JP2009164286A - Insert-molded product,and molding method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an insert-molded product such that defects such as warpage can be suppressed and the production cost is further reducible, and a molding method thereof. <P>SOLUTION: An insert-body in a flat plate shape is clamped with support pins from both top and reverse surfaces at a predetermined position in the space of molding, and a molten resin is injected from both right and left ends; when the insert-body is supported without the support pins, support pin tips are retracted to molding surfaces, the charging of the resins is completed, and the resin is solidified to obtain the insert-molded product. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an insert molded product having a planar insert and a resin layer in which the insert is integrated in a concealed state in a resin layer and a molding method thereof.

  Molded products in which electronic parts such as ICs, diodes and capacitors are protected by sealing them in a resin layer are often used in electronic devices. As a method for producing such a molded product, an insert molding method is used. As an insert molding method, a resin layer is formed by filling a resin in a space in a molding die with a resin in a state where the insert is held by a holding member and covering the entire insert, and obtaining an insert molding by curing the resin layer. Is the method. The insert molded product obtained from the mold by this method is in a state in which the holding member is bonded, and a step of cutting the holding member is required to obtain a finished product. Therefore, as a method of reducing the number of parts used for molding by using an ejector pin instead of a holding member and reducing the production cost, Japanese Patent Application Laid-Open No. 58-141533 discloses an insert article in a cavity between upper and lower molds. There has been disclosed an insert molding method in which an insert article whose lower surface is supported by an ejector pin is held and molding is performed by pouring the ejector pin back to the molding surface at the time of injection of a thermosetting resin or slightly shifted timing. This publication discloses a case where an insert article is held by an output terminal on its side and an ejector pin on the lower surface, and a case where it is held by a plurality of ejector pins provided on the lower surface. Moreover, in this publication, the thermosetting resin is injected so as to be filled first from the lower surface side of the insert article.

On the other hand, in JP-A-5-21492, JP-A-9-76282, JP-A-9-216254, JP-A-11-254476, and JP-A-11-254478, an article to be inserted is a molding space. There is disclosed an insert molding method in which a holding member or a supporting member is held therein and a molten resin is filled, and then the holding member is retracted from the molding space and further filled with resin. In the molding methods described in these publications, the entire space in the molding die is filled with resin in a state in which the insert article is held by the holding member or the support member, and after the position of the insert article is secured, the holding member or A method is adopted in which the support member is retracted to the molding surface and the resin corresponding to the space generated by the retraction is further filled. In JP-A-9-76282, JP-A-9-216254, JP-A-11-254476, and JP-A-11-254478, holding members or support members are used on both upper and lower surfaces of the insert article. The point is disclosed.
JP 58-141533 A JP-A-5-21492 Japanese Patent Laid-Open No. 9-76282 JP-A-9-216254 JP-A-11-254476 JP 11-254478 A

  In the molding of insert-formed products in which electronic parts are sealed with a resin layer, the product cost can be further reduced by reducing the frequency of occurrence of defective products with warpage and exposure of inserts as much as possible, that is, increasing the production yield. It has become important to do. In particular, a flat insert molded product often has a strict standard for warpage depending on the purpose of use.

  Therefore, the present invention has an object to provide an insert molded product that can meet the demand for such an insert molded product, can suppress the occurrence of defects such as warpage, and can further reduce the production cost, and a molding method thereof. To do.

The method for molding an insert molded product according to the present invention is a method for molding a plate-like insert molded product having a plate-shaped insert product and a resin layer that contains the insert product and is integrated in a concealed state,
(1) preparing an insert having a flat substrate and a flat convex portion provided on at least one of the upper surface and the lower surface of the substrate;
(2) Inserting the insert into a mold for insert molding with support pins facing the upper surface side and the lower surface side, and supporting the insert in a molding space;
(3) Filling the molding space with resin, filling the resin in all or part of the molding space, and holding the insert in the molding space without the support pins. In a state where the tip of the support pin is retreated up to the molding surface simultaneously, and filling the resin into the space formed by the retraction of the support pin;
(4) With the retreat to the molding surface at the tip of the support pin completed,
And after completion of pressure holding,
Curing the resin to obtain an insert molded product;
(5) recovering the insert-molded product out of the insert-molding mold;
It is a shaping | molding method of the flat-plate-shaped insert molded product characterized by having.

  The insert molded product of the present invention is an insert molded product formed by the above molding method.

