JP4949986B2 - Circuit board mounting case with connector - Google Patents

Description

  The present invention relates to a circuit board mounting case with a connector, and more particularly to a circuit board mounting case with a connector in which a resin connector is injection-molded in an opening provided in a wall of a metal case body. .

  FIG. 1 is an explanatory sectional view showing an example of such a circuit board mounting case (hereinafter also simply referred to as a case) 1 with a connector, and FIG. 2 is a perspective view thereof. The case 1 includes a tray-shaped metal case main body (hereinafter also simply referred to as a main body) 2 that opens upward, and a side wall (hereinafter referred to as a wall) 3 that stands up around the bottom wall (hereinafter also simply referred to as a wall) 3. (Also simply referred to as a wall) and a resin-made connector 11 formed in the opening 7 of 5. In the connector 11, a part of the terminal fitting 21 is wrapped, and each end thereof protrudes (exposes) inside and outside the case body 2, and a circuit board 31 mounted in the case 1 The end 21a of the terminal fitting 21 protruding into the case 1 is connected. In such a case 1, the case main body 2 and the terminal fitting 21 are used as inserts, and they are positioned and loaded (arranged) in a molding die (injection molding die) (not shown), and in the cavity (space) corresponding to the connector 11. It is manufactured by injection molding in which resin is injected (filled). In this case 1, the resin forming the connector is sandwiched between the inner and outer surfaces 5a and 5b of the case body 2 at the periphery of the opening 7 for forming the connector.

  The fixing of the connector 11 to the main body 2 of the case 1 is not due to the resin forming the connector 11 being bonded to the surface of the case main body 2, but the clamping force due to the contraction in the cooling and solidification of the resin in molding. Depends on. Therefore, in the case 1 having such a configuration, the gap between the case main body 2 and the resin connector 11, which is a joint portion by sandwiching the case main body 2, due to a difference in thermal expansion coefficient between different materials, Alternatively, a gap due to molding shrinkage of the resin may be generated, and further, a gap may be generated in the contact portion due to external force such as vibration received after molding. That is, as in the case of the above structure, it is difficult to ensure high sealing performance at the joint between the case body 2 and the connector 11 only by the shrinkage stress of the resin. For this reason, a seal failure is caused by aging, and in some cases, the connector 11 with respect to the main body 2 is loosened, which may cause rattling.

  Under these circumstances, when a resin connector is integrally formed with this type of case main body, an invention has been proposed for improving the sealing performance of the close contact portions (Patent Document 1). As described above, the invention described in Patent Document 1 is not only formed by integrally forming a resin connector at the opening portion of the case body as an insert product, but also at the time of molding the connector. Forming a seal unit in which a backup material is encased in a material, the elastic seal material is closely attached to the wall surface of the case, and the seal unit is attached to a portion of the terminal insertion hole which is an opening of the case. The part is injection-molded. According to this technique, a stress due to molding shrinkage acts after molding on the sealing material that is in close contact with the wall of the case body in addition to injection molding pressure acting at the time of molding. This injection molding pressure and the stress are always generated in the injection molding of the resin, and both act as a compressive force on the sealing material, so that the sealing performance of the close contact portion between the case and the connector is improved. Has been.

  By the way, as a technique for strongly integrating the metal body and the resin, for example, an aluminum alloy shaped solution is immersed in an aluminum alloy shaped product and subjected to fine etching treatment on the surface. Positioning and loading into a mold as an insert product, a thermoplastic resin mainly composed of polybutylene terephthalate resin (hereinafter referred to as PBT) or polyphenylene sulfide resin (hereinafter referred to as PPS) is injected onto the surface of the mold, and then high temperature and high pressure are injected. There has been known an invention in which the resin can be firmly bonded to the shaped object by bonding (contacting) below (Patent Document 2). The principle of this invention is that when an aluminum alloy shaped article is immersed in the aqueous solution, etching is performed, and at the same time, an amine compound is formed in a gap between fine irregularities (or a microporous layer) formed on the surface. Chemisorbed. Then, when a thermoplastic resin is formed on such a surface by injection molding so as to contact under high temperature and high pressure, the resin penetrates deeply into the fine irregularities of the surface or the minute gaps of the fine porous layer. It is said that the anchor effect is exhibited.

