JP5067554B2 - Jig for heat treatment of chip-shaped electronic components - Google Patents

Description

  The present invention relates to a heat treatment jig used for heat treatment of a chip-shaped electronic component.

  For example, in a chip-shaped electronic component having an internal electrode such as a chip-shaped ceramic capacitor, it is necessary to provide terminal electrodes (external electrodes) that are electrically connected to the internal electrode at both ends of the substrate. In forming the terminal electrode, first, an electrode paste in which a conductive powder such as Cu, an organic binder, and a solvent are mixed is applied to a ceramic substrate, and a baking process is performed to form a base electrode film. In this baking treatment, organic components such as an organic binder and a solvent are volatilized and emitted, and a base electrode film containing Cu as a main component is formed on the ceramic substrate.

  Next, electroplating is performed to form a Ni plating film and a Sn plating film on the base electrode film. Thereby, a terminal electrode is completed.

  Conventionally, when baking a base electrode film, chip-like electronic components coated with electrode paste are randomly stacked on a jig made of a stainless steel wire mesh, and the jig is mounted on a stainless steel wire frame. Placed on a mesh belt and passed through a tunnel firing furnace.

  As a jig used in this case, as described in Patent Document 1, generally, a jig having a structure in which a metal net is stretched on a metal frame has been used.

  However, with a structure in which a metal net is stretched on a metal frame, sufficient mechanical strength cannot be ensured, and if used repeatedly, the bottom of the metal net will be bent or deformed, and chip-like electronic There is a risk of adhesion to parts.

  In order to improve the mechanical strength, a structure in which a metal net is doubled is also known. In this case, although the strength is satisfactory, the escape of volatile gas is poor and the atmosphere is controlled. There are cases where it cannot be performed or reduced, which may adversely affect the characteristics of the electronic component.

  As a means for improving mechanical strength, as disclosed in Patent Document 2, a structure in which a metal frame is arranged at the bottom of a mesh of a heat treatment jig is also known. In addition, there are some which fix the metal frame and the mesh by welding by spot welding or the like.

  However, when the metal frame and the mesh are fixed by spot welding or the like, there is a problem that the parts cannot be attached and the gas cannot escape from the welded part, which may cause deterioration of the characteristics of the electronic parts. .

In particular, the outer shape of the chip-shaped electronic component has recently been reduced in size and thickness to the limit, and the mesh pore diameter is correspondingly significantly reduced, making it difficult for gas to escape. This is an extremely important matter for maintaining the characteristics of electronic components.
JP 2000-169243 A JP-A-2005-19698

  An object of the present invention is to provide a heat treatment jig that is lightweight, has good gas escape, and can ensure satisfactory mechanical strength.

  In order to solve the above-described problems, a jig for heat treatment according to the present invention is used for heat treatment of a chip-shaped electronic component, and includes a receiving member on which the chip-shaped electronic component is loaded. The receiving member has a stacking surface having a large number of through holes. The loading surface is an uneven surface due to repeated mountain and valley folds.

  The heat treatment jig according to the present invention is a chip-like electronic component in which a base electrode film is formed by applying an electrode paste mixed with conductive powder such as Cu, an organic binder, and a solvent to a ceramic base. It is used in a process for baking an electrode film.

  In the baking process, chip-shaped electronic components having an unbaked base electrode film are randomly stacked on the heat treatment jig according to the present invention. And this jig for heat processing is mounted in the frame which consists of a stainless steel wire, and it puts on a mesh belt and passes a tunnel baking furnace. While the jig for heat treatment passes through the tunnel firing furnace, the organic binder and solvent in the base electrode film applied to the ceramic base are volatilized and emitted, and the base electrode film mainly composed of Cu is formed on the ceramic base. It is formed.

  Here, since the receiving member constituting the heat treatment jig according to the present invention has a loading surface having a large number of through holes, a chip-shaped electronic component having a base electrode film formed on the loading surface is provided. Can be accommodated in bulk, randomly.

  Since the loading surface on which the chip-shaped electronic components are stacked is an uneven surface due to repeated mountain and valley folds, a mechanical strength reinforcing effect can be obtained due to repeated mountain and valley folds. For this reason, a receiving member can be thinned and the weight as the whole jig for heat processing can be reduced in weight.

  In addition, the effect of reinforcing the mechanical strength due to repeated mountain and valley folds is obtained, so a structure in which a metal mesh body is stretched double, a structure in which a metal frame is placed at the bottom of the mesh, and a metal frame and mesh are spotted. There is no need to employ a structure that is fixed by welding. For this reason, the problem of outgassing, which has been a problem in the past, is eliminated, and outgassing is promoted, so that a chip-shaped electronic component with stable characteristics can be obtained.

  Furthermore, since the loading surface is an uneven surface due to repeated mountain and valley folding, the surface area of the loading surface is increased. For this reason, under the condition that the amount of chip-shaped electronic components stacked on the loading surface is constant, the loading density of the chip-shaped electronic components on the loading surface is reduced, and in the heat treatment process, the organic binder and solvent are removed from the electrode paste. The action of volatilizing and escaping (outgassing) is promoted.

  In addition, since the loading surface is an uneven surface due to repeated mountain and valley folding, the uneven surface acts to diversify and agitate the flow direction of the atmospheric gas supplied from above or below the loading surface. Bring. For this reason, the outgassing is further promoted.

  The receiving member can be constituted by a net-like body in which metal meridians and metal latitudes are woven, or can be constituted by using a porous thin plate provided with a large number of through holes at high density.

  Further, the loading surface may have a cross-sectional mountain shape having valley folds on both sides of the mountain fold, or may have a cross-sectional sawtooth shape. In both cases of the cross-sectional mountain shape and the cross-sectional sawtooth shape, the above-described operational effects are exhibited. In particular, in the case of a sawtooth cross section, there is a portion that rises substantially vertically, so the upper part of this portion is used as an opening region that is not filled with chip-shaped electronic components, and both atmospheric gases supplied from above and below are used. , And thereby causing atmospheric gas collision, turbulent flow, and agitation, can further promote the outgassing action.

  As described above, according to the present invention, it is possible to provide a heat treatment jig that is lightweight, has good gas release, and can satisfy mechanical strength.

  Other objects, configurations and advantages of the present invention will be described in more detail with reference to the accompanying drawings. However, the attached drawings are merely examples.

  FIG. 1 is a perspective view showing an embodiment of a heat treatment jig according to the present invention, and FIG. 2 is an enlarged sectional view taken along line 2-2 of FIG. The illustrated heat treatment jig is used for heat treatment of chip-shaped electronic components such as a chip-shaped ceramic capacitor and a chip-shaped inductor, and includes a support member 1 and a receiving member 2.

  The support member 1 constitutes a rectangular outer frame. As a material of the support member 1, when it is assumed that the base electrode film is baked in a temperature range of 700 ° C. to 900 ° C., a material that is stable in this temperature range, for example, SUS304 (Fe-18Cr-Ni) , MN (63Ni-30Cu), Ha (Ni-Cr-Mo), titanium and the like are preferable.

  The receiving member 2 is disposed inside the support member 1, and its periphery is fixed to and supported by the support member 1. The receiving member 2 can also be made of the same metal material as the supporting member 1. The receiving member 2 has a stacking surface 20 having a large number of through holes. The loading surface 20 is a concavo-convex surface formed by repeated mountain folds P and valley folds V.

  As shown in FIG. 3, the receiving member 2 can be configured by using a porous thin plate in which a large number of through holes 22 are provided in the base 21 at a high density, and as shown in FIG. It is also possible to form a net-like body woven with metal latitude lines 23. The receiving member 2 shown in FIGS. 1 and 2 can be obtained by bending the porous thin plate shown in FIG. 3 and the net-like body shown in FIG.

  The size and distribution density of the “eyes” of the through holes 22 (FIG. 3) and the net-like body (FIG. 4) prevents the chip-like electronic components from coming out, and makes the chip-like electronic components uniform and efficient. It is set so that it can be heated well. In this type of chip-shaped electronic component, for example, a so-called “0603” type having a length of 0.6 mm and a width of 0.3 mm has been remarkably advanced in size and thickness. The hole diameter and distribution density of the through-holes 22 are set so that such chip-shaped electronic components can be handled and the gas is efficiently vented.

  FIG. 5 shows chip-shaped electronic components loaded on the heat treatment jig according to the present invention. The chip-shaped electronic component 3 is in a state before baking, and is provided with unfired base electrode films 31 and 32. The base electrode films 31 and 32 include, for example, a conductive component mainly composed of a metal powder such as Cu, and an organic binder. Obtained by drying.

  If the chip-shaped electronic component 3 is, for example, a chip-shaped ceramic capacitor, the base electrode films 31 and 32 are applied to both ends of the ceramic substrate 30 in the longitudinal direction. A large number of internal electrode films 33 are embedded in the ceramic substrate 30, and opposite ends of two adjacent internal electrodes 33 and 33 are connected to the base electrode films 31 and 32, respectively. In other types of chip-shaped electronic components, terminal electrodes may be provided on three or four sides of the ceramic substrate. In the case of such a type, the base electrode film is formed corresponding to the position where the terminal electrode is formed.

  As shown in FIG. 5, the heat treatment jig according to the present invention is a process in which a non-fired base electrode film 31, 32 is baked on a chip-shaped electronic component coated and dried with the base electrode film 31, 32. Used.

  In this baking process, as shown in FIG. 6, a large number of chip-shaped electronic component groups 3 are randomly stacked and accommodated in a heat treatment jig. Then, this heat treatment jig is placed on a frame made of stainless steel wire, placed on a mesh belt, and passed through a tunnel firing furnace. While the heat treatment jig passes through the tunnel firing furnace, the organic binder and solvent in the unfired base electrode films 31 and 32 are volatilized and emitted, and the ceramic base 30 is baked with Cu as a main component. The underlying electrode films 31 and 32 are formed.

  Here, since the receiving member 2 constituting the heat treatment jig according to the present invention has a stacking surface 20 having a large number of through holes 22 opened, an unfired base electrode film 31 is formed on the stacking surface 20. , 32 can be randomly stacked.

  Since the stacking surface 20 on which the chip-shaped electronic components are stacked is an uneven surface due to repeated mountain folds P and valley folds V, an effect of reinforcing mechanical strength due to repeated mountain folds P and valley folds V can be obtained. For this reason, it is possible to withstand the load of the loaded chip-like electronic component group 3 while reducing the thickness of the receiving member 2 and reducing the weight of the heat treatment jig as a whole.

  Moreover, since the mechanical strength reinforcement effect can be obtained by repeating mountain folds P and valley folds V, a structure in which a metal net is stretched double, a structure in which a metal frame is arranged at the bottom of the mesh, and further, a metal frame and a mesh There is no need to adopt a structure that is fixed by welding by spot welding or the like. For this reason, the problem of outgassing, which has been a problem in the past, is eliminated and outgassing is promoted.

  Furthermore, since the loading surface 20 is an uneven surface due to repeated mountain folds P and valley folds V, the surface area of the loading surface 20 is increased. For this reason, under the condition that the amount of the chip-like electronic components 3 stacked on the loading surface 20 is constant, the loading density of the chip-like electronic components 3 on the loading surface 20 decreases, and in the heat treatment step, the base electrode film 31, From the inside of 32, the action (gas release) of the organic binder and the solvent evaporating and escaping is promoted.

  Further, since the loading surface 20 is a concavo-convex surface due to repeated mountain folds P and valley folds V, the concavo-convex surface changes the flow direction with respect to the atmospheric gases F1, F2 supplied from above or below the loading surface 20. Diversify and bring about stirring. For this reason, the outgassing is further promoted.

  The loading surface 20 in the illustrated embodiment has a mountain-shaped cross section having valley folds V on both sides of the mountain fold P. Therefore, the atmospheric gases F1 and F2 supplied from above or below the loading surface 20 flow in the direction from the mountain fold P to the valley fold V according to the inclination, thereby causing a stirring action. This action further promotes outgassing.

  7 is a perspective view showing another embodiment of the jig for heat treatment according to the present invention, and FIG. 8 is a cross-sectional view taken along line 8-8 of FIG. In the illustrated heat treatment jig, the loading surface 20 is an uneven surface having a sawtooth cross-section formed by repeated mountain folds P and valley folds V. The cross-sectional sawtooth shape refers to a cross-sectional shape in the case where there is a large difference between the angles θ1 and θ2 of the slopes inclined downward toward the valley fold V on both sides with respect to one mountain fold P. 7 and 8 show typical cases where the angle θ1 is smaller than 45 degrees and the angle θ2 is approximately 90 degrees.

  FIG. 9 is a diagram showing a baking process using the heat treatment jig shown in FIGS. 7 and 8, and a large number of chip-shaped electronic components 3 are randomly stacked on the heat treatment jig. The chip-shaped electronic component group 3 is loaded on a slope that is inclined upward from a valley fold V almost directly below the mountain fold P toward another mountain fold P. The chip-shaped electronic component group 3 is preferably formed by the chip-shaped electronic component group 3 on the upper part of the wall surface (in the illustrated case, a substantially right-angle wall surface) formed between the valley fold V and the mountain fold P substantially above it. Are loaded so as to produce an open area that is not blocked.

  Thus, in the case of a sawtooth cross-section, there is a wall surface that rises substantially vertically, so the upper part of this portion is used as an opening region that is not filled with the chip-like electronic component 3 and is supplied from above and below. By letting both of the gases F1 and F2 pass, thereby causing collision, turbulence, and agitation of the atmospheric gases F1 and F2, the gas escape action can be further promoted.

  The present invention has been described in detail with reference to the preferred embodiments. However, the present invention is not limited to these embodiments, and various modifications can be made by those skilled in the art based on the basic technical idea and teachings. It is self-evident that

It is a perspective view which shows one Embodiment of the jig for heat processing which concerns on this invention. FIG. 2 is an enlarged sectional view taken along line 2-2 of FIG. It is sectional drawing of the porous thin plate which can be used for the receiving member of the jig for heat processing which concerns on this invention. It is sectional drawing of the mesh body which can be used for the receiving member of the jig for heat processing which concerns on this invention. It is an expanded sectional view which shows an example of the chip-shaped electronic component mounted in the jig for heat processing concerning this invention. It is a figure explaining the effect | action in the heat processing process using the jig for heat processing which concerns on this invention. It is a perspective view which shows another embodiment of the jig for heat processing which concerns on this invention. FIG. 8 is a cross-sectional view taken along line 8-8 in FIG. 7. It is a figure explaining the effect | action in the heat processing process using the jig for heat processing shown in FIG.7 and FIG.8.

Explanation of symbols

1 Support member 2 Receiving member 20 Loading surface
P Yamaori
V Taniori

Claims (3)

A jig used for heat treatment of chip-shaped electronic components,
Including a receiving member for loading the chip-like electronic component;
The receiving member has a loading surface in which a large number of through holes are opened, and the loading surface is an uneven surface due to repeated mountain and valley folding,
The concavo-convex surface is configured by alternately repeating an ascending slope and a descending slope in one direction in which the mountain fold and the valley fold are repeated,
Each of the rising slopes is a flat slope facing the mountain fold from the valley fold in the one direction, and has a plurality of through holes.
Each of the descending slopes is a flat slope from the mountain fold to the valley fold in the one direction, and has a plurality of through holes.
Of the ascending slope and the descending slope, at least each of the descending slopes can randomly stack a large number of the chip-shaped electronic components in a plane.
Heat treatment jig. A heat treatment jig according to claim 1,
Each of the rising inclined surfaces stands upright with respect to the one direction,
Heat treatment jig. 3. The heat treatment jig according to claim 1, wherein the receiving member is a mesh body in which metal meridians and metal latitudes are woven . 4.

Images