Further, another aspect of the insert molded article of the present invention is a flat insert molded article having a flat insert article and a resin layer containing the insert article and integrated in a concealed state,
The flat insert has a flat substrate and one or more flat protrusions provided on at least one of the upper surface and the lower surface of the substrate,
The thickness (t _C ) of the resin layer provided on the surface of the convex portion is 0.1 mm or more,
The thickness (t _a0 ) of the resin layer formed on the surface of the upper surface of the substrate without the convex portion and the thickness (t _b0 ) of the resin layer formed on the surface of the lower surface of the substrate without the convex portion. The ratio (t _a0 / t _b0 ) is 1 / 0.5 to 0.5 / 1,
When the volume of the resin layer on the entire upper surface of the substrate is V _a0 and the volume of the resin layer on the entire lower surface of the substrate is V _b0 , the ratio (V _b0 / V _a0 ) is 1. It is an insert molded product characterized by being /0.5 to 0.5 / 1.

  ADVANTAGE OF THE INVENTION According to this invention, generation | occurrence | production of defects, such as curvature, can be suppressed, and the insert molding which can further reduce production cost, and its shaping | molding method can be provided.

  The insert molded product of the present invention includes at least a plate-like insert product and a resin layer that includes the insert product and is integrated in a concealed state. The insert is concealed by a resin layer covering the whole, so that it cannot be seen with the eyes. That is, the resin layer is formed as a layer having a low light blocking property or a low light transmitting property. The insert has a flat substrate and a flat protrusion provided on at least one part of the upper surface and the lower surface of the substrate. The surface of the convex portion (the surface protruding from the substrate surface) faces the surface on which the convex portion of the substrate is provided, and these are generally parallel.

  An example of an insert molded product in the case where convex portions are provided on both the upper surface and the lower surface of the substrate is schematically shown in FIG. Fig.1 (a) is a top view (top view) of the surface which has the convex part of an insert thing, and shows as what can see an insert thing. FIG.1 (b) is sectional drawing in the AA line of Fig.1 (a). FIG.1 (c) is a bottom view of the surface which has the convex part of an insert thing, and shows as what can see an insert thing. This insert-molded product is formed by integrating an insert having two convex portions a1 and a2 on the upper surface of the substrate 2 and having convex portions b1 and b2 on the lower surface with the resin layer 1 into a flat plate shape. .

  The thickness of the insert molded product is represented by T1. The substrate 2 of the insert has a thickness T2, and the thicknesses (heights) of the protrusions a1, a2, b1, and b2 are represented by Ta1, Ta2, Tb1, and Tb2, respectively. The area of each convex surface is represented by Sa1, Sa2, Sb1, and Sb2. The area in the state where there are no protrusions on the upper and lower surfaces of the substrate is S0.

  The position of the insert in the planar direction is located at the center of the insert molding, and the thickness of the resin layer along each edge is represented by t5 and t4 (see FIG. 1 (a)).

  The thicknesses of the resin layers on the upper and lower surfaces of the substrate 2 where the inserts are not provided are ta0 and tb0, respectively. Moreover, the thickness of the resin layer on each convex part is represented by ta1, ta2 (not shown), tb1, tb2 (not shown).

  Although FIG. 1 shows an example in which two convex portions are provided on both the upper and lower surfaces of the substrate, the number of convex portions can be variously selected according to the purpose.

M protrusions (m is an integer of 1 or more) are provided on the upper surface of the substrate, and n (n is an integer of 1 or more: n and m may be the same or different) on the lower surface; When one of n and m, where only one of the lower surfaces has a convex portion, may be 0), each convex portion can be defined as follows: .
Convex parts on the upper surface of the substrate: a1, a2, ai ... am
Convex part on the lower surface of the substrate: b1, b2, bj... Bn
Area of the upper surface of each convex portion on the upper surface of the substrate: Sa1, Sa2, Sai ... Sam
Area of the lower surface of each convex portion on the lower surface of the substrate: Sb1, Sb2, Sbj... Sbn
The thickness of the resin layer on each convex part on the upper surface of the substrate: tca1, tca2, tcai ... tcam
Thickness of resin layer under each convex portion on the lower surface of the substrate: tcb1, tcb2, tcbj... Tcbn
Height of each convex part on the upper surface of the substrate: Ta1, Ta2, Tai... Tam
Height of each convex portion on the lower surface of the substrate: Tb1, Tb2, Tbj ... Tbn
Using the above definition, the resin amount (Va0) on the entire upper surface of the substrate and the resin amount (Vb0) on the entire lower surface of the substrate satisfy the following conditions.
The resin layer thickness (tca1, tca2, tcai... Tcam) on each convex portion on the substrate upper surface and the resin layer thickness (tcb1, tcb2, tcbj... Tcbn) below each convex portion on the substrate lower surface are At least 0.1 mm.
-The following formulas (4) to (6) are satisfied.
Va0 = (S0−ΣSai) × ta0 + Σ (Sai × tcai) (4)
Here, Σ represents the sum of i = 1 to m.
Vb0 = (S0−ΣSbj) × tb0 + Σ (Sbj × tcbj) (5)
Here, Σ represents the sum of j = 1 to n.
1 / 0.5 ≦ V _b0 / V _a0 ≦ 0.5 / 1 Formula (6)
In the formula (6), 1 / 0.8 ≦ V _b0 / V _a0 ≦ 0.8 / 1 is preferable.

  FIG. 2 schematically shows an example of an insert molded product when a convex portion is provided only on the upper surface of the substrate. Fig.2 (a) is a top view (top view) of the surface which has the convex part of an insert thing, and shows as what can see an insert thing. FIG.2 (b) is sectional drawing in the AA line of Fig.2 (a). In this insert molded product, an insert product composed of the substrate 2 and the convex portion a1 is integrated with the resin layer 1 and molded into a flat plate shape. The convex part a1 can be provided only on the lower surface of the substrate 2 or on both the upper and lower surfaces. As a preferable aspect on each surface having the convex part, a preferable aspect on the upper surface in the following description can be used similarly.

The thickness (ta1) of the resin layer provided on the upper surface of the convex portion a1 shown in FIG. 1B is 0.1 mm or more, preferably 0.3 mm or more, and more preferably 0.5 mm. Further, the ratio (ta0 / tb0) between the thickness (tb0) of the resin layer on the lower surface of the substrate and the thickness (ta0) of the resin layer on the upper surface of the substrate is 1 / 0.5 to 0.5 / 1. And the thickness of the resin layer on the upper surface of the convex portion is tca1, the area of the upper surface of the convex portion is Sa1, and the area of the upper and lower surfaces of the substrate (state without the convex portion) is S0. The volume Va0 of the resin layer on the entire upper surface of the substrate and the volume Vb0 of the resin layer on the entire lower surface of the substrate are expressed by the following equations (7) to (9):
Va0 = Sa1 × tca1 + (S0−Sa1) × ta0 (7)
Vb0 = S0 × tb0 (8)
1 / 0.5 ≦ Vb0 / Va0 ≦ 0.5 / 1 (9)
It is preferable to satisfy.
More preferably,
1 / 0.8 ≦ V _b0 / V _a0 ≦ 0.8 / 1
And

  About the thickness (width) of the resin layer shown in FIGS. 1 and 2, tb0 = 0.5 mm to 5 mm, ta0 = 0.5 to 5 mm, tc (tca1 to tcam, tcb0 to tcbn) = 0.1 mm to 5 mm, It is more preferable to select from each range of t4, t5 = 0.5 mm to 5 mm.

Although it does not specifically limit as a flat insert, What satisfy | fills the following requirements (1) and (2) is preferable.
(1) The difference between the shrinkage due to the molding shrinkage of the resin and the shrinkage of the insert during molding is within the elongation at break of the resin.
(2) The difference in expansion amount in the product guaranteed temperature range resulting from the difference between the thermal expansion coefficient of the insert and the thermal expansion coefficient of the resin is within the elongation at break of the resin.

  Examples of inserts include a glass plate, a metal plate, a ceramic plate, a resin plate, and a flat plate on at least one of the upper and lower surfaces of a substrate made of a composite material of these substrate materials (for example, a glass epoxy substrate). It is preferable that the integrated IC circuit board is integrated and mounted as a convex portion. The substrate may be provided with through-holes, depressions, grooves, and the like for various purposes such as alignment.

  Conventionally known resins can be widely used as the resin for forming the resin layer, and preferred specific examples include olefinic resins such as polyethylene, polypropylene, polymethylpentene, and cycloolefin, polystyrene, styrene / butadiene copolymer resins, and ABS. Resin, polyacetal, polyamide 6,66,11,12, polyamide resin such as MXD6,9T, 46 etc., polyphthalamide, modified polyamide 6T, polycarbonate, PBT, PET, PCT, polyethylene naphthalate, etc. Thermoplastic polyester, modified PPE resin, PPS resin, SPS (syndiotactic polystyrene), LCP (liquid crystal polymer), polyarylate, polysulfone, polytersulfone, polyphenylenesulfone, polyketone, PEEK, polyimide, polyetherimide , TPI and the like.

  Furthermore, as a polymer alloy, a composite of several different resins such as polycarbonate and ABS resin, polyphenylene ether and polystyrene, or the like may be used. Further, in the molding material of the present invention, glass fiber, potassium titanate fiber, ceramic fiber, calcium carbonate, calcium silicate, magnesium silicate, calcium sulfate, barium sulfate, iron oxide, as long as the effects of the present invention are not impaired. In addition to reinforcing fillers such as mica, asbestos, ceramics, glass beads, glass powder, talc, mica, crystal nucleating agents, pigments, dyes, plasticizers, mold release agents, lubricants, heat stabilizers, antioxidants, ultraviolet rays You may contain conventional auxiliary components, such as an absorber, a foaming agent, a flame retardant, and a coupling agent.

