JPH01262068A - Heating member by electrification - Google Patents

Abstract

PURPOSE:To shunt a current to the circuit wiring of an IC board from a heating body and to prevent the generation of the wiring disconnection of a lead wire by increasing the electric resistance of the part coming into contact with the lead wire of the heating body in the case of soldering the heating body by electrification by bringing it into contact with the lead wire of an IC. CONSTITUTION:In the case of soldering an IC to a board plural lead wires are subjected to soldering by pressing to the board by the electrification heating body 13 heated in high temp. by the Joule heat by electrification. In this case no wiring is cut by the shunt of a current to the board from the heating body at the wiring pattern of the board. In order to prevent this Si, C, O, N, Ge, Zr, Y, periodic table III group and V group elements are included on the surface part brought into contact with the lead wire of the heating body 13 (slanting line part) and the electric resistivity of the surface part is made at >=100 times the heating main body 13. The wiring cut due to the shunt of a current to the wiring circuit of the board from the heating body is eliminated.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a current-carrying heating member that applies electricity to a conductive substance to generate Joule heat to process a workpiece such as a lead wire. .

(Conventional technology) In recent years, factory automation has made remarkable progress.

An example of this is equipment for soldering integrated circuits (ICs) to substrates. In this device, Fe, Mo, W, Ta
, Cu, A7, stainless steel or other 024 electrically conductive material is energized to generate Joule heat by applying electricity to the base material, and by pressing multiple lead wires against the board at once with the heating member, soldering is performed. It is carried out.

Usually, ICs have lead wires on three or four sides, so
Two or four heating members are installed in parallel or surrounding them on all sides, and are electrically connected in series. They may be connected in parallel, but in this case, there will be more current troughs required for the entire device.

(Unsolved problem to be solved by the invention) However, when soldering is performed by directly contacting the heating member made of a tetraelectric substance with the lead wire of an IC, the heating member is There was a problem in which the current was shunted from the board to the wiring on the board, causing the wiring on the board to break.

In the present invention, the specific resistance of at least the portion of the heating member in contact with the lead wire of the IC is set to be 100 times or more the specific resistance of the conductive substance to prevent wiring breakage due to shunt of current from the heating member to the circuit wiring of the board. was the main topic.

[Structure of the invention]

(Means for Solving the Problems) In the electrical heating member of the present invention, the specific resistance of at least the portion of the surface of the base material made of a conductive material that is in contact with the lead wire is 100 times or more the specific resistance of the base material. It is characterized by

The portions with high specific resistance are silicon, carbon, and oxygen.

The base material contains a large amount of at least one element selected from element Z, germanium, zirconium, yttrium, elements of group 1 of the periodic table, and elements of group 1 of the periodic table.

In automated soldering, the temperature is raised and lowered in cycles of several seconds, so the material of the portion with high resistivity must have high thermal conductivity. Therefore, if the quotient of the specific resistance is an insulating film with a thickness exceeding 1 μm, the thermal conductivity is IWm
' must be 11 or more. Silicon, germanium, and graphite are known for their thermal conductivity. Thermal conductivity of nitrides and carbides of silicon and germanium is very high in crystalline form, but it is quite high even in amorphous form. In addition, all the materials containing the above-mentioned elements are elements with high thermal conductivity. In order to form these high resistivity regions, a base material consisting of a 24-electrode substance is heated in an atmosphere of nitrogen, hydrocarbons, and oxygen.
It is heated to 00°C or higher to contain these elements. Others include ion implantation.

Sputtering ion grating, vacuum vaporization.

Nograzu rcVD, ECR plasma cVD, MCVD,
A method such as photo-CVD may also be used.

In addition, in the case of carbon, oxygen, and hydrocarbons, the content of the above elements is suitably 0.01 atomic % or more and 20 atomic % or less, since the larger the number of particles, the more brittle the material becomes.

For zirconium, yttrium, gallium, silicon, germanium, etc., it is appropriate to use 50 atoms or less.

(Function) By reducing the specific resistance of at least the portion of the heating member in contact with the lead wire of the IC, current shunting from the heating member to the circuit wiring on the board does not occur, and breakage of the wiring can be prevented.

(Example) The heating member of the present invention is formed by processing a conductive material as shown in FIG. 1 to form an insulating portion on the surface.

Automated soldering is used in an apparatus in which the heating members are installed so as to surround them on all sides as shown in FIG. 2, and they are electrically connected in series to a 50 Hz AC power source.

The processing steps are as shown below. After the IC is placed on the board and automatically transported, the heating member comes down and the I
At the same time, while pressing the lead wire C with a pressure of about 2 kg@/am2, a current of about 50 OA was supplied to the heating member at the cutting edge.
Heat to about 00°C.

