What is claimed is:
1. An excavator comprising:
a traveling device;
an excavating implement including a boom movable up and down by a boom cylinder, an arm pivotally attached to a top end of said boom to be swingable by an arm cylinder, and a bucket pivotally attached to a top end of said arm to be driven by a bucket cylinder for scooping and dumping action;
a swivel base supported by said running device and supporting said excavating implement, said swivel base having control valves for supplying and draining pressure oil tofrom said cylinders, respectively; and
a group of flexible hoses connected between said control valves and said cylinders for transmitting said pressure oil therebetween, said group of flexible hoses having a length absorbing portion disposed in said swivel base for absorbing variations in hose length occurring with vertical movement of said boom.
2. An excavator as defined in claim 1, wherein:
said swivel base has a swing bracket pivotally attached thereto for swinging said excavating implement about a vertical axis;
said boom has a forked portion connected to said swing bracket; and
said forked portion defines a guide surface inclined downward toward said swing bracket to guide said group of flexible hoses in a space surrounded by said forked portion.
3. An excavator as defined in claim 2, wherein said forked portion has a clamp for holding said group of flexible hoses extending through said space to follow said guide surface.
4. An excavator as defined in claim 2, wherein said group of flexible hoses extends fore and aft through said swing bracket.
5. An excavator as defined in claim 2, wherein:
said group of flexible hoses includes a first group of hoses extending through said swing bracket to said boom cylinder, and a second group of hoses connected to said arm cylinder and said bucket cylinder; and
said second group of hoses is passed upward through a space formed in a bottom portion of said boom.
6. An excavator as defined in claim 5,
wherein said group of hoses further includes a third group of hoses connected to a service port, said first, second and third groups of hoses being arranged parallel to one another on a surface of said boom and connected to steel pipes through a relay unit.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
What is claimed is:
1. A method of integrated circuit assembly before encapsulation including at least one step of soldering under mechanical pressure a first element on a second element, including temporarily maintaining a predetermined spacing, at least partially without solder paste, between the surfaces to be assembled of the first and second elements.
2. The method of claim 1, including using a solder paste comprising balls of a diameter greater than the individual diameter of other components of the deposited solder paste, to avoid filling the predetermined spacing defined by the ball diameter.
3. The method of claim 2, wherein the balls have a diameter much greater than the final thickness desired for the soldering.
4. The method of claim 3, wherein the ratio between the balls and the individual diameter of the other components is greater than 5, preferably on the order of 10.
5. The method of claim 3, wherein the balls have a diameter ranging between 0.1 and 0.6 mm, preferably on the order of 0.4 mm.
6. The method of claim 2, wherein the balls of greater diameter are formed of the same alloy as the other components of the solder paste.
7. The method of claim 2, including successively performing the steps of:
depositing a layer of solder paste on the second element,
depositing the balls by means of needles at the tips of which they are maintained before dispense by solder paste.
8. The method of claim 7, wherein the needle tips are dipped in the solder paste layer, then in a bed of balls before being dipped again in the paste layer where the balls remain by capillarity.
9. The method of claim 1, wherein the first element is a ceramic pad and the second element is a metal heat sink.
10. The method of claim 1, wherein the first element is a heat sink and the second element is a connection grid.