  As shown in FIGS. 2 and 3, X1, Y1, and T1 shown in FIGS. 2 and 3 are selected from the ranges of X1 = 2 to 120 mm, Y1 = 2 to 120 mm, and T1 = 1 to 20 mm. It is preferable to do.

  As the mold for molding the insert molded product, various types of molds such as a mold composed of an upper mold and a lower mold can be used as long as the position of the support pin can be moved. An example of the molding method according to the present invention will be described with reference to FIGS.

  FIG. 3 is a plan view schematically showing a state in which the insert is held in the molding die. FIG. 4A is a cross-sectional view taken along the line AA of FIG. 3 so that the support pin portion can be seen.

  As shown in these drawings, the inserts are sandwiched by a pair of support pins 6a and 6b so as to face the upper surface, and are held in the mold. In the illustrated example, four pairs of opposing support pins 6a and 6b are provided to hold a support object. That is, the insert is held in the mold only by the support.

  The area | region of the board | substrate 2 which the pair of support pins 6a and 6b is pressing is provided in the position which buffers each other in the upper and lower surfaces. That is, when the region where the tip of the support pin 6a on the upper surface side of the substrate 2 is in contact with the substrate 2 is projected as it is, the projected contour is the tip of the support pin 6b on the lower surface side. These are provided so as to face each other so as to have a portion overlapping with a region in contact with. For example, a pair of upper and lower support pins having the same shape can be arranged coaxially.

  If one of the pair of opposing support pins 6a and 6b is a support pin that presses the substrate with a constant pressure, and the other support pin is fixed so that the position can be adjusted, the position of the support in the molding die can be adjusted. This is very convenient for adjustment. It is preferable that the support pin fixed so that the position can be adjusted is provided so that the fixed position can be changed in increments of 0.01 mm, for example. The support pin 6b is configured to push the substrate with a constant pressure, and the support pin 6a is configured to be fixed in steps of 0.01 mm, so that the support pin follows the position when the position of each support pin 6a is changed. Since 6b moves while pushing the substrate, it is possible to align the insert in the molding die while maintaining the clamping state of the insert with the support pins. Further, when the insert is sandwiched between the support pins, the position of the support pin 6a is adjusted in a state where the insert is placed only on the support pin 6b, so that the thickness of the substrate can be reduced. The fixing position of the support pin 6a can be secured at the corresponding position, which is suitable when processing substrate support objects having different thicknesses.

  The insert is sandwiched by the support pins in the space 5 in the molding die, and is fixed at positions where predetermined tca1, ta0 and tb0 shown in FIG. As shown in the schematic side partial views of FIGS. 2B and 5, a positioning groove 8 is provided on the side surface of the insert, and projections 6 a-1 and 6 b-1 are formed at the tip of the support pin. By fitting these, the horizontal positioning of the insert is facilitated. The alignment protrusion may be provided on at least one of the pair of upper and lower support pins. For example, only the protrusion 6b-1 may be provided. When the protrusions are provided only on one side, it is not necessary to provide the grooves 8 on the substrate surface on the side without the protrusions.

  As the support pins, various shapes such as a cylindrical round pin as illustrated, an elliptic pin having an elliptical cross section, and a square pin having a rectangular (rectangular, etc.) cross section can be used. Furthermore, a two-stage pin having an insert positioning rib or the like, an eccentric pin, or the like may be used.

  The number of pairs of support pins is preferably at least two, and an example of the arrangement when two pairs are used is shown in FIGS. 10 (a) and 10 (b). The upper limit of the logarithm is not particularly limited and can be appropriately set according to the size of the insert.

  The molding apparatus automatically controls at least one of the holding position of the insert by the support pins and the amount of injected resin and the VP switching position in the space in the molding die by automatic control means according to the thickness of the substrate. It is good to have a configuration that can be used. This automatic control means automatically calculates the position of the support pin tip and the amount of injected resin by inputting the substrate and convex thickness of the insert, and the volume (width and length) of the substrate and convex part. Means can be used.

  An example of the relationship between the VP switching position and the support pin operation is shown in FIGS. 6 to 8 together with the resin injection speeds (v1 to v5). When the support pin is completely retracted, it may be before or after the VP switching position to the pressure holding stage, and can be appropriately selected according to a desired molding operation. In the case of the example shown in FIG. 6, it is preferable that v3 = 0, the stage where the space is completely filled with resin, and the VP switching position are almost simultaneous. Further, in the case of the example shown in FIG. 8, it is preferable that substantially v2 = 0, and the support pin backward start and the VP switching position are substantially the same. The temperature control in the mold can be performed by a conventional method, and can be appropriately selected according to a desired molding operation.

As the calculation formula for the position of the insert used for injection molding and the injection amount of the resin, the following rules in consideration of the volume of the support pin can be used.
The thickness of the-protrusion layer resin provided on the surface of the (t _c) is, 0.1 mm or more.
The ratio between the thickness (t _a0 ) of the resin layer formed on the surface of the substrate having no protrusions and the thickness (t _b0 ) of the resin layer formed on the surface of the substrate having no protrusions (T _a0 / t _b0 ) is 1 / 0.5 to 0.5 / 1.
The volume of the resin layer that can be injected over the entire upper surface of the substrate is V _aS , the volume of the resin layer that can be injected over the entire lower surface of the substrate is V _bS , and the total volume of the support pins on the upper side of the substrate is V _sp1 When the total volume of the lower support pins is V _sp2 , the volume V _{a0 of the} resin layer that can be injected without the support pins on the entire upper surface of the substrate, and the support pins on the entire lower surface of the substrate The volume V _{b0 of the} resin layer that can be injected without filling the following formulas (1) to (3).
V _aS = V _a0 −V _sp1 (1)
V _bS = V _b0 −V _sp2 (2)
0.8 ≦ V _aS / V _bS ≦ 1.2 (3)
It is as follows when prescription | regulation of said Formula (1)-(3) is represented according to the definition used in previous Formula (4)-(6).
V _aS = (S0−ΣSai) × ta0 + Σ (Sai × tai) −Vsp1 (11)
Here, Σ represents the sum of i = 1 to m.
V _bS = (S0−ΣSbj) × tb0 + Σ (Sbj × tbj) −Vsp2 (12)
Here, Σ represents the sum of j = 1 to n.
0.8 ≦ Vbs / Vas ≦ 1.2 Formula (13)
In addition, when providing a convex part only on the single side | surface of a board | substrate (refer FIG. 2), Formula (1)-(3) is as follows.
Vas = (S0−Sa1) × ta0 + Sa1 × tca1−Vsp1 (14)
Vbs = S0 × tb0−Vsp2 (15)
0.8 ≦ Vbs / Vas ≦ 1.2 (16)
At this time, “function of insert thickness (FIG. 2B: T2 (or T2 + Ta1)), tb0 (or ta0) and VP switching position”, which is a parameter for automatic control, is created. These functions can be created in advance by manual molding and / or corrected by automatic control molding, and a calculation formula for automatic control can be set.

  In this state, a resin (resin composition) is injected from the gate 4 to start filling. As shown in the figure, the injection of the resin is performed at a position facing the side surface crossing the longitudinal direction of the substrate 2, preferably on the central axis in the thickness of the substrate 2, and the injection port is provided along the full width of the side surface of the substrate. It is preferable. When the resin is injected from such a gate position, the resin is filled on both side surfaces in the longitudinal direction of the substrate 2 and on the upper surface side and the lower surface side. When the filling progresses and the insert can be held in a predetermined position without the support pin as shown in FIG. 4B, the support pin starts to be retracted.

  The holding time is the state in which resin is continuously present between the upper and lower surfaces of the substrate and the molds facing each other, and even if no further resin injection is required, the insert is not supported by the mold (mold) It can be held without touching the surface, and the insert has no deformation (deflection, etc.). The amount of resin required to obtain this state is from “the minimum amount that can hold an insert without a support pin in place” to “fill the space in the mold with the insert held with the support pin. It is possible to select from the range up to “amount to be exhausted”.

In addition, since the resin flows in the mold after moving the support pins, the substrate may move slightly. The presence / absence and extent of this movement vary depending on the viscosity (fluidity) of the resin. Therefore, it is preferable to check the following two points on the molded product and remove the support pins to determine the timing.
(1) Weld of molded product (center resin joint) (2) Position / state of insert in molded product (cross-section confirmation)
The operation of each support pin at the start of retracting the support pin is set so as to obtain an effect such as warpage prevention as an object of the present invention.

  The pair of upper and lower support pins holding the insert substrate facing each other at a predetermined position starts to retreat simultaneously in the vertical direction.

  In addition, the support pin operation timing can be arbitrarily set according to the product, such as starting all the support pins at the same time, starting the support pins near the center first, and then moving back the ones close to the gate. Can be set. An example of the additional arrangement of support pins when performing a two-stage operation is shown in FIG. One-step operation can be performed using only four sets of support pins provided on the edge of the insert 2, and three additional support pins are arranged around the convex part a 1, The support pins can be retracted first, and then the four support pins at the edge can be retracted thereafter, so that the support pins can be retracted by two-stage operation.