In addition, by applying the principle of the invention described in Patent Document 2, not only a shape made of aluminum or an alloy thereof, but also other metal bodies (magnesium, zinc or an alloy thereof, etc.) A fine porous layer (or fine irregularities) is formed on the surface, the amine compound is adsorbed on the surface, and then the fine irregularities on the surface on which the amine compound is adsorbed are the same as described above. It is said that the resin can be firmly joined also by injection molding the resin (Patent Document 3). In the invention described in Patent Document 3, a fine unevenness or a microporous layer formed by adsorbing an amine compound on the surface of a metal body is formed by anodizing the shape and fine unevenness on the surface. And after forming a microporous layer, it can be realized by immersing it in one or more aqueous solutions selected from ammonia, hydrazine, or a water-soluble amine compound and adsorbing the amine compound on the surface thereof. Has been.
JP-A-10-74560 JP 2003-200453 A JP 2005-342895 A

  In the technique described in Patent Document 1 described above, even if a compression force is obtained by a backup by a seal unit between the resin forming the connector and the surface of the metal case body, the deterioration of the operation over time is avoided. Absent. Therefore, even in this technique, there is a problem in durability, such as a risk of causing a seal failure relatively early. In addition, in this case, a seal unit in which a backup material is enclosed in an elastic seal material is required as a separate part. In addition, since the insert requires a process of attaching it to the opening of the case, there is a problem that not only the part management process but also the process in injection molding becomes complicated.

  On the other hand, according to the techniques described in Patent Documents 2 and 3, since the resin can be bonded or bonded with high strength to the surface of the metal shaped object by the anchor action, such a technique is used for a circuit board mounting case with a connector. It may be applied to That is, using the techniques described in Patent Documents 2 and 3, fine irregularities formed by adsorbing an amine compound on the surface of the metal case body corresponding to the opening for forming the connector. Alternatively, a fine porous layer is formed, and such a case body is used as an insert product, and the resin forming the connector is formed by injection molding in a state where it is joined to the surface having the fine irregularities or the porous layer. Is an idea. However, even if the techniques described in Patent Documents 2 and 3 are used as they are, simply bonding the resin forming the connector to the outer surface of the case main body shows how high the adhesive strength is. However, as long as it is impossible to eliminate the occurrence of poor adhesion and the like, high reliability is not necessarily obtained with respect to adhesive strength.

  In view of the problems of the technology described in Patent Document 1, the present invention is made by combining each known technology described in Patent Documents 2 and 3 so that the resin connector is integrated with the case body by injection molding. Another object of the present invention is to provide a circuit board mounting case with a connector, in which the connector can be bonded to the case body with extremely high bonding strength.

Before disclosing the invention according to claim 1 for achieving the above object, a reference invention different from the invention according to claim 1 is disclosed. In this reference invention , a connector mainly composed of a thermoplastic resin enclosing a terminal metal fitting is integrally formed in an opening for forming a connector of a metal case body by injection molding, and the connector is formed at the periphery of the opening. In a circuit board mounting case with a connector formed by sandwiching both inner and outer surfaces of a wall forming the case body along
Of the inner and outer surfaces of the wall along the periphery of the opening, the surface on which the connector is formed and joined is roughened, and the connector is joined by injection molding in a state of joining to the roughened surface. It is formed.

In the reference invention , the roughened surface is preferably the entire surface (the entire region) where the connector is formed and contacted, but as long as the bonding strength of the connector is increased, it is narrower than this. It may be good or wide. In the above reference invention , the surface roughness (surface roughness) of the roughened surface is sufficient if the resin enters the irregularities of the surface at the time of injection molding to obtain an anchoring action. The roughness may be set depending on the type of resin and the injection conditions. In the above reference invention , the roughening means that the case body is formed by press-molding a metal plate or a die-cast product, and the smooth surface of the molded product is grinder, file, or sandpaper. A technique such as rubbing the surface, a physical or mechanical technique such as a shot blasting process, or an anodizing process may be used. In addition, what is necessary is just to select and use resin (thermoplastic resin) for an appropriate material, and it is good also as what mixed compositions, such as glass fiber, in it.

In order to achieve the above object, according to the first aspect of the present invention, a connector mainly composed of a thermoplastic resin and enclosing a terminal fitting is integrally formed by injection molding in a connector forming opening of a metal case body. In a case for mounting a circuit board with a connector, the connector being formed in such a manner that the inner and outer surfaces of the wall forming the case body are sandwiched along the peripheral edge of the opening.
Of the inner and outer surfaces of the wall along the periphery of the opening, the surface on which the connector is formed and joined , and the inner peripheral surface of the opening are innumerable irregularities or porosity formed by adsorbing nitrogen-containing compounds on the surface A layer is formed, and the connector is formed by injection molding in a state of being bonded to the surface having the unevenness or the porous layer.

