JPS6376338A - Heating device for semiconductor - Google Patents

Abstract

PURPOSE:To realize the change in a heating condition according to the state of an object to be heated and according to its accommodated location by a method wherein, at a heating device for a semiconductor, a region to accommodate the object to be heated is installed in a story-like structure inside a heating chamber so that a circulating path can be formed around this heating chamber made of metal. CONSTITUTION:If an 'array of lead frames' 8 is accommodated in a region 3 installed in a story-like structure, the information on its location or the like is input to a control device 15 by an input device 16. On the basis of this information, a heater 10 and a blower 11 are driven. If a laminar hot blast is fed in a predetermined direction, the rate of the rise in temperature at the 'array of lead frames' 8 becomes slow at the downwind side. Therefore the sense of rotation of the blower is switched at regular intervals so that the direction of an air blast can be reversed. In addition, even when a new object to be heated is accommodated after completion of the heating operation of the 'array of lead frames' in one region 3 installed in a story-like structure, a low-temperature hot blast is not fed to the other region 3 where the temperature is kept constant by each circulation path. Therefore, it is possible to prevent the drop in temperature and to keep the temperature constant.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an improvement in an apparatus for heating or drying a semiconductor device having a resin sealing layer.

(Prior Art) It is well known that in manufacturing a semiconductor device, a semiconductor device is manufactured by building a circuit or an element onto a semiconductor substrate and then performing an assembly process to complete the semiconductor device. This assembly process also involves the so-called D
IP or IDF (InterDigitated
After mounting on a lead frame (Frame) type lead frame, predetermined wire bonding process, resin sealing process, Cut &
A semiconductor device is obtained through a bending process and a plating process.

In this resin sealing step, the sealing resin tablet is set in a molding device to perform sealing, and after the next heating step, the semiconductor element is embedded in the sealing resin layer to prevent contamination from the outside. As a type of this heating device, the structure shown in FIG. 2 is adopted, and the object to be heated is a lead frame in which a resin sealing layer in which a semiconductor element is embedded is fixed.

As mentioned above, this lead frame is of the DIP or IDF type, which is applied to multi-pin type semiconductor devices, and this is a unit body obtained by dividing certain areas of metal frames arranged opposite each other. A lead having a free end extending from the metal frame in the centripetal direction is provided, and a semiconductor element is fixed to a bed section provided at the centripetal position and bridging between the metal frames. After electrically connecting the semiconductor element and the lead portion, the semiconductor element is embedded in the sealing resin layer as described above. The sealing resin layer in most models is formed into a substantially flat rectangular parallelepiped with a rectangular cross section, and in some models it is square in cross section.

By the way, the view of the heating device shown in FIG. 2 includes a metal heating chamber 21 having a heat insulating door (not shown) that can be opened and closed on one side, a circulation path 22 provided around it, and a hot air mechanism formed in this circulation path 22. It consists of 23 parts. This hot air mechanism 23 has a heater 24
and a blower 25, and a circulation path 2 facing the blower 25.
A through hole 26 is installed in the third wall.

In this metal heating chamber 21, a lead frame 27 in which the flat sealing resin described above is fixed is arranged. In this arrangement, the hot air is sent along the short side of the sealing resin layer having a rectangular cross section, and the through hole 26 is installed near the center of the plurality of lead frames 27 as shown in FIG. .

Although the temperature of the heater varies depending on the model, that is, the volume of the sealing resin layer, a heat load of several hundred degrees Celsius is applied for several hours, and the lead frame is housed in a tray framed by columns.

(Problems to be Solved by the Invention) In such a heating device, hot air is forcibly sent in a fixed direction by a single blower, and depending on the shape of the object to be heated and the installed position, the direction in which the hot air is sent and the The idea is to vary the strength of the hot air to achieve uniform or efficient heating. Furthermore, although only two rows of lead frames, or trays, are shown in Fig. 2, many lead frame rows or trays are installed in this heating chamber, but in many cases, a larger number of lead frames are installed, and since the lead frames are taken out after a certain period of time has elapsed, the temperature of the object to be heated may vary. is often not constant. Therefore, the temperature of the heated sealing resin layer is lowered, and it takes time to raise the temperature to a predetermined temperature. The present invention provides a novel heating device for semiconductors that eliminates the above-mentioned dots, and particularly aims at making it possible to change heating conditions depending on the state of the object to be heated and the installation position.

[Structure of the invention]

(Means for Solving the Problems) In the semiconductor heating device according to the present invention, areas in which objects to be heated are placed in a metal heating chamber are hierarchically provided, and a circulation path is formed around the metal heating chamber. do. A through hole is formed in the circulation path wall facing the hierarchically installed area, and a hot air mechanism is continuously arranged through the hole. Therefore, in areas that are installed hierarchically, it is possible to heat multiple lead frames stored in trays with laminar hot air, and also automatically control the heater temperature of each hot air mechanism, the rotation speed of the blower, etc. Add possible mechanisms.