The timing for completing the backward movement of the support pin can be appropriately set according to a desired molding process. For example, the relationship when the support pins start to retract simultaneously can be as follows.
(1) The support pin retracting speed is made uniform (constant), and the timing is differentiated while reaching the retracting completion position between the support pins of different lengths.
(2) The difference in the retraction speed of the support pin between the upper side (v upper) and the lower side (v lower) is {for example, (v lower) = (v upper) * tb0 / ta0} To.
(3) A difference is made in the retracting speed of the support pin between the upper side (v upper) and the lower side (v lower), and the timing is different while reaching the backward completion position between the support pins of different lengths. For example, the lower side (v lower) is set to the speed between the case (1) and the case (2), and the lower support pin is retracted before the upper support pin.

  When ta0 (upper) = 1.2 mm and tb0 (lower) = 1.0 mm, (v lower) can be set in the range of (v upper) to (v upper) * 1 / 1.2}.

Further, by simultaneously operating the upper and lower support pins, it is possible to more effectively prevent the occurrence of warpage. In addition, the retreating speed of each support pin may not be constant, and may be variable during the retreating period.
In the illustrated example, at the start of the retraction of the support pin, the space in the molding die is partially filled with the resin 1, and the region including the central portion 7 is left as a space as an unfilled region. Yes. That is, since the resin is injected simultaneously from both the left and right sides at a set speed (for example, the amount of resin per short time), the space including the central portion 7 is left, and the other portions are filled with the resin. A state is obtained in which the left and right ends of the support are held by the resin. FIG. 4C shows a state immediately after the support pin is pulled out.

  The pull-out speed of the support pin can be adjusted in relation to the resin injection speed. FIG. 4 (d) shows a state in which the back of the support pin tip to the molding surface (product end surface) has been completed and the resin has been completely filled into the molding mold inner space. In the illustrated example, the filling of the resin is completed when the resins filled from both the left and right sides are combined at the central portion in the molding die. The retraction speed of the support pin is preferably set so that the space volume per unit time formed by the movement of the support pin during retraction is smaller than the resin injection volume per unit time. Such a setting is made possible by adjusting at least one of the retracting speed of the support pins and the injection speed of the resin.

  It is preferable that the resin injection speed (injection speed; holding pressure; pressure holding speed) can be arbitrarily set, and the injection speed can be adjusted as appropriate.

  The final filling completion position of the resin in the mold is preferably set at the center portion 7 of the upper surface and / or the lower surface of the insert.

  When the back of the support pin to the molding surface is completed and all of the space in the mold is filled with molten resin (at the time of holding pressure), the resin can be solidified to obtain an insert molding it can. When a resin composition having fluidity by heating and melting is used, the inside of the mold is maintained at a temperature at which the molten resin can be solidified, and the resin is taken out after waiting until the resin is solidified.

  As shown in FIG. 3, the gate width W1 should not exceed the width Y2 of the insert. Although W1 = Y2 is preferable, W1 <Y2 may be satisfied within the range in which the effect of the present invention can be obtained from the viewpoint of mold design. Further, the gate thickness d1 is set in a range not exceeding the thickness T2 of the insert. d1 = T2 is preferable, but d1 <T2 may be satisfied within the range in which the effects of the present invention can be obtained from the viewpoint of the design of the mold.

  As described above, the example in which the insert with the convex portion provided on the upper surface of the substrate is disposed in the mold with the upper surface of the substrate facing upward has been described with reference to FIG. 1 and the like. In the example shown in FIG. An insert molded product can be obtained in the same manner as described above by placing the product upside down, that is, by placing the surface of the substrate on which the convex portions are provided facing downward in the mold.

  Hereinafter, the present invention will be described in more detail with reference to examples.

  In addition, the measurement of curvature measured the cross section of the obtained insert molding using the tool microscope, and judged it using the maximum value (Lmax) of the distance shown in FIG. If this Lmax is 0.1 mm or less, it can be determined that there is no warpage.

Example 1
As the insert, the following parts having the sizes shown in FIG. 2 were used. The substrate is a glass epoxy substrate, and the convex portion is a flat IC circuit chip.
X2 = 48mm
Y2 = 23mm
T2 = 3.3mm
X3 = 8mm
Y3 = 8mm
Ta1 = 0.5mm
The size of the insert molding is as follows.
X1 = 51mm
Y1 = 25mm
T1 = 5.4mm
Prepare a molding die designed to obtain an insert molding of the above size, place the insert in the mold, and sandwich it between four sets of support pins as shown in FIG. Fixed position. The gap at that time was set as follows. The support pin holding pressure was selected from about 15 to 35 MPa.
tb0 = 1mm
ta0 = 1.1mm
tca1 = 0.6mm
t4 = 1.5mm
t5 = 1mm
Also, support pins with a diameter of 4 mm were used (up to 4 pairs).
in this case,
(Tb0 / ta0) = 0.91
Vsp1 = 55.3 mm ³ , Vsp2 = 50.2 mm ³ , (Vbs / Vas) = 0.935 (= 1054/1127).

  The shape of the gate is rectangular, and W1 = 22 mm and d1 = 0.4 mm.

  Resin (trade name: PEEK90GL30 (Victrex)) was poured from the gate in a molten state, and all support pins started to be pulled simultaneously with the mold filled completely with resin while holding the insert with the support pins. The back-up speed of each support pin was made uniform. In the state where the back of all the support pins to the molding surface is completed and the resin filling is completed (holding pressure is completed), the resin temperature is lowered in the mold to solidify the molten resin. An insert molding was obtained. When the warpage of the obtained insert molding was measured, Lmax was 0.1 mm or less, and no warpage was observed. In addition, the resin temperature at the time of molding (until completion of pressure holding) and the temperature in the mold were set by a conventional method within a range of 370 to 420 ° C. resin temperature and 170 to 210 ° C. mold temperature.

In the above molding process, the following conditions were adopted.
-Support pin retraction speed: 0.9mm / sec to 1.5mm / sec (0.04mL / sec to 0.05mL / sec)
・ Support pin diameter: Φ4mm × 4 ・ Resin injection speed (filling the whole space with resin (while moving support hood) / before VP switching): 10 ~ 20mL / sec.
・ Resin injection speed (filling the entire space with resin (moving support hood) / after VP switching): MAX6.3mL / sec
Moreover, the physical properties of PEEK as a raw material, an insert (glass epoxy substrate), and PEEK after molding are as follows.
・ PEEK
Mold shrinkage: 0.4-1.0%, linear expansion coefficient 22 * ^10-6 / K, elongation at break: 2%
・ Linear expansion coefficient of glass epoxy board; length / width / height = 10-16 × 10 ^-6 / 10-16 × 10 ^-6 / 60 × 10 ^-6 / K
・ Elongation difference between product resin (PEEK) and insert (glass epoxy) (during molding)
Assuming that the ultimate temperature of the insert during molding was 200 ° C., the difference in elongation (X / Y / T) = 0.3% or less / 0.4% or less / 0.7% or less was obtained. This calculation result is less than 2% PEEK elongation at break.
・ Elongation difference (thermal expansion) between product resin (PEEK) and insert (Garaepo)
The calculation was performed assuming that the temperature during storage was -70 to + 150 ° C with respect to normal temperature. Difference in elongation (+ 150 ° C.) (X / Y / T) = − 0.1 to 0% / − 0.1 to 0% / 0.6% or less, Difference in elongation (−70 ° C.) (X / Y / T) = 0.1% Or less / 0.1% or less / −0.3 to 0%, and the calculation result is less than PEEK breaking elongation of 2%.

Example 2
According to the flow shown in FIG. 6 (v3 = 0), in the state where 5% of the space in the mold is left as a space (resin filling rate 95%) in the central part (the part indicated by 7 in FIG. 4) in the mold. Then, when the support pin started to retract and the remaining space was completely filled with resin, an insert molded product was obtained in the same manner as in Example 1 except that VP switching was performed.

Comparative Example 1
An insert molded product was obtained in the same manner as in Example 1 except that tb0 = 1.3 mm and ta0 = 0.8 mm. When the warpage of the obtained insert molding was measured, Lmax = 0.3 mm, and significant warpage was observed.

(A) is a typical top view of an insert molding, (b) is an AA line sectional view in (a), and (c) is a typical bottom view of an insert molding. (A) is a typical top view of an insert molding, (b) is an AA line sectional view in (a). FIG. 5 is a schematic plan view of a state where the insert is held in a molding die. (A)-(d) is the figure which represented each process of the insert molding method as typical sectional drawing of the AA line of FIG. It is a figure which shows the relationship between the front-end | tip protrusion of a support pin, and the groove | channel for alignment provided in the insert. It is a figure which shows an example of a shaping | molding process flow. It is a figure which shows an example of a shaping | molding process flow. It is a figure which shows an example of a shaping | molding process flow. It is a figure for demonstrating the evaluation method of curvature. It is a figure which shows an example of the clamping position when using two pairs of support pins.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Resin layer 2 Board | substrate a1 Convex part 4 Gate 5 Molding space 6a Upper surface side support pin 6b Lower surface side support pin 7 Center part

Claims (11)

A method for forming a flat insert product having a flat insert product and a resin layer containing the insert product and integrated in a concealed state,
(1) preparing an insert having a flat substrate and a flat convex portion provided on at least one of the upper surface and the lower surface of the substrate;
(2) Inserting the insert into a mold for insert molding with support pins facing the upper surface side and the lower surface side, and supporting the insert in a molding space;
(3) Filling the molding space with resin, filling the resin in all or part of the molding space, and holding the insert in the molding space without the support pins. In a state where the tip of the support pin is retreated up to the molding surface simultaneously, and filling the resin into the space formed by the retraction of the support pin;
(4) With the retreat to the molding surface at the tip of the support pin completed,
And after completion of pressure holding,
Curing the resin to obtain an insert molded product;
(5) recovering the insert-molded product out of the insert-molding mold;
A method for forming a flat insert-molded product, comprising:   The method according to claim 1, wherein a space volume per unit time formed by movement of the support pin during retraction is smaller than a resin injection volume per unit time.   3. The method according to claim 1, wherein gates are provided on opposite side surfaces of the substrate, a resin is injected from these gates toward a central portion of the substrate, and filling of the resin is completed in the central portion.   The molding according to any one of claims 1 to 3, wherein one of the opposing upper surface side and lower surface side support pins is a support pin that presses the substrate with a constant pressure, and the other support pin is fixed so as to be position-adjustable. Method.   The difference between the shrinkage amount due to the molding shrinkage rate of the resin and the shrinkage amount of the insert at the time of molding is within the elongation at break of the resin, and the thermal expansion coefficient of the resin is equal to the thermal expansion coefficient of the insert. The molding method according to any one of claims 1 to 4, wherein the difference in expansion amount in the product guarantee temperature range resulting from the difference is within the elongation at break of the resin.   According to the thickness of the substrate and the convex portion, the holding position of the insert by the support pin in the molding space and the amount of the injected resin, and at least one of the support pin retreat start and the VP switching position are determined. The molding method according to claim 1, which is automatically controlled by an automatic control means.   The molding method according to claim 1, wherein a thickness (tc) of the resin layer provided on the upper surface of the convex portion is 0.1 mm or more. When the insert is supported by all of the support pins,
The thickness (t _c ) of the resin layer provided on the surface of the convex portion is 0.1 mm or more,
The thickness (t _a0 ) of the resin layer formed on the surface of the upper surface of the substrate without the convex portion and the thickness (t _b0 ) of the resin layer formed on the surface of the lower surface of the substrate without the convex portion. The ratio (t _a0 / t _b0 ) is 1 / 0.5 to 0.5 / 1,
The volume of the resin layer that can be injected over the entire upper surface of the substrate is V _aS , the volume of the resin layer that can be injected over the entire lower surface of the substrate is V _bS , and the total volume of the support pins on the upper side of the substrate is V _sp1 , where V _sp2 is the total volume of the support pins below the substrate, the volume V _{a0 of the} resin layer that can be injected without the support pins on the entire upper surface of the substrate, and the lower surface of the substrate The volume V _{b0 of the} resin layer that can be injected without the support pins on the entire surface is _expressed by the following formulas (1) to (3):
V _aS = V _a0 −V _sp1 (1)
V _bS = V _b0 −V _sp2 (2)
0.8 ≦ V _bS / V _aS ≦ 1.2 (3)
The shaping | molding method in any one of Claims 1-7 which satisfy | fills.   An insert molded product formed by the molding method according to any one of claims 1 to 8. A plate-like insert molded article having a plate-like insert and a resin layer containing the insert and integrated in a concealed state,
The flat insert has a flat substrate and one or more flat protrusions provided on at least one of the upper surface and the lower surface of the substrate,
The thickness (t _C ) of the resin layer provided on the surface of the convex portion is 0.1 mm or more,
The thickness (t _a0 ) of the resin layer formed on the surface of the upper surface of the substrate without the convex portion and the thickness (t _b0 ) of the resin layer formed on the surface of the lower surface of the substrate without the convex portion. The ratio (t _a0 / t _b0 ) is 1 / 0.5 to 0.5 / 1,
When the volume of the resin layer on the entire upper surface of the substrate is V _a0 and the volume of the resin layer on the entire lower surface of the substrate is V _b0 , the ratio (V _b0 / V _a0 ) is 1. An insert molded product characterized by being /0.5 to 0.5 / 1.   The difference between the shrinkage amount due to the molding shrinkage rate of the resin and the shrinkage amount of the insert at the time of molding is within the elongation at break of the resin, and the thermal expansion coefficient of the resin is equal to the thermal expansion coefficient of the insert. The insert molded product according to claim 10, wherein the difference in expansion amount within the guaranteed product temperature range is within the elongation at break of the resin.

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