  In the present invention, the unevenness or porous layer refers to an unevenness or porous layer that can be formed by etching, anodizing, or both. The means for adsorbing the amine compound on the surface is to immerse the main body in an aqueous solution of the amine compound as disclosed in Patent Document 2 when the case main body is made of aluminum or an aluminum alloy. Thus, the concavo-convex or porous layer is simultaneously formed on the surface, and at the same time, the nitrogen-containing compound can be adsorbed. This is because the nitrogen-containing compound is chemically adsorbed on the surface irregularities or the porous layer due to etching by the immersion. On the other hand, when the case body cannot be made by such means as in the case of a metal made of magnesium alloy or zinc alloy other than aluminum or aluminum alloy, as disclosed in Patent Document 3, anodization is performed. Treat the surface to form an uneven or porous layer, and then immerse the body in an aqueous solution of an amine compound (for example, an aqueous solution of ammonia, hydrazine, and / or a water-soluble amine compound) Can adsorb nitrogen-containing compounds. Of course, this method can also be applied to aluminum alloys. In addition, in this invention, the magnitude | size (diameter, depth, or depth) of the hole which makes an unevenness | corrugation and a porous layer changes with kinds and processing conditions of the metal which makes a case main body.

According to the reference invention , the connector is molded in such a manner as to sandwich the portion along the peripheral edge of the opening among both the inner and outer surfaces of the wall of the metal case body, but both the inner and outer surfaces are roughened. Therefore, the resin penetrates or fits into the irregularities of the roughened surface together with the shrinkage effect in the solidification process after cooling, and has an anchor effect. In such a reference invention , a separate part such as a backup material is not required, and the joining strength of the connector to the main body is increased without incurring complicated processes in the injection molding. That is, compared with the conventional case where the resin sandwiches the smooth surfaces of both the inner and outer surfaces of the case body, the anchor action due to intrusion or fitting into the irregularities on the roughened surface, Due to the significant increase in the resin bonding area due to the surfaceization, the bonding force and adhesion of the resin to both the inner and outer surfaces of the wall of the case body are enhanced.

Further, in the invention according to claim 1, innumerable irregularities or porous layers formed by adsorbing a nitrogen-containing compound on the surface are formed on the surface where the connector is formed and contacted. Since the connector is formed by injection molding in a state where it is bonded to the surface having the conductive layer, the connector is bonded to the case body with high strength. In addition, the case of the present invention has a structure in which the resin constituting the connector is not only joined to one surface (one side) of the wall, but also is joined by sandwiching the inner and outer surfaces of the wall. Therefore, extremely high bonding strength and high reliability of the bonding can be obtained with respect to the case body, and high sealing performance is also maintained.

Before describing the embodiment of the present invention described in claim 1, another embodiment of the above-described reference invention (hereinafter also referred to as this reference embodiment or this reference example) is shown in FIGS. Will be described in detail with reference to FIG. In the figure, reference numeral 1 denotes a circuit board mounting case with a connector, and 2 denotes a metal case body, which is made of aluminum, zinc, magnesium, or an alloy thereof, and is a rectangular parallelepiped container (tray) that opens upward. It has a shape, is formed by press molding or die casting, and is manufactured through a predetermined finishing process. In the present embodiment , the connector forming opening 7 is provided on two opposing side walls 5 and 5 among the side walls 5 and 6 rising from the bottom wall 3 forming the bottom plate of the case body 2. In this reference example , the connector forming opening 7 has a U-shaped cutout shape cut from an upper end (an end opposite to the substrate) 5c of the side wall 5.

In the opening 7 for forming the connector of the case body 2, the connector 11 is formed by injection molding with a composition containing a terminal fitting 21 and containing a thermoplastic resin as a main component. The connector 11 is integrally formed so as to sandwich the inner and outer surfaces 5a, 5b of the side walls 5, 5 forming the case body 2 along the periphery of the opening 7. However, in this reference example , the connector 11 is formed so as to sandwich not only the side wall 5 but also a part of the bottom wall 3. The connector forming openings 7 are respectively formed on the opposing side walls 5 and 5, and the connectors 11 are formed in the two openings 7. However, in order to simplify the explanation, FIG. The state where the connector 11 is formed only on one side is shown. Thus, the case 1 has a circuit board 31 mounted therein, and the electrode terminal and the end 21a protruding inside the case of the terminal fitting 21 wrapped in the connector 11 are joined by soldering or the like. Fixed.

Such a case 1 is formed in the interior of the case body 2 and the terminal fitting 21 by inserting them into an injection mold for case molding (not shown) as an insert product and closing the mold by a conventionally known manufacturing method. It is formed by injecting resin at a predetermined pressure and temperature in the cavity for the connector 11. On the other hand, in the present embodiment , as shown in FIG. 3, of the side walls 5, 5 and the bottom wall 3 along the periphery of the opening 7 in the case body 2, a surface wider than the surface where the connector 11 is formed ( The shaded portion shown in FIG. 3 is roughened in the part before injection molding. Note that the surface to be roughened may be only the surface on which the connector 11 is formed, but may be wider or may be the entire surface of the main body 2. Further, in the present embodiment , the inner peripheral surface 7a of the opening 7, that is, the thickness surface of the side wall 5 is also roughened in the same manner. Such roughening can be easily obtained by applying sandpaper having a predetermined count (granularity) corresponding to the desired roughening.

In the case 1 of the present embodiment , the connector 11 is integrally formed by injection molding in a state where it is joined to the both surfaces 5a, 5b, 3a, 3b of the walls 5, 3 of the roughened case body 2. Yes. That is, the connector 11 has a shape that sandwiches the walls 5 and 3 forming the case body 2 along the periphery of the opening 7. The resin forming the connector 11 is joined to the roughened surface.

Thus, in this reference embodiment , in the injection molding of the resin, the resin is joined in a form of being pressed against the roughened portion including both the inner and outer surfaces of the walls 5 and 3, so that it is microscopically viewed. Then, the surface is roughened, so that it enters into the minute recesses that are uneven, and is cooled and solidified. Therefore, compared with the case where the resin merely sandwiches the smooth surfaces of both the inner and outer surfaces of the case body 2 as in the conventional case, in this embodiment, the resin penetrates or fits into the unevenness of the roughened surface. Since the anchoring action is obtained, the adhesion of the resin to the inner and outer surfaces of the wall of the case 1 is improved and the clamping is stabilized accordingly, so that the connector 11 is fixed to the case body 2 with high reliability. In addition, high sealing performance is maintained.

Now, an embodiment of the present invention described in claim 1 will be described with reference to FIGS. However, the case 1 of the present embodiment is not different from the case 1 described above in the appearance or basic structure. Therefore, the description regarding the shapes of the case 1 and the main body 2 is omitted. That is, the main body 2 forming the case 1 of the present embodiment is inserted into an injection mold (not shown) as an insert product, and the connector 11 is injection-molded. A fine unevenness or fine porous layer formed by adsorbing (chemically adsorbing) a nitrogen-containing compound, specifically, an amine-based compound, on the surface (in this embodiment, the entire surface of the main body) on which 11 is formed Is formed. The case 1 in which the connector 11 is formed by injection molding is in a state in which the resin injected under high temperature and high pressure is joined to the surface having the fine irregularities or the microporous layer in the injection molding. .

  In this embodiment, since the resin constituting the connector 11 has a structure in which the walls 5 and 3 are sandwiched, extremely high adhesive strength to the case body 2 is expected. That is, according to the present invention, a fine unevenness or a microporous layer is formed by adsorbing an amine compound on the surfaces 5a, 5b, 3a, 3b of the walls 5, 3 of the body 2 to which the connector 11 is formed and joined. Since the resin forming the connector 11 is formed by contact under high temperature and high pressure by injection molding in a state where it is bonded to the surface having this fine unevenness or fine porous layer, the resin It penetrates deeply into the fine irregularities or the minute gaps of the fine porous layer. Due to this anchoring action and effect, the connector 11 is formed on the main body 2 with high bonding strength, but the resin is not only bonded to one surface of the wall 5 of the case 1 but also the walls 5 and 3 are connected to the inside and outside. Since both surfaces 5a, 5b, 3a and 3b are sandwiched, extremely high adhesive strength can be obtained.

  In addition, as a means for forming a fine unevenness or a fine porous layer formed by adsorbing an amine compound on the surfaces of the walls 5 and 3 of the case main body 2, when the case main body 2 is made of an aluminum alloy, the above also applies. However, as disclosed in publicly known patent document 2, by immersing it in one or more aqueous solutions selected from ammonia, hydrazine, and / or water-soluble amine compounds, A fine unevenness or a fine porous layer is simultaneously formed, and at the same time, an amine compound can be adsorbed. This is explained by the fact that the amine compound is chemically adsorbed on the fine unevenness or fine porous layer of the surface due to the etching by the immersion.

Further, when the case main body 2 is a magnesium alloy or a zinc alloy, as disclosed in Patent Document 3, an anodizing treatment is performed to form a fine unevenness or a fine porous layer on the surface, and then Thus, the amine compound can be adsorbed on the surface by dipping in any one aqueous solution selected from ammonia, hydrazine, and / or a water-soluble amine compound. Of course, this method can also be applied to aluminum alloys. In such a case, fine irregularities or a microporous layer may be formed not only on the wall of the case body 2 but also on the entire surface, but unnecessary portions may be masked so that they are not formed.
By dipping

  Then, as described above, the case main body 2 subjected to such a treatment is positioned and loaded into the injection mold together with the terminal fittings, and the desired thermoplasticity is placed in the connector cavity inside the case main body 2. The above-described case 1 is obtained by injecting the resin composition at high temperature and high pressure and opening the mold after cooling and solidification. Examples of the thermoplastic resin include polybutylene terephthalate resin, polyphenylene sulfide resin, nylon resin, and compositions containing these resins as main components. Examples of the composition other than these resins include glass fiber, carbon fiber, and aramid fiber.

  The present invention is not limited to the contents described above, and can be embodied with appropriate modifications without departing from the scope of the present invention. For example, in each of the above examples, the connector forming opening 7 in the case main body 2 is embodied as a notch shape cut out from the end portion 5c of the wall 5, as shown in FIGS. Like the case 1 and the main body 2, the opening 7 may have an independent hole shape. In the case of the independent hole-shaped opening 7 as described above, since the peripheral length of the opening 7 can be ensured long, when the connector 11 is formed, the area where the resin is bonded to the wall 5 can be further ensured. Thus, the joint strength can be further improved. The case body 2 shown in FIGS. 4 and 5 is the same as that shown in FIGS. 2 and 3 except for the opening 7, and therefore, the same reference numerals are given and description thereof is omitted.

  In each of the above examples, the case body 2 is positioned and loaded in the injection mold together with the terminal fitting, the thermoplastic resin composition is injection molded, and the terminal fitting 21 and the connector 11 are insert-molded into the case body 2. However, a circuit board mounting case in which only the connector 11 is injection-molded into the case body 2 and then the terminal fitting 21 is outsert-molded may be used. Furthermore, for the purpose of improving the adhesion between the terminal fitting 21 and the connector 11, the surface of the terminal fitting 21 where the connector 11 is formed and joined may be roughened.

Sectional drawing of the case with a circuit board mounting with a connector explaining the embodiment of the present invention, and the principal part enlarged view. The perspective view for description of the circuit board mounting case with a connector of FIG. In FIG. 2, the perspective view of only the case main body before forming a connector. The perspective view for description of the case which demonstrates another example of the opening for connector formation in FIG. In FIG. 4, the perspective view of only the case main body before forming a connector.

DESCRIPTION OF SYMBOLS 1 Case for circuit board mounting with connector 11 Metal case main body 3, 5, 6 Wall 3a which forms case main body, 5a Wall outer surface 3b, Wall inner surface 7 Opening for connector formation 11 Connector 21 Terminal fitting

Claims (1)

A connector mainly composed of a thermoplastic resin enclosing a terminal fitting is integrally formed in an opening for forming a connector of a metal case main body by injection molding, and the connector is formed along the periphery of the opening. In a circuit board mounting case with a connector formed by sandwiching both the inner and outer surfaces of the wall forming the main body,
Of the inner and outer surfaces of the wall along the periphery of the opening, the surface on which the connector is formed and joined , and the inner peripheral surface of the opening are innumerable irregularities or porosity formed by adsorbing nitrogen-containing compounds on the surface A circuit board mounting case with a connector, wherein a layer is formed, and the connector is formed by injection molding in a state of being joined to a surface having the unevenness or a porous layer.

Images