(Function) In this way, the through holes are formed facing each other in the circulation path wall facing the object to be heated, and a hot air mechanism equipped with a heater and an air blower is installed here, and the rotation direction of this air blower is controlled. If it is set in the forward or reverse direction, laminar hot air will flow through each layered area and then through the circulation path.

Therefore, in heating each region, the influence between regions can be removed and efficient utilization can be achieved. Furthermore, by attaching a control mechanism to each hot air mechanism, the flow velocity and flow direction of the hot air can be freely changed and uniform heating can be achieved.

(Example) The present invention will be described in detail in FIG. 1, and although some parts overlap with the conventional technology for convenience, new numbers will be used to explain the invention.

This semiconductor heating device includes a metal (Afi) heating chamber 2 having an insulating door (not shown) that can be opened and closed, a circulation path 3 provided around the heating chamber 2, and a hot air mechanism 7 formed in this circulation path.
Consists of. This metal heating chamber 2゜2 has partition shelves 4, 4
Areas 3 and 3 which are divided by and will be formed hierarchically in the future
It is written as

The objects to be heated are placed in the hierarchically formed regions 3 and 3. To explain again, the lead frame is a unit body obtained by dividing a certain area of metal frames arranged facing each other. A lead with a free end extending from this metal frame in the centripetal direction is provided.

A semiconductor element is fixed to a bed portion bridging between the metal frames provided at the centripetal position.

In this semiconductor element, the formed electrodes and leads are connected by thin metal wires to achieve electrical continuity, and then a so-called molding process is performed to form a substantially flat sealing resin layer.

The cross-sectional shape is rectangular for many models, and square for a few models.

In order to place this lead frame in the layered area 3゜3, it is necessary to stack them on a tray framed by pillars, and the number of sealing resin layers that are fixed to the lead frame is usually several. be.

By the way, there are through holes 6 in the circulation path wall located between the hot air mechanism 7 and the lead frame row 8 which is the object to be processed.
・It is designed to allow hot air to hit the lead frame rows. This hot air mechanism is composed of a heater 10, a blower 11, and a temperature sensor 9, and the rotating directions of the blowers 11 and 11 facing each other are set in a forward-reverse relationship so that one blows air and the other draws air.
Laminar hot air is applied to a row of lead frames, which are the objects to be processed, and then flowed through a circulation path.

The temperature sensor 9 of each hot air mechanism is electrically connected to the temperature detection circuit 12 shown in FIG. Connecting. Furthermore, this control device 1
5, an input device 16 and a memory circuit 17 are also interconnected to enable automatic control of the hot air mechanism 7.

In this control mechanism, when the lead frame row 8 is placed in the hierarchically arranged area 3, information such as its position is inputted to the control bag @15 by the input device 16, and the heater 10 and the blower 11 are controlled based on this information. drive

However, if laminar hot air is applied in a fixed direction, the temperature increase rate of the lead frame row 8 on the leeward side will be slow.

The rotation direction of the blower is changed at regular intervals to reverse the blowing direction.

Furthermore, even if the heating of the lead frame row in the area 3 formed in one layer is finished and a new object to be heated is placed, low-temperature hot air will not enter the area 3, which is maintained at a constant temperature by each circulation path. Prevents temperature drop and maintains a constant temperature.

〔Effect of the invention〕

In this way, in the present invention, the object to be treated is heated by laminar hot air, and this hot air flows through the circulation path, so it can be used efficiently by eliminating the influence between the areas installed in a hierarchical manner. becomes possible. Furthermore, since each hot air mechanism is equipped with a control mechanism, the flow rate and flow of the hot air can be freely changed, allowing uniform heating.

[Brief explanation of the drawing]

FIG. 1 is a sectional view schematically showing a heating device according to the present invention, FIG. 2 is a block diagram of a control circuit attached to this device, and FIG.
The figure is a sectional view showing the main parts of a conventional device.

Claims (1)

[Claims] A unit body obtained by dividing a metal heating chamber with a door that can be opened and closed on one side to form a hierarchical area, a circulation path surrounding the chamber, and a certain area of metal frames placed facing each other. A lead frame having a lead having a free end extending from the frame in the centripetal direction, electrically connecting the lead to an electrode of a semiconductor element fixed at the centripetal position, and having a resin sealing layer embedding the semiconductor element. , a row of stacked lead frames arranged in parallel to each other in a hierarchical region of the metal heating chamber, a hot air mechanism formed in the circulation path facing the longitudinal direction of the lead frame row, and a hot air mechanism formed in the circulation path facing the lead frame row; a hot air mechanism formed in the circulation path facing each other in the longitudinal direction;
A semiconductor characterized in that the mechanism is provided with a through hole provided in the circulation path wall located between the lead frame in the longitudinal direction, and the resin sealing layer is heated by a thermal laminar flow generated from the hot air mechanism. heating device.