JP2920675B2 - Ceramic press forming equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a press forming apparatus for forming a ceramic product.

[Prior Art] Ceramics are widely used for substrates for semiconductor packages or other electronic parts, parts for industrial machines, and the like.

As a method for forming such ceramics, a press forming method is generally used. For example, as shown in FIG. 3, a space formed by the die 11 and the lower punch 13 is filled with the ceramic raw material 14 by using a press forming apparatus including a die 11, an upper punch 12, and a lower punch 13, Press molding was performed by pressing with the upper punch 12.

At this time, the press molding pressure is always constant,
If there is variation in the ceramic raw materials, the dimensions and green density of the obtained molded body change. Therefore, the green density was obtained by sampling the molded body at regular intervals and measuring its weight and thickness to check whether the density was within a predetermined range.

[Problems of the prior art] However, in the conventional press molding method as described above,
Since only a part of the obtained molded body was sampled, it was not possible to detect an abnormality in green density occurring between samplings.

In addition, the work of sampling and measuring the density is manual and time-consuming.

[Means for Solving the Problems] In view of the above, the present invention provides a press forming apparatus including a proximity sensor for detecting the height of an upper punch with respect to a die, and the upper punch having been detected by the proximity sensor. Means for determining whether the point height is within the normal range, and when the bottom dead center height is outside the normal range, a feedback signal is issued to adjust the filling amount of the raw material. It is.

[Example] Hereinafter, an example of the present invention will be described.

As shown in FIG. 1, the press forming apparatus of the present invention comprises an upper ram 1 having an upper punch and a die set 2 having a die. The upper ram 1 reciprocates up and down with respect to the die set 2. It is supposed to. A metal plate 3 is attached to the upper ram 1, while a proximity sensor 4 is attached to the die set 2 at a position facing the metal plate 3. Further, a detector 5 and a sequencer 6 are connected to the proximity sensor 4, and a plurality of press molding devices are collectively managed by a computer (not shown).

The proximity sensor 4 is a magnetic sensor that detects a distance from the metal plate 3 by a change in a magnetic field, and has an extremely excellent distance detection accuracy of about 0.5 μm. In addition,
The proximity sensor 4 may be a non-contact, high-precision sensor, and is not limited to the magnetic sensor, but may be a laser sensor using laser light. However, the magnetic sensor is superior in terms of detection accuracy.

 Next, a press molding method using this apparatus will be described.

First, the temperature of the press forming equipment and the ceramic raw material,
Humidity is managed so that it is within a certain range of conditions. Then, when press forming is performed, the height h of the metal plate 3 with respect to the proximity sensor 4 according to the vertical movement of the upper ram 1.
When the height h reaches the minimum value h _min , the upper punch is at the bottom dead center position, and the bottom dead center height h _min
Is detected by the detector 5. Next, by the sequencer 6,
It is determined whether the bottom dead center height h _min is within a normal range stored in advance or a feedback range set outside the normal range. As a result, if it is within the normal range, the obtained molded body is regarded as having normal dimensions and green density, and press molding is continued.

When the bottom dead center height h _min is not within the normal range but is within the feedback range, the feedback signal 7 is output from the sequencer 6 while the press forming apparatus is driven, and the die set 2 is automatically set. , The fine adjustment of the raw material filling amount is performed. Further, when the bottom dead center height h _min is not within the feedback range, it is regarded as a sudden abnormality, the drive of the press forming apparatus is stopped, and manual adjustment is performed.

The above steps are summarized in a flowchart as shown in FIG.

Thus, according to the press molding apparatus of the present invention, by controlling the temperature and the humidity within a certain range, the water content of the ceramic raw material and the crushing property can be made constant,
By simply detecting the height of the bottom dead center at the time of press molding, it is possible to easily detect the dimensions and green density of all the obtained molded bodies. Further, when an abnormality occurs, the information can be fed back so that the adjustment can be performed automatically.

In the above press molding method, the temperature and humidity are controlled under certain conditions. However, the present invention is not limited to this, and other methods can be used. For example, the temperature of the ceramic raw material to be pressed, the moisture content due to changes in humidity, and the data of the crushability are input to the computer in advance,
The temperature and the humidity at the time of press molding are measured by a sensor, and when the sequencer 6 determines the height h _min of the bottom dead center, correction may be made according to the conditions at that time.

Here, a semiconductor package substrate was press-formed using the above-described press-forming apparatus of the present invention. the material is,
Al ₂ O ₃ as a main component, SiO ₂ , MgO, CaO as a sintering aid,
A black alumina ceramic containing TiO ₂ , MnO ₂ , CrO ₂ , Fe ₂ O ₃ etc. is used as a coloring agent, and the size of the molded body is 36.8 ×
It was set to 14.7 x 2.0 mm.

The temperature of the press forming equipment and the ceramic raw material is ± 2
Press molding was performed such that the temperature and humidity were controlled to be within ± 10%, and the height h _{min of the} bottom dead center was within a range of ± 20 μm. As a result, the dimensional accuracy of the obtained compact was ± 0.3
% Or less, indicating that a molded article having extremely excellent dimensional accuracy can be obtained.

[Effects of the Invention] As described above, according to the present invention, the press forming apparatus includes the proximity sensor for detecting the height of the upper punch with respect to the die, and the bottom dead center of the upper punch detected by the proximity sensor. By having a means for determining whether the height is within the normal range, and when the bottom dead center height is outside the normal range, a feedback signal is issued to adjust the filling amount of the raw material. In addition, abnormalities in dimensions and green density can be detected for all the molded bodies, and there is no need for manual checking. Further, when there is an abnormality, it can be automatically adjusted by a feedback signal, and a number of effects such as a molded article having extremely excellent dimensional accuracy can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an embodiment of the press forming apparatus of the present invention. FIG. 2 is a flowchart showing a molding method using the press molding apparatus of the present invention. FIG. 3 is a sectional view showing a schematic structure of a ceramic press forming apparatus. 1: Upper ram, 2: Die set 3: Metal plate, 4: Proximity sensor 5: Detector, 6: Sequencer

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B28B 3/02

Claims (1)

(57) [Claims] 1. A press forming apparatus for forming a ceramic material into a predetermined shape, comprising a proximity sensor for detecting a height of an upper punch with respect to a die, and a bottom dead center of the upper punch detected by the proximity sensor. Means for determining whether the height is within the normal range, and when the bottom dead center height is outside the normal range, a feedback signal is issued to adjust the filling amount of the raw material. Characteristic press forming equipment for ceramics.