the reflow furnace to measure the temperature profile in the furnace instead of the printed circuit board for production. By sending the data to the analyzer, it is already stored in the analyzer and judged as OK. The standard profile is compared with the standard profile on the analyzer screen, and OK, NG
Can be confirmed.

At the site, a large number of types of printed circuit boards are produced, but all of these types can be handled by one sensor block. That is, in the conventional method, for each printed circuit board, a printed circuit board to which a sensor for profile measurement is attached must be created, and it must be managed such as re-discarding due to deterioration or the like due to use over ten times. According to this, all of them are unnecessary and can be used repeatedly under the same conditions as many times as possible, which leads to great labor saving and resource saving for the site staff, and also easy and accurate management of the temperature profile of the reflow furnace. Can be executed efficiently.

[0020]

[Brief description of the drawings]

FIG. 1 Standardized sensor module Thermocouple 2. 2. Polyimide plate Thermocouple dedicated connector

FIG. 2 Standardized sensor unit Thermocouple 2. 2. Polyimide plate Thermocouple dedicated connector 4. Stainless plate 5. Sensor module mounting bracket

FIG. 3 Standardized sensor block Thermocouple 2. 2. Polyimide plate Thermocouple dedicated connector 4. Stainless plate 5. Sensor module mounting bracket 6. Telescopic bar 7. 7. Extension rod fixing screw Thermocouple connector fixing section

Claims (4)

[Claims] 1. A sensor module in which a tip of a thermocouple is fixed to a standardized substrate by a certain method. 2. A sensor unit which can be easily attached to and detached from a standardized metal plate of the sensor module according to claim 1. 3. A mechanism in which a plurality of the sensor units according to claim 2 are mounted on two extendable rods and can be easily set at an arbitrary position in a reflow furnace. 4. An apparatus in which the open end of the thermocouple according to claim 1 is connected to a dedicated connector and can be easily connected to a temperature data transmitter.