After the solder is applied and the lead wires and circuit board are connected,
When the electricity is turned off and the solder hardens, the heating member is raised and this process is completed.

Hereinafter, a method for manufacturing the heat-resistant member of the present invention by forming an insulating portion on the surface of a base material made of a conductive material will be described.

Example 1 In this example, the surface of the base material was coated with an insulating film having the components shown in Table 1 by plasma CVD method. FIG. 3 is a schematic diagram of a parallel plate type capacitively coupled plasma CVD apparatus. Inside the vacuum chamber 6, a flat electrode 7 and a high frequency electrode 8 are grounded. The vacuum chamber 6 is provided with a gas inlet 12.

To coat the conductive heating member with an insulating film using this device, the conductive heating member 13 is first placed on the ground electrode 7, and the inside of the chamber 6 is pumped for 10 minutes using a vacuum pump (not shown).
The exhaust is about 4 Torr.

Next, the heating member 13 is heated from 150°C to about 450'0 using the heater 9 attached to the ground electrode 7, and source gases such as SiH4, H2, CH4, etc. are supplied into the chamber 6 from the gas inlet 12. , the degree of vacuum in the chamber 6 is set to 0.
The atmosphere was evacuated to maintain a pressure of 0.05 to 1.0 Torr. When power is applied to the high frequency electrode 8, a glow discharge occurs between the electrodes, the raw material gas becomes a glaze, and the insulating thin film is turned into a heating member 13.
coated with. The raw material gas and film forming conditions were the energization shown in Table 1. For example, when forming a film with a composition of 8 i CN, the source gas is "CC81H4100SCC,N
2500SCCM.

CH4400SCCM was operated by four people through the gas inlet 12, the reaction pressure in the chamber 6 was maintained at 1.0 Torr, and a voltage of 500 W was applied to the high frequency electrode 8 to form a film.

In this case, a film with a thickness of 3.0 μm was formed in a film formation time of 40 minutes.

Below, the components of the insulating film formed similarly for films of other components, the raw material gas and its flow rate, the reaction pressure in the chamber,
'Power applied to high frequency electrode sVC.

The film formation time and film thickness are as shown in Table 1.

According to the plasma CV 1) method, the heating member is heated to 150°C.
Since the process can be carried out at a relatively low temperature of 450' to 450'O, a coating that adheres closely to the base material can be obtained without impairing the properties of the heating member.

Margin Example 2 In this example, a high resistivity portion was formed on the surface of the base material using an ion witness device such as the one shown in Figure 4. First, the raw material solid 14 was put into an open 15I-P, and the reaction gas was introduced into the tank. Next, by passing a current through the filament 17,
/iHeated, the elements in the solid raw material were knocked out by the reaction gas and ionized.

It was converged by the ejected IFI focus 18 and further accelerated by the accelerator 19. Next, the magnet 20 removes P, li among the ejected ions.
A magnetic field is applied so that only the desired ions are extracted through the slit 21, and then a Y-scanner 22 and an X-x scanner 23 are used.
An electric field was applied. By irradiating the tetraelectric mother plate 13 with the ions that have become energized by the magnetism and the eyelid, the ions are injected into the tetraelectric base material 13.

The ions implanted by this ion implantation method are
C is nitrogen, carbon, oxygen, phosphorus, and boron.

Examples include inium, yttrium, silicon, and germanium. Containing a large amount of silicone, yttrium, gallium, silicon, germanium, etc. does not result in a high specific resistance, but also improves wear resistance and provides an electrically heated member that can withstand tens of thousands of uses. .

As shown in Fig. 5, if a portion of the heating member with high resistivity is formed only in the portion directly in contact with the workpiece (the shaded portion), heat is generated mainly in the portion with low resistivity.
Overall, less current is required. That is, the non-ion-implanted portion of the base material becomes a current locking terminal, and the ion-implanted portion becomes a heater. Note that the depth of the cylindrical portion of this specific resistance is suitably 1000 or more and 5 mm or less.

〔Effect of the invention〕

As described in detail above, according to the current-carrying heating member of the present invention, no current flows to the circuit wiring of the board, and therefore, it is possible to prevent wiring breakage in one circuit.

[Brief explanation of the drawing]

Figure 3 is a schematic diagram of the equipment used in the plasma CVD method, Figure 4 is the ion implantation equipment. FIG. 5 is a perspective view showing an example of a heating member into which ions have been implanted. 13...Electric heating member. Agent Patent Attorney Noriyuki Chika 16” Yamashita −〇υ Figure 2 Figure 5 Figure 4

Claims (1)

[Claims] A member that is made of a conductive substance, heats the conductive substance by passing an electric current through it, and processes a workpiece, and has a specific resistance of at least a portion in contact with the workpiece that is 100 times or more the specific resistance of the conductive substance. An energized heating member